JP2004349716A - Manufacturing method of plate member and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device thin and light weighted by losing a flexible sheet, and a pattern for the semiconductor device of more detailed BGA (ball grid array) structure in such a manner that the spacing of conductive pattern is narrowed by the adoption of half etching simultaneously. <P>SOLUTION: The semiconductor device of BGA structure is manufactured using chip maker's back process in such a way that the device forms: a plate member 10 forming a second bonding pad 17, an interconnect line 18, and a conductive coat 11 processed by the pattern substantially identical to that of an electrode 19 for external extractions; and a plate member 30 processed by the half etching via the conductive coat 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a plate-like body and a semiconductor device, and particularly to solving the problem of a BGA (Ball Grid Array) structure.

  In recent years, the adoption of IC packages in portable devices and small-sized / high-density mounting devices has been advanced, and the concept of mounting the conventional IC packages and that of the conventional IC packages is about to change significantly. The details are described in, for example, a special issue “CSP technology and mounting materials and devices supporting the same” in Electronic Materials (September 1998, p. 22-).

  FIG. 15 relates to a BGA employing the flexible sheet 50 as an interposer substrate. FIG. 15A is a plan view, and FIG. 15B is a cross-sectional view taken along line AA.

  On this flexible sheet 50, a copper foil pattern 51 is bonded via an adhesive. An IC chip 52 is fixed on the flexible sheet 50, and bonding pads 53 are formed of the copper foil around the IC chip 52. A solder ball connection pad 55 is formed via a wiring 54 formed integrally with the bonding pad 53, and a solder ball 56 is formed on the solder ball connection pad 55.

  In FIG. 15A, the flexible sheet 50 is indicated by an outer solid line, and a bold rectangle is the IC chip 52. As is clear from the drawing, inside the bonding pad groups 53 formed around the IC chip 52, the solder ball connecting pad groups 55 are dispersedly formed in a matrix.

On the back side of the solder ball connection pads 55, an opening 57 is formed by processing the flexible sheet 50, and a solder ball 56 is formed through the opening 57.
Special Issue on Electronic Materials (September 1998, p. 22-) "CSP Technology and Mounting Materials and Devices Supporting It"

  The above-described flexible sheet 50 is used as a substrate similarly to a ceramic substrate, a printed substrate, or the like, and is the thinnest member among these substrates. However, the cost of the flexible sheet is higher than the price of the ceramic substrate or the printed circuit board, and there is a problem that the cost of the BGA is significantly increased when the processing cost of the opening 57 is included.

  Further, a semiconductor device mounted on a portable device is desired to be thinner and lighter, and the BGA is also desired to be thinner and lighter. However, considering the step of forming the Cu foil pattern, the step of mounting the IC chip 52, and the step of bonding the thin metal wires 58, the flexible sheet 50 is a member that must be adopted as a support substrate. It was impossible to eliminate the problem from the viewpoint of the production method.

  Further, the Cu foil pattern is bonded on the flexible sheet 50 with an adhesive, and there is a problem that the Cu foil pattern is deformed or peeled off. In particular, the number of pads of the IC chip 52 is increasing year by year, and if this is to be realized by BGA, it is necessary to make the Cu foil pattern finer. As a result, the bonding area between the wiring 54 and the bonding pad 53 is reduced, and the problem that the Cu foil pattern is deformed or peeled further occurs.

  Considering the manufacturing process further, a semiconductor maker transmits predetermined pattern data to a flexible sheet maker, the flexible sheet maker makes a pattern and manufactures a flexible sheet, and the semiconductor maker purchases the completed flexible sheet. There is a problem that it takes a very long time to manufacture the. Therefore, there is a problem that the semiconductor maker cannot deliver the BGA to the user in a short delivery time.

  There is also a problem that the heat dissipation of the IC chip 52 is poor due to the interposition of the flexible sheet 50.

The present invention has been made in view of the above-mentioned many problems, and firstly, has a first surface formed of a flat surface, and a second surface provided opposite to the first surface and formed of a flat surface. A plate-like body having
A bonding pad provided on the periphery of the semiconductor element mounting area on the second surface, a wiring extending integrally with the bonding pad to the semiconductor element mounting area, and an external take-out provided integrally with the wiring; The problem is solved by forming the first conductive film having substantially the same pattern as the electrode.

Second, a plate-like body having a first surface formed of a flat surface, and a second surface formed of a flat surface provided to face the first surface,
A bonding pad provided on the periphery of the semiconductor element mounting area on the second surface, a wiring extending integrally with the bonding pad to the semiconductor element mounting area, and an external take-out provided integrally with the wiring; The problem is solved by forming a photoresist having substantially the same pattern as the electrodes.

  Third, the problem is solved by providing a conductive film in a region corresponding to the bonding pad and forming the photoresist so as to cover the conductive film.

  By conducting half-etching via a conductive film or a photoresist formed on the plate, a conductive pattern supported by the plate can be formed. Therefore, a semiconductor maker can independently manufacture a plate-shaped body to a semiconductor device independently by having a photolithography facility.

  In addition, the fixing of the semiconductor element, the electrical connection using a thin metal wire, and the sealing process using an insulating resin can use this plate-shaped body as a support substrate, and a flexible sheet as a conventional support substrate can be used. Became unnecessary. In particular, the bonding pad exists in a fine and island-like manner, and the wiring is long and thin, so that the wiring is arranged in an unstable state. However, since the wiring is integrated with the plate-like body, deformation such as warpage or peeling can be eliminated. .

  In addition, by performing half etching in which the pattern of the plate-like body is stopped halfway without being removed by pressing or etching from the front to the back, the interval between the conductive patterns can be narrowed, and a finer pattern can be formed. Furthermore, after the insulating resin is completely sealed and fixed, the back surface of the plate-like body is polished or etched so that the pads and the wiring can be separated from each other. The wiring can be arranged without deformation even if the wiring is drawn long.

  In the case of half-etching using a photoresist as a mask, wire bonding can be easily realized in the next step by leaving a conductive film on a bonding pad portion.

  Fourth, the problem is solved by forming a guide hole into which the guide pins are inserted in substantially the same pattern as the guide pins on opposite sides of the plate-like body. The die can be mounted with high precision.

  Fifth, the problem is solved in that the plate-like body is made of a conductive foil, and the conductive coating is made of a material different from the material of the conductive foil.

  By forming the conductive film, the side surface of the convex portion becomes curved, and further, the eaves are formed on the conductive film itself. The bonding pads and wirings, which are conductive patterns, are buried in the insulating resin with an anchor effect.

Sixth, a plate-like body having a first surface formed of a flat surface, and a second surface having a convex portion formed at a desired height and facing the first surface. ,
The protruding portion forms a bonding pad provided around the semiconductor element mounting area, a wiring extending integrally with the bonding pad to the semiconductor element mounting area, and an external extraction electrode provided integrally with the wiring. This will solve the problem.

  Seventh, the problem is solved by providing a conductive film on the surface of the projection.

  Eighth, the problem is solved by providing a conductive film at least in a region corresponding to the bonding pad.

  Ninth, the problem is solved in that the plate-like body is made of a conductive foil and the conductive coating is made of a material different from the material of the conductive foil.

  The plate-like body having the conductive pattern formed by the protrusions enables mounting of a semiconductor element, electrical connection with a pad, sealing, and the like by using a post-process facility of a semiconductor maker. Therefore, as in the case of a conventional lead frame, a plate-like body can be supplied from, for example, a manufacturer, and a semiconductor manufacturer can manufacture a BGA type semiconductor device.

  In addition, the fixing of the semiconductor element, the electrical connection using a thin metal wire, and the sealing using an insulating resin can employ this plate-like body as a support substrate, and can eliminate a conventional flexible sheet. . Particularly, the bonding pads exist in an island shape or are arranged in an unstable state, but since they are integrated with the plate-like body, deformation such as warpage or peeling can be eliminated. Further, the wiring is extended for a long time, causing warping, twisting and the like. However, since the wiring is integrated with the plate-like body, these problems can be solved.

  Further, since the structure is formed by half etching, the interval between pads or wirings can be reduced, and a finer pattern can be formed. Furthermore, after the insulating resin is completely sealed and fixed, the pad, die pad and wiring can be separated by polishing or etching the back surface of the plate-like body, and the plate-like body is arranged at a predetermined position without displacement. be able to.

  Tenthly, the problem is solved by forming protrusions having substantially the same pattern as the guide pins or guide holes into which the guide pins are inserted, on opposite sides of the plate-like body.

  Eleventh, the problem is solved by arranging a predetermined pattern composed of the convex portions in a matrix on the plate-like body, which enables mass production.

  Twelfth, the problem is solved by forming the plate-like body from a laminate of Cu, Al, Fe-Ni alloy, Cu-Al or a laminate of Al-Cu-Al.

  Thirteenth, the problem can be solved by providing the side surface of the projection with an anchor structure.

  Fourteenth, the conductive film can be solved by forming an eave on the upper surface of the projection.

  Fifteenth, since the conductive film is made of Ni, Au, Ag or Pd, it can have an anchor effect, and at the same time, wire bonding and die bonding can be performed.

Sixteenth, a flat back surface over the entire surface corresponding to the resin sealing region, and a region formed in a sheet shape with a predetermined thickness from the back surface and surrounded by a contact region with the upper mold,
A bonding pad provided around the semiconductor element mounting area, a wiring extending integrally with the bonding pad to the semiconductor element mounting area, and a projection serving as an external extraction electrode provided integrally with the wiring are formed. Plate-like body having a surface that is
At least the region surrounded by the contact region with the upper mold is solved by forming a closed space by the surface and the upper mold.

Seventeenth, a flat back surface over the entire surface corresponding to the resin sealing region, and a bonding pad formed in a sheet shape with a predetermined thickness from the back surface and provided in a region surrounded by a contact region with the upper mold. Preparing a plate-shaped body having a surface on which a wiring extending integrally with the bonding pad and extending to the semiconductor element mounting region and a projection serving as an external extraction electrode provided integrally with the wiring are formed;
A semiconductor element is mounted on the semiconductor element mounting area, and the bonding pad and the semiconductor element are electrically connected,
The plate-shaped body is mounted on a mold, and a space formed by the plate-shaped body and the upper mold is filled with a resin.
A step of removing the plate-like body exposed on the back surface of the filled resin and separating each of the protrusions.

  18. The method of manufacturing a semiconductor device according to claim 17, wherein an entire area of the back surface of the plate-shaped body corresponding to the resin sealing area is brought into contact with a lower mold.

  Nineteenthly, the contact area of the lower mold is solved by dispersing and arranging vacuum suction means.

  Since the plate-like body is formed in a sheet shape, the back surface of the plate-like body is in contact with the lower mold over the entire surface, and the conductive patterns such as pads are arranged in the closed space. There is no discharge to the back of the plate.

  As described above, the semiconductor device is formed of the conductive pattern, the semiconductor element, and the insulating resin that seals them, and the flexible sheet can be eliminated. Therefore, a thin and lightweight semiconductor device can be realized. In addition, the conductive paths are buried, and the conductive coating is formed on the surface of the conductive foil, so that bonding pads and wiring having eaves on the surface can be formed, and the anchor effect can be generated, thereby warping the conductive pattern. Thus, a BGA type semiconductor device in which deformation such as omission is suppressed can be realized.

  As is clear from the above description, the plate-shaped body of the present invention has a structure capable of half-etching a conductive pattern via a conductive film or a photoresist. Further, the plate-like body may be formed as a conductive pattern from the front to the back without being removed by pressing or etching, but stopped halfway. With the structure that can adopt the half etching, the interval between the conductive patterns can be narrowed, and a finer pattern for a semiconductor device having a BGA structure can be obtained. In addition, since the second bonding pad, the wiring, and the external extraction electrode are integrally formed with the plate-like body, deformation, warpage, and the like can be suppressed. Furthermore, after the insulating resin is completely sealed and fixed, the conductive pattern can be separated by polishing or etching the back surface of the plate-like body, and the conductive pattern is arranged at a predetermined position without displacement. be able to. In addition, wiring required for a semiconductor device having a BGA structure can be arranged without any deformation.

  In addition, by disposing the entire conductive pattern in the resin sealing region, burrs generated from the conventional lead frame can be eliminated.

  In addition, since the same pattern as the guide pins is formed, it can be opened as a guide pin when sealing with an insulating resin. Further, by opening the guide pins in advance, the plate-like body can be set on the guide pins of the mold for sealing, and resin sealing with high positional accuracy can be performed.

  When the plate is made of Cu as the main material and the conductive film is made of Ni, Ag, Au or Pd or the like, the conductive film can be used as an etching mask. Can be formed into a curved structure, or a canopy of a conductive film can be formed on the surface of the conductive pattern, so that a structure having an anchor effect can be obtained. Therefore, it is possible to prevent the conductive pattern located on the back surface of the insulating resin from coming off and warping.

  Further, a semiconductor device manufactured from a plate-like body is a semiconductor device which is composed of semiconductor elements, a conductive pattern and an insulating resin with a minimum necessary amount, and has no waste of resources. Therefore, a semiconductor device whose cost can be significantly reduced can be realized. In addition, since a support substrate such as a flexible sheet is not used, thermal resistance of the support substrate is eliminated, and heat dissipation of the semiconductor element is improved. Further, by setting the coating thickness of the insulating resin and the thickness of the conductive foil to optimal values, a very small, thin, and lightweight semiconductor device can be realized.

  In addition, since the back surface of the conductive pattern is exposed from the insulating resin, the back surface of the conductive pattern can be immediately used for connection to the outside, so that there is no need to process through holes and the like as in a conventional flexible sheet. Have.

  In addition, the semiconductor device has a structure in which the surface of the separation groove and the surface of the conductive pattern have a flat surface substantially matching each other. Since it can be moved horizontally as it is, it is extremely easy to correct the displacement of the external extraction electrode.

  Further, the side surfaces of the conductive pattern have a curved structure, and further, eaves can be formed on the surface. Therefore, an anchor effect can be generated, and the conductive pattern can be prevented from warping or coming off.

  Further, the whole is supported by the plate-shaped body until the insulating resin is applied, and the insulating resin is used as a supporting substrate for separation and dicing of the conductive pattern. Therefore, as described in the conventional example, there is an advantage that the support substrate is not required and the cost can be reduced.

The present invention relates to a semiconductor device in which bonding pads are arranged around a semiconductor chip, and external extraction electrodes are dispersed and arranged in a matrix using wiring integrated with the bonding pads. In general, a device in which a solder ball is attached to an external extraction electrode is called a BGA, but a device that is fixed by ordinary soldering is also referred to as a BGA-structured semiconductor device.

First Embodiment for Explaining a Plate FIG. 1A shows a plate which is more effective than a conventional BGA employing a flexible sheet and can realize a thinner package.

  As shown in FIG. 1A, the plate-shaped body 10 is formed by forming a conductive pattern printed on a flexible sheet with a conductive film 11 in a conventional BGA.

That is, the plate-shaped body 10 has a first surface 12 formed of a flat surface, and a second surface 13 provided opposite to the first surface 12 and formed of a flat surface.
On the second surface 13, a first conductive film 11 </ b> A having substantially the same pattern as the second bonding pad 17 is formed around the semiconductor element mounting region 14. This conductive film 11A is provided corresponding to the first bonding pad 16 on the semiconductor element 15 shown in FIG. 3, and is formed in substantially the same pattern as the second bonding pad 17. Further, a second conductive film 11B and a third conductive film 11C having substantially the same pattern as the wiring 18 and the external extraction electrode 19 provided integrally with the second bonding pad 17 are formed. The conductive films 11A to 11C may be made of the same material or different materials. However, for the conductive films 11A to 11C, a material effective as an etching resistant mask is selected as will be understood in a later manufacturing method, and the surface of the conductive film 11A is formed by a metal thin wire 20 made of Au or Al by a ball bonding method or an ultra A material that can be implemented by the sonic bonding method is selected.

  As will be understood from the description of FIGS. 13 to 13, when a face-down type element (SMD) is used as the semiconductor element 15, a material to which a brazing material and a conductive paste can be fixed is selected for the conductive film 11 </ b> A.

  As shown in FIG. 1B, the plate-like body 10 may be provided with an etching-resistant mask MSK such as a photoresist instead of the conductive film 11. In this case, a conductive film 20 is formed on at least a portion corresponding to the second bonding pad 17 so that bonding or face-down bonding using a thin metal wire can be performed, and the entire pattern including the conductive film is formed of a photoresist MSK. Coated.

  The feature of the present invention resides in the plate-like body 10. As will be understood from the description below, half-etching is performed through the conductive coating 11 of the plate-shaped body 10 or the photoresist MSK, and the semiconductor element 15 is mounted thereon and sealed with the insulating resin 21. Then, the plate-shaped body 10 exposed on the back surface of the insulating resin 21 is etched, polished or ground until the conductive pattern 22 including the second bonding pad, the wiring 18 and the external extraction electrode 19 is separated. Process with etc. By employing this manufacturing method, the semiconductor device can be composed of three materials: the semiconductor element 15, the conductive pattern 22, and the insulating resin 21 that embeds the semiconductor element 15 and the conductive pattern 22. The plate-shaped member 10 can finally function as a semiconductor device 23 having a BGA structure.

  The greatest feature of this structure is that a conductive film 11 or an etching-resistant mask MSK is formed on the surface of the plate-shaped body 10 so that half-etching can be performed.

  Generally, as the etching progresses in the vertical direction, the etching also progresses in the horizontal direction. For example, in the case of isotropic etching, this phenomenon is conspicuous, and the etching depth in the vertical direction is substantially the same as the etching length in the horizontal direction. Also, in the anisotropy, the length etched in the lateral direction is much smaller than the isotropic, but is etched in the lateral direction.

  For example, in the case of forming the conductive patterns 53 to 55 on the flexible sheet 50 in the semiconductor device having the BGA structure shown in FIG. 15, it is necessary to remove the pattern so as to penetrate from the front to the back of the attached Cu foil. is there. However, the space between the conductive patterns is also etched in the lateral direction, and the distance between the conductive pattern 22 and the adjacent conductive pattern has a correlation with the Cu foil thickness, and cannot be smaller than a certain limit value. It was difficult to form a pattern. The same phenomenon occurs when a semiconductor device having a BGA structure is realized by using an etching type lead frame. Also, even when the lead frame is pulled out by pressing, the thickness of the lead frame is almost the minimum distance between the lead frame patterns, and there is a limit to the fine pattern.

  However, if the conductive film 11 or the etching mask MSK is formed on the plate 10 and then half-etched to a depth suitable for forming a fine pattern, the amount of etching in the lateral direction can be suppressed, and a finer conductive film can be formed. The pattern 22 can be realized.

  For example, a conductive film 11 such as Ni, Ag, Au, or Pd is formed as a patterned conductive film on a plate-like body 10 having a thickness of 2 ounces (70 μm). The distance between the conductive patterns is the narrowest, which is substantially 70 μm. However, if the plate 10 is etched to a depth of 35 μm using the conductive film 11 as an etching resistant mask, the interval between the conductive patterns can be reduced to substantially 35 μm. In other words, double mounting efficiency can be realized. The finer the pattern, the smaller the depth of the half etching with respect to the plate-shaped body 10 becomes.

  In addition, in the plate-like body 10 of the present invention, wet etching is preferable in consideration of etching equipment, mass productivity, and manufacturing cost. However, the wet etching is non-anisotropic, and the etching in the lateral direction is relatively large. Therefore, half-etching using the conductive film 11 and the etching resistant mask MSK is excellent in forming a finer conductive pattern 22.

  Further, in the plate-shaped body 10 of the present invention, since the half-etched conductive pattern 22 is integrated with the plate-shaped body 10, the conductive pattern 22 may be shifted or warped as long as the plate-shaped body 10 is fixed. Is gone. Therefore, it has a feature that the bonding to the second bonding pad 17 can be stably performed.

  Furthermore, in the semiconductor device having the BGA structure formed by the above-described lead frame, the conductive pattern needs to be supported by the suspension lead, but is not required in the present invention. Therefore, the conductive pattern 22 can be arranged at an arbitrary position without considering the intersection with the suspension lead, and there is an advantage that the design of the conductive pattern 22 is facilitated.

  Providing the guide hole 24 in the plate 10 is convenient for mounting the plate 10 on a mold.

  The guide hole 24 has substantially the same shape as the guide pin, is circularly patterned at a corresponding position with a conductive film or photoresist, and is opened along the pattern by drilling, punching, etching, or the like before molding. good. Alternatively, a device that has been opened in advance may be prepared. By inserting the guide pins of the mold into the guide holes 24, it is possible to mold with high positional accuracy.

  As described above, the conductive pattern 22 appears by being half-etched via the conductive coating 11 or the etching resistant mask MSK, which can be adopted as a conventional flexible sheet or a conventional lead frame.

  A semiconductor device maker generally has a factory that is divided into a pre-process and a post-process. In a post-process in which the present plate-shaped body 10 is used for molding, an etching facility is not usually installed. Accordingly, by installing the film forming equipment and the etching equipment for the conductive film 11, the plate material 10 on which the conductive film 11 or the etching mask MSK is formed is purchased from the metal material maker that manufactures the lead frame, and the semiconductor maker is purchased. Can manufacture a semiconductor device 23 having a BGA structure using the plate-like body 10.

The conductive pattern 22 may have a shape like a wiring having a substantially constant width from one end to the other end as shown in FIG. 1C. Although the pads 11A and the electrodes 11C in FIGS. 1A and 1B are circular or rectangular, the shapes are arbitrary.

2. Second Embodiment for Explaining Plate-like Body As shown in FIG. 2, this plate-like body 30 is half-etched via the conductive film 11 or the etching resistant mask MSK to form a conductive pattern 22 in a convex shape. It was done.

That is, a plate-like body having a first surface 12 formed of a flat surface, and a second surface 13 having a convex portion 31 formed at a desired height and facing the first surface 12. 30 and
The protrusions 31 constitute a second bonding pad 17 provided around the semiconductor element mounting area 14, a wiring 18 integrated with the second bonding pad, and an external extraction electrode 19 integrated with the wiring. It is.

  The plate-like body 30 has substantially the same configuration and effect as the plate-like body 10 described in the first embodiment. The difference is that the conductive pattern 22 is half-etched.

  Therefore, here, the point that the half-etching is performed will be described. That is, the semiconductor maker, especially the post-process, does not have lithography equipment for plating and etching the plate-like body 10 made of Cu. Therefore, if the plate 30 having the conductive pattern 22 composed of the convex portion is purchased by half etching, the plate 30 can be handled in the same manner as the conventional lead frame, and the BGA can be processed by the existing equipment in the post-process. The semiconductor device 23 having the structure can be manufactured.

In addition, the conductive pattern 22 including the convex portion can be formed by pressing the plate-like body 10. In the case of pressing, since the first surface 12 is protruded, it is necessary to flatten the first surface 12 by polishing or grinding if necessary.

Third Embodiment Explaining a Manufacturing Method of a Semiconductor Device Employing a Plate Body FIGS. 1 to 4 show a process until a semiconductor device 23 having a BGA structure is manufactured using the above-described plate member 10 or 30. It will be explained and adopted. 1A is a half-etched plate-like body 10 of FIG. 1A, and FIG. 2B is a half-etched plate-like body 10 of FIG. 1B. FIG. 2C is a half-etched version of the plate body 10 of FIG. 1C. In addition, in FIG. 3 and subsequent figures, description is made assuming that the device is manufactured by employing FIGS. 1A and 2A.

First, a plate-like body 10 is prepared as shown in FIG. The plate-like body 10 has a first surface 12 and a second surface 13 which are flat, and a conductive coating 11 in which a conductive pattern 22 is formed on the second surface 13 or an etching-resistant mask MSK such as a photoresist. Is formed. In FIG. 1A, the conductive film 11 is formed on the entire surface of the conductive pattern 22, and the conductive film 11 is hatched with oblique lines. 1B employs a photoresist MSK instead of the conductive film 11, and the photoresist MSK covers a conductive film 11A formed at least in a portion corresponding to the second bonding pad 17. FIG. The photoresist MSK is hatched at points (see FIG. 1 above).
Subsequently, the plate-like body 10 is half-etched via the conductive film 11 or the photoresist MSK. The etching depth is shallower than the thickness of the plate 10. Note that the shallower the etching depth, the finer the pattern can be formed.

  Then, by half-etching, the conductive pattern 22 appears on the second surface 13 of the plate-like body 10 in a convex shape as shown in FIG. The plate 10 may be a Cu material, an Al material, an Fe—Ni alloy material, a laminate of Cu—Al, or a laminate of Al—Cu—Al. In particular, the Al-Cu-Al laminate can prevent warpage caused by a difference in thermal expansion coefficient.

For example, if a semiconductor maker has an etching facility in a post-process, the plate-like body 10 of FIG. 1 is purchased from a lead frame maker. By purchasing the plate-shaped body 30 having a convex shape, it is possible to shift to the following steps. (See Figure 2 above)
Subsequently, the semiconductor element 15 is fixed to the semiconductor element mounting area 14, and the first bonding pad 16 and the second bonding pad 17 of the semiconductor element 15 are electrically connected. In the drawing, since the semiconductor element 15 is mounted face-up, a thin metal wire 26 is employed as a connecting means. In the case of face-down mounting, the connection means may be a brazing material such as a solder bump or a solder ball, a conductive paste such as Ag or Au, a conductive ball or an anisotropic conductive resin.

  In this bonding, the second bonding pad 17 is integral with the plate 30 and the back surface of the plate 30 is flat. For this reason, the plate 30 is brought into abutment with the table of the bonding machine. Therefore, if the plate 30 is completely fixed to the bonding table, the second bonding pad 17 can transmit the bonding energy to the fine metal wire 20 and the second bonding pad 17 efficiently without displacement. The connection strength of the thin metal wire 20 can be improved. For example, as shown in FIG. 9, the bonding table can be fixed by providing a plurality of vacuum suction holes V on the entire surface of the table.

  The semiconductor element 15 and the plate 30 are fixed using an insulating adhesive 32, and a filler such as Si oxide or Al oxide is mixed into the insulating adhesive 32 in consideration of heat dissipation. Is also good.

  Then, the insulating resin 21 is formed so as to cover the conductive pattern, the semiconductor element 57, and the connection means.

  For example, when sealing is performed using a mold, a guide hole 24 is opened at this stage, and a guide pin of the mold is inserted therein. Since the first surface 12 of the plate 30 is flat, the surface of the lower mold is also flat. The insulating resin 21 may be either thermoplastic or thermosetting.

  This mold can be realized by transfer molding, injection molding, dipping or coating. As the resin material, a thermosetting resin such as an epoxy resin can be realized by transfer molding, and a thermoplastic resin such as a liquid crystal polymer and polyphenylene sulfide can be realized by injection molding.

  In the present embodiment, the thickness of the insulating resin 21 is adjusted so as to cover about 100 μm from the top of the fine metal wire 20. This thickness can be increased or reduced in consideration of the strength of the semiconductor device 23.

In addition, since the conductive pattern 22 is formed integrally with the sheet-like plate 30 in the injection, there is no displacement of the conductive pattern 22 at all unless the plate 30 is displaced.
Also in this case, the lower mold and the back surface of the plate 30 can be fixed by vacuum suction. Alternatively, a holding pin provided in the mold may be used.

As described above, the conductive pattern 22 formed as the convex portion 31 and the semiconductor element 15 are embedded in the insulating resin 21, and the plate-shaped body 30 below the convex portion 31 is exposed from the back surface. (See Figure 3 above)
Subsequently, the plate-like body 30 exposed on the back surface of the insulating resin 21 is removed, and the conductive patterns 22 are individually separated.

  Various methods are conceivable for the separation step here, and the back surface may be removed by etching, or may be polished or ground. Further, both may be adopted. For example, if the insulating resin 21 is cut until the insulating resin 21 is exposed, there is a problem that shavings of the plate-like body 30 and thin burr-like metal that is thinly spread out into the insulating resin 21. Therefore, before the insulating resin 21 is exposed, the shaving is stopped, and after that, if the conductive pattern 22 is separated by etching, the metal of the plate-shaped body 30 is added to the insulating resin 21 located between the conductive patterns 22. Can be formed without penetrating. Thereby, short circuit between the conductive patterns 22 at minute intervals can be prevented.

  In the half etching, the thickness of the insulating resin 21 between the conductive patterns 22 varies due to the variation in the etching depth. Therefore, after the conductive pattern 22 is separated, the package having a constant thickness can be formed with high precision by grinding the surface to a target thickness by polishing or grinding.

  When a plurality of units constituting the semiconductor device 23 are formed, there is a step of dicing as individual semiconductor devices 23 after this separation step. This dicing line is indicated by a thick dotted line in the drawing.

  Here, a dicing apparatus is used to separate the individual pieces, but it is also possible to use a chocolate break, press or cut.

  The conductive pattern 22 exposed on the back surface may be covered with an insulating resin R as shown in FIG. 4B to expose a portion corresponding to the external extraction electrode 19. The exposed external electrode 19 is connected to a conductive ball such as a solder ball, covered with a brazing material such as a solder or a conductive paste such as an Ag paste, and anisotropically conductive. Connection means such as application of a resin is selected.

  Further, in FIG. 4C, etching is performed via a photoresist formed on the external extraction electrode 19 to make the external extraction electrode 19 convex. The insulating resin R is coated so that the external extraction electrode 19 is exposed.

As shown in FIGS. 4B and 4C, by coating the back surface with the insulating resin R, the wiring on the mounting substrate side can be passed through this lower layer. (See Figure 4 above)
According to the above-described manufacturing method, a light, thin, short, and small BGA structure semiconductor device can be realized by using a plurality of conductive patterns 22, the semiconductor element 15, and the insulating resin 21.

  Next, effects produced by the above-described manufacturing method will be described.

  First, since the conductive pattern 22 was half-etched and supported integrally with the plate 30, the flexible sheet used as the support substrate could be eliminated.

  Secondly, since the conductive pattern 22 having a convex shape formed by half-etching the plate-shaped body 30, the conductive pattern 22 can be miniaturized. Therefore, the width of the conductive pattern 22 and the interval between the conductive patterns 22 could be reduced, and a package having a smaller planar size could be formed.

  Thirdly, since the semiconductor device is composed of the three elements, the semiconductor device 23 can be configured with a minimum requirement, wasteful materials can be eliminated as much as possible, and a thin semiconductor device 23 with significantly reduced cost can be realized.

  Fourth, the second bonding pad 17, the wiring 18, and the external extraction electrode 19 are formed as projections by half-etching, and individual separation is performed after sealing, so that it is adopted in a lead frame. No need for tie bars or suspension leads, making pattern design easier.

Although only one semiconductor element is mounted on the semiconductor device having the BGA structure, a plurality of semiconductor elements may be mounted.

Fourth Embodiment for Explaining Plate-like Body FIG. 5 shows a plate-like body 10 in which a conductive pattern 22 is formed by a conductive film 11 similarly to the first embodiment. Note that an etching resistant mask such as a photoresist may be formed instead of the conductive film 11. In this case, a conductive film is formed on a portion corresponding to the bonding pad, and a pattern of a photoresist including the conductive film is formed.

  The pattern in FIG. 5 is a more specific example of FIG. 1. Specifically, a pattern unit 34 that is one semiconductor device is formed in a matrix shape by a conductive pattern surrounded by a dotted line and surrounds the pattern unit 34. As described above, the mold contact area 35 is formed in a ring shape with a predetermined width. That is, the pattern of FIG. 5 shows a conductive pattern formed in one cavity.

  Alignment marks 36 and 37 are provided inside the mold contact area 35. The line connecting the alignment marks 36A and 37A indicates a horizontal dicing line, and the line connecting the alignment marks 36B and 37B indicates a vertical dicing line. Each alignment mark is formed by at least one short straight line, and the direction of the blade of the dicing apparatus is adjusted based on the straight line. Here, the alignment mark is formed of two straight lines with a desired interval (margin) so that the blade can be shaved with a desired accuracy.

  Further, a first pattern 38 and a second pattern 39 for forming a guide hole are formed outside the mold contact area 35 described above. The cross in the second pattern 39 is a centering mark when a guide hole is formed by a drill. Further, a guide hole having the same shape as the first pattern may be provided in advance without forming this pattern.

As described above, except for the dicing line mark and the mold contact area 35, the configuration is the same as that of the first embodiment, and thus the features and effects of this embodiment are omitted.

Fifth Embodiment for Explaining Plate-shaped Object The present plate-shaped object 30 has the shape shown in FIG. 6 and is formed in a half via the conductive film 11 shown in the fourth embodiment or an etching resistant mask such as a photoresist. It is etched and has a convex portion 31. Note that the first alignment mark 38 and the second alignment mark 39 may also be formed in a convex shape by half etching.

  The plate-like body 30 can be handled in the same manner as a conventional lead frame, for example, SIP, DIP, QIP, or the like.

That is, a plate-shaped body 30 having a first surface 12 formed of a flat surface and a second surface 13 having a convex portion 31 formed at a desired height and facing the first surface 12. Consisting of
The convex portion 31 forms a second bonding pad 17 provided around the semiconductor element mounting region, a wiring 18 integrated with the second bonding pad 17, and an external extraction electrode 19 integrated with the wiring 18. Become.

The plate-like body 30 is in a state in which each pattern is half-etched, and can fix, electrically connect, and seal the semiconductor element as it is, and can be manufactured with existing equipment in a later process. It has features.
The effects have been described in the first embodiment and the fourth embodiment, so that the description is omitted here.

Sixth Embodiment for Describing a Method for Manufacturing a Semiconductor Device Next, a method for manufacturing a semiconductor device will be described with reference to FIGS.

  First, as shown in FIG. 5, a plate-like body 10 is prepared. The material of the plate 10 is selected in consideration of the adhesiveness of the brazing material, the bonding property, and the plating property, and the material is selected from a conductive foil mainly composed of Cu, a conductive foil mainly composed of Al and a conductive foil mainly composed of Al. A sheet-shaped conductive foil made of an alloy such as Fe-Ni, a laminate of Cu-Al, a laminate of Al-Cu-Al, or the like is employed. On the surface of the plate-like body 10, the second bonding pad 17, the wiring 18, the external take-out electrode 19, the mold contact area 35, the alignment marks 36, 37, the patterns 38, 39 are provided with the conductive film 11 or the photoresist. And the like.

The thickness of the conductive foil used as the plate-like body 10 is preferably about 10 μm to 300 μm in consideration of the later etching, and here, a copper foil of 70 μm (2 oz) was used. However, it is basically good to be 300 μm or more and 10 μm or less. (See Figure 5 above)
Subsequently, the plate-like body 10 excluding the regions to be the second bonding pads 17, the wiring 18, the external take-out electrode 19, the mold contact area 35, the alignment marks 36, 37, and the patterns 38, 39 is removed. There is a step of removing shallower than 10 thicknesses.

  Here, the separation groove 40 is formed shallower than the thickness of the plate-like body 10 using the conductive film 11 or photoresist as an etching resistant mask.

  In the present manufacturing method, non-anisotropic etching is performed by wet etching or dry etching, and the side surfaces thereof are rough and curved.

  In the case of wet etching, ferric chloride or cupric chloride is generally used as an etchant, and the conductive foil is dipped in the etchant or the etchant is showered.

  Particularly, the etching in the lateral direction is difficult to proceed immediately below the conductive film 11 or the photoresist serving as an etching mask, and the deeper portion is etched in the lateral direction. Therefore, since the opening diameter of the opening corresponding to the position becomes smaller as going upward from one side surface of the separation groove 40, the opening becomes a reverse tapered structure and has a structure having an anchor structure. In addition, by employing a shower ring, etching proceeds in the depth direction and etching in the horizontal direction is suppressed, so that this anchor structure appears remarkably.

  In the case of dry etching, anisotropic and non-anisotropic etching is possible. At present, it is said that it is impossible to remove Cu by reactive ion etching, but it can be removed by sputtering. In addition, anisotropic and non-anisotropic etching can be performed depending on sputtering conditions.

  Materials that can be considered as the conductive film include Ni, Ag, Au, Pt, and Pd. Moreover, these corrosion-resistant conductive films have a feature that can be used as they are as bonding pads.

  For example, an Au thin wire can be adhered to a conductive film of Ag or Au. Ni enables ultrasonic bonding with the Al wire. Therefore, there is an advantage that these conductive films can be used as bonding pads as they are.

Of course, here, the convex portion may be formed by anisotropic etching. (See FIG. 6 above)
Subsequently, as shown in FIG. 7, there is a step of mounting the semiconductor element 15 in the semiconductor element mounting area 14.

  The semiconductor element 15 is a transistor, a diode, an IC chip, or the like. Although the thickness is increased, it is also possible to mount an SMD (face-down semiconductor element) such as a wafer-scale type CSP or BGA.

  Here, the bare IC chip 15 is fixed by an insulating adhesive 32, and the first bonding pad 16 and the second bonding pad 17 on the IC chip 15 are bonded by ball bonding by thermocompression bonding or web bonding by ultrasonic waves. It is connected via a thin metal wire 20 to be fixed.

The second bonding pad 17 shown in the figure has a very small size, but is integrated with the plate 30. Therefore, the energy of the bonding tool can be transmitted to the bonding pad 17, and the bonding property is improved. Further, in cutting the thin metal wire after bonding, there is a case where the thin metal wire is pulled. At this time, since the second bonding pad 17 is integrated with the plate 30, the phenomenon that the bonding pad 17 floats can be eliminated, and the pull-cut property can be improved. (See Figure 7 above)
Further, as shown in FIG. 8, there is a step of attaching the insulating resin 21 to the separation groove 40. This can be achieved by transfer molding, injection molding, dipping or coating. As the resin material, a thermosetting resin such as an epoxy resin can be realized by transfer molding, and a thermoplastic resin such as a liquid crystal polymer and polyphenylene sulfide can be realized by injection molding.

  In the present embodiment, the thickness of the insulating resin 21 is adjusted so as to cover about 100 μm from the top of the fine metal wire 20. This thickness can be increased or reduced in consideration of the strength of the semiconductor device.

  The feature of this step is that the plate 30 serves as a supporting substrate until the insulating resin 21 is covered and cured. A conventional BGA requires a supporting substrate for a flexible sheet, but the present invention does not require a supporting substrate.

  Furthermore, since the insulating resin 21 is filled in the separation groove 40 having the curved structure, an anchor effect occurs in this portion, and the conductive pattern 22 is hardly peeled off from the insulating resin 21.

  Before the insulating resin 21 is coated, for example, a silicone resin or the like may be potted to protect a connection portion of a semiconductor chip or a thin metal wire.

  FIG. 9 illustrates this molding method. FIG. 9A is a cross-sectional view showing a state where the cavity 101 in the mold 100 is filled with the insulating resin 21. It can be seen that the back surface of the plate 30 is in contact with the lower mold 100A and the upper mold 100B is in contact with the mold contact area. The symbol V is a vacuum suction hole. FIG. 9B shows a state where the plate 30 is mounted on the lower mold 100A. Reference numeral 102 denotes a guide pin attached to the lower mold 100A, and the guide pin 102 is exposed through a guide hole opened in the plate 30.

FIG. 9C is a diagram illustrating the relationship between the cavity 101, the runner 103, and the pot 104 formed in the mold. As shown in the figure, several cavities 101 are arranged in the horizontal direction, and a large number of semiconductor devices can be obtained in one frame. Reference numeral 105 shown by a dotted line indicates an arrangement area of the plate-like body. For example, a plate-like body 106 as shown in FIG. 11 is mounted in the same manner as a conventional lead frame. This is formed by integrally forming a plurality of the plate-like bodies 30 of FIG. The semiconductor device itself manufactured by this plate-shaped body has a feature that it is small in size, can be manufactured in a large number in one cavity, can be mass-produced, and leads to a reduction in manufacturing cost. (See FIGS. 8 and 9 above)
Subsequently, there is a step of taking out the sealed plate 30 from the mold 100, removing the plate 30 exposed on the back surface of the insulating resin 21, and separating the conductive pattern 22.

  FIG. 10A is a plan view showing a line to be separated, and FIG. 10B is a plan view showing the back surface of the insulating resin 21 and the back surface of the second bonding pad 17 or the back surface of the insulating resin 21 and the wiring 18 and the external extraction electrode. 19 shows the case where the back surfaces are the same. This is made possible by shaving until the separation groove 40 is exposed by the polishing device. Note that an insulating film R such as a solder resist may be formed on the back surface to expose only a portion that needs electrical connection.

  In FIG. 10C, the polishing is stopped in the middle, and a projection 111 is formed on the other end 110 of the external extraction electrode 19. This can be achieved by forming a photoresist on a portion corresponding to the convex portion 111 and etching the other portion. Then, an insulating film R is formed so that the convex portion 111 is exposed. By doing so, it is possible to prevent a short circuit with the conductor on the mounting board side that passes under the semiconductor element 15.

Finally, the mold body is placed on a dicing table, the position of the blade is adjusted with reference to the alignment marks 36 and 37, and diced along a dotted line, thereby completing a semiconductor device.

Seventh Embodiment for Demonstrating Method of Manufacturing Semiconductor Device Next, FIGS. 12 to 14 show a case where a face-down type semiconductor element 150 is mounted on a plate 151 to manufacture a semiconductor device having a BGA structure. .

  When the thin metal wire 20 is used, the conductive pattern 22 protrudes from the semiconductor element mounting region. However, if the present face-down type is adopted, the protruding portion can be reduced or eliminated. In addition, since the top of the thin metal wire 20 is high, the thickness of the package is increased. However, by adopting the face-down type, the thickness can be reduced.

  The face-down type semiconductor element employs solder balls 152, and solder or gold bumps are employed in place of the solder balls 152.

  When the semiconductor element 150 is fixed with a brazing material such as solder, the external extraction electrode 153 is mainly made of Cu, so that it is not necessary to form a conductive film on the surface like a bonding pad. However, it is necessary to make an eaves to generate an anchor effect.

  Also, the manufacturing method is the same as that of the previous embodiment, and therefore will be described only briefly.

  First, as shown in FIG. 12, a plate 151 is prepared, and a solder ball 152 of the semiconductor element 150 is fixed to the plate 151.

  Subsequently, as shown in FIG. 13, sealing is performed using an insulating resin 154.

  Then, as shown in FIG. 14, the conductive pattern is separated by removing the plate-like body 151 located on the back surface of the insulating resin 154 from the back surface, and diced along the dotted line to complete the semiconductor device.

As shown in FIGS. 10B and 10C, the back surface of the package may be covered with an insulating resin R to expose a portion corresponding to the external extraction electrode.

As can be said in all the examples, a plate-shaped body is coated with a conductive film having a small etching rate, and a half-etching is performed through the conductive film, so that an eaves and a curved structure can be realized and an anchor effect can be provided. it can.

For example, when Ni is deposited on a Cu foil, Cu and Ni can be etched at once by ferric chloride or cupric chloride, and the Ni is eaves formed by a difference in etching rate, which is preferable. .

It is a figure explaining the plate-shaped object of the present invention. It is a figure explaining the plate-shaped object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the plate-shaped object of the present invention. It is a figure explaining the plate-shaped object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is the figure which adopted the plate-shaped object as a lead frame. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. It is a figure explaining the manufacturing method of the semiconductor device which adopted the tabular object of the present invention. FIG. 9 is a diagram illustrating a conventional semiconductor device having a BGA structure.

Explanation of reference numerals

10 Plates
11 Conductive coating
12 First surface
13 Second surface
14 Semiconductor element mounting area
15 Semiconductor elements
16 First bonding pad
17 Second bonding pad
18 Wiring
19 External extraction electrode
20 Fine metal wire
21 Insulating resin
22 Conductive pattern
23 Semiconductor devices

Claims (14)

A plate-like body having a first surface formed of a flat surface, and a second surface having a convex portion formed at a desired height and facing the first surface;
The protruding portion forms a bonding pad provided around the semiconductor element mounting area, a wiring extending integrally with the bonding pad to the semiconductor element mounting area, and an external extraction electrode provided integrally with the wiring. A plate-like body characterized in that:   The plate-shaped body according to claim 1, wherein a conductive film is provided on a surface of the projection.   The plate-like body according to claim 2, wherein a conductive film is provided at least in a region corresponding to the bonding pad.   The plate-shaped body according to any one of claims 1 to 3, wherein the plate-shaped body is made of a conductive foil, and the conductive coating is made of a material different from a material of the conductive foil.   5. The plate-like body according to claim 1, further comprising a protrusion having substantially the same pattern as the guide pin or a guide hole into which the guide pin is inserted. A plate-like body as described in Crab.   The plate-like body according to any one of claims 1 to 5, wherein a predetermined pattern including the protrusions is arranged in a matrix on the plate-like body.   The plate-like body according to claim 1, wherein the plate-like body is made of a laminate of Cu, Al, Fe-Ni alloy, Cu-Al, or a laminate of Al-Cu-Al.   The plate-like body according to claim 1, wherein a side surface of the protrusion has an anchor structure.   The plate-like body according to claim 1, wherein the conductive film forms an eave on an upper surface of the protrusion.   The plate-like body according to claim 9, wherein the conductive film is made of Ni, Au, Ag, or Pd. A flat back surface over the entire surface corresponding to the resin sealing region, and a region formed in a sheet shape with a predetermined thickness from the back surface and surrounded by a contact region with the upper mold,
A bonding pad provided around the semiconductor element mounting area, a wiring extending integrally with the bonding pad to the semiconductor element mounting area, and a projection serving as an external extraction electrode provided integrally with the wiring are formed. A plate-like body having a surface
A plate-like body characterized in that at least a region surrounded by a contact region with the upper mold forms a closed space with the surface and the upper mold. A back surface that is flat over the entire surface corresponding to the resin sealing region; a bonding pad formed in a sheet shape with a predetermined thickness from the back surface and provided in a region surrounded by a contact region with the upper mold; Prepare a plate-shaped body having a surface on which a projection extending as an external extraction electrode provided integrally with the wiring and the wiring extending integrally with the semiconductor element mounting region is formed,
A semiconductor element is mounted on the semiconductor element mounting area, and the bonding pad and the semiconductor element are electrically connected,
The plate-shaped body is mounted on a mold, and a space formed by the plate-shaped body and the upper mold is filled with a resin.
Removing the plate-like body exposed on the back surface of the filled resin to separate the projections from each other.   13. The method of manufacturing a semiconductor device according to claim 12, wherein the entire region of the back surface of the plate-shaped body corresponding to the resin sealing region is brought into contact with a lower mold.   14. The method according to claim 13, wherein the contact area of the lower mold is provided with vacuum suction means dispersed therein.

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