JP2001257228A - Transfer bump sheet, semiconductor device, and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer bump sheet which is capable of transferring bumps onto a semiconductor chip at a high yield and at a low cost and to enable a semiconductor device in which bumps are transferred onto a semiconductor chip by the use of the transfer bump sheet to be manufactured at a low cost. SOLUTION: A transfer bump sheet has such a structure that conductor terminals which are formed into bumps after they are transferred are arranged in array on a base sheet, where the base sheet is formed of resin which is deteriorated in adhesion to the conductor terminals around a temperature at which the conductor terminals are transferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer bump sheet for mounting flip-chip connection bumps on a semiconductor chip by collectively transferring the bumps, and a semiconductor device having flip-chip connection bumps formed on a semiconductor chip. And a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the demand for higher functionality and lighter, thinner and smaller electronic devices, high-density integration and high-density mounting of electronic components have been progressing. Semiconductor packages have been increasingly miniaturized and have more pins than ever before.

[0003] With the miniaturization of semiconductor packages,
In a conventional package using a lead frame, the miniaturization has reached its limit. Recently, a BGA (Ball) has been used as a package mounted on a circuit board.
Grid Array) and CSP (Chip Sca)
le Package), a new area mounting type packaging system has been proposed. In these semiconductor packages, various insulating materials such as plastics and ceramics, which are called a semiconductor mounting substrate, having electrodes of a semiconductor chip and a function of a lead frame of a conventional semiconductor package, and terminals of a substrate composed of conductive wiring are provided. Electrical connection methods include wire bonding and TA.
B (Tape Automated Bonding)
A method, and furthermore, an FC (Flip Chip) method and the like are known, but recently, a structure of a BGA or a CSP using an FC connection method, which is advantageous for miniaturization of a semiconductor package, has been actively proposed. This FC connection method is generally
A bump is formed in advance on the electrode of the semiconductor chip, and the position of the bump and the terminal on the wiring board are adjusted.
This is a method of connecting by thermocompression bonding.

As methods for forming bumps directly on a semiconductor chip, a vacuum deposition method, a printing method, a solder ball alignment method, a stud bump method, an electrolytic plating method and the like are known.

[0005] In the vacuum deposition method, a metal mask is used and Sn is used.
And Pb are deposited, and a solder bump is formed by wet back. Since a metal mask is used, it is not possible to cope with a narrow pitch. In addition, since the growth rate of the bump is slow, there is a problem that it takes time to form the bump at a predetermined height.

[0006] The printing method (Japanese Patent Application Laid-Open No. 6-168949) is a method of forming solder bumps by forming projections of the solder paste by a screen printing method or the like and reflowing the solder paste. Although low cost and high productivity, it is difficult to cope with narrow pitches because the solder paste may bleed during printing and come into contact with the solder paste projections formed on the adjacent electrodes. In addition, when a narrow pitch is used, there is a problem that the bump cannot be formed at a predetermined height.

[0007] Solder ball alignment method (Japanese Unexamined Patent Publication No. 5-1293)
No. 74) adsorbs a ready-made solder ball with a suction tool having holes of the same arrangement as the electrode arrangement of the semiconductor chip, aligns the solder ball on the electrode of the semiconductor chip,
This is a method of forming solder bumps by reflow. Although the bump pitch depends on the solder ball diameter, especially when the solder ball becomes minute, the solder ball becomes dirty or dusty, and the effects of static electricity may cause a suction error or extra solder ball adhesion, or may cause a problem with the suction tool. There is a case where a plurality of solder balls are adsorbed in a grape shape in one hole, and there is a problem that a solder bump cannot be reliably formed.

A stud bump method (Japanese Patent Laid-Open No. 34949/1990)
Japanese Patent Application Laid-Open No. HEI 4-159743) is a method of forming a gold bump or a solder bump by bonding and cutting a gold wire or a solder wire to an electrode of a semiconductor chip. This method can cope with a narrow pitch, and when using a gold wire, it is possible to directly form a gold bump on an electrode (aluminum pad) of a semiconductor chip, so there is no need to form a barrier metal. There is an advantage. However, in this method,
In order to form bumps one by one on the electrode of the semiconductor chip,
Not only does it take a long time to manufacture, but in the case of gold wires, the cost is high and the manufacturing cost is high. Furthermore, since there is a possibility that the semiconductor chip may be damaged, there is a problem that it is not possible to cope with the bump area.

In the electrolytic plating method (JP-A-7-111264, JP-A-9-191013, etc.), a plating mask is formed on a semiconductor chip, and exposure and development are performed to form openings at the positions of the electrodes. Thereafter, a bump is formed by electrolytic plating. In this method, since the bumps are formed to a desired size only by plating, the manufacturing time and the manufacturing cost are increased. In addition, it is difficult to make the current distribution in the plating tank completely uniform by electrolytic plating.
Variations in the height of the formed bumps occur. Since the height variation of the bump becomes more prominent as the plating time is longer, it is difficult to solve the problem by forming the bump using only solder.

As described above, the method of forming bumps directly on a semiconductor chip has various problems, and the biggest problem is to improve the yield of bump formation.

On the other hand, a transfer bump method has been developed in which bumps determined to be non-defective are collectively transferred to the semiconductor chip, instead of forming bumps directly on the semiconductor chip, thereby improving the yield. In this method, the bumps on the transfer bump sheet side are transferred collectively to the semiconductor chip side by aligning the semiconductor chip with the transfer bump sheet in which bumps are previously formed on the base sheet, and applying heat and pressure. .

Conventionally known methods for forming a bump on a transfer bump sheet include a vacuum deposition method, a printing method, a bump punching method, an electrolytic plating method, and an etching method.

The vacuum deposition method (Japanese Patent Application Laid-Open No. Hei 6-97177) has problems that it is difficult to cope with a narrow pitch and that it takes time to form bumps, as in the above-described vacuum deposition method.

The printing method (Japanese Patent Application Laid-Open No. Hei 4-263433, etc.) is similar to the above-mentioned printing method, and is low in cost and high in productivity, but it is difficult to cope with a narrow pitch. There is a problem that it cannot be formed in

The bump punching method (Japanese Patent Application Laid-Open No. 7-193068) is a method in which a metal ribbon is punched into a bump shape by a die and a punch and arranged on a base sheet. This method has the advantage that the material of the metal ribbon can be freely selected, but has the problem that it takes a long time to manufacture since the bumps are formed one by one on the base sheet. In addition, although the pitch can be reduced by reducing the diameter of the punch, there is a problem that the life of the punch is shortened due to the small diameter.

The electroplating method (Japanese Patent Application Laid-Open Nos. H11-211028 and H8-8258, etc.) requires a manufacturing time and a manufacturing cost similarly to the above-described electroplating method, and the bump height varies. There is a problem.

The etching method (JP-A-4-217336, JP-A-7-66545, etc.) is a method of forming a bump by etching a metal foil on a base sheet. Since the bump is formed by etching the metal foil, the manufacturing time can be shortened as compared with the method of forming the bump by electrolytic plating, and the bump height can be reduced by using the metal foil having a uniform thickness. There is an advantage that can be uniform.

Japanese Patent Application Laid-Open No. 4-217336 proposes a method using a gold foil as an example of a metal foil. Since the gold foil is etched to leave bumps in necessary portions, most of the gold is removed by etching.
In this case, the manufacturing cost must be high. on the other hand,
JP-A-7-66545 proposes a method using a solder foil as a metal foil. Although the solder foil is inexpensive as compared with the gold foil, it is expensive and the availability is limited as compared with a general metal foil such as a copper foil, so that the manufacturing cost has to be increased.

On the other hand, as a material of the base sheet of the transfer bump system, a metal foil, a resin or the like can be considered. When a metal foil is used for the base sheet, the conductor terminals need to be formed by plating or printing, and it is difficult to make the heights of the conductor terminals uniform. When a resin is used for the base sheet, a metal foil for forming the conductor terminal can be laminated on the base sheet, and the metal foil can be etched to form the conductor terminal. it can. However, the following problem arises. When the adhesive force between the resin of the base sheet of the transfer bump sheet and the conductive terminals is strong, workability in manufacturing the transfer bump sheet is good, but disadvantages such as 100% of the conductive terminals and not transferring to the semiconductor chip occur. . On the other hand, when the adhesive force between the resin of the base sheet of the transfer bump sheet and the conductor terminals is weak, the conductor terminals can be transferred 100% to the semiconductor chip, but the conductor terminals are missing during the production of the transfer bump sheet. And other problems. In the development of the transfer bump sheet, controlling the adhesive force between the base sheet of the transfer bump sheet and the conductor terminals is a key.

In recent years, in order to obtain the bonding reliability of a bump (for example, the bonding strength after being left at a high temperature), a bump having a metal core such as a copper core solder bump is used instead of a bump composed of only solder. A way to do that has been proposed. The solder ball alignment method can cope with the problem by using a ready-made copper core solder ball (Japanese Patent Application Laid-Open No. H11-317416), but leads to a significant cost increase as compared with a normal solder ball. In addition, the bump punching method can be dealt with by using a metal ribbon in which both sides of a copper foil are plated with solder, but it is difficult to deal with the bump punching method itself because it has a problem. In the electrolytic plating method, after the steps of solder plating, copper plating, and solder plating,
Although copper core solder bumps can be formed by reflow, manufacturing costs are increased due to further complication of the manufacturing process. On the other hand, it is impossible to form a copper core solder bump by the vacuum deposition method, the printing method, and the stud bump method.

[0021]

SUMMARY OF THE INVENTION The present invention has been made as a result of diligent research in view of such problems of the structure and manufacturing method of a conventional transfer bump sheet, and has no height variation in a semiconductor chip. It is an object of the present invention to provide a transfer bump sheet capable of transferring bumps with good yield, a semiconductor device having a bump mounted on a semiconductor chip using the transfer bump sheet, and a method of manufacturing the same.

[0022]

In order to achieve the above-mentioned object, a transfer bump sheet according to the present invention is a transfer bump sheet for mounting bumps for flip-chip connection by batch-transfer onto a semiconductor chip. A structure in which conductor terminals that become bumps after transfer are arranged on a base sheet, wherein the base sheet is made of a resin whose adhesive property with the conductor terminals is reduced due to heat history of transferring the conductor terminals. More preferably, the base sheet comprises the resin and a reinforcing plate formed on the surface of the resin facing the conductor terminals.

Further, the resin of the base sheet of the transfer bump sheet of the present invention comprises (a) a polyfunctional epoxy resin, (b) an epoxy resin curing agent, (e) an inorganic filler, or (a) a polyfunctional epoxy resin. It is characterized by comprising a resin, (b) an epoxy resin curing agent, (c) a photopolymerizable monomer, (d) a photopolymerization initiator, and (e) an inorganic filler.

Further, the conductor terminal of the transfer bump sheet of the present invention comprises a metal core formed by etching a metal foil and a metal coating covering a part or the entire surface of the metal core. Alternatively, it is a solder, and more preferably, the material of the metal core is copper.

The semiconductor device of the present invention is a semiconductor device in which a flip chip connection bump is formed on a semiconductor chip, and the bump is formed by using the above-mentioned transfer bump sheet.
It is characterized by being formed by collectively transferring conductor terminals.

In the method of manufacturing a semiconductor device according to the present invention, the bumps for flip-chip connection are formed on the semiconductor chip by batch-transferring the conductor terminals in accordance with the positions of the electrodes of the semiconductor chip using the above-described transfer bump sheet. It is characterized by forming.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION A transfer bump sheet according to the present invention has a structure in which conductor terminals which become bumps after transfer are arranged on a base sheet. The resin used for the base sheet is one or more of an epoxy resin, a maleimide resin, a fluorine resin, an acrylic resin, a silicone resin and the like. It is possible to mix a thermoplastic resin with excellent sheet-forming ability, but the heat history of transferring the conductor terminals reduces the adhesiveness between the conductor terminals and the peeling of the conductor terminals from the base sheet. Those which can secure the property are preferable.

For this purpose, it is effective to use a resin having a high modulus of elasticity, and a resin having a high modulus of elasticity and a wide elastic area can be compressed at a high temperature such as when transferring a bump and cooled during cooling. Tension state, shrinkage corresponding to these can not be done,
As a result, the bonded portion is easily broken due to stress concentration.
Furthermore, it is also possible to utilize the decomposition by oxidation of the base sheet when heated at a high temperature in the air. Therefore,
Resins composed of highly crosslinked thermosetting resins are preferred. In particular, a resin comprising (a) a polyfunctional epoxy resin, (b) an epoxy resin curing agent, and (e) an inorganic filler is preferable.

The component (A) used in this resin is not particularly limited as long as it is a polyfunctional epoxy resin. When a solid epoxy resin is used at room temperature, the properties of the base sheet and the laminating property to the reinforcing plate, etc. It is preferable to use a liquid epoxy resin in combination.

As the component (b), generally used various curing agents such as diamine, acid anhydride and imidazole can be used, and a combination which can obtain a cured resin having a high cross-linking structure and a high elastic modulus is preferable.

As the inorganic filler of component (e), crystalline silica, fused silica, finely ground silica, alumina, clay calcium carbonate and the like can be used. By adding these inorganic fillers, a resin cured product having a higher elastic modulus can be obtained.

More preferred resins used for the base sheet include resins composed of a mixture of a highly crosslinked thermosetting resin and a photopolymerizable resin. Particularly, (a) a polyfunctional epoxy resin and (b) an epoxy resin curing agent A resin composed of (c) a photopolymerizable monomer, (d) a photopolymerization initiator, and (e) an inorganic filler is suitable, and it is possible to set a low transfer temperature. Of these, (a), (b), and (e)
As the components, the same components as described above can be used.

As the photopolymerizable monomer of the component (c),
Any type that dissolves a solid epoxy resin, polymerizes it by irradiation with active energy rays, and can be solidified, and furthermore, a substance that partially oxidatively decomposes near the temperature at which the conductor terminal is transferred, and reduces the adhesiveness to the conductor terminal Regardless. By the blending of the photopolymerizable monomer, the bump transfer can be performed even if the bump transfer temperature is set lower than the case where the blending is not performed, and the dimensional change due to the thermal expansion during the bump transfer can be reduced.

As the photopolymerization initiator of the component (d), benzoin alkyl ethers, acetophenones, thioxanthones, alkylanthraquinones and the like can be used. Resins in which these components are appropriately blended can be used in the present invention, and if necessary, additives to which additives such as ultraviolet inhibitors, thermal polymerization inhibitors, and plasticizers can be used.

Further, handling properties are improved by forming the base sheet into a structure comprising the resin and a reinforcing plate formed on the resin surface facing the conductor terminals. Also, if a material with a low expansion coefficient is used as the reinforcing plate,
The dimensional stability at the time of transferring the bump is remarkably improved, and the displacement of the transferred bump can be reduced. The material of the reinforcing plate is not particularly limited as long as it has a linear expansion coefficient of 30 ppm or less. For example, metals, particularly easily available and inexpensive copper (copper plate or copper foil) are preferable.

The resin as described above is coated on a metal foil by a method such as screen printing or a roller coater and dried.
Alternatively, after application and drying, irradiation with active energy rays is performed by an exposure machine such as a UV conveyor, whereby only the photopolymerizable resin component is polymerized, and a solidified thermosetting resin layer is obtained. As the active energy ray, an ultraviolet ray, an electron beam or the like can be used, but from the viewpoint of easy handling and cost, it is preferable to use an ultraviolet ray. Further, by laminating the above-mentioned reinforcing plate on the solidified thermosetting resin layer by applying heat and pressure, a base sheet composed of the resin and the reinforcing plate can be formed.

The resin used in the present invention has a function of holding conductive terminals after the thermosetting resin is cured or the photopolymerized resin and the thermosetting resin are polymerized and cured after the production of the transfer bump sheet. After the transfer of the conductor terminal, the conductor member has a peeling function due to its thermal history.

The method for forming the conductor terminals of the transfer bump sheet of the present invention includes a printing method, an electrolytic plating method, an electroless plating method and an etching method. The conductor terminals are formed by etching a metal foil. The method is more preferred.
The configuration of the conductor terminal includes a metal core formed by etching a metal foil, and a metal film covering a part or the entire surface of the metal core. The conductor terminal includes a metal layer (metal core) and a metal Those formed with two layers of the coating layer are preferred. Furthermore, metal coating is aluminum,
It is more preferable to use gold that can be alloyed with tin, gold, or the like, or solder that is a typical bonding material.

The metal core of the conductor terminal may be any metal or alloy that can be etched, but is preferably formed by etching using a readily available metal foil such as a copper foil. preferable. By using copper, the electrical resistance can be significantly reduced, and furthermore, the improvement in bump bonding reliability can be expected. Metals or alloys other than copper can be used for the transfer bump sheet of the present invention as long as they are etchable and suitable for the core of the bump.

The reason why the metal core is formed by etching the metal foil is to suppress variations in the height of the metal core. The easily available copper foil is not limited to the same lot, and has a very small thickness variation, so that it is suitable as the metal core of the transfer bump sheet of the present invention.

The solder used for the solder film and the solder layer may be any solder as long as it can be subjected to electrolytic plating or electroless plating, for example, Sn-Pb eutectic solder. Further, so-called lead-free solders, such as Sn-Sb, Sn-Cu, and Sn-Ag, which have been rapidly developed in recent years, can also be used as long as they can be plated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a view for explaining an example of a method for manufacturing a transfer bump sheet according to the first embodiment of the present invention. FIG. 1E shows a structure of the transfer bump sheet obtained by the first manufacturing method. FIG. The transfer bump sheet 101 includes a base sheet 102 and conductor terminals 103.
, And the conductor terminal 103 includes a metal core 105 and a solder coating 108.

In the first manufacturing method, first, a two-layer sheet including a base sheet 102 and a metal foil 110 is prepared (a). The method of forming the base sheet 102 may be a method of laminating the base sheet or a method of uniformly applying a resin varnish, drying and irradiating with an active energy ray. Next, an etching mask 121 is formed on the metal foil 110 (b), and subsequently, the metal core 1 forming a part of the conductor terminal 103 by etching the metal foil 110 is formed.
05 is formed (c). Next, the etching mask 121
(D), and the metal core 105 is formed by electroless plating.
Metal film 10 constituting a part of conductor terminal 103 on the surface of
8 (e) to form the transfer bump sheet 101 of the present invention.
Is obtained.

The metal core 105 occupying most of the conductor terminals 103 is formed by etching a metal foil 110 having a uniform thickness.
The thickness of 05 is very uniform. Also, the metal film 108
Is formed by electroless plating, the thickness of the metal film 108 becomes very uniform. When the electroless plating is displacement plating, even if the thickness of the metal film 108 varies somewhat, it does not affect the thickness of the conductor terminal 103. Therefore, the thickness of the conductor terminal 103 is very uniform, and no bump transfer error due to the thickness variation of the conductor terminal 103 occurs. Therefore, when bumps are formed on a semiconductor chip using the transfer bumps according to the first embodiment, the bump height hardly varies.

FIG. 2 is a view for explaining a method of manufacturing a transfer bump sheet having a reinforcing plate according to the present invention.
FIG. 3 is a cross-sectional view showing a structure of a transfer bump sheet obtained by this manufacturing method. The transfer bump sheet 201 includes a base sheet 202 and conductor terminals 203, and the base sheet 202 is formed of a resin 211 and a reinforcing plate 2.
It is characterized by being composed of 12 parts.

In the second manufacturing method, first, a two-layer sheet including the resin 211 and the metal foil 210 is prepared (a). The two-layer sheet can be obtained by uniformly applying a resin composed of a mixture of a photopolymerizable resin and a thermosetting resin on the metal foil 210 and irradiating the resin with active energy rays. Next, the reinforcing plate 212 is laminated on the opposite surface of the resin 211 that is not in contact with the metal foil 210 by heating and pressing (b). Next, the etching mask 22 is formed on the metal foil 210.
1 (c), and subsequently, a metal core 205 constituting a part of the conductor terminal 203 by etching the metal foil 210.
(D). Next, the etching mask 221 is peeled off (e), and a metal coating 208 constituting a part of the conductor terminal 203 is formed on the surface of the metal core 205 by electroless plating (f). 201 is obtained.

The method of manufacturing the transfer bump sheet shown in FIG. 2 is similar to the method of manufacturing the transfer bump sheet 101 of the first embodiment (FIG. 1) except that a step of forming a reinforcing plate 212 is added. A transfer bump sheet having a plate can be manufactured.

FIG. 3 is a diagram for explaining a method of collectively transferring bumps to a semiconductor chip using the transfer bump sheet 201 obtained by the second manufacturing method, that is, a method of manufacturing a semiconductor device. (D) is a sectional view showing a structure of a semiconductor device obtained by this manufacturing method. First, the transfer bump sheet 201 is placed at a predetermined position on the substrate receiving base 341 of the bonding apparatus, and the semiconductor chip 330 is sucked by the heating / pressing tool 340 having the suction holes 342. Transfer bump sheet 201 and semiconductor chip 330
Then, a positioning mark formed in advance is read by an image recognition device, and the conductor terminals 203 of the transfer bump sheet 201 and the electrodes 331 of the semiconductor chip 330 are opposed to each other to accurately align (a). Next, the heating / pressing tool 340 is lowered, and the semiconductor chip 330 is pressed in parallel to the transfer bump sheet 201 at a predetermined temperature and pressure (b). First metal layer (in this case, a solder coating) 20
When 8 reaches the melting temperature, the metal film 208 changes to a shape in which the surface tension is balanced (c). After heating and pressing for a predetermined time, the heating and pressing tool 340 is raised, and the semiconductor chip 330 and the transfer bump sheet 201 are raised.
Is removed from the heating and pressing tool 340. After solidification of the metal layer (in this case, the solder film) 208, the base sheet 202 is removed to obtain a semiconductor device 334 to which the bumps 332 are collectively transferred (d).

The transfer bump sea 20 according to the second embodiment
When using No. 1, the metal core 335 of the bump 332 is exposed on the end surface (the lower surface in the figure) of the transferred bump 332 as shown in FIG. This can be solved by preparing a bonding material such as a solder paste in advance on the pads on the substrate side. The same applies to the first embodiment.

As described above, in the transfer bump sheet according to the present invention, the base sheet of the transfer bump is made of a resin whose adhesiveness to the conductor terminal is reduced due to the heat history of transferring the conductor terminal. , Hold the conductor terminals securely,
When transferring the conductor terminals, 100% of the conductor terminals can be transferred with good yield, and the manufacturing cost can be greatly reduced. Further, since the metal layer and the metal core serving as the core of the bump are formed by etching, the manufacturing time and the manufacturing cost can be greatly reduced as compared with the case where the bump is formed only by electrolytic plating or electroless plating. Also, judging from the viewpoint of the size of the bump and the bonding reliability, if the ratio of the etching step can be increased by increasing the thickness of the metal foil as much as possible, the bump can be formed by electrolytic plating or electroless plating. As compared with the forming method, the manufacturing time and the manufacturing cost can be further reduced.

The semiconductor device manufactured by using the transfer bump sheet according to the present invention has a uniform bump height, and does not cause mounting errors due to bump height variations when mounted on a wiring board. Furthermore, since the bump has a copper core, it is possible to ensure the bonding reliability after being left at a high temperature.

[0052]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

(Preparation of Resin for Base Sheet) (Example 1) Novolak epoxy resin (epoxy equivalent 2
00, softening point 70 ° C) 100 parts, liquid bisphenol F type epoxy resin (epoxy equivalent 175) 40 parts,
2-phenyl-4-methylimidazole 2 as a curing agent
Parts, 40 parts of silica (average particle diameter of 10 μm or less) was added as an inorganic filler, and dissolved in 70 parts of cyclohexanone to obtain an epoxy resin solution, which was used as a base sheet resin.

Example 2 100 parts of a brominated novolak epoxy resin (epoxy equivalent: 260, softening point: 65 ° C.)
20 parts of a liquid bisphenol F type epoxy resin (epoxy equivalent: 175) was added to hydroxyethyl methacrylate 8
0 parts, and 2-phenyl-4 as a curing agent.
-3 parts of methylimidazole, 3 parts of a photopolymerization initiator (Irgacure 651 manufactured by Ciba Geigy), and 200 parts of silica (average particle size of 10 μm or less) as an inorganic filler are added, and sufficiently stirred and mixed using a three roll. A non-solvent liquid resin was used as a base sheet resin.

Comparative Example 1 20 parts of a high heat-resistant thermoplastic polyimide resin composed of 4,4'-oxydiphthalic dianhydride and 1,3-bis (3-aminophenoxy) benzene was mixed with N
-Methyl-2-pyrrolidone was dissolved in 80 parts to obtain a highly heat-resistant thermoplastic polyimide solution, which was used as a resin for a base sheet.

(Preparation of Transfer Bump Sheet) Thickness 70 μm
After the liquid resins of Examples 1 and 2 and Comparative Example 1 were cast and applied to a rolled copper foil (metal foil 210) with a comma coater, Example 1 was heated at 90 ° C. for 20 minutes. Was dried using a dryer at 80 ° C., 120 ° C., and 180 ° C. for 10 minutes each to form a resin layer (resin 211) having a thickness of 20 μm. In Example 2, a high-pressure mercury lamp exposure machine was used to irradiate active energy rays under the condition of about 1 J / cm ² to form a resin layer (resin 2
11) was formed. On the surface of the resin layer that is not in contact with the copper foil,
A 70 μm-thick rolled copper foil (reinforcing plate 212) was heated and pressed for lamination, and at the same time, Examples 1 and 2 were cured by a dryer at 150 ° C. for 30 minutes. Next, an etching mask (etching mask 221) is formed on a rolled copper foil (metal foil 210) having a thickness of 70 μm.
The μm rolled copper foil (metal foil 210) was etched to form a copper column (metal core 205). Next, the etching mask (etching mask 221) is peeled off, and Sn-Pb
Copper column (metal core 2)
05), a Sn-Pb eutectic solder film (solder film 308) having a thickness of 10 μm was formed, and the pitch was 250 μm.
m, a copper column (metal layer 104) having a diameter of 100 μm
Six transfer bump sheets 201 having the reinforcing plate of the present invention were formed.

Using the transfer bump sheets prepared in Examples 1 and 2 and Comparative Example 1, bumps were transferred to semiconductor chips. The transfer conditions are as follows: the temperature of the heating / pressing tool: 150 ° C., the temperature of the substrate pedestal: 250 ° C. or 3
00 ° C., load: 6 kgf / 4096 bumps, heating and pressing time: 10 seconds. Ten samples were produced for each example and comparative example.

A transfer experiment was performed under the above conditions, and the transfer rate of the bump, the height variation of the transferred bump, and the position variation of the transferred bump were evaluated. Table 1 shows the evaluation results.
Shown in The transfer rate of the bumps was 100% when all the bumps were transferred. The height variation of the transferred bumps was determined by selecting an arbitrary 100 bumps and using a laser displacement meter. Positional variation is any one of the transferred bumps
00 bumps were selected, and the amount of deviation between the center position of the pad of the semiconductor chip and the center position of the bump was measured by a measuring microscope.

[0059]

[Table 1]

[0060]

According to the present invention, it is possible to manufacture and provide a low-cost transfer bump sheet on which 100% of bumps can be collectively mounted on a semiconductor chip, and it is possible to greatly improve productivity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a method for manufacturing a transfer bump sheet according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a method for manufacturing a transfer bump sheet having a reinforcing plate according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a method of transferring bumps onto a semiconductor chip at once using a transfer bump sheet having a reinforcing plate of the present invention (a method of manufacturing a semiconductor device).

[Explanation of symbols]

 101, 201: Transfer bump sheet 102, 202: Base sheet 103, 203: Conductor terminal 105, 205: Metal core 108, 208: Metal coating 110, 210: Metal foil 211 ... Resin 212 ... Reinforcement plate 121,221 ... Etching mask 330 ... Semiconductor chip 331 ... Electrode 332 ... Bump 333 ... Passivation film 334 ... Semiconductor device 335 ... Metal core 340: Heating and pressing tool 341: Substrate receiving base 342: Suction hole

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Kato 2-5-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Inventor Hitoshi Aoki 2-5-2-8 Higashishinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. F-term (reference) 4J036 AA01 DB15 DC41 FA03 FA05 FA10 JA07

Claims (9)

[Claims] 1. A transfer bump sheet for mounting flip-chip connection bumps on a semiconductor chip by batch-transfer to a semiconductor chip, wherein conductor terminals to be bumps after transfer are arranged on a base sheet. The transfer bump sheet, wherein the base sheet is made of a resin whose adhesive property with the conductor terminal is reduced by heat history of transferring the conductor terminal. 2. The transfer bump sheet according to claim 1, wherein the resin of the base sheet comprises (a) a polyfunctional epoxy resin, (b) an epoxy resin curing agent, and (e) an inorganic filler. 3. The resin of the base sheet is composed of (a) a polyfunctional epoxy resin, (b) an epoxy resin curing agent, (c) a photopolymerizable monomer, (d) a photopolymerization initiator, and (e) an inorganic filler. The transfer bump sheet according to claim 1, wherein: 4. The conductive terminal comprises a metal core formed by etching a metal foil and a metal coating covering a part or the entire surface of the metal core.
A transfer bump sheet according to claim 3. 5. The transfer bump sheet according to claim 4, wherein the metal coating is gold or solder. 6. The transfer bump sheet according to claim 4, wherein the material of the metal core is copper. 7. The transfer bump according to claim 1, wherein the base sheet comprises the resin and a reinforcing plate formed on the surface of the resin facing the conductor terminals. Sheet. 8. A semiconductor device having bumps for flip-chip connecting a semiconductor chip, wherein the bumps are:
8. A semiconductor device formed by batch-transferring conductor terminals using the transfer bump sheet according to claim 1. 9. A flip chip connection to a semiconductor chip by batch-transferring conductor terminals according to the positions of the electrodes of the semiconductor chip using the transfer bump sheet according to claim 1. A method of manufacturing a semiconductor device, comprising: forming a bump.