JP2005159184A - Manufacturing method of electronic device - Google Patents

Abstract

An electronic device manufacturing method capable of effectively preventing the occurrence of burrs when dividing a mother board and obtaining an electronic device with high connection reliability.
A conductor that is partitioned into a plurality of substrate regions arranged in a matrix and that is formed on at least one main surface so as to straddle a boundary between adjacent substrate regions and that serves as an external terminal electrode on the inner surface. A mother board 1 having a recess 3 to which a pattern 2 is applied is prepared, and thereafter, an electronic component element 4 is mounted on each substrate region on the other main surface of the mother board 1, and in the recess of the mother board 1. After the cream solder is filled, the cream solder is heat-treated to form a solder pool 7 and the mother board 1 is placed on the adhesive sheet 8 so that one main surface of the mother board 1 and the solder pool 7 in the recess are formed. Are adhered to the adhesive sheet 8 by cutting the mother substrate 1 together with the conductor pattern 2 and the solder reservoir 7 along the outer periphery of each substrate region with the dicer 9 from the other main surface side of the mother substrate 1. Multiple one-to-one correspondence with substrate area Method of manufacturing an electronic device including the step of dividing the number of electronic devices.
[Selection] Figure 4

Description

  The present invention relates to a method of manufacturing an electronic device used by being incorporated in a communication device such as a mobile phone or a personal computer, or an electronic device.

  2. Description of the Related Art Conventionally, electronic devices including various electric circuits have been used in communication devices such as mobile phones, electronic devices, and the like.

  As such a conventional electronic device, for example, as shown in FIG. 7, a multilayer body 50 is formed by laminating a plurality of insulator layers, and a wiring pattern 51 for signal wiring and ground wiring is formed inside the multilayer body 50. In addition, a predetermined electric circuit is configured by mounting the electronic component element 52 electrically connected to the wiring pattern 51 on the upper surface of the laminate 50.

  Further, at the four corners of the lower surface of the laminate 50, cutout portions 54 having external electrode terminals 53 attached to the inner surface are formed. The notch 54 becomes a space for accommodating solder when the electronic device is mounted on an external wiring board such as a mother board and soldered. Also, the melted solder from the external electrode terminal 53 attached to the notch 54 crawls up to form a fillet, thereby improving the bonding strength between the electronic device and the external wiring board. Can be retained.

  As the above-described conventional method for manufacturing an electronic device, a multi-piece method is used in which individual electronic devices are obtained by dividing a large mother substrate partitioned into a plurality of substrate regions.

  Specifically, a mother board divided into a plurality of board regions is prepared, and a concave portion is formed on one main surface of the mother board with a conductor pattern serving as an external terminal electrode attached to the inner surface. An electronic component element such as a semiconductor element or a piezoelectric element is mounted on the other main surface of the mother board.

  Next, the mother board is placed on the pressure-sensitive adhesive sheet, and with one main surface of the mother board in close contact with the pressure-sensitive adhesive sheet, a dicer is used from the other main surface side of the mother board along the outer periphery of each substrate region. A plurality of electronic devices can be obtained by cutting the mother substrate (see, for example, Patent Document 1).

In order to mount the electronic device thus obtained on an external wiring board such as a mother board, solder is previously applied to lands provided on the external wiring board, and the external electrode terminal 53 is connected to the land. The solder is placed so as to be in contact with the solder, and then the solder is heated and melted to solder the external electrode terminal 53 and the land.
JP 2003-174258 A

  However, in the above-described conventional method for manufacturing an electronic device, the mother board is placed on the adhesive sheet with the one main surface side where the recess is formed facing the adhesive sheet. An enclosed cavity region will be formed.

  When the dicer reaches the cavity region when the mother substrate is cut from the other main surface side by the dicer, the insulator layer extruded by the dicer and the conductor pattern for the external electrode terminal deposited on the inner surface of the concave portion are dicered. Is bent in the pushing direction, that is, the inner surface side of the recess, thereby forming a burr. When such burrs exist, when soldering the electronic device to the external wiring board, the rising of the molten solder is hindered by the burrs, and the fillet formation is insufficient. As a result, there is a drawback that the bonding strength between the electronic device and the external wiring board cannot be maintained well, and the connection reliability of the electronic device is lowered.

  The present invention has been devised in view of the above disadvantages, and an object of the present invention is to effectively prevent the generation of burrs when dividing the mother board, and to obtain an electronic device with high connection reliability. It is to provide a method for manufacturing an apparatus.

  The method for manufacturing an electronic device according to the present invention is divided into a plurality of substrate regions arranged in a matrix, and is formed on at least one main surface so as to straddle a boundary between adjacent substrate regions and on an inner surface. Preparing a mother board having a concave portion to which a conductor pattern to be an external terminal electrode is attached, and then mounting an electronic component element on each board region of the other main surface of the mother board; and After the cream solder is filled in the recesses, the cream solder is heat-treated to form a solder pool, and the mother board is placed on an adhesive sheet so that one main surface of the mother board and the solder in the recesses The substrate B is cut by a dicer from the other main surface side of the mother board along the outer periphery of each board region together with the conductor pattern and the solder. Territory When those characterized by comprising a step C of dividing the plurality of electronic device corresponding to the one-to-one, a.

  According to the method for manufacturing an electronic device of the present invention, the recess formed on the mother board is filled with cream solder and cured, and then the mother board is placed on the adhesive sheet. The area surrounded by the sheet is filled with solder. Therefore, when dividing the mother board using a dicer, the conductor layer for the external electrode terminals on the insulator layer and the inner surface of the recess is not bent to the inner surface side of the recess by the dicer, and it is effective to generate burrs in this portion. Can be prevented. As a result, when the electronic device is soldered to an external wiring board such as a mother board, the melted solder smoothly crawls along the conductor pattern for the external electrode. As a result, a good fillet can be formed, the connection strength between the electronic device and the external wiring board can be kept high, and the connection reliability of the electronic device can be improved.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view of an electronic device manufactured by the manufacturing method of the present invention, and FIG. 2 is a cross-sectional view of the electronic device shown in FIG. The electronic device shown in FIG. 1 includes a laminated body 21 formed by laminating a plurality of insulator layers. The wiring pattern 21 for signal wiring and ground wiring is formed inside the laminated body 21, and the wiring pattern 21 is formed. A predetermined electric circuit is configured by mounting the electronic component element 4 electrically connected to the upper surface of the laminate 21.

  Further, at the four corners of the lower surface of the laminate 21, there are provided cutout portions 24 with the external electrode terminals 23 attached to the inner surface, and solder pools 25 are formed in the cutout portions.

  In order to mount the above-described electronic device on an external wiring board such as a mother board, the solder pool 25 is placed in contact with a land provided on the external wiring board, and then the solder pool 25 is heated and melted. This is done by soldering the land and the external electrode terminal 23 of the electronic component. FIG. 3 is a cross-sectional view of the electronic device mounted on an external wiring board. As shown in the figure, the melted solder scoops up the external electrode terminal 23 to form a fillet 25a, thereby favorably maintaining the bonding strength between the electronic device and the external wiring board 26. be able to.

  Next, a method for manufacturing the electronic device described above will be described with reference to FIG.

(Process A)
First, as shown in FIG. 1 (a), it is partitioned into a plurality of substrate regions arranged in a matrix, and is formed on at least one main surface so as to straddle the boundary between adjacent substrate regions and the inner surface. Then, a mother board 1 having a recess 3 with two conductor patterns to be external terminal electrodes attached thereto is prepared, and thereafter, electronic component elements 4 are mounted on each board region on the other main surface of the mother board 1.

  The mother board 1 is composed of a large laminate 6 in which a plurality of insulator layers 6a to 6c are laminated with a wiring pattern 5 such as signal wiring or signal wiring interposed therebetween. For example, the large laminate 6 includes a signal wiring and a ground on the surface of a ceramic green sheet obtained by adding and mixing an appropriate organic binder, organic solvent, etc. to a ceramic material powder made of glass-ceramic, alumina ceramic or the like. Printed and applied to a predetermined pattern using a conventionally well-known screen printing method or the like, a conductive paste to be a wiring pattern 5 such as wiring, etc. Is done.

  A recess 3 is formed on one main surface of the mother board 1. The recess 3 is formed by forming a through hole in advance in a ceramic green sheet to be the lowermost insulator layer 6c of the large laminate 6 by punching or the like and laminating it. Furthermore, a conductor pattern 2 to be an external terminal electrode is formed by printing and applying a conductor paste on the inner surface of the recess 3 and firing it simultaneously with the ceramic green sheet.

  Examples of the conductive paste material for the wiring pattern 5 and the conductive pattern 2 include Ag-based powders such as Ag, Ag-Pd, and Ag-Pt, borosilicate-based low-melting glass frit, organic binders such as ethyl cellulose, organic A mixture of solvents is used.

  The large laminate 6 thus obtained has a substrate region arranged in a matrix, that is, in a matrix of vertical m columns × horizontal n rows (m and n are natural numbers of 2 or more), Various electronic component elements 4 such as a semiconductor element and a crystal vibration element are mounted on each substrate region of one main surface of the large laminate 6 to complete the mother substrate 1.

  In the present embodiment, as shown in FIG. 5, a predetermined discard area 10 is provided between the substrate areas arranged in a matrix, and a marking 11 is provided at a predetermined position of the discard area. Has been. This marking 11 is for recognizing a cutting position when cutting a large substrate in step C described later.

(Process B)
Next, as shown in FIG. 4B, after the cream solder is filled into the recesses 3 of the mother board 1, the cream solder is heat-treated to form a solder pool 7, and the mother board 1 is placed on the adhesive sheet 8. The main surface of the mother board 1 and the solder pool 7 in the recess 3 are brought into close contact with the adhesive sheet 8.

  As the solder pool 7, for example, Pb-free solder such as Sn—Ag solder, Sn—Ag—Cu solder, Sn—Zn solder, etc. is preferably used, and a flux or the like is used as a precursor made of such a material. After the cream solder obtained by adding and mixing is applied to the recesses by a screen printing method or the like, the cream solder is heated and cured to form the recesses.

  Further, before the cream solder is cured, the air mixed between the cream solder and the recess 3 is removed in a vacuum state, whereby the inner surface of the recess 3 and the solder pool 7 can be more closely attached. At this time, since a dent may be formed on the exposed surface of the solder, in this case, the cream applied in advance so that the exposed surface of the solder pool 7 and one main surface of the mother board 1 are flush with each other. It is preferable to apply cream solder once again on the solder. By filling the concave portion 3 with solder cream so that the exposed surface of the solder pool 7 and one main surface of the mother substrate 1 are on the same plane, the mother substrate 1 is stably placed on the adhesive sheet 8. be able to.

  In this way, the mother board 1 in which the solder pool 7 is formed in the recess 3 is fixed to the pressure-sensitive adhesive sheet 8 with one main surface thereof being in close contact with the pressure-sensitive adhesive sheet 8. The pressure-sensitive adhesive sheet 8 has adhesiveness, and fixes the mother substrate 1 on the stage of the dicing apparatus, and prevents the divided pieces from scattering when the mother substrate 1 is divided in the process C described later. It is for keeping.

(Process C)
Finally, as shown in FIG. 1C, the mother board 1 is cut with a dicer 9 from the other main surface side of the mother board 1 along the outer periphery of each board area together with the conductor pattern 2 and the solder 7. 1 is divided into a plurality of electronic devices corresponding one-to-one with the substrate region.

  The mother substrate 1 is cut by recognizing the cutting position by reading the marking 11 attached to the surrogate area 10 with an image recognition device, and then cutting the matrix area along the outer periphery of each substrate area by the dicer 9. Thus, a plurality of electronic devices shown in FIG. 1 can be obtained at the same time.

  In this cutting operation, when the dicer 9 reaches the area surrounded by the concave portion 3 and the adhesive sheet 8, this area is filled with the solder pool 7, so that the insulation pushed out by the dicer 9 Since the conductor pattern 2 for the external electrode terminal deposited on the inner surface of the body layer or the recess 3 is scraped by the dicer 9 without being bent toward the inner surface of the recess 3, it is possible to effectively prevent the occurrence of burrs. it can. Thus, when soldering the electronic device to an external wiring substrate such as a mother board, the fillet can be satisfactorily formed without hindering the rising of the molten solder. As a result, the connection strength between the electronic device and the external wiring board is maintained in a good state, and an electronic device with high connection reliability can be provided.

  Further, after the mother board 1 is cut, the solder pool 7 is left in the recess 3 and used as a bonding material when the electronic device is mounted on the external wiring board. Specifically, the electronic device is placed on the land of the external wiring board via the solder pool 7, and then the solder pool 7 is heated and melted, whereby the external electrode terminal 23 of the electronic device and the external wiring board are The land is soldered. Also, if solder is applied in advance to the lands of the external wiring board, when the solder is melted, the self-alignment effect due to the surface tension of the solder can improve the accuracy of the electronic component mounting position. .

  In addition, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.

  For example, after mounting the electronic component element 4 in the above-described step A, a shield cover may be attached so as to cover the electronic component element 4 in each substrate region. When attaching the shield cover, the shield cover may be individually attached to each substrate region, but it is preferable to use a large mother cover in consideration of productivity. Specifically, first, as shown in FIG. 6 (a), the mother cover 12 having a plurality of receiving recesses 13 corresponding to the substrate region is placed in the receiving recesses in the electronic component elements 4 of each substrate region. Is attached to the mother board 1 in such a manner as to be arranged. Next, as shown in FIG. 6B, the mother cover 12 and the mother cover 12 together with the mother substrate 1 are simultaneously cut using a dicer 9, whereby the electronic device with the shield cover 14 attached thereto is manufactured.

  In addition to attaching the shield cover 14 in the process A as described above, the electronic component element 4 may be covered with a resin material. In this case, after the electronic component element 4 is mounted on the mother board 1, a liquid resin material is applied so as to cover the electronic component element 4 over the entire substrate area, and the resin material applied together with the mother board 1 is used with the dicer 9. By cutting, an electronic device in which the electronic component element 4 is covered with a resin material is manufactured.

  In the above-described embodiment, the large laminate 6 is manufactured using a ceramic material. Instead, the large laminate 6 may be manufactured using a resin material such as a photosensitive resin. Absent. In this case, since the insulating layer made of a resin material has a lower hardness than the insulating layer made of ceramic and can be cut relatively easily, there is an advantage that the workability of the cutting work is improved.

It is a perspective view of the electronic device manufactured by the manufacturing method of this invention. FIG. 2 is a cross-sectional view of the electronic device shown in FIG. FIG. 2 is a cross-sectional view showing a state where the electronic device shown in FIG. 1 is mounted on an external wiring board. (A)-(c) is sectional drawing for demonstrating the manufacturing method which concerns on one Embodiment of this invention. It is a perspective view for demonstrating the manufacturing method concerning one Embodiment of this invention. (A) And (b) is sectional drawing for demonstrating the manufacturing method concerning other embodiment of this invention. It is sectional drawing of the conventional electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mother board 2 ... Conductor pattern 3 ... Recessed part 4 ... Electronic component element 5 ... Wiring pattern 6 ... Large-sized laminated body 6a-6c ... Insulator layer 7 ... Solder pool 8 ... Adhesive sheet 9 ... Dicer 10 ... Disposal area 11 ... Marking

Claims (1)

It is divided into a plurality of substrate regions arranged in a matrix, and is formed on at least one main surface so as to straddle the boundary between adjacent substrate regions, and a conductor pattern serving as an external terminal electrode is attached to the inner surface. Preparing a mother board having a concave portion formed, and then mounting the electronic component element on each substrate region of the other main surface of the mother board, and
After the cream solder is filled in the recesses of the mother board, the cream solder is heat-treated to form a solder pool, and the mother board is placed on an adhesive sheet so that one main surface of the mother board and the recesses Step B for bringing the inner solder into close contact with the adhesive sheet;
The mother board is cut with a dicer from the other main surface side of the mother board along the outer periphery of each board area together with the conductor pattern and the solder, thereby making the mother board a plurality of one-to-one correspondence with the board area. A method of manufacturing an electronic device, comprising a step C of dividing the electronic device.

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