JPH077033A - Manufacture of semiconductor packaging device - Google Patents

Abstract

PURPOSE:To prevent resin from being squeezed out from a mold to outer lead wires in a resin mold for an electronic component packaging device. CONSTITUTION:An area from a peripheral edge on the surface of a wiring board 10 up to a through hole inside is coated with a bonding agent 15 at a specified thickness. An inner lead wire 21 of a lead frame 20 is heated and contact-bonded with a bonding agent layer, thereby fixing the inner lead with the wiring board 10. During this operation, the bonding agent softened by the heat is pressed by the inner lead wire and swelled between the inner lead wires so that the top of the bonding agent may be substantially flush with the top of the inner lead wires. A peripheral edge of a cavity of a top force 51 of a molding die 50 is laid out on the inner lead wire near the rear side-peripheral edge of the wiring board while a peripheral edge of a cavity of a bottom tool 52 is aligned with an area near the rear side-peripheral edge of the wiring board and clamped. When resin is injected into the cavity, no resin will be squeezed out from the cavity since there is no clearance between the top force and the inner lead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electronic component mounting apparatus, and more particularly to a method of manufacturing an electronic component mounting apparatus of a type in which a lead frame is fixed to a wiring board, electronic components are assembled and then resin molding is performed. Regarding

[0002]

2. Description of the Related Art Conventionally, as an effective assembly method for a semiconductor device having a multi-pin fine pitch lead, for example, after fixing the lead of a lead frame to a printed wiring board having an electronic component mounting portion and mounting a semiconductor chip, A method of resin-sealing the resin has been used. Further, in the lead frame, a dam bar is provided between the outer leads slightly outside the resin mold portion in order to prevent the molding resin from jumping out from the gap corresponding to the thickness of the leads between the upper and lower molds of the molding die. .
The resin burrs protruding from the cavity of the mold to the dam bar were removed by the dam bar removing mold at the same time as the punching of the dam bar.

However, when the lead pitch of the lead frame becomes a fine pitch of 0.4 mm or less, it becomes difficult to manufacture a die for removing the dam bar, and therefore it becomes expensive, and the workability of the dam bar removing operation itself is poor and the yield is high. There was also the problem of making it worse. As a method of solving such a problem, for example, as disclosed in Japanese Patent Laid-Open No. 3-136267, a resin tape in which an adhesive is laminated on a polyimide base film is used between outer leads on the outside of the resin mold portion. A method has been proposed in which a dam is provided by filling the mold resin to prevent the molding resin from protruding from the cavity portion to between the leads.

[0004]

However, according to the above manufacturing method, the dam is formed by using the dry film, the prepreg, etc., and the material cost is significantly increased. However, there is a problem in that the price of the electronic component mounting apparatus becomes expensive, although the lead frame manufactured at low cost is adopted. Further, there is also a problem that it takes time to form the dam itself and productivity of the electronic component mounting apparatus is deteriorated. Further, the alignment of the multi-pin fine-pitch lead frame and the wiring board needs to be performed with high precision, but when the lead frame provided with the resin dam and the wiring board are joined by soldering or the like, the resin Since the dam bar is hardened and shrunk by heating, the accuracy of alignment of the leads with respect to the wiring board deteriorates, and there is also a problem that the connection between the two is disturbed. The present invention is intended to solve the above-mentioned problems, and is capable of easily preventing the resin from jumping out from the cavity portion of the molding die to the leads in the resin molding process of the electronic component mounting apparatus. An object is to provide a method for manufacturing a device.

[0005]

In order to achieve the above-mentioned object, the structural feature of the invention according to claim 1 is that a wiring board having an electronic component mounting portion is provided with a predetermined inward direction from the peripheral portion on the front surface side. Layer forming step of providing a resin layer of a predetermined thickness within the range, a lead adhering step of adhering and fixing a plurality of leads of the lead frame to the surface side of the wiring board, and an electronic component mounting portion of the wiring board to which the leads are adhering and fixing The electronic part assembling step of assembling the electronic parts to the mold and the peripheral parts of the cavities provided in the upper mold and the lower mold of the molding die are arranged near the inside of the peripheral part of the wiring board to form the upper mold and the lower mold. After tightening, a resin molding step of press-fitting a mold resin into the cavity portion is provided.

Further, the structural feature of the invention according to claim 2 is that, in the method of manufacturing an electronic component mounting apparatus according to claim 1, a part of a portion of the wiring substrate covered with the mold resin is predetermined. There is a through hole having a shape.

[0007]

In the invention according to claim 1 configured as described above, between the leads that are adhesively fixed to the front surface side of the wiring board, there is a fixed thickness provided from the peripheral portion of the wiring board toward the inside. Since it is filled with the resin layer, when the upper die of the molding die is placed on the lead provided with the resin layer, a gap is created between the resin layer between the leads and the die matching surface of the upper die. There is no. Also, the lower die matching surface and the back surface of the wiring board are in close contact with each other. Therefore, when the upper mold and the lower mold are clamped in this state and the mold resin is pressed into the cavity, the mold resin does not jump out from the cavity to the outer leads. Will not be removed. That is, according to the invention of claim 1, it is possible to prevent the generation of resin burr from the resin mold portion by a simple method, so that the electronic component mounting apparatus can be manufactured at high yield at low cost and with high reliability. You can Further, in the present invention, since the resin dam is not provided between the leads as in the conventional case, there is a problem such as misalignment between the leads and the wiring substrate due to curing shrinkage of the dam due to heat applied during heat bonding between the leads and the wiring substrate. Does not occur.

Further, in the invention according to claim 2 configured as described above, since a through hole having a predetermined shape is provided in a part of a portion of the wiring substrate covered with the mold resin, the invention according to claim 1 is provided. In addition to the effects described above, the molding resin is integrated between the upper and lower surfaces of the wiring board through the through holes, improving the adhesion between the molding resin and the leads and wiring board, and improving the reliability of the electronic component mounting device. To do.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are schematic cross-sectional views showing a manufacturing process of a semiconductor chip mounting device according to the present invention. First, a multi-cavity double-sided copper-clad laminate B using a base material in which a glass cloth is impregnated with a bismaleimide triazine resin
A through hole 11 is provided in the above, and a conductor circuit pattern is formed by a known subtractive method or the like. next,
A solder resist layer 13 is applied by printing on a part of the conductor circuits 12 on both sides of the double-sided copper-clad laminate B by screen printing and heat-cured (see FIG. 1A). As a result, a solder bridge at the solder joint portion of the through hole 11 can be avoided, and the conductor circuit 1 at the time of bonding a heat sink, which will be described later, can be avoided.
It is possible to ensure the insulation with 2. However, the formation of the solder resist layer 13 may be omitted depending on the application and the like. After that, the square holes constituting the semiconductor chip mounting portion 14 of the double-sided copper-clad laminate B are formed by router processing, laser processing, or the like, and the multiple-sided copper-clad laminate B is individually processed by router processing, dicing, or the like. The wiring board 10 is divided (see FIG. 1A).

Next, an epoxy adhesive 15 is applied to a portion from the peripheral portion on the front surface side of the wiring board 10 to the through hole 11 on the inside by screen printing, dispenser or the like.
It is applied to a thickness of 0 to 100 μm (see FIG. 1 (b)). The adhesive may be polyimide, triazine, or the like that has excellent heat resistance and insulation properties, and has fluidity during thermocompression bonding. This wiring board 10
A lead frame 20 (pitch 0.4 m) formed of a copper alloy, an iron-nickel alloy, or the like supporting a plurality of leads thereon.
The inner lead 21 of m, width 0.18 mm, thickness 0.125 mm) is adhesively fixed (see FIG. 1B). At that time, a part of the inner lead 21 is aligned so as to overlap the upper portion of the predetermined through hole 11. The inner leads 21 are bonded by thermocompression bonding by a press, heat curing after pressure bonding at room temperature, and the like, the adhesive 15 is softened and pressed by the inner leads 21 between the inner leads 21. Get excited. Therefore, as shown in FIG. 3, the space between the inner leads is filled with the adhesive 15, and the upper surfaces of the inner leads 21 and the upper surface of the adhesive layer 15 between the inner leads 21 are substantially flush with each other.

Next, by placing the back surface side of the wiring board 10 on the molten solder surface of a solder bath (not shown), the molten solder 16 flows into the through holes 11 and rises, and Reach the front side opening position. Then, the solder 16 reaching the front surface side opening position rises on the front surface side land of the through hole 11 and is connected to the inner lead 21, and a solder fillet is formed on the inner lead 21 (see FIG. 1C). ). As the solder, tin-lead, tin-silver, tin-antimony solder, etc. can be used. However, considering the heat deterioration of the wiring board at the time of solder joining and the heat resistance of the solder after joining, tin 9: lead 1 It is preferable to use a solder of the following composition.

Next, at the position of the semiconductor chip mounting portion 14 on the back surface side of the wiring board 10, a heat sink 30 made of oxygen-free copper which also serves as a semiconductor chip attachment is adhered and fixed by an adhesive 31 such as epoxy (see FIG. See c)). As the heat dissipation plate 30, a metal such as aluminum having good heat conductivity, a ceramic material, or the like may be used. The semiconductor chip 40 is die-bonded onto the heat sink 30 at the position of the semiconductor chip mounting portion 14 of the wiring board 10 using a resin paste 41 or the like, and the electrode pads of the semiconductor chip 40 and the wiring board 1
The conductor circuits 12 of 0 and the inner leads 21 are connected by wire bonding (see FIG. 2D). At this time, the plurality of common electrodes such as the power supply portion and the ground portion of the semiconductor chip 40 are connected to the common electrode on the back surface through the through holes 14a near the semiconductor chip mounting portion 14,
Further, by collectively connecting the common electrode to the inner leads 21 through the through holes 11, the lead inductance of the wiring can be reduced, and the number of inner leads can be reduced.

Next, the upper die 51 and the lower die 52 are provided, and the cavity portion 53 is provided inside, and the peripheral edge portion 5 of the cavity portion 53 is provided.
As shown in FIG. 2D, the wiring board 10 is set on the lower mold 52 by using the resin molding die 50 designed so that 3a and 53b are slightly inside the peripheral portion of the wiring board 10. , The upper mold 51 is overlaid and clamped, and the cavity 5
Epoxy resin 61 is press-fitted in 3 to perform resin molding. At this time, the die-matching surface 51a of the upper die 51 is in close contact with the inner leads 21, and is also in close contact with the filled adhesive layer 15 even between the inner leads 21. 52a is also the wiring board 10
It is in close contact with the back of the. Therefore, the press-fitted mold resin 61 does not fly out from between the inner leads 21 to the outside of the cavity 53, and a resin burr is not formed between the outer leads 22. This resin-molded semiconductor device is shown in FIG. as a result,
It is not necessary to remove the resin burr after the molding process, and each outer lead of the lead frame 20 is immediately cut and formed into a final semiconductor device (see FIG. 2E).

As described above, in the first embodiment described above, the inner leads are bonded and fixed to the adhesive layer having a constant thickness provided from the peripheral portion of the wiring board toward the inner side. Since it is possible to prevent the occurrence of resin burr between the outer leads by a simple method of filling the adhesive layer with the adhesive layer, it is possible to manufacture the electronic component mounting device at a high yield at low cost and with high reliability. Further, in the first embodiment, since the resin dam is not provided between the leads as in the conventional case, the dam is cured and shrunk by the heat applied when the solder joint is formed between the inner lead and the wiring board, so that the inner lead and the wiring board are contracted. There is no problem such as misalignment.

In the first embodiment, the adhesive layer having a constant thickness is provided from the peripheral portion of the wiring board to the inner through hole. However, as a modification, the inner lead arrangement position of the wiring board is arranged. It is also possible to form a resin layer having a thickness of approximately the inner lead between them by a printing method or the like, dispose the inner lead on the wiring board between the resin layers, and adhere to the wiring board by soldering or the like. With this, the same effect as that of the above embodiment can be obtained.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, the wiring board 1
No. 0, which is to be resin-molded near the peripheral edge (FIG. 6A)
A cylindrical through hole 17 is provided between the inner leads 21 (on the right side of the dotted line). And the wiring board is
A recess for mounting a semiconductor chip is provided in the center and no heat sink is provided. The other structure is the same as that of the first embodiment, and the description thereof is omitted. By configuring the second embodiment as described above, when the resin molding is performed, the molding resin 61 is integrated between the upper and lower surfaces of the wiring board 10 through the through holes 17, so that the molding resin 61 and the inner leads 21 are integrated. Also, the adhesion between the wiring boards 10 is improved, and the reliability of the electronic component mounting device is improved. The shape of the through hole is not limited to a cylindrical shape, as shown in FIG. 6B, and may be a slit shape, or may be provided including a portion where the inner lead 21 is bonded to the wiring board 10. Good. Further, the position of the through hole is not limited to the vicinity of the peripheral portion of the wiring board, and can be changed appropriately according to the shape of the wiring board.

Although a double-sided copper-clad wiring board of a glass cloth substrate impregnated with a resin such as a bismaleimide triazine resin is used as the wiring board in the above-mentioned embodiment, a ceramic laminated board or the like may be used. Good. Further, the structure of the wiring board is not limited to the one described in each of the above embodiments, and wiring boards having various structures can be used. Further, although the semiconductor chip mounting device in which the semiconductor chip is mounted on the wiring board is described in the above embodiment, other electronic components may be mounted.

[Brief description of drawings]

FIG. 1 is a cross sectional view schematically showing a part of a manufacturing process of a semiconductor chip mounting device according to a first embodiment of the present invention.

FIG. 2 is a cross sectional view schematically showing a part of the manufacturing process of the semiconductor chip mounting device.

3 is a sectional view taken along the line III-III of FIG.

FIG. 4 is a perspective view showing a state after resin molding of the semiconductor chip mounting apparatus.

FIG. 5 is a sectional view of a semiconductor chip mounting device according to a second embodiment.

FIG. 6 is a partial plan view showing a bonded portion between a wiring board and an inner lead in the same semiconductor chip mounting apparatus.

[Explanation of symbols]

10: Wiring board, 11; Through hole, 12; Conductor circuit, 13; Solder resist layer, 14; Semiconductor chip mounting part, 15; Adhesive layer, 16; Solder, 17; Through hole,
20; lead frame, 21; inner lead, 22;
Outer lead, 30; Heat sink, 31; Adhesive, 40;
Semiconductor chip, 41; Adhesive, 50; Resin mold, 51; Upper mold, 52; Lower mold, 53; Cavity part, 6
1; Mold resin.

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Claims (2)

[Claims] 1. A resin layer forming step of providing a resin layer having a predetermined thickness in a predetermined range from a peripheral portion on the front surface side of a wiring board having an electronic component mounting portion toward the inside, and a lead frame on the front surface side of the wiring board. A lead bonding process for bonding and fixing a plurality of leads, an electronic component mounting process for mounting electronic components on the electronic component mounting portion of the wiring substrate to which the leads are bonded and fixed, and an upper mold and a lower mold for the molding die. And a resin molding step of placing a mold resin into the cavity after the mold is clamped in the cavity by disposing the periphery of the cavity near the inside of the periphery of the wiring board. And a method of manufacturing an electronic component mounting device. 2. The method of manufacturing an electronic component mounting apparatus according to claim 1, wherein a through hole having a predetermined shape is provided in a part of a portion of the wiring board covered with the mold resin. Manufacturing method of component mounting device.