JPH07202070A - Electronic component mounter and its manufacture - Google Patents

Abstract

PURPOSE:To fine down the pitches of the tip of the conductor wiring of a semiconductor chip mounter. CONSTITUTION:The first layer wiring board 10 is provided with an aperture 11 at the center, and a through hole 12 in the vicinity of the periphery. An adhesive layer 14 is provided near the periphery of the first wiring board, and the tip of the inner lead 31a of a lead frame 30 is arranged on and bonded to the through hole 12. The first wiring board is soaked in solder bath, and solder junction is made between the lead frame and the through hole by the solder having gone up through the through hole. The second wiring board 20 is provided with an aperture 21 larger than the aperture 11 at the center, and is provided with a through hole 22 in the vicinity of the periphery. The second wiring board is bonded onto the first wiring board and the lead frame, and solder junction is made between the lead frame and the through hole. The peripheral wall of a chip mounter is provided with a step, and this step is made the connector terminal for wire bonding, whereby the terminal pitches are roughly doubled substantially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting apparatus, and more particularly to a bonding terminal for connecting a conductor wiring, which is manufactured by using a so-called lead frame and arranged on a wiring board, to a terminal of an electronic component. Relates to an electronic component mounting device having a fine pitch.

[0002]

2. Description of the Related Art Conventionally, in the electronic component mounting apparatus of this type, the pitch of the conductor wirings of the wiring board is made fine so that the pitch of the bonding terminals for connection with the terminals of the electronic component is made fine. The limit of the conductor pitch of the electronic component mounting apparatus is about 180 μm in consideration of the crushed width of the bonding wire.

[0003]

However, there is a great demand for high-density mounting of electronic component mounting devices, and the pitch of bonding terminals is required to be a very fine pitch of 100 μm or less. In order to obtain such characteristics, for example, for a pin grid array package substrate, the method disclosed in Japanese Patent Publication No. 2-5014 can be used. According to the publication, a plurality of wiring boards each having a different area size of the semiconductor element accommodating opening are stacked in order of increasing area, and boards having no opening on the upper and lower sides are bonded together. Then, after performing a plurality of treatments such as drilling and copper plating on the laminated substrates, the substrate on the front surface side is capped. In this way, steps are provided on the peripheral wall of the semiconductor element accommodating portion, and the bonding positions on the wiring board side of wire bonding are dispersed in a plurality of steps to effectively achieve a fine pitch of the bonding terminals. However, according to the above method, there are problems that the manufacturing process of the laminated substrate becomes long and the thickness of the substrate must be increased in order to withstand the stress applied to the substrate in the manufacturing process. The present invention is intended to solve the above problems, and an object thereof is to provide an electronic component mounting apparatus having a simple structure and effectively making the pitch of the bonding terminals of the wiring board very fine, and a manufacturing method thereof. To do.

[0004]

In order to achieve the above-mentioned object, a structural feature of the invention according to claim 1 is that a first wiring board having a plurality of first through holes in a position near an outer periphery is provided. , Having a shape larger than that of the first wiring board, having a plurality of second through holes in the vicinity of the outer circumference, and providing an opening,
A second wiring board adhered to a part of the front surface side of the first wiring board via an adhesive layer; and a plurality of leads sandwiched between the end portions of the first wiring board and the second wiring board, And a lead frame in which at least a part of one side of the plurality of leads is joined to the first through hole by solder, and at least a part of the opposite side of the plurality of leads is joined to the second through hole by solder. There is something.

In order to achieve the above object, the above-mentioned claim 2
The structural feature of the invention according to the invention is that a plurality of leads of a lead frame are provided via an adhesive layer provided in the vicinity of the outer periphery on the front surface side of the first wiring board having a plurality of first through holes in the vicinity of the outer periphery. A lead frame bonding step of fixing at least a part of the inside to the front surface side of the first wiring board in a state where the lead frame is bonded to the first through hole;
A first solder joint forming step of forming a solder joint between the first through hole and the lead frame by injecting solder from the back surface side of the wiring board through the first through hole; Adhesion of a second wiring board having a plurality of second through holes in the vicinity of the first wiring board having openings and provided with openings to the first wiring board and the lead frame via an adhesive layer And a second solder joint forming step of forming a solder joint between the second through hole and the lead frame by injecting solder from the front surface side of the second wiring board through the second through hole. .

[0006]

In the invention according to claim 1 configured as described above, the first wiring board and the second wiring board sandwiching the lead frame are joined to the lead frame by soldering through the respective through holes. By doing so, a laminated substrate is formed. Since the opening of the second wiring board is sized so that a part of the conductor wiring of the first wiring board is exposed on the surface of the first wiring board, the electronic component housing portion composed of the first and second wiring boards A step can be provided on the peripheral wall. Therefore, it is possible to disperse the connection positions of the wire bonding with the electronic components of the laminated substrate in a plurality of stages. As a result, the pitch of the wire bonding connection positions on the substrate side of the electronic component mounting apparatus can be effectively made twice as fine as the conventional pitch.

In the invention according to claim 2 configured as described above, the first wiring board having the plurality of first through holes in the vicinity of the outer periphery is provided with the adhesive layer provided near the outer periphery thereof. The lead frame is bonded and fixed with at least a part of the lead frame placed on the first through hole, and solder is raised from the back surface side of the first wiring board through the first through hole to form the lead frame. Solder joints are formed between the first through holes.
Then, on the opposite side of the lead frame, the back surface side of the second wiring board, which is also larger in shape than the first wiring board, has a plurality of second through holes in the vicinity of the outer periphery, and has an opening, is bonded. It is adhered to the first wiring board and the lead frame via the agent layer, and further, solder joint is formed between the second through hole and the lead frame. As a result, the manufacturing process of the laminated electronic component mounting apparatus can be shortened as compared with the conventional method, and the manufacturing cost can be reduced.

According to the second aspect of the invention,
A part of the conductor wiring of the first wiring board and a part of the conductor wiring of the second wiring board are provided with a step, and the connection positions for wire bonding with the electronic components of the laminated board are provided in a plurality of stages. Can be done. As a result, the pitch of bonding on the substrate side can be effectively made finer by a factor of about two. Further, according to the invention of claim 2,
Since only good products can be selected and used for the first wiring board and the second wiring board, it is possible to increase the manufacturing yield of the electronic component mounting apparatus and also increase its reliability. Further, according to the invention of claim 2, since the electronic component mounting apparatus has the wiring boards on both sides of the lead frame, the flow of the resin injected into the mold in the subsequent resin molding step can be prevented. The top and bottom parts of the lead frame are made uniform. Therefore, a filled and homogeneous resin mold layer without voids can be obtained, and the reliability of the electronic component can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a part of a semiconductor chip mounting apparatus according to an embodiment, and FIG. 2 is a schematic sectional view of the semiconductor chip mounting apparatus in an assembly process. This semiconductor chip mounting device is the first
A layer wiring board 10, a second layer wiring board 20, a lead frame 30, and a conductor plate 40 are provided.

The first layer wiring board 10 is a square and has a length of 0.1 m.
This is a copper-clad glass / triazine substrate having a thickness of m, and a plurality of through holes 1 having a diameter of 0.3 mm and having an opening 11 for mounting a semiconductor chip in the center and penetrating the substrate surface in the peripheral portion
2 is provided. A conductive layer is formed on the inner wall of the through hole 12 by copper plating, nickel plating, and gold plating. Then, on the front surface side of the first-layer wiring board 10, by photo-etching the copper layer on the surface of the board 10, 38 conductive wires 13 are formed in each of 38 directions from the vicinity of the opening 11 toward the four directions, that is, a total of 152 conductive wires 13 are formed. Therefore, a part of the outer end of each conductor wiring 13 is electrically connected to the through hole 12. Further, gold plating 13a for wire bonding is formed on at least the inner end portion of the conductor wiring 13, and its bonding terminal has a pitch of 0.16 mm.

The second-layer wiring board 20 is the first-layer wiring board 1.
It is a square 0.1 mm thick copper-clad glass / triazine substrate larger than 0, and has an opening 2 for mounting a semiconductor chip, which has a larger area than the opening 11 of the first layer wiring board 10 in the center.
1 is provided. Further, the second layer wiring board 20 is provided with a plurality of through holes 22 of 0.3 mmφ penetrating the board surface in the peripheral portion. A conductive layer is formed on the inner wall of the through hole 12 by copper plating, nickel plating, and gold plating. Then, on the front surface side of the second-layer wiring board 20, by etching the copper layer on the surface of the board 20 by photoetching, 38 wires each are provided from the opening 21 toward the four directions, for a total of 15 pieces.
Two conductor wirings 23 are formed, and each conductor wiring 23
A part of the outer end portion of is connected to the through hole 22. Further, gold plating 23a for wire bonding is formed on at least the inner end portion of the conductor wiring 23, and the bonding terminals thereof have a pitch of 0.16 mm.

The lead frame 30 has a thickness of 0.15 mm.
Of copper alloy, and has 304 leads 31 connected to a frame (not shown). The lead is supported by a dam bar 31c in the middle, and is separated into an inner lead 31a on the inside and an outer lead 31b on the outside. Then, the inner lead 31a
It is sandwiched between the first wiring board 10 and the second wiring board 20, the front surface side is located on the through hole 22 of the second wiring board 20, and the back surface side is the through hole 12 of the first wiring board 10.
Located on top. The back surface side of the inner lead 31a and the through hole 12 of the first wiring board 10 are fixed by solder 12a as shown in FIG. 2, and the front surface side of the inner lead 31a and the through hole 22 are also solder 2
It is fixed by 2a. The conductor plate 40 has a thickness of 1.3.
It is made of oxygen-free copper and has a lower surface plated with Ni, and a heat-resistant epoxy-based adhesive sheet 41 having a thickness of 60 μm is attached to the surface except the central semiconductor chip mounting portion 40a. ing. Conductor plate 40
Is used for bonding a semiconductor chip and has a function as a heat dissipation plate.

Next, assembly of the semiconductor chip mounting device will be described with reference to FIG. First, the first layer wiring board 1
The adhesive 14 is applied to a predetermined position on the surface side of 0, and the lead frame 30 is adhered thereon by aligning the tips of the inner leads 31a with the through holes 12 (see FIG. 2).
(See (a)). Then, the first layer wiring board 10 to which the lead frame 30 is adhered is brought into contact with the jet solder bath with the back surface side facing down, so that the lead frame 30 uses the solder 12a that has moved up the through hole 12 to form the first layer wiring. It is easily and firmly fixed to the substrate 10 (see FIG. 2).
(See (b)).

Next, an adhesive sheet 24a having a thickness of about 0.2 mm is formed around the opening 21 on the back surface side of the second layer wiring board 20.
Then, an adhesive sheet 24b having a thickness of about 0.06 mm is attached near the outer periphery. This second layer wiring board 20 is
It is adhered to the wiring board 10 and the lead frame 30.
Then, after a jig (not shown) is attached to the surface side of the second layer wiring board 20 so that the solder does not adhere to other than a predetermined position, the surface side of the second layer wiring board 20 is brought into contact with the jet solder bath. As a result, the lead frame 30 is easily and firmly fixed to the second-layer wiring board 20 by the solder 22a that has risen in the through hole 22 (see FIG. 2C). Furthermore, the laminated semiconductor chip mounting device is obtained by covering the first opening on the back surface side of the first layer wiring board 10 and adhering the conductor plate 40 via the adhesive layer 41 (FIG. 2 (c)). )reference).

In the semiconductor chip mounting apparatus obtained as described above, the openings for accommodating the semiconductor chips are formed in two steps, large and small. Therefore, the conductor wiring provided in each of these steps is connected to the wire with the semiconductor chip. It can be used as a bonding terminal for bonding connection. Therefore, as compared with the case of the single-layer wiring board, the wiring pitch can be substantially doubled by providing the wirings with the same pitch, and the mounting density of the semiconductor chip mounting device can be increased to about double the conventional one. . In addition, the above-mentioned laminated type semiconductor chip mounting device can be manufactured by bonding the wiring boards, adhering the lead frame to the laminated board with the adhesive layer, and immersing the laminated board in the solder layer. Since the process is simpler than that of the stacked type semiconductor chip mounting device, it is provided at a very low cost. Furthermore, since the above-mentioned laminated type semiconductor chip mounting device selects good wiring boards and stacks them, the manufacturing yield is higher and the product reliability is superior to the conventional ones. There is.

Next, the semiconductor chip S is die-bonded to the semiconductor chip mounting portion 40a of the conductor plate 40 with an adhesive. Then, the electrodes of the semiconductor chip S and the conductor wirings 13 of the first layer wiring board 10 and the conductor wirings 23 of the second layer wiring board 20 are connected by wire bonding (see FIG. 2D). The first layer wiring board 10 with the semiconductor chip S assembled is resin-sealed so that the outer surface of the conductor plate 40 is exposed. At this time, in the semiconductor chip mounting apparatus, since the wiring boards are provided on both sides of the lead frame 30, the molding resin R injected from the gate of the molding die flows evenly on both sides of the lead frame 30.
Therefore, since the mold resin is uniformly filled in the mold, defects such as voids do not occur and a reliable mold resin layer is formed. Further, by cutting the lead frame and bending the leads, a completed semiconductor device is obtained as shown in FIG.

Next, a second embodiment will be described with reference to the drawings. In the second embodiment, as shown in FIG. 4, the heat dissipation plate is not provided as the semiconductor chip mounting portion but is provided on the first wiring substrate 50. Then, the second wiring board 60 having the opening is provided on the first wiring board. After mounting the semiconductor chip S on the semiconductor chip mounting portion 50a, the connection terminals for wire bonding are connected to the first wiring board 50 and the second wiring board 6.
It can be dispersed and provided in 0. Therefore, by providing the wirings having the same pitch as compared with the case where the number of wiring boards is one, it is possible to obtain the bonding terminals having the wiring pitch which is substantially doubled, and to increase the mounting density of the semiconductor chip mounting device to 2
It is possible to obtain the same effect as that obtained in the first embodiment described above, such as being able to double the amount. The present embodiment is particularly effective when heat dissipation from the semiconductor chip does not pose a problem. In addition, a recess (not shown) may be provided in the semiconductor chip mounting portion by counterboring.

In each of the above embodiments, the case where one semiconductor chip is mounted on the conductor plate has been described, but a plurality of semiconductor chips may be mounted on the conductor plate. Further, in the above embodiment, another electronic component chip may be assembled instead of the semiconductor chip. Further, in each of the above-mentioned embodiments, the lead frame is laminated by sandwiching both sides of the wiring board, but wiring boards having different sizes of openings may be further laminated on this wiring board. Thereby, the steps of three or more steps can be used as connection terminals for wire bonding. Further, in each of the above embodiments, the shape, material, number, etc. of the wiring board, the lead frame, the conductor plate, etc. can be appropriately changed according to the intended use.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a semiconductor chip mounting apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing a cross section in the assembly process of the semiconductor chip mounting apparatus.

FIG. 3 is a schematic view showing a cross section of a semiconductor device in a completed state using the same semiconductor chip mounting device.

FIG. 4 is a sectional view showing a part of a semiconductor chip mounting device according to a second embodiment.

[Explanation of symbols]

10; First layer wiring board, 11; Opening part, 12; Through hole, 13; Conductor wiring, 14; Adhesive sheet, 20; Second layer wiring board, 21; Opening part, 22; Through hole, 2
3; conductor wiring, 24a, 24b; adhesive sheet, 30;
Lead frame, 31a; inner lead, 31b; outer lead, 40; conductor plate, 41; adhesive sheet,
S: Semiconductor chip.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H05K 3/46 Q 6921-4E N 6921-4E

Claims (2)

[Claims] 1. A first wiring board having a plurality of first through holes in the vicinity of the outer circumference, and a plurality of second through holes having a shape larger than that of the first wiring board and in the vicinity of the outer circumference, In addition, it is sandwiched between a second wiring board provided with an opening and adhered to a part of the front surface side of the first wiring board via an adhesive layer, and an end portion of the first wiring board and the second wiring board. A plurality of leads, at least a part of one surface of the plurality of leads is joined to the first through hole by soldering, and at least a part of the other surface of the plurality of leads is soldering the first surface. An electronic component mounting apparatus, characterized in that a lead frame joined to two through holes is provided. 2. At least a part of a plurality of leads of a lead frame via an adhesive layer provided in the vicinity of the outer periphery on the front surface side of a first wiring board having a plurality of first through holes in the vicinity of the outer periphery And a lead frame bonding step of fixing the same to the front surface side of the first wiring board in a state of being arranged on the first through hole, and through the first through hole from the back surface side of the first wiring board to which the lead frame is bonded. Inject solder,
A first solder joint forming step of forming a solder joint between the first through hole and the lead frame; and a plurality of second through holes having a shape larger than that of the first wiring board and near the outer periphery. A second wiring board adhering step of adhering the back surface side of the second wiring board provided with the opening to the first wiring board and the lead frame via an adhesive layer; and a front surface side of the second wiring board A second solder joint forming step of forming a solder joint between the second through hole and the lead frame by injecting solder through the second through hole. Production method.