JPH06177268A - Fabrication of semiconductor device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a method for manufacturing a semiconductor device having a plastic package, which has good marking visibility and improved productivity. [Structure] Holding pins 17 are provided on the molding dies 16a and 16b.
Is provided, and while holding the non-mounting surface of the semiconductor chip 11 of the heat sink 12 by the holding pin 17, a resin film 14a is formed on the non-mounting surface of the heat sink 12 by resin molding, and the resin film 14a is formed by the laser beam L. The pattern 19 is marked by removing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device having a plastic package.

A semiconductor device has a package with a company name, model number,
Lot numbers and the like are stamped, and these stamps identify the integrated circuit contained therein. Therefore, these markings need to have good visibility.

[0003]

2. Description of the Related Art In the conventional semiconductor device, when printing a company slip, model number, lot number, etc. on a package,
The marking was done.

FIG. 11 shows a perspective view of a conventional example. In the figure, reference numeral 1 denotes a resin package in which the heat dissipation plate 2 is exposed from the surface of the resin package 1 and constitutes a so-called low thermal resistance plastic package. The heat sink 2 is copper (Cu)
And the pattern 3 was imprinted on the heat dissipation plate 2 with ink.

[0005]

However, the conventional marking with ink requires a process for fixing the ink on the surface of the package after the ink is applied, resulting in an increase in the number of manufacturing steps and poor productivity.

In addition, when used in a so-called low thermal resistance plastic package in which a heat sink is exposed in marking a plastic package by a laser beam, marking a pattern on the heat sink, and also on the heat sink at the time of lead plating with solder. Since the solder is plated, a pattern is marked on the solder, and the pattern is erased when the solder melting temperature is greatly exceeded when the semiconductor device is mounted. Therefore, it is necessary to mark the portion other than the heat sink, and the marking position is restricted. Further, even if the resin package is irradiated with a laser beam for marking, the marking color by the laser beam is dark, and the resin package color is also black due to carbon, which causes poor visibility due to low contrast. There was a point.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a method of manufacturing a semiconductor device which has good visibility of a marking and high productivity.

[0008]

SUMMARY OF THE INVENTION The present invention is a semiconductor in which a semiconductor chip and a heat radiating plate for radiating heat generated in the semiconductor chip are integrally molded in a resin package with leads for connecting the semiconductor chip to the outside. In the method of manufacturing a device, a resin film forming step of forming a resin film on the surface of the heat dissipation plate, and a marking step of locally removing the resin film with a heat ray and locally exposing the heat dissipation plate for imprinting. And have.

[0009]

The resin film is formed on the surface of the heat sink, and the resin film is locally removed by heat rays to expose the heat sink and mark the pattern.

Therefore, the contrast between the pattern and other portions can be increased due to the difference in material between the resin film and the heat dissipation plate, and the visibility of the pattern can be improved.

Further, since most of the heat sink is covered with the resin film, the heat sink can be protected. At this time, the resin film is 20
Since it is very thin up to 50 μm, it does not interfere with the heat dissipation effect of the heat dissipation plate.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a manufacturing process diagram of a first embodiment of the present invention. In the figure, 11 is a semiconductor chip, 12 is a heat sink, and 13
Indicates a lead frame, and 14 indicates a package.

The semiconductor chip 11 is formed, for example, by forming a large number of highly integrated circuit elements on a silicon crystal substrate of several mm square. The heat sink 12 is made of copper (Cu), aluminum (A
l), a material such as ceramic having good heat conduction is formed in a flat plate shape.

The lead frame 13 is made of copper (Cu) alloy, iron (Fe) -nickel (Ni) alloy (for example, 42 alloy).
It is formed by etching or pressing a material such as. The package 14 is made of an epoxy resin material, and includes a semiconductor chip 11, a heat sink 12, and a lead frame 1.
Part of 3 is enclosed integrally.

The lead frame 13 has a connecting lead 13a and a supporting lead 13b, and the heat sink 12 is a supporting lead 1.
Held by 3b. FIG. 2 shows a perspective view of a connecting portion between the heat dissipation plate 12 and the support lead 13b according to the first embodiment of the present invention. The heat sink 12 has a convex portion 12a-1 formed on the mounting surface 12a of the semiconductor chip 11. The convex portion 12a-1 is engaged with a hole 13b-1 formed at the tip of the support lead 13b. , The heat sink 12 by caulking the convex portion 12a-1
Is held by the support lead 13b.

After the heat dissipation plate 12 is held by the support leads 13b, the semiconductor chip 11 is bonded to the mounting surface 12a of the semiconductor chip 11 with an adhesive or the like. Next, semiconductor chip 1
1 and the connection lead 13a are wire-bonded and connected by a wire 15 made of a gold (Au) material.
The state is as shown in FIG.

Next, as shown in FIG. 1 (A), the semiconductor chip 11, the heat dissipation plate 12, and the lead frame 13 which are integrally formed are molded into molds 16a, 1 as shown in FIG. 1 (B).
Store in 6b. A holding pin 17 that is configured to be attachable / detachable and that holds the non-mounting surface 12b of the semiconductor chip 11 of the heat dissipation plate 12 is attached to the bottom surface of the molding die 16b. The amount of protrusion of the holding pin 17 from the bottom surface is set to about 20 to 50 μ, and holds the heat dissipation plate 12 at a position of 20 to 50 μ from the bottom surface of the molding die 16b.

The heat radiating plate 12 is a mold die 16a, 16b.
When held inside, the elasticity of the support lead 13b causes arrow A
It is pressed in the direction and comes into close contact with the holding pin 17. As described above, a gap of 20 to 50 μ is reliably held between the bottom surface of the molding die 16b and the non-mounting surface 12b of the semiconductor chip 11 of the heat dissipation plate 12.

Next, epoxy resin is injected into the molding dies 16a and 16b. The resin package 14 is formed by penetrating the holding pin 17 after the resin is substantially fixed.

Through the above steps, as shown in FIG. 1C, the recess 14b is formed in the package 14 by the holding pin 17, and the non-mounting surface 12b of the semiconductor chip 11 of the heat sink 12 has a thickness of 20 to 50 μm. A thin resin film 14a is formed.

Next, the outer lead 13a-1 portion of the lead 13 extending outward from the package 14 is solder-plated, and then the resin film 14a is formed by the laser generator 18 on the resin film 14a as shown in FIG. 1 (D). The laser light L is emitted according to the letters and numbers to be imprinted. Laser light L is several meters
A portion 14 having an output of about W and irradiated with laser light L
At a-1, the resin film 14a evaporates, and the heat dissipation plate 12 below the resin film 14a appears.

By irradiating the resin film 14a with the laser beam L according to the letters, numbers, etc. to be stamped such as a company slip, lot number, etc., the resin film 14a is removed in accordance with the letters, numbers, etc. to be stamped, and heat is radiated. The board 12 is exposed, and a company slip, a lot number, etc. are stamped.

After the marking is completed, the semiconductor device is completed by cutting from the lead frame and bending the tips of the connecting leads 13a as shown in FIG. 1 (D). In this embodiment, the tips of the connection leads 13a are bent for surface mounting.

FIG. 3 is a perspective view of a semiconductor device manufactured by the above manufacturing process. According to the semiconductor device manufactured by the process of FIG. 1, the imprinted pattern 19 has the color of the radiation plate 12 and can be clearly recognized by the contrast with the color of the package 14 made of resin mixed with carbon. Therefore, the visibility of the stamped company slip and lot number can be improved.

Since the heat radiation plate 12 is covered with the resin film 14a except the pattern 19 and the hole 14b, the heat radiation plate 1
2 can be protected. Further, the resin film 14a formed on the heat dissipation plate 12 is as thin as 20 to 50 .mu.m and the resin film 14a is
The hole 14b and the pattern 19 formed at the time of forming do not prevent the heat dissipation effect of the heat dissipation plate 12.

FIG. 4 shows a manufacturing process diagram of the second embodiment of the present invention. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

This embodiment differs from the first embodiment in the shape of the heat sink. FIG. 5 shows a perspective view of the heat sink of the second embodiment.

A convex portion 21a is formed on the heat dissipation plate 21 by a processing method such as pressing or shaving. The height of the convex portion 21a is 2
The thickness is 0 to 50 μm.

The heat radiating plate 21 has a first
The protrusions 21 are held by the leads 13 in the same manner as in the embodiment.
It is assembled such that the surface having a is the non-mounting surface of the semiconductor chip 11.

Next, as shown in FIG. 4B, the molds 16a and 16b of the first embodiment are held in the molds 22a and 22b from which the holding pins 16b-1 are removed, and the resin is injected. , The package 14 is formed.

At this time, the convex portion 21a of the heat dissipation plate 21 is pressed against the bottom surface of the molding die 21b by the elasticity of the lead 13. For this reason, a gap of 20 to 50 μm in height is formed between the bottom surface of the molding die 21b and the convex portion 21a at a portion other than the convex portion 21a on the non-mounting surface of the semiconductor chip 11 of the heat dissipation plate 21. 2 as shown in 4 (C)
A resin film 14a having a thickness of 0 to 50 μm is formed.

The marking is performed by irradiating the resin film 14a with the laser beam L from the laser generator 18 according to the marking pattern as in the first embodiment.

FIG. 6 shows a perspective view of the second embodiment of the present invention. In this embodiment, in addition to the imprint pattern 19, the convex portion 21a is exposed to the outside, and the heat dissipation effect is high. Further, in the manufacturing process, the holding pin 17 is not required when the package 14 is molded, and manufacturing with a conventional molding die is possible.

FIG. 7 shows a perspective view of the third embodiment of the present invention. In the figure, the same components as those in FIG.
The description is omitted. This embodiment differs from the second embodiment in the shape of the heat sink. FIG. 8 shows a perspective view of the heat sink. Heat sink 3
Similar to the heat dissipation plate 21, 1 has a convex portion 31a formed on the non-mounting surface side of the semiconductor chip 11 by pressing or shaving. However, the convex portion 31a is formed so as to be symmetrical with respect to a line segment I that connects the resin injection port (gate) of the molds 22a and 22b and the air discharge hole (vent). With the above structure, the resin can be smoothly injected into a narrow gap of about 20 to 50 μm, and the resin film 14a can be formed well.

FIG. 9 shows a sectional view of the fourth embodiment of the present invention. In the figure, the same components as those in FIG.
The description is omitted. The present embodiment is applied to a semiconductor device in which the semiconductor chip 11 and the heat dissipation plate 12 are provided separately, and the semiconductor chip 11 is held on a stage 13d integrally formed with the support lead 13c. Eggplant

FIG. 10 shows a sectional view of the fifth embodiment of the present invention. In the figure, the same components as those in FIG.
The description is omitted.

In this embodiment, TSOP (Thin Small Out-lin)
It is applied to a semiconductor device of an ed package), and the semiconductor chip 11 is mounted on the stage 13d integrally formed with the support lead 13c to achieve a thin structure. In this embodiment, since there is no heat sink, the resin film 14a is formed on the non-mounting surface of the semiconductor chip 11 of the stage 13d by the same process as in the first to third embodiments.

The stage 13d is the lead frame 1
Since it is made of the same metal material as that of No. 3, at the time of imprinting, it is possible to imprint with high visibility and good visibility as with the heat dissipation plate.

Although the lead frame 13 has a surface mounting type in the first to fifth embodiments, the present invention is not limited to this, and the lead frame 13 is not limited to this, and the DIP (Dual In-line Package), SI
It can be widely applied to semiconductor devices sealed with a resin package such as P (Single In-line Package).

[0040]

As described above, according to the present invention, since the resin film formed on the heat dissipation plate is locally removed and the marking is performed, the visibility of the marking can be confirmed by the contrast between the resin film and the heat dissipation plate. Since the resin film is formed on the heat dissipation plate, the heat dissipation plate can be protected by the resin film, and the heat dissipation plate and the wiring are less likely to contact each other when mounted on a printed circuit board, etc., and the circuit can be protected. It has features such as

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the first embodiment of the present invention.

FIG. 3 is a perspective view of the first embodiment of the present invention.

FIG. 4 is a manufacturing process drawing of the second embodiment of the present invention.

FIG. 5 is a perspective view of a heat dissipation plate according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a second embodiment of the present invention.

FIG. 7 is a perspective view of a third embodiment of the present invention.

FIG. 8 is a perspective view of a heat dissipation plate according to a third embodiment of the present invention.

FIG. 9 is a sectional view of a fourth embodiment of the present invention.

FIG. 10 is a sectional view of a fifth embodiment of the present invention.

FIG. 11 is a perspective view of a conventional example.

[Explanation of symbols]

 11 semiconductor chip 12 heat sink 13 lead frame 14 package

Claims (6)

[Claims] 1. A resin package (1) with a semiconductor chip (11) and a heat radiating plate (12) for radiating heat generated in the semiconductor chip (11) together with leads (13) for connecting the semiconductor chip (11) to the outside. 14) In the method of manufacturing a semiconductor device integrally molded with, a resin film forming step of forming a resin film (14a) on the surface of the heat dissipation plate (12), and locally heating the resin film (14a) by heat rays. And a stamping step of stamping the heat sink (12) locally by exposing the heat sink (12). 2. A lead frame (13) for connecting the semiconductor chip (11) and a stage (13d) holding the semiconductor chip (11) to the outside.
A method of manufacturing a semiconductor device integrally molded together with a resin package (14), comprising forming a resin film (14a) on a non-mounting surface of the semiconductor chip (11) of the stage (13d). A forming step and a marking step of locally removing the resin film with a heat ray and locally exposing a non-mounting surface of the semiconductor chip (11) of the stage (13d). A method for manufacturing a characteristic semiconductor device. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the resin film forming step is simultaneously performed during a molding step of the package (14). 4. The resin film forming step is detachably attached to a molding die (16a, 16b) of the package (14), and the heat dissipation plate is provided at a position corresponding to the film thickness of the resin film (14a). (12) The semiconductor chip (11)
Holding pin (16b-1) that holds the non-mounting surface (12a) of
The heat sink (12) by the mold (16
a, 16b) to mold the package (14), and after the package (14) is formed, the holding pin (16)
4. The method of manufacturing a semiconductor device according to claim 3, further comprising the step of removing b-1) from the molding die (16a, 16b). 5. The heat sink (1) in the resin film forming step.
2) Non-mounting surface (12a) of the semiconductor chip (11)
The convex portion (1) having a height corresponding to the film thickness of the resin film (14a)
2. The method of manufacturing a semiconductor device according to claim 1, wherein the resin film (14a) is formed by forming 2d) and performing a molding process of the package (14). 6. The resin film forming step comprises:
6. The method for manufacturing a semiconductor device according to claim 1, wherein the film thickness of a) is formed to 50 μm or less.