JPH0258243A - Manufacture of semiconductor device with heat sink - Google Patents

Abstract

PURPOSE:To prevent the structures of molding metal molds from complicating and moreover, to prevent the positional deviation of a heat sink from generating by a method wherein a void part formed by the heat sink held by a top force and a resin substrate held by a bottom force is provided with a gate for pouring a molding resin and the like. CONSTITUTION:An IC chip 1 is mounted on a resin substrate 2 having a plurality of contact terminals 20 and with the IC chip 1 resin-sealed by an injection molding using dies 90 and 91, a metallic heat sink 8 is integrally formed with a sealing resin 6, which is formed by the injection molding, by an insert molding on the upper surface part of the resin 6. In case a semiconductor device with such the heat sink is manufactured, a bottom force 91 constituting said die 91 is provided with substrate holding parts 91a and 91b for holding the substrate 2 and a top force 90 constituting said die 90 is provided with heat sink holding parts 90a and 90b for holding the heat sink 8. Moreover, a void part formed by the heat sink 8 held by the force 90 and the substrate 2 held by the force 91 is provided with a gate 91c for pouring the molding resin 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a resin-sealed semiconductor device in which a heat sink is insert-molded.

[Conventional technology]

A pin grid array (hereinafter abbreviated as PGA) will be described as an example of a resin-sealed semiconductor device.

In recent years, PGAs equipped with IC chips have been able to be replaced and converted to other functions, expanding the scope of application of the device, and ceramics have been used as circuit boards for PGAs for this purpose. Ta.

This ceramic substrate has excellent insulating properties and is therefore highly reliable as a product. However, since the wiring pattern is printed and baked, it shrinks, making it difficult to increase the number of wiring patterns or create finer patterns. there were. In addition, increasing the number of patterns increases the size as much as possible, and also has the disadvantage that the price of each pattern is high.

In recent years, as an alternative to this ceramic substrate, it has been proposed to develop a PGA using a resin substrate as a substrate that can be processed into fine patterns and is inexpensive. We proposed a pancaging structure in which the upper surface of a resin substrate on which an IC chip is mounted and the fractured surface around the resin substrate, which has a plurality of contact bins on the lower surface side, are completely covered with molded resin.

However, despite the fact that the resin-sealed PGA can be made smaller and cheaper through fine pattern processing than the PGA using a ceramic substrate, it still has not become popular due to problems with its heat dissipation properties. .

In other words, since the IC mounted on the PGA is an LSI with a large chip size, it generates a lot of heat due to the operating current.
An increase in the temperature of the SI causes problems such as a decrease in the read speed and, in extreme cases, thermal destruction of the LSI.

In order to solve the above problem, the present applicant has already proposed a resin-sealed PGA structure in which a metal heat dissipating member is insert-molded on the upper surface of the molded resin in Japanese Patent Application No. 63-25516 and Japanese Patent Application No. 63-72190. It is proposed by et al.

[Problem to be solved by the invention]

Figure 4 shows the PG of the previous application in which the heat dissipation plate 8 was insert molded.
It is a sectional view of the main part of the molding die showing the molding state of A, and the upper mold 90 is provided with a heat dissipation plate holding part constituted by a positioning recess 90a and a vacuum hole 90b, and the heat dissipation plate 8 is It is positioned and held by the suction force of the vacuum hole 90b.

Further, the lower mold 91 is provided with a substrate holding portion constituted by a recess 91a and a contact bin recess 91b, and the recess 91a has a plurality of contact bins 20 on the lower surface side.
and a resin substrate 2 on which an IC chip 1 is mounted on the upper surface side.
is held in position.

Further, at the position of the bartending line (PL) where the upper mold 90 and the lower mold 91 are in close contact, there is a sprue 91 for injecting the molding resin 6 through a convex portion 91d formed in the lower mold.
c is provided.

Conventionally, the reason for providing this sprue 91c at the position of the bartending line (PL) is to simplify the structure of the molding die as much as possible to reduce manufacturing costs and to improve durability.

In other words, as shown in Figure 4, the general structure of a molding die is that the lower mold is carved to form a complicated recess for storing a circuit board, etc., and the upper mold is not carved with less complicated engravings. It has a structure that does not undergo any processing, and the sprue 9
1c can be said to have the simplest structure, having a side gate configuration consisting of a convex portion 91d provided by engraving on the lower mold 91 and the lower surface of the upper mold 90.

However, if we consider the case where the molding resin 6 is injected from the sprue 91c in the mold shown in FIG.
When the heat dissipation plate 8 is not present as in Japanese Patent No. 244139, good insert molding is performed by injecting the molding resin 6 from the upper surface side of the resin substrate 2.

However, if the heat sink 8 is present as shown in FIG.
When the inflow pressure of the injected molding resin 6 is applied to the side surface of the heat radiating plate 8 as shown by arrow A, a problem arises in that the heat radiating plate 8 is misaligned and is molded in a displaced state.

The displacement of the heat sink 8 is caused by the fact that the inflow pressure of the molded resin B is stronger than the holding force applied to the heat sink 8 by the suction force of the vacuum holes 90b.

Therefore, as a method for preventing the displacement of the heat sink 8, it is possible to provide a knock pin in the lower mold 91 and to firmly hold the heat sink 8 against the upper mold 90 by the knock pin. However, this method of providing seven knock-bins complicates the structure of the molding die and leaves marks from the knock-bins on the molded product, leaving problems in terms of appearance and reliability.

An object of the present invention is to provide a method of manufacturing a semiconductor device with a heat sink without complicating the structure of a molding die and without causing displacement of the heat sink.

[Means to solve the problem]

The gist of the present invention for achieving the above object is as follows.

An IC chip is mounted on a resin substrate having a plurality of contact terminals, and the IC chip is sealed with resin by injection molding using a molding die, and the upper surface of the sealing resin formed by the injection molding includes: In a method for manufacturing a semiconductor device with a heat sink in which a metal heat sink is integrated by insert molding, a lower mold constituting the molding die includes a substrate holding portion for holding the resin substrate; Further, the upper mold has a heat sink holding part for holding the heat sink, and a gap formed by the heat sink held by the upper mold and the resin substrate held by the lower mold. It is characterized by having a sprue for injecting molding resin into the mold.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

(First Embodiment) Fig. 1 is a cross-sectional view of main parts showing a PGA molding die in which a heat dissipation plate is insert-molded according to the first embodiment of the present invention.
The figure is a perspective view of the PGA of the present invention.

The difference between FIG. 1 and FIG. 4 is that the height of the convex portion 91d of the lower mold 91 is lowered, and a convex portion 90d is also formed in the upper mold 90 corresponding to this convex portion 91d. That's what I did.

By setting the convex portions 90d and 91d at appropriate heights, the upper mold 90 is formed by the heat sink 8 held in place and the resin substrate 2 held in the lower mold 91. A sprue 91c is provided at the position of the cavity 10.

Next, considering the case where the molding resin 6 is injected from the sprue 91C in the mold shown in FIG. The heat dissipation plate 8 is attached to the upper mold 90 by applying it to the side.
As a result, the heat dissipation plate is held more firmly against the heat dissipation plate holding portion, and there is no need to worry about misalignment.

Therefore, as shown in Fig. 3, a PGA in which the heat sink 8 is correctly insert-molded is completed, and the remaining gate 6a is
exists in the middle part of molded resin B.

(Second Embodiment) FIG. 2 is a sectional view of essential parts showing a PGA molding die according to a second embodiment of the present invention. The difference from FIG. 1 is that by forming a recess 90c in the upper mold 90 to accommodate the heat dissipation plate 8, the position of the bartending line (PL) is moved downward, and the lower surface of the stopper mold 90 and the bottom A sprue 91c is formed by a convex portion 91d provided on the mold 91.

In the above configuration, as in the first embodiment, the sprue 91c is provided at the position of the cavity 10, so that the inflow pressure of the molded resin 6 is applied to the heat sink 8 as shown by arrow B. It has the effect of strongly holding against the parts.

〔Effect of the invention〕

As described above, according to the present invention, by setting the sprue of the molding metal in the gap formed by the heat sink and the resin substrate, it is possible to prevent the heat sink from shifting. The heat dissipation plate can be held in an extremely simple manner, such as by vacuum suction.

As a result, the structure of the molding die can be made simple and does not require a knock bottle, and the completed molded product will not have knock bottle marks or displacement of the heat sink, so the appearance This has a great effect in providing a semiconductor device with a heat sink with excellent quality and reliability.

[Brief explanation of the drawing]

Figures 1 and 2 are sectional views of essential parts showing a PGA molding die in which the heat sink of the present invention is insert-molded, Figure 3 is an external perspective view of the PGA of the present invention, and Figure 4 is a view of a conventional heat sink. FIG. 2 is a cross-sectional view of a main part showing a molding die for insert-molded PGA. 1...IC chip, 2...resin substrate, 6...molded resin, 8...heat sink. 90... Upper mold? 1...Lower mold. Figure Figure U Figure

Claims (1)

[Claims] An IC chip is mounted on a resin substrate having a plurality of contact terminals, and the IC chip is sealed with resin by injection molding using a molding die, and the upper surface of the sealing resin formed by the injection molding includes: In a method for manufacturing a semiconductor device with a heat sink in which a metal heat sink is integrated by insert molding, a lower mold constituting the molding die includes a substrate holding portion for holding the resin substrate; Further, the upper mold has a heat sink holding part for holding the heat sink, and a gap formed by the heat sink held by the upper mold and the resin substrate held by the lower mold. 1. A method for manufacturing a semiconductor device with a heat sink, characterized in that a sprue is provided for injecting molding resin into the semiconductor device.