JPH07109898B2 - Transparent resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To improve the quality and increase the yield, preventing external stress from applying improperly to a resin package in the mold separating process of transfer molding, by making a light transmitting window section facing a semiconductor chip in the resin package a specular surface, making the upper and lower planes excluding the light transmitting window section matte surfaces, and besides making the peripheral side of the package a specular surface with a draft. CONSTITUTION:Concerning a resin package 5, the light-transmitting window section 5a of a package facing the photoelectric receiving plane of a semiconductor chip 1 is made to have a specular surface, and the upper and lower planes of a package excluding the region of the light transmitting window section is made to be matte surfaces 5b. In addition, the peripheral side 5c of the package is made to be a specular surface with a draft (taper angle theta). By doing this, when a die is opened in the mold separating process of transfer molding, external stress is prevented from being improperly applied to the resin package 5 being a molding, and troubles of the resin package 5 such as cracks, warps, or exfoliation of resin from sealed parts are securely prevented. Accordingly, the quality and yield of the products can be improved greatly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is intended for photometric light-receiving elements and the like, and is formed by encapsulating a semiconductor chip in a transparent resin package, particularly a resin package molded by a transfer molding method. The present invention relates to a resin-sealed semiconductor device.

[Conventional technology]

As the transparent resin-encapsulated semiconductor device described above, a part of the surface of the resin package is formed with a light-transmitting portion of a mirror surface facing the light-receiving surface of the light-receiving element sealed inside the resin package, and A package in which the surface of the package excluding the window is entirely satin has been already proposed by the same applicant as Japanese Patent Application No. 62-329134.

Next, FIG. 5 shows the configuration of the above-mentioned conventional transparent resin-sealed semiconductor device. In the figure, 1 is a semiconductor chip as a light receiving element, 2 is a die pad on which the semiconductor chip 1 is mounted, 3 is an external lead, 4 is a bonding wire, and 5 is a transparent resin package. Resin package 5 here
Region A of the transparent window portion 5a facing the light receiving surface of the semiconductor chip 1 is a mirror surface, and the outer surface excluding the transparent window portion 5a (upper,
The lower and side surfaces are all formed as a satin surface 5b.

The resin package 5 is molded using a transfer molding die 6 shown in FIG. Here, the mold 6 is composed of an upper mold 6a and a lower mold 6b, and an inner peripheral wall surface of the mold defining the cavity 6c corresponds to the light-transmissive window portion 5a and the satin-finished surface 5b forming the mirror surface of the resin package 5. The areas are smoothed and roughened, respectively. Then, as shown in the figure, a semiconductor chip or the like is set in the mold 6 in the cavity, and a transparent resin is injected in this state to seal a component such as the semiconductor chip 1 as shown in FIG. 5 is molded.

In the transparent resin-sealed semiconductor device manufactured in this way, the regular photometric light beam incident on the light-transmitting window portion 5a, which is a mirror surface, passes through the layer of the transparent resin 5 as it is and reaches the light-receiving surface of the semiconductor chip 1. On the other hand, the stray light from the surroundings incident on the surface of the package other than the transparent window 5a is hardly diffused and scattered by the satin surface 5b and hardly reaches the conductor chip 1. The reliability of the operating characteristics of the device can be improved.

[Problems to be Solved by the Invention]

By the way, when the resin package of the above-mentioned transparent resin-encapsulated semiconductor device is transfer-molded, problems such as the following juice occur on the manufacturing surface, particularly when the molded product is released from the mold.

That is, as described with reference to FIG. 5, the conventional resin package 5 has a satin side surface on the package side, and correspondingly, the cavity peripheral wall surface of the transfer molding die 6 shown in FIG. 6 is also roughened. There is. Here, when the outer shape corner portion of the resin package 5 and the cross-sectional shape of the die 6 corresponding thereto are enlarged and shown in FIG. The side of
The shape of the undercut is uneven. For this reason, after injecting the resin of the mold 6 to mold the resin package 5, when the mold 6 is opened in the arrow direction in the releasing step,
The convex portion P formed on the surface of the side surface of the resin package, which is a molded product, and the wall surface convex portion Q on the die side interfere with each other, and galling occurs between them.

On the other hand, the epoxy resin, which is a molding material for the transparent resin package 5, is usually used without adding a reinforcing material in order to maintain the transparency of the resin package. However, the epoxy resin without the addition of reinforcement is at high temperature (80
When the temperature rises above (° C), the strength decreases. Therefore, as described above, when external stress due to galling is applied from the mold 6 side of the resin package 5 in the releasing process, the resin package 5 is cracked or warped, or a sealing component such as a semiconductor chip is produced. Problems such as peeling between the resin and the resin occur, which is a major cause of deterioration in quality and yield.

Although it is possible to deal with the above-mentioned undercut of the matte surface by providing a loose core on the side surface of the cavity on the die side, this method complicates the die structure, and in particular, takes a large number of pieces. This transfer molding die can hardly be put to practical use.

The present invention has been made in view of the above points, and by improving the resin package, it does not have a slight adverse effect on the operation characteristics of the semiconductor device, and the transfer molding can be easily released. An object of the present invention is to provide a transparent resin-encapsulated semiconductor device capable of avoiding an undesired external stress applied to a resin package in the process and improving quality and yield.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention is a semiconductor device in which a semiconductor chip including a light receiving element is sealed in a transparent resin package by a transfer molding method, and a transparent window portion facing the semiconductor chip in the resin package. The roughness 0.
A mirror surface of less than 05 μm, the upper and lower surfaces of the package excluding the light-transmitting window are made a matte surface with a roughness of 2 to 15 μm, and the side surface of the package is tapered with a draft of 5 to 15 °.
It is characterized by having a mirror surface of μm.

[Action]

By forming the side surface of the resin package as a mirror surface as described above, there is no undercut in this part, and by tapering the draft, it is a molded product in the mold release process of the transfer molding for molding the resin package. The mold can be opened without galling or other interference between the resin package and the mold, which prevents the resin package from being applied with an undesired external stress.

On the other hand, when the semiconductor device is incorporated in a product of a photometric system, it is common to have a light-shielding structure that prevents extra stray light from entering the semiconductor device from the side in terms of design. In addition, as the operating characteristics of the light receiving element, the light receiving element rarely malfunctions due to stray light transmitted from the side at an angle close to a right angle with the regular light transmitting surface with respect to the light receiving surface. Therefore, even if the side surface of the resin package encapsulating the semiconductor chip is formed into a mirror surface, there is no risk of adversely affecting the operation performance such as malfunction of the semiconductor device due to stray light incident on this side surface.

〔Example〕

1 and 2 are configuration diagrams of an embodiment of the present invention, and FIG. 3 is a first diagram.
FIG. 4 is a partial cross-sectional view showing the structure of a transfer molding die corresponding to the semiconductor device shown in FIG. 4, and is a partially enlarged view of a main part showing a released state. The same members corresponding to FIGS. 5 and 7 are the same. The reference numeral is attached.

That is, in the resin package 5 in which the semiconductor chip 1 or the like is sealed according to the present invention, the transparent window portion 5a of the package facing the light receiving surface of the semiconductor chip 1 is a mirror surface, and the transparent window portion 5a is formed.
The upper and lower surfaces of the package excluding the area are formed as a satin-finished surface 5b, and the package peripheral side surface 5c is formed as a mirror surface having a tapered taper (taper angle θ). Also,
The transfer molding die 6 for molding the resin package 5 has a peripheral side surface of the resin package 5 as shown in FIG.
The peripheral side surface of the cavity 6c corresponding to 5c is finished smooth.

In the actual product, the roughness of the mirror surface of the translucent window 5a in the resin package 5 is 0.05 μmS or less, the roughness of the matte surface 5b is about 2 to 15 μmS, and the roughness of the side surface 5c is about 0.1 to 0.3 μmS. In addition, the draft angle θ is set to about 5 to 15 °, and the cavity of the transfer molding die 6 is adjusted according to the conditions of this specification.
The wall surface of 6c is smooth and roughened.

Here, when the resin package 5 is molded using the mold 6 of FIG. 3, the state when the mold 6 is opened in the releasing step of transfer molding is as shown in FIG. That is, since the peripheral side surface of the resin package 5 is a mirror surface and does not have an undercut portion, there is no galling interference between the resin package 5 and the mold 6 as shown in FIG. As a result, the resin package 5 can be released from the mold 6 without being unduly applied with an external stress.

Even if the semiconductor chip 1 as the light receiving element sealed by the resin package 5 emits stray light from the side toward the peripheral side surface 5c of the resin package 5 forming a mirror surface, the light receiving element may malfunction. It has been sufficiently confirmed from the test results that there is no such thing.

〔The invention's effect〕

Since the resin-encapsulated semiconductor device according to the present invention is configured as described above, it has the following effects.

(1) By forming the peripheral side surface of the resin package as a mirror surface with a taper of a draft, when the mold is opened in the releasing process of transfer molding, an undesired external stress is applied to the resin package as a molded product. As a result, problems such as cracks and warps in the resin package or peeling between the sealing component and the resin can be reliably avoided, and product quality and yield can be greatly improved.

(2) Since the side surface of the resin package is a mirror surface, it does not adversely affect the operation performance of the semiconductor device, and the upper and lower surfaces of the resin package excluding the light-transmitting window portion are a satin-finished surface to allow incident light from the surroundings. High reliability as a semiconductor device can be obtained by preventing malfunction due to stray light.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a resin-sealed semiconductor device according to an embodiment of the present invention, FIG. 2 is a top view of FIG. 1, and FIG. 3 is a structural view of a transfer molding die corresponding to FIG. 4 is the third
FIG. 5 is a partially enlarged view showing a releasing state by a mold in the figure, FIG. 5 is a sectional view showing the configuration of a conventional resin-sealed semiconductor device, and FIG.
The figure is a block diagram of the transfer mold corresponding to FIG.
FIG. 7 is a partially enlarged view showing a releasing state by the mold of FIG. In the figure, 1: semiconductor chip, 5: transparent resin package, 5a: translucent window (mirror surface), 5b: satin surface, 5c: side surface (mirror surface), 6: transfer molding die, θ: taper angle of draft .

Front Page Continuation (72) Inventor Takayasu Nomoto 1-1 Tanabe Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Fuji Electric Co., Ltd. (56) References JP 63-153869 (JP, A) JP 63- 21878 (JP, A) Actually open 51-60769 (JP, U)

Claims (1)

[Claims] 1. A semiconductor device in which a semiconductor chip including a light receiving element is encapsulated in a transparent resin package by a transfer molding method, wherein a transparent window portion facing the semiconductor chip in the resin package has a roughness of 0.05 μm or less. The mirror surface and the upper and lower surfaces of the package excluding the light-transmitting window are made to have a matte surface with a roughness of 2 to 15 μm, and the side surface of the package is a mirror surface having a roughness of 0.1 to 0.3 μm with a taper of 5 to 15 °. A transparent resin-sealed semiconductor device characterized by the above.