JPH06342855A - Semiconductor package with inner lid - Google Patents

Abstract

PURPOSE:To suppress an effect of heat shrinkage of a wire due to the displacement of gel in a part being in contact with an inner lid and in the periphery of the part and thereby to ensure high reliability, by providing the inner lid so that it comes into contact with the gel. CONSTITUTION:An electrode 7 of a chip 2 and an electrode 8 of a base 1 are connected by a wire 9. Since the wire 9 is liable to corrode, the chip 2 and the wire 9 are coated with a gel-like coating agent 10 so as to ensure moisture resistance. Next, a ring-shaped inner lid 11 having an insulated surface is put on so that it is in contact with the surface of this gel-like coating agent 10, and then the gel-like coating agent 10 is gelatinized by baking. The inner lid 11 has bent legs 12 at four corners and thereby a prescribed height thereof is maintained. By providing a hole 13 for letting out air in the central part of the inner lid 11, a gas produced on the occasion when the gel-like coating agent 10 is gelatinized by baking (heating) is let out. Lastly, a cap 14 is stuck so as to protect the inside mechanically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package with an inner lid, and more particularly to a technique for improving the reliability of a semiconductor integrated circuit. In particular, a semiconductor chip having a fine multi-pin has a high humidity resistance. Package suitable for realizing low cost while
Regarding the structure.

[0002]

2. Description of the Related Art A semiconductor chip is mounted on a base having a wiring pattern for taking out electrodes, and the corresponding electrodes of the base and the semiconductor chip are connected by wires to form a gel-like cord. There is a semiconductor package structure in which the semiconductor chip and the wire are covered with a coating agent. Conventional gel gel
Tote type packages use a cap for mechanically protecting the gel-like coating agent portion, but an inner lid for restraining the displacement of the gel-like coating agent is provided. Not not.

[0003]

In the above-mentioned prior art, as in a fine pitch multi-pin semiconductor chip (LSI), an LS that uses fine wires or requires multi-step bonding.
In the case of I, even if a soft gel-like coating agent is used,
There is a problem that the wire is easily deformed by the thermal expansion (contraction) of the gel coating agent.

An object of the present invention is to deform a wire by a gel-like coating agent (hereinafter, also simply referred to as a gel) even in an LSI that uses the fine wire as described above or requires multi-step bonding. The object of the present invention is to realize a package that suppresses the effect of thermal expansion (contraction), especially the effect of thermal contraction, and can secure sufficiently high reliability.

The above and other objects and novel features of the present invention will be apparent from the description of the present specification and the accompanying drawings.

[0006]

The outline of the representative ones of the inventions disclosed in the present application will be briefly described as follows.

The above object is achieved by providing an inner lid for restraining the displacement of the gel.

[0008]

The gel used to secure the moisture resistance of the wire is flexible, but has a drawback that it has a large coefficient of thermal expansion. Therefore, when using fine wires or when applied to a semiconductor package with multi-stage bonding,
Under an accelerated temperature condition such as an environmental test, there is a possibility that the thermal expansion and contraction of the gel may cause a stress to deform the wire. However, by providing the inner lid so as to make contact with the gel, it is possible to suppress the displacement of the gel in the portion in contact with the inner lid and in the periphery thereof. Therefore, the deformation of the wire can be prevented by providing an inner lid near the wire.

[0009]

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

Embodiment 1; FIG. 1 is a sectional view showing an embodiment of the present invention. The base 1 is made of a resin wiring substrate having a laminated structure, and wirings 3 for leading electrodes from semiconductor elements in a semiconductor chip (hereinafter simply referred to as a chip) 2 are routed between layers. The terminal portion 4 for electrode connection has a two-stage structure so that multiple pins can be connected. Base
A large number of lead pins 5 are erected on the space 1. From the back surface of this base 1, a metal heat diffusion plate 6 for heat dissipation and fixing of the chip 2 is attached. The chip 2 is fixed to the center of the heat diffusion plate 6 with an adhesive. After that, the corresponding electrodes 7 and 8 of the chip 2 and the base 1 are connected by the wire 9 by a bonding method such as an ultrasonic wire bonding method. Since the wire 9 is easily corroded, the tip 2 and the wire 9 are coated with a gel-like coating agent 10 in order to secure moisture resistance. Next, a ring-shaped inner lid 11 having an insulated surface is placed so as to come into contact with the surface of the gel-like coating agent 10 and then baked to gel the gel-like coating agent 10. To do. The inner lid 11 has legs 12 bent into four corners so that it does not fall below a certain height. FIG. 3 shows an example perspective view of the inner lid 11. The inner lid 10 has a hole 1 for venting air in the center thereof.
3 is provided. Hole 13 for venting air in the inner lid 10
By providing the above, it is possible to degas when the gel coating agent 10 is gelated by baking (heating). Finally, the cap 14 is attached to protect the inside mechanically. Although not shown, the heat diffusion plate 6
A fin for heat dissipation is attached to the.

According to the present embodiment, the shrinking force which adversely affects the wire 9 when the resin, which is in the form of gel of the coating agent 10 during baking, is cooled to room temperature, has a ring-like shape. Since the inner lid 11 supports the wire 9, it is possible to prevent excessive stress from being applied to the wire 9. On the contrary, when the temperature rises, the contraction force of the gel 10 is released, but the inner lid 11 is not constrained upward, so the gel 10 can be freely restored to its initial state after curing. . That is, there is no problem because the entire system tends to decrease in stress. As described above, in the LSI that performs the resin coating, the reliability can be improved by providing the inner lid even in a complicated structure such as multi-step bonding.

Embodiment 2; FIG. 2 is a sectional view showing another embodiment. In the example of FIG. 1, the bent leg 12 is attached to the inner lid 11, but in FIG. 2, a protrusion 15 for receiving the inner lid 11 is provided in advance on the side of the base 1 to form the inner lid 11. Is an example in which a flat plate obtained by punching a plate such as an Al plate can be used.

It goes without saying that this embodiment also has the same effects as the embodiment of FIG.

The base 1 is composed of a multilayer wiring resin substrate made of, for example, BT resin (bismaleimide-triazine resin). The chip 2 is made of, for example, a silicon single crystal substrate, has a large number of circuit elements formed therein by a well-known technique, and is given one circuit function. A specific example of the circuit element includes, for example, a MOS transistor, and these circuit elements form a circuit function of a logic circuit and a memory, for example. The lead pin 5 is made of, for example, a Ni—Fe alloy. The wire 9 is made of, for example, an aluminum thin wire. Gel coating agent 10 used in the present invention
For example, a sealing material made of silicone gel can be used. The gel is in a liquid state before being heated and cured, and there are one-liquid type and two-liquid type. For example, in the case of a two-liquid type consisting of a main agent and a curing agent, when these are mixed, they are cured by reaction (crosslinking reaction) and cured. Get things. The curing system includes condensation type, addition type, ultraviolet curing type and the like. A commercially available product can be used as the silicone gel, for example, KJR9010, X-3 manufactured by Shin-Etsu Chemical Co., Ltd.
5-100, JCR6110 manufactured by Toray Silicone Co., etc. can be used. The X-35-100 [A (main agent), B
(Curing agent) 2-liquid type, penetration degree 100], the curing reaction mechanism is platinum addition type, 2-liquid low temperature high temperature gel -75 to 250
It can be used in the temperature range of ° C. The inner lid 11 is made of, for example, aluminum.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, although the hole 13 of the inner lid 11 is provided at one place in the central portion in the above embodiment, it may be provided over the entire surface.

[0017]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

Since the displacement due to the thermal contraction of the coating resin can be suppressed by providing the inner lid, there is an effect that the reliability can be improved even in an LSI having a complicated structure such as multi-step bonding.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a perspective view showing an embodiment of an inner lid used in the present invention.

[Explanation of symbols]

 1 ... Base 2 ... Semiconductor chip 3 ... Wiring 4 ... Terminal part for electrode connection 5 ... Lead pin 6 ... Heat diffusion plate 7 ... Electrode 8 ... Electrode 9 ... Wire 10 ... Gel Coating agent 11 ... Inner lid 12 ... Bent foot 13 ... Air vent hole 14 ... Cap 15 ... Protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kuroda 2326 Imai, Ome City, Tokyo, Hitachi, Ltd. Device Development Center (72) Inventor Masayuki Shirai 2326 Imai, Ome City, Tokyo Hitachi, Ltd. Device Development In the center (72) Inventor Toshihiro Tsuboi 5-20-1, Josuihonmachi, Kodaira-shi, Tokyo Inside Hitsuritsu Cho-LS Engineering Co., Ltd. (72) Inventor Hiroshi Kosaku, 5 Mizumizuhoncho, Kodaira-shi, Tokyo Nichore Super LSI Engineering Co., Ltd. (20) Masayuki Kikuchi 5-20-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Hitate Super LSI Engineering Co., Ltd. In the company

Claims (3)

[Claims] 1. A gel-like cord is formed by mounting a semiconductor chip on a base having a wiring pattern for taking out electrodes, and connecting the corresponding electrodes of the base and the semiconductor chip with a wire. In the semiconductor package structure in which the semiconductor chip and the wire are covered with a coating agent, the gel-like coat
A semiconductor package with an inner lid, comprising an inner lid that comes into contact with a coating agent and a cap attached. 2. The semiconductor package with an inner lid according to claim 1, wherein the inner lid is provided with a hole for venting air. 3. The inner lid is provided with bent legs,
2. The semiconductor package with an inner lid according to claim 1, wherein the base is provided with a projection for receiving the inner lid.