JPS60137045A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate coating of radiation shielding material by sealing a semiconductor element assembling structure in which a plate made of a material having a radiation generating amount smaller than a molding resin is bonded to the main surface of a semiconductor element with the resin. CONSTITUTION:A plate 7 formed of a material having a radiation generating amount smaller than a molding resin 6 is bonded with an adhesive 8 onto a main surface of a semiconductor element 1. As a result, radiation shielding effect is enhanced by the plate which can be readily selected in its thickness and which can be formed in thickness so as not to disturb the reduction in the thickness of a package. Since the thickness of the resin can be sufficiently increased, mechanical strength and moisture resistance are not lost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resin-sealed semiconductor device, such as a semiconductor memory device, which is sealed with a resin, and which needs to be protected from radiation emitted from the sealing resin. Related to semiconductor devices.

Conventional Structures and Problems In semiconductor devices mainly having a memory function, malfunctions may occur due to incidence of radiation emitted from the package material, particularly alpha rays. In order to prevent such malfunctions, a method of covering (supporting) the main surface of a semiconductor element with a shielding material such as polyimide resin or silicone resin is widely used. FIGS. 1 and 2 are cross-sectional views showing the structure of a resin-sealed semiconductor device in which this measure has been taken.

In the resin-sealed semiconductor device having the structure shown in FIG. After the connection, the main surface of the semiconductor element 1 is covered with a shielding material 6, and finally it is sealed with a molding resin 6.

Note that the covering with the shielding material 6 usually extends to the connecting portion of the thin metal wire 4, as shown in the figure.

When rapid temperature changes are repeatedly brought to this resin-sealed semiconductor device, shearing force acts on the thin metal wire 4 at the boundary between the shielding material 5 and the molding resin 6 due to the difference in coefficient of thermal expansion. However, there was a risk of a disconnection accident occurring on the Kinasagi 1 thin line. Since the shielding material 5 is coated with the thin shielding material 5 by dropping the liquid shielding material and subsequently hardening by heat treatment, the thickness of the shielding material 5 becomes large in the medium heat area, as shown in the figure. The thickness of the molding resin corresponding to this part is thinner than the other parts, which may lead to a decrease in mechanical strength and moisture resistance.

Therefore, the thickness of the molding resin must be set so that a thickness that does not cause any inconvenience to the shielding material is ensured on the central part of the shielding material. Problems arise that limit the ability to

In the resin-sealed semiconductor device having the structure shown in FIG. 2, the thickness of the shielding material 5 is made uniform over the entire area.
According to this structure, it is possible to bind the molding resin to a sufficient thickness and also to reduce the thickness. By the way, the shielding material 5 shown in the figure is spin-coated on the entire surface of a semiconductor wafer, and after it is cured, the shielding material on the wire bonding part (bonding board) and the scribe lane is selectively removed. Alternatively, it can be formed through a forming process such as selectively coating onto a predetermined area by screen printing and then curing. It is difficult to do 1-). For this reason, apply.

It is necessary to repeat the curing process, and a decrease in workability is unavoidable.

In fact, polyamide resins and silicone resins used as radiation shielding materials do not contain fillers such as silica in order to minimize the radiation generated from them. For this reason, the thermal conductivity is lower than that of molding resin, and if the thickness is about 50 μm or more, which is required for radiation shielding, the heat generated from the semiconductor knob during one operation will be reduced. There was also the problem of insufficient radiation dissipation.Purpose of the InventionThe object of the present invention is to provide a structure that can shield radiation.It is possible to eliminate all the problems that existed in conventional resin-sealed semiconductor devices. An object of the present invention is to provide a resin-sealed semiconductor device.

Structure of the Invention The resin N-shaped semiconductor device of the present invention has a structure in which the main surface of a semiconductor element fixed to a substrate support is sealed with a synthetic resin. With this configuration, there is no need to apply radiation shielding material, and radiation shielding benefits are
The problems associated with the application of No. 1 are eliminated.

Description of examples The present invention will be described in detail below with reference to FIG.

FIG. 3 is a cross-sectional view showing the internal structure of the resin-sealed semiconductor device of the present invention. The plate-shaped body 7 formed using a small amount of material is the adhesive 8.
It is glued by.

That is, in the past, a radiation shielding layer was applied, but in the present invention, a plate-shaped body is bonded, and this point differs from the conventional structure. By the way, a semiconductor substrate, for example, a silicon single crystal thin plate, is used as the plate-like body serving as a radiation shield.

The area of this plate-like body may be as wide as fυ the surface area of the semiconductor element that is affected by one radiation, and the thickness of the plate-like body may be about 1100 to 200 μm1.Furthermore, It is desirable that the surface of the plate-shaped body be electrically insulated, but when the plate-shaped body is formed from a silicon single crystal plate, a stable silicon dioxide film (SiOz film) can be easily formed on the entire surface. can do.

In fact, the adhesive 8 used to bond the plate-shaped body 7 must also be one that generates a small amount of radiation. A sufficiently purified polyimide resin is suitable as such an adhesive. The adhesive can be supplied between the adhesive surfaces by dropping a small amount onto the main surface of the semiconductor element 2 and pressing it with the plate-shaped body 7 to spread it between the adhesive surfaces, or by applying the adhesive between the adhesive surfaces. Plate body 7
This may be done by applying a plate-like adhesive in advance to the surface of the semiconductor element 2, and then lightly pressing the other side onto the main surface of the semiconductor element 2. After supplying the adhesive in this manner, a predetermined curing process is performed to complete the bonding of the plate-shaped bodies 7. It goes without saying that when bonding such plate-like bodies, it is necessary to take sufficient care to avoid creating voids between the bonding surfaces.

Thereafter, the resin-side stop type semiconductor device of the present invention is formed through connection using the thin metal wire 4 and sealing with a molding resin.

In the above explanation, an example was given in which the plate-like body was made from a silicon single crystal thin plate, but it is important to use a material that generates less radiation than the molding resin. A manufactured plate-like body may also be used.

Effects of the Invention The resin-sealed semiconductor device of the present invention is a plate-shaped body whose thickness can be easily selected and does not shield radiation. Moreover, the thickness can be made so that it does not become an obstacle to making the Pasoké 7 thinner.

In addition, the thickness of the molding resin on the outside of the plate-shaped body can be made sufficiently thick to reduce the thickness of the PC.
Therefore, a thin resin-sealed semiconductor device with no loss in mechanical strength and side temperature properties can be realized. moreover,
By selecting the size of the plate and setting the contact position 16, it is possible to position the wire bond portion on the semiconductor element and the thin metal wire extending from there toward the external lead only within the molding resin. There are also effects such as being able to prevent disconnection accidents of thin wires, and increasing the heat dissipation effect since the adhesive is the only material with lower thermal conductivity than the molding resin.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing the structure of a conventional resin-sealed semiconductor device equipped with radiation protection measures;
FIG. 3 is a sectional view showing the structure of the resin-sealed semiconductor device of the present invention. -1...Substrate support, 2...Semiconductor element,
3... External lead - 4... Thin metal wire,
6...Resin for molding, 7...Plate-shaped body for radiation shielding, 8...Adhesive.

Claims (4)

[Claims] (1) A semiconductor element assembly structure is formed using a molding resin, in which a plate-shaped body made of a particle that generates less radiation than the molding resin is adhered to the main surface of the semiconductor element fixed on a substrate support. A resin-sealed semiconductor device characterized by being sealed. (2) The resin-sealed semiconductor device according to claim 1, wherein the plate-like body is a thin silicon plate. (3) Resin sealing according to claim 1, wherein the plate-like body is a silicon thin plate, and its surface is covered with a silicon dioxide film. shaped semiconductor device. (4) The resin-sealed semiconductor device according to claim 1, wherein the semiconductor element has a memory function.