JPS62136051A - Semiconductor device - Google Patents

Abstract

PURPOSE:To contrive to be low in cost and improve damp-proof property, by sealing an IC chip with resin and installing a transmitting window with the upper part of the IC chip serving as a cavity. CONSTITUTION:Above an IC chip 11 formed of ROM die-mounted on the stage 12 of a lead frame, a cavity 17 having a sectional area larger than the size of a cell part in the IC chip is formed and covered with a window which is made of transmitting material SiO2 or alumina and has larger expansion than the cavity. The window is made to adhere with epoxy resin which is strong in adhesiveness and high in damp-proof property. A transmitting thin film 15 for protecting the IC chip 11, when resinous sealing being performed, is formed of silicone resin on the surface of the IC chip 11. Thus, a large decrease in cost is available, and the package sealed with resin becomes superior in damp- proof property.

Description

[Detailed description of the invention] [Summary]! ? This is a plastic type EFROM characterized by a structure in which the OM part is hollow and a glass window is attached.

[Industrial application field]

The present invention relates to a semiconductor device, and more specifically, in place of a conventional ceramic EFROM (erasable/programmable read-only memory), the EFROM is sealed with resin, but the upper part of the ROM part is made hollow, and the upper part of the cavity is This relates to an EFROM package that has a glass window that allows ultraviolet rays to pass through.

[Conventional technology]

The ceramic EPROM package shown in the sectional view of FIG. 7 is a known one, and in the same figure 31 is R.
An IC chip with an OM formed thereon, 32 is a ceramic body,
33 is a ceramic cap, 34 is a glass window provided in the cap 33, 35 is a glass seal, 36 is a metallized layer, 37 is a lead, and a light 38 is irradiated onto the IC chip 31 through the glass window 34. The formed memory is erased and written to.

[Problem that the invention seeks to solve]

The ceramic body 32 is formed by laminating and sintering ceramic green sheets, which has the problem of requiring a large number of steps and significantly increasing costs.

Therefore, it was proposed to form an EFROM package by resin sealing, and a structure shown in the cross-sectional view of FIG. 8 was proposed. In addition, in FIG. 8, 41 is a ROM
42 is a sealing resin such as epoxy resin, 43 is a ceramic window material, and 44 is a lead. Light 45 is irradiated through the ceramic window material 43 to erase and write in the ROM.

In such a structure, the adhesion between the ceramic window material 43 and the sealing resin (for example, epoxy resin) 42 is poor, and
The ceramic window material 43 has a different coefficient of thermal expansion.
There is a problem that a gap is formed between the contact surface of the epoxy resin 42 and the epoxy resin 42, and water and moisture enter from the gap, that is, the moisture resistance is poor.

The present invention was created in view of these points, and an object of the present invention is to provide an HFROM that is low in cost and has excellent moisture resistance.

Means for Solving Problem C] FIG. 1 is a sectional view of an embodiment of the present invention, and in the same figure, 11
12 is an IC chip on which ROM is formed, and 12 is an IC chip 1.
1 is a die-attached lead frame stage, 13 is a lead, 14 is a wire connecting the electrode of the IC chip 11 and the lead 13, and 15 is an elastic material such as silicone resin coated on the IC chip 11. A thin film of a material that transmits ultraviolet light (hereinafter referred to as translucent); 16 is a sealing resin such as epoxy resin; 17 has a cross section larger than the cell part of the IC chip;
) and the bonded part of the wire bonded to the electrode of the IC chip (
14a), 18 is a transparent window made of silicon dioxide (5i02) or alumina that covers the cavity with a larger spread than the cross section of cavity 17, and 19 is a cap 18 made of epoxy resin. It is an adhesive that adheres to resin.

In the embodiment shown in FIG. 1, the IC chip 11 is an EPI? Although an OM package is provided, the upper part of the IC chip 11 is a cavity 17, and the structure is such that light irradiated through a translucent window 18 irradiates the IC chip 11, and the translucent thin film 15 is It functions to protect the IC chip 11 during resin sealing.

[Effect]

In the EPROM package having the above structure, the window 18
is bonded to the epoxy resin 16 with an adhesive 19, so the IC chip knob 11 is sufficiently protected from external water and humidity, and the light for erasing and writing in the ROM is transmitted through a translucent window. Since the light is irradiated onto the IC chip 11 through the cavity 17 and the light-transmitting thin film 15 of silicone resin coated thinly enough to have light-transmitting properties, the ROM can be erased and written without any problem.

〔Example〕

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

(Example 1) Referring again to FIG. 1, stage 1 of the lead frame
IC chip 11 with ROM formed on it
For example, the IC chip 11 is resin-sealed with epoxy resin 16, but unlike conventional plastic-type packages in which the IC chip 11 is completely sealed with resin, the IC chip 11 is sealed with resin.
A cavity 17 having a cross-sectional area larger than the dimensions of the cell portion 11a of the IC chip is formed above the IC chip.
2 or covered with a window 18 made of alumina. The material for the window 18 is not limited to those mentioned above, and the sealing resin is not limited to epoxy resin, but may be any other material that has been sealed.

The window 18 is made of an adhesive 19 that has strong adhesive properties and is therefore highly moisture resistant.
Glue to epoxy resin. To do this, a recess corresponding to the dimensions of the IC chip 11 is formed in the upper part of the epoxy resin, and the window 18 is bonded to this recess.

On the surface of the IC chip 11, a transparent material 11115 is formed of silicone resin, for example, to protect the IC chip 11 during resin sealing. This thin film 15 is the IC chip 11
Apply to completely cover the surface.

FIG. 2 is a cross-sectional view showing in detail the state in which the transparent thin film 15 is coated, and in this figure, 11a indicates the cell portion of the IC chip. Since the wire 14 has already been bonded to the electrode of the IC chip, there is no problem in covering the bonded portion of the wire with silicone resin. In the illustrated example, the height of the ball-shaped adhesive portion 14a of the wire is 50 p m −, and the IC chip 11
The thickness of the silicone resin was about 400 to 500 μm, and the thickness of the silicone resin was about 100 to 200 μm. Transparent thin film 15
may be made of an elastic, translucent gel-like resin other than silicone resin.

The package shown in Figure 1 is IC chip attachment/wire attachment Silicone resin coating/cure mold forming window installation It can be made by the following process.

The light-transmitting thin film functions to protect the IC chip 11 during the above-described molding. In molding, the mold is designed so that the inner wall 16a of the molding resin (the boundary between the cavity 17 and the molding resin) is located approximately midway between the cell portion 11a of the IC chip and the bonding portion 14a of the wire.

The mold described above is partially shown in the cross-sectional view of FIG.
2 indicates a lead frame. A protrusion 23 is formed on the upper mold 21b so that a cavity 17 is formed.

The upper mold and the lower mold are sealed with resin in the closed state as shown in the figure, but when the upper mold and the lower mold are clamped, the thin film 15 is removed from the upper mold 21
The protrusion 23 of b presses against it to prevent the sealing epoxy resin from entering. Then, the protrusion 23 is
The impact on the C-chip 11 is alleviated by the downward deflection of the stage 12 of the lead frame 22 and by the thin film 15.

FIG. 4 is a schematic plan view of a portion of the lead frame 22, and the portion other than the cavity 17 in the figure is sealed with epoxy resin. In the figure, the entire lower part of the IC chip 11 is sealed with resin, and a cavity 17 is formed only above the IC chip.
is formed.

(Example 2) As (Example 1) shown in detail in FIG.
If it is difficult to locate the bonded portion 14a in the middle of the bonded portion 14a, please refer to FIG. 5, which is a sectional view of Embodiment 2 of the present invention, and FIG. As shown,
It is possible to cover the wire 14 with the transparent thin film 15 up to the highest part so that the inner wall 16a of the molded resin protrudes outside the wire bonding portion 14a (the range indicated by A in FIG. 6). This example can also be made using the same steps as Example 1.

〔Effect of the invention〕

As described above, according to the present invention, the EFROM package is formed by resin sealing instead of the conventional expensive ceramic package, and the cost is reduced to 1/1/1720.
In addition, the resin-sealed package has excellent moisture resistance.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of Embodiment 1 of the present invention, Fig. 2 is a cross-sectional view showing a part of the apparatus shown in Fig. 1 in detail, and Fig. 3 is a partial view of a mold used for molding the apparatus shown in Fig. 1. 4 is a partial plan view of a lead frame used in the device shown in FIG. 1, FIG. 5 is a sectional view of Embodiment 2 of the present invention, and FIG. 6 is a detailed view of a part of the device shown in FIG. 5. FIG. 7 is a sectional view of a conventional example, and FIG. 8 is a sectional view of another conventional example. 1 to 6, 11 is an IC chip, 11a is a cell part of the IC chip, 12 is a stage of a lead frame, 13 is a lead, 14 is a wire, 14a is a bonded part of the wire, 15 is a transparent thin film , 16 is an epoxy resin (sealing resin), 16a is an inner wall, 17 is a cavity, 18 is a window, 19 is an adhesive, 21a is a lower mold, 21b is an upper mold, 22 is a lead frame, 23 is a protrusion of the upper mold It is. Agent Patent Attorney Akifuku Agent Patent Attorney Yoshiyuki Osuga (23°2°. 'ni + I!
Figure';,,z+7 ＼ Lead 13 A view of the first building to the lead two Figure 4 F- Oak ya

Claims (1)

[Claims] An IC in which an erasable/writable read-only memory is formed.
A plastic type package is formed by sealing the chip (11) with a resin (16), and the surface of the IC chip (11) is provided with an ultraviolet-transparent elastic thin film (15), and the cell portion of the IC chip (11) is A cavity (17) with a cross-sectional area larger than that area is formed above (11a), and the cavity (17) has an extension larger than the cross-sectional area and is glued to the sealing resin (16) and transmits ultraviolet rays. A semiconductor device characterized by a structure covered by a magnetic window (18).