JPS629731Y2 - - Google Patents

Description

[Detailed explanation of the invention] (1) Technical field of the invention This invention is a light-shielding film, such as an ultraviolet erasable film.
The present invention relates to an EPROM (Erasable Programmable ROM) integrated circuit (IC), and more particularly to a light-shielding film used as a glass window cover to prevent erasure of memory contents.

(2) Background of the technology Ultraviolet erasable EPROM ICs are storage devices in which memory contents are written electrically and erased using ultraviolet irradiation.

FIG. 1 is a perspective view of the EPROM IC package. Referring to the figure, the EPROM IC package 1 is provided with a glass window 2 for irradiating ultraviolet rays on an IC chip 4 for erasing stored contents.

The memory contents are erased, for example, by irradiating the glass window 2 with ultraviolet light with a wavelength of 2537 Å from a mercury (Hg) lamp. For example, the memory contents are gradually erased by ultraviolet light contained in office lighting or near ultraviolet light in visible light, and the device becomes unusable within one to two years. I began to experience this.

Conventionally, the glass window 2 of the package 1 has been covered with a cover 3 (hereinafter referred to as a light-shielding film) in order to prevent the above-mentioned storage contents from being erased. The light-shielding film 3 is a polyimide film attached to the glass window 3.
The film is cut into a shape large enough to cover the film, and is attached to the package using an adhesive layer formed on the underside of the film.

FIG. 2 is a plan view a of a light-shielding film formed and pasted on a mount according to the prior art, and a cross-sectional view b taken along the cutting line A-A in the plan view a.
Referring to FIG. 2A, a plurality of light-shielding films each having a size of, for example, 10 mm x 15 mm are pasted on a mount 21. On the other hand, the structure of the light-shielding film 22 is such that an adhesive layer 23 is formed on the lower surface of the polyimide film 22, as shown in the cross-sectional view of FIG. Note that the film 22 in cross-sectional view b
The thickness of the adhesive layer 23 is exaggerated and shown to be thicker than it actually is for purposes of explanation.

To attach it to the EPROM IC package, peel off one of the above light-shielding films 22 from the mount 21,
This is done by pressing the surface of the adhesive layer 23 of the film onto the attachment location of the package.

(3) Conventional technology and problems By the way, the conventional light-shielding film mentioned above is
It blocks ultraviolet light but allows visible light to pass through.
As mentioned above, there is a problem in that the stored contents are destroyed and erased by the near ultraviolet light among the transmitted visible light.
Furthermore, since the surface of the light-shielding film is smooth and glossy, it is difficult to clearly write symbols or memos to indicate the memory contents or the IC insertion position on the film surface, which is inconvenient for those who use the IC. .

On the other hand, it is not an easy task to peel off the thin light-shielding film that is adhered to the mount one by one from the mount, and it may cause damage to the film, so some kind of improvement is needed.

(4) Purpose of the invention In view of the above-mentioned conventional problems, the present invention is a light-shielding film that blocks ultraviolet light and visible light, allows symbols or memos to be written on the surface, and can be easily peeled off from the backing paper. The purpose is to provide.

(5) Structure of the invention According to the invention, in an ultraviolet-erasable EPROM in which a light-shielding film for blocking ultraviolet rays consisting of an upper layer of a film and a lower layer of an adhesive layer is attached to an ultraviolet irradiation window, This is achieved by providing an ultraviolet erasable EPROM characterized in that the lower layer of the film is an adhesive layer mixed with a black pigment, and the upper layer surface is treated to have an uneven surface.

(6) Embodiments of the invention Hereinafter, embodiments of the invention will be explained in detail with reference to the attached drawings.

FIG. 3 is a diagram showing the structure of a light-shielding film for explaining an embodiment of the present invention, FIG. 3a is a plan view,
FIG. 1B is a cross-sectional view taken along line B-B in the plan view A.
2 and the thickness of the adhesive layer 33 are exaggerated for the sake of illustration.

Referring to the figure, a plurality of light-shielding films 32 having a predetermined shape are pasted on a mount 31, and the light-shielding films 32 are attached parallel to the long sides of the mount 31.
A cut line 34 is formed along a straight line that crosses a portion of the mount near the long side of No. 2.

On the other hand, the adhesive layer 33 on the lower surface of the polyimide film 32 is mixed with a black pigment such as carbon to measure the visible light absorption effect, and the surface of the film 32 is matte-treated to form an uneven shape. It also facilitates the writing of characters, symbols, etc. using ink, stamps, pencils, ballpoint pens, etc.

In order to attach the above-mentioned light-shielding film 32 to the window glass portion of the package, first, a portion 31a of the mount 31 is cut out along the cut line 34 provided on the mount 31. As a result, a part of the light-shielding film 32 protrudes from the mount 31, so that the peeling operation can be easily performed. Opposite cutout 31
Similarly, the portion b is cut out, and the portion of the light-shielding film that protrudes from the mount 31 is pinched, peeled off one by one, and pasted onto the package. Note that the black pigment may be any material other than carbon, as long as it blocks visible light, such as an oxide.

(7) Effects of the invention As explained in detail above, according to the invention, ultraviolet light and visible light can be blocked, notes etc. can be written on the surface, and peeling from the mount is easy. Since we can provide a light-shielding film that can be used to protect the memory contents of EPROM ICs, it is not only possible to prevent destruction of the memory contents of EPROM ICs, but also to ensure the classification and placement of ICs according to their memory contents through notes written on the surface of the light-shielding film. This is highly effective in improving the manageability of semiconductor devices.

[Brief explanation of the drawing]

Figure 1 is a perspective view of an EPROM IC package, Figure 2 is a diagram showing the structure of a conventional light-shielding film, where a is a plan view, b is a sectional view, and Figure 3 is a light-shielding diagram for explaining an embodiment of the present invention. In the drawings, a is a plan view and b is a cross-sectional view of the film. 1... EPROM IC package, 2... Glass window, 3, 22, 32... Light shielding film, 21, 3
1... Mounting paper, 23... Adhesive layer, 33... Adhesive layer containing black pigment, 34... Cut line.

Claims (1)

[Scope of utility model registration request] In an ultraviolet-erasable EPROM in which a light-shielding film that blocks ultraviolet rays, consisting of an upper layer of the film and a lower adhesive layer, is attached to the ultraviolet irradiation window, the lower layer of the light-shielding film is an adhesive layer mixed with a black pigment, and the upper layer surface is an ultraviolet erasable EPROM characterized by a surface treated with an uneven pattern.