JPH0226784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a PROM or
It is about EPROM.

EPROM uses a large number of microscopic semiconductor storage elements as a memory by applying electric charge to them, and erases this electric charge using ultraviolet rays. The charge was lost due to the ultraviolet light, and the writing was lost, which was a major bottleneck in handling.

The present invention provides a removable ultraviolet shield at the program window opening of a photo-erasable semiconductor memory.

Embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, a case 2 housing a semiconductor memory 1 includes a conductive connector pin 3 for supplying electric charge to the memory 1, and a case 2 that houses a semiconductor memory 1. The EPROM of the present invention is provided with a light passing window 4 for erasing writing by irradiating it with ultraviolet light 8, and a removable ultraviolet shield 5 is provided to cover the window 4.
shows.

In the ultraviolet shield 5, a shield 6 having a property of specifically blocking ultraviolet rays 8 is adhered to the periphery of the window 4, that is, the program window opening, using a pressure-sensitive removable adhesive 7.

The ultraviolet shield 6 is, for example, a transparent or opaque flexible film made of methyl methacrylate as a main component and copolymerized with an acrylic monomer, and the adhesive 7 is made of polyisobutylene, polybutene, polyvinyl ether, or acrylic acid ester copolymer. It is a removable pressure-sensitive adhesive that does not harden, and can be used to adhere or peel off the film 6 around the window 4 as necessary.In the case of erasing, the film 6 can be peeled off and removed from the window 4. Erasing is performed by irradiating the semiconductor recording element 1 with ultraviolet light.

FIG. 3 shows the shield film 6
This shows the results of an experiment on the UV shielding properties of shielding film 6 after 5000 hours of sunlight irradiation.
The light transmittance at each wavelength is shown. By covering the window 4 with the shield film 6 and sealing it with the adhesive 7, ultraviolet rays from the window 4 can be completely blocked.

Figure 4 shows the changes in tensile strength when various materials are irradiated with a high-pressure mercury lamp. Although the tensile strength of other materials decreased dramatically after 1000 hours of irradiation, the ultraviolet blocking shield film 6 Since the film 6 does not change or deteriorate at all, it is extremely durable without being damaged even if the film 6 is repeatedly peeled off and bonded during erasing.

As mentioned above, the shielding film 6 of the present invention is extremely excellent in its blocking properties and durability, especially against ultraviolet rays, so if it is removably adhered to the window 4 of the EPROM or PROM, the semiconductor element 1 Not only is it completely unaffected by external light, it is also pressure-sensitive so that it will not be damaged by repeated adhesion and peeling during erasing, and the adhesive can be removed and reused, protecting semiconductor elements from ultraviolet rays. Not only that, but if necessary, you can temporarily remove the shield, erase or reprogram the program, and then shield it again to protect it.

According to the present invention, the transmission and leakage of ultraviolet rays in external light to the semiconductor memory element of the EPROM are blocked, thereby preventing accidents such as long-term storage or erasure of written programs due to indoor fluorescent lights. The functions of elements or equipment can be maintained safely and reliably.

In addition, the UV-blocking film is flexible and removably adhered, and does not deteriorate or lose its strength, so it has many advantages such as being easy to adhere and peel when repeatedly writing programs and erasing, and being durable. can be obtained.

In addition to providing a removable ultraviolet blocking shield in the opening of the PROM element as described above, the present invention also includes a device in which a removable ultraviolet blocking shield is provided over the entire device using the PROM element. It is something.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention. FIG. 2 is a side view showing a partial cross section of FIG. 1, showing an embodiment of the present invention. FIG. 3 is also an example of the present invention, and shows a curve showing the ultraviolet shielding characteristics. FIG. 4 is a curve showing the strength characteristics of an ultraviolet blocking shield according to an embodiment of the present invention. 4...Program window opening, 6...UV blocking shield.

Claims (1)

[Claims] 1 A light-erasable type that features a flexible sheet that blocks ultraviolet rays and is made of methyl methacrylate as a main component and copolymerized with acrylic monomers, and the program window opening is sealed in a removable and removable manner by covering it with a removable pressure-sensitive adhesive. semiconductor memory.