JPH03124049A - Package of erasable prom - Google Patents

Abstract

PURPOSE:To prevent a beam of light from being incident from a window for ultraviolet-ray irradiation and to retain written information for a long time by a method wherein a lead terminal is extracted from the side of the window and the side of the irradiation window is used as a package mounting face with reference to a mounting board. CONSTITUTION:A chip 2 is mounted on a ceramic package 4; the package is provided with a window 1 for irradiation on the surface of the chip 2. Lead terminals 3 which have been fused and bonded to the package 4 by using a sealing glass 6 are bent to the side of the window 1 and are extracted. Consequently, when the package 4 is mounted, a package face 4A having the window 1 is brought into close contact with or is close to a board; it is possible to prevent the window 1 from being irradiated with a beam of light thanks to the package 4. Thereby, it is possible to retain written information for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to semiconductor memories, particularly ultraviolet erasable type PRO.
Regarding the structure of M (EPROM) package.

[Prior Art 1 An example of the structure of an fE P ROM is shown in FIG. 3. The ceramic package 4 has an irradiation window l on the upper surface of the chip 2 housed therein, and irradiates the main surface of the chip 2 with ultraviolet rays.
I strained it to erase the memory contents. The lead terminals 3 connected to the bonding wires 5 are connected to the back side of the chip 2 as shown in the figure, that is! ■The bow is placed on the opposite side of the wealth window I.

[Three problems to be solved by the invention] EPROMs are usually mounted on a mounting board after writing information with a PI'; Due to the ultraviolet rays contained in fluorescent light, it is difficult to preserve captured information for a long time. Therefore, in order to preserve the information for a long time, it is necessary to put a light-blocking sticker on the bright light window to prevent the intrusion of ultraviolet rays. There were some drawbacks.

It is an object of the present invention to provide a package for EPROM that eliminates the above-mentioned drawbacks.

[Means for Solving the Problems 1] In the EPROM package according to the present invention, the lead terminal is drawn out to the ultraviolet QQ radiation window side, and the 111↓Ikawa window side is the package'A hundred side with respect to the mounting board.

[Function] When the package is installed, the package surface with the irradiation window is in close contact with or close to the base plate, so the irradiation window is protected from direct sunlight, fluorescence, etc. by the package.

[Embodiment J] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of the embodiment, and FIG. 2 is its AA' cross-sectional view. The ceramic package 4 mounts the chip 2 and has the irradiation window 1 on the upper surface of the depth 2, which is the same as in the conventional example. However, the lead terminals 3 fused to the ceramic package 4 with the sealing glass 6 are! It is bent toward the Jq radiation window I side and pulled out. Note that 5 is a bonding wire that connects the chip 2 and the lead terminals 3.

In this embodiment, the internal structure of the package is the same, but the direction in which the lead terminals are drawn out is opposite to that of the conventional example, and when mounting on a printed circuit board, the package surface 4A is tightly attached to the printed circuit board. or in close proximity. This prevents the irradiation of the light beam onto the t-numa Qt window l.

FIG. 1 shows a case where one EPROM chip is fixed, but if two EPROM chips are fixed, the structure can be made completely the same by using only two irradiation windows.

[Effects of the Invention] As explained above, when the EPROM sealed in the package of the present invention is mounted on the board, sunlight, fluorescence, etc. will not enter through the light Q1 window (and the written information will be prevented). can be stored for a long time.There is no need to apply light-shielding stickers like in the past.

[Brief explanation of drawings]

FIG. 1 is an external view of one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA' in FIG. 1, and FIG. 3 is a sectional view of a conventional example. 1... Irradiation window, 2--chip, 3... Lead terminal, 4... Ceramic case.

Claims (1)

[Claims] 1. A package for an ultraviolet erasable PROM (EPROM), characterized in that lead terminals are drawn out to the ultraviolet ray irradiation window side, and the irradiation window side is used as the package mounting surface for the mounting board.