HD6475348R Datasheet, PDF (332/487 Pages) Hitachi Semiconductor – Single-Chip Microcomputer

17.7 Handling of Windowed Packages
1. Glass Erasing Window: Rubbing the glass erasing window of a windowed package with a
plastic material or touching it with an electrically charged object can create a static charge on
the window surface which may cause the chip to malfunction.
If the erasing window becomes charged, the charge can be neutralized by a short exposure to
ultraviolet light. This returns the chip to its normal condition, but it also reduces the charge
stored in the floating gates of the PROM, so it is recommended that the chip be reprogrammed
afterward.
Accumulation of static charge on the window surface can be prevented by the following
precautions:
(1) When handling the package, ground yourself. Don’t wear gloves. Avoid other possible
sources of static charge.
(2) Avoid friction between the glass window and plastic or other materials that tend to
accumulate static charge.
(3) Be careful when using cooling sprays, since they may have a slight ion content.
(4) Cover the window with an ultraviolet-shield label, preferably a label including a
conductive material. Besides protecting the PROM contents from ultraviolet light, the
label protects the chip by distributing static charge uniformly.
2. Handling after Programming: Fluorescent light and sunlight contain small amounts of
ultraviolet, so prolonged exposure to these types of light can cause programmed data to invert.
In addition, exposure to any type of intense light can induce photoelectric effects that may lead
to chip malfunction. It is recommended that after programming the chip, you cover the erasing
window with a light-proof label (such as an ultraviolet-shield label).
3. 84-Pin LCC Package Mounting: When mounted on a printed circuit board, the 84-pin LCC
package must be mounted in a socket. The recommended socket is listed in table 17-12.
Table 17-12 Socket for 84-Pin LCC Package
Manufacturer
Sumitomo 3-M
Product Code
284-1273-00-1102J
319