V - Index of

-------------------------Rellablllty of Hitachi Ie Memories
• Table 6.
Reliability Data on 64K and 128K EPROM
HM6264P (Plastic)
HM616P (Plastic)
Test item Test
Sam-
Total
condition
Fail-
Failure
pies
component
Sam-
Total
Fail·
Failure Remarks
hours
ures mg;) pies component hours
ures m~;)
High· 150 CI7V 100 0.10x1OS 1",1 2.02xI0-S - - -
temperature I 25"CJIIV 162 0.20xlCj4 2",2
·t~?~;1
1.55x 10-' - - - xl
PSG
pulse 125"C/7V 1014 1.l6x 10" 2,,3
fa.lure K I
2.67xI0'" - - - -
operation
.2\l',~r x I
125 C/5.5V - - - - 9940 2.28x 10" 2*~ 1.36x 10~ failure x 2
Hightemperature
RH
85 W5% 304 0.30xl04 0 3.07x 10-4 1430 2.35x 104 4*s 2.23x 10-4 ·s
Ah.2
P:J.'~Iva.·
Pressure 121"C~ ~.20xI04
cooker 100% H
55 0 4.18xlO-s 250 4.40x104 0 2.09xI0-s tlon x 2
'" Confidence level 60%.
2.2.2 Reliability Test Data on ERROM
EPROM has two types; the conventional EPROM
with transparent window and the one time programmable
ROM (OTPROM). The latter is packaged in
plastic package. The reliability test data on the
representative EPROM types of 64K EPROM
(HN482764, HN482764P), 128K EPROM
(HN4727128) are shown in Table 7.
• Table 7 Reliability Data on 64K and 128K EPROM
HN482764 (Cerdip, Plastic)
HN4827128 (Cerdic)
Test item Test
Sam- Total
condition component
Fail-
Failure
Sam-
Total Fail- Failure Remarks
pies
hours
ures
rate* component rate'"
(l/hr)
pies
hours
ures
(fihr)
~~f::'·temp. I 25 u C/5.5V 131 0.43x104 0 2.14x 10'" 100 0.10xl0'" 0 9.20xI0-6
operation 125"Cj7V 760 0.6lxlOS 0 1.5lxlO-4 - - - ·1
- Data
High- 200°C 117 1.l7xlOs 1*1 1. 73x I O-s 80 0.40xlOs 0 2.30x 10-5 dissipatemperature
250°C 106 1.06x I OS 5*1 5.94x 10-4 65 0.33x lOs 1*1 6.l2x IO-S tion x 38
Storage 300 u C 67 0.67x10 5 25u 3.73x 10'" 50 0.25x1Os 6*1 2.93x 10-4
Hightemperature
rJ;W 5% 200 0.20x10 4 0 4.60x 10-4 - - - - Data of
Pressure 121 C
cooker 100% k
64KOTP
H 78 0.16x102 0 5.75xI0-s - - - -
... Conftdence level 60%.
The failure in table 7 is due to the data dissipation
in memory cells. Getting thermal energy, electrons
in memory cells are activated and go through the
floating gate. In actual usage, however, it has no
problem because this phenomenon depends on tem·
perature (about 1.0eV of activated energy) greatly.
The moisture resistance of OTPROM is also satisfactory.
The example of PROM derating are shown in Table
8. When users apply the derating, the parameter is
generally only the temperature because IC memories
are specified the operating condition. Especially to
lower the junction temperature during mounting is
important to stabilize operation on access time,
refresh time and other characteristics.
~HITACHI
Hitachi America Ltd. • 2210 O'Toole Avenue • San Jose, CA 95131 • (408) 435-8300 11