I am using the IPC Technology Roadmap 1995 and I have some doubts
about the tables in Part A, Section 4.

        I cannot understand the meaning of the Technical Driver Number
of Levels under Device Voltage. Does this apply to the supply voltages?

        My second doubt is about Reliability. MTBFs of some hundreds of
hours seems to me to be low. I was expecting much higher figures (say
tens of thousands...). I am not a specialist of reliability and so
I may be asquing some stupid thing, but, actually, I don't understand.

        Can somebody help me?

        Thank you.


_____________________________________________________
Guilherme Silva Arroz

Instituto Superior Técnico
Av. Rovisco Pais
1000 LISBOA
PORTUGAL

Tel.: +351-1-8417624            Faz: +351-1-8417499
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