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| From [log in to unmask] Fri Nov 1 16: |
54:42 1996 |
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Wed, 30 Oct 1996 16:48:36 -0600 |
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Address,
I asked this question once before but probably didn't send correctly.
Is there anyone out there currently assembling chip resistors
underneath a J-leaded PLCC-44? IPC-SM-782 does not spec the contact
lead to package distance. I may be placing any of following 0603,
0805 and 0402 under the PLCC-44.
Concerns I have:
Without running a Thermal Profile with thermocouples will there be
enough heat to reflow the underlying chip or will the PLCC-44 device
rob it of heat?
I'm I correct to assume the chip may crack should the pressure from
the head be too strong and obviously if there is enough room under the
device. The assembler does not have a variable pressure control for
pick and place heads.
And again is it feasible. I have other options but none that are as
efficient as the one described.
Please advise,
John Gulley - QA
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