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Thu, 4 Apr 2002 07:10:56 EST |
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Hi Wee Mei,
To your questions:
>Q1 : Single-sided board reliability.
>- in the usual fabrication process, single sided board only have pads on
>one side and the holes are not plated-through. What is the chances that
>the component will fly off or pads lifted during vibration test?
A: It will depend on the severity of the vib test and the weight of the
component. Single-sided boards should be regarded as Class 1.
>- if everything remain but the hole wall is plated, will the solder
>joint now be more robust to withstand vibration or the component will
>stay put or pads will not be lifted?
A: This will certainly be more robust.
>Q2 : warpage
>- I noticed that warpage indicated in the IPC standard usually are
>confined to boards that are 4 sided. For my board, flatness is a must
>but the board is of odd shape or irregular shape. How do I perform the
>warp test and acceptance?
A: Put the boards on a flat surface; if they are warped they will rock. The
amount of rocking is a measure of the warp severity--you have to figure out
what is good enough.
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 386-437-8747, Fax: 386-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com
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