Looking for Filled via -- Embedded within pad - criteria

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All: IPC does not directly state any criteria for ph... - Sep 02, 2004 by cburress

Dunno about something formal. After you specify your hole s... - Sep 02, 2004 by davef

davef, Thanks for the reply. I've talked with IPC a... - Sep 16, 2004 by cburress

cburress

#30368

Looking for Filled via -- Embedded within pad - criteria | 2 September, 2004

All:

IPC does not directly state any criteria for physical characteristics of what a filled via should look like when embedded within a surface mount component's pad. I am using several of these in my design, and have received PCBs that exhibit protrusions (mounds) of plated material within my pad. This is due to the plated barrell heighth not being controlled during manufacture; therefore, leading to a high point within my pad of nearly .0035". I am looking for some quality data or IPC requirements for this scenario. Any/all help is greatly appreciated.

Thanks, CB.

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davef

#30377

Looking for Filled via -- Embedded within pad - criteria | 2 September, 2004

Dunno about something formal. After you specify your hole size and fill material, why not say something like: " Surface to be planar prior to final plating and metallization. Boards must be suitable for via in pad technology."

We do not allow plating bumps [mounds] greater than 2 thou.

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cburress

#30557

Looking for Filled via -- Embedded within pad - criteria | 16 September, 2004

davef,

Thanks for the reply. I've talked with IPC and they are currently reviewing this and attempting to compose some criteria. They "informally" recommend no greater than .002" also.

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