Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


COB module design / layout

dvandit

#2634

COB module design / layout | 26 October, 2000

We are planning on replacing a SMT 100Pin QFP with a COB module that will have two dies that are functionaly equivalent to the old part that will not be available. Questions: 1)Suggestions on substrate material FR-4 or something better? 2)Are there design guidlines for wire bonding pattern on the substate? Thanks

reply »

#2635

Re: COB module design / layout | 26 October, 2000

In response to your questions: 1) Suggestions on substrate material FR-4 or something better?

Most PBGA are on BT. That might good for you, also.

2) Are there design guidelines for wire bonding pattern on the substrate?

Several things: 1 Doesn�t your CAD program puke-out wire bond pads? If not, it might be a worthy option to purchase. Bond finger pitch: 4/4 thou [0.1/0.1mm] 5/3 thou [0.125/0.75mm] Trace width/space: 4/4 thou [0.1/0.1mm] Via diameter: 12 thou [0.3mm] 2 The decision to wire bond er to ball bond is not trivial. John Lau covers the topic in recent FC books. 3 IPC has issues about 17 documents named Fred orzit "Implementation of Flip Chip and Chip Scale Technology". If you figure how to tell one from the next, please help.

Finally, I think the plural of die is dice. Yano, the same ideal as mice and meeces.

reply »

#2636

Re: COB module design / layout | 8 November, 2000

the current design must be a die-up one, so routing for a flip-chip on board will be a bit difficult. it almost HAS to be wire bonded, to me...

reply »

SP700avi inline stencil printer

ii-feed SMD Intelligent Feeder