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

Printed Circuit Board Assembly & PCB Design Forum

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uBGA

Bob barr

#13773

uBGA | 16 October, 1998

I need the following information on uBGA's - body size, ball pitch and ball diameter. Are they a plastic package (with the resulting moisture sensitivity of a PBGA)? Also, does the uBGA put any special requirements on pick and place equipment?

Thanks,

Bob

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Scott McKee

#13774

Re: uBGA | 16 October, 1998

| I need the following information on uBGA's - body size, ball pitch and ball diameter. Are they a plastic package (with the resulting moisture sensitivity of a PBGA)? Also, does the uBGA put any special requirements on pick and place equipment? | | Thanks, | | Bob | The device I've placed is 6mm X 9mm X 0.8mm Pitch is .8mm with a .35mm ball size. I currently place it without using vision with good success - these little critters will self align, I've not needed to tweek after placement with good X-ray results. I have not had any sent to me with moisture warning labels to date... As you know, I have the Mydata TP9-2U. The reason I'm not using vision as it currently needs a symetrical package (6x6, 20x20, etc.) for vision to work -- 2.0 software will fix this and is currently being shipped with all new machines; I hope to get my upgrade in a couple of months.

Hope this helps, Scott

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Craig Ramsey

#13775

Re: uBGA | 20 October, 1998

Dear Bob,

The Tessera microBGA technology defines a family of CSP devices. The most common microBGA type is the TV46 that has been selected by Intel for use with their flash memory devices. A microBGA package in general consists of the silicon die, a silicone elastomeric layer and a polyimide flexible circuit interposer. The polyimide flex circuit redistributes the terminations of the die to an array of eutectic solder balls. Flex circuit beam leads are single-point bonded to the bond pads of the die. The silicone rubber protects the surface of the die and accommodates the differential thermal expansion of the silicon die and the polyimide flex circuit. All of these materials enjoy excellent moisture resistance and this is said to be one of the main reasons why Intel selected the microBGA technology for the flash memories. The TV46 package, in particular, is 6 by 8 mm overall with a 6 by 8 array of 0.40 mm diameter balls on 0.75 mm centers. Two balls are missing near the center of the array.

A large number of semiconductor packaging companies have purchased licenses from Tessera that allow them to manufacture microBGA packages. Some suppliers do not hold very tight tolerances between the edges of the package and the array of balls. This means that optimal placement location results can be achieved by aligning on the balls.

Quad offers two non-contact vision alignment methods for microBGA packages. Our proprietary horizontal imaging system, QuadAlign(TM), aligns on the microBGA balls. Our Vu12(TM) upward vision camera introduced at last year's NEPCON-West show can additionally inspect for ball presence/absence, pitch and shape.

Best Regards, Craig Ramsey VP Marketing Quad Systems Corporation

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