BGA Requirements

Chat about pick and place machines, reflow ovens, assembly techniques and other SMT tips & trix

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
IHeartEngineering
 
Posts: 12
Joined: Sun Aug 28, 2011 4:36 pm

BGA Requirements

Post by IHeartEngineering »

What equipment/techniques are required to build production quality boards with BGA parts?
We have 20-40 boards to build with one 32-Lead Ceramic Ball Grid Array part per board.

adafruit
 
Posts: 12151
Joined: Thu Apr 06, 2006 4:21 pm

Re: BGA Requirements

Post by adafruit »

well what failures are you seeing? :)

IHeartEngineering
 
Posts: 12
Joined: Sun Aug 28, 2011 4:36 pm

Re: BGA Requirements

Post by IHeartEngineering »

Since each part is over $25, I'd like to have zero failures.
What kind of failures should we expect if we hand place the parts using a microscope with a tacky flux?
With the rest of our board we have been getting 95+% good parts with solder paste, reflow and a touch of hand rework now and again.

adafruit
 
Posts: 12151
Joined: Thu Apr 06, 2006 4:21 pm

Re: BGA Requirements

Post by adafruit »

it really depends completely on how good you are with hand placement. you're probably going to have to bite it and just try placing a few.

mikeselectricstuff
 
Posts: 164
Joined: Fri Jun 11, 2010 9:21 pm

Re: BGA Requirements

Post by mikeselectricstuff »

Practicality depends on the pitch, but you need to have a good quality paste print (stainless stencil, inspect every one with a microscope ), and accurate placement, straight-down with no sideways wobble splurging the paste across pads- you may need some mechanical aid for this.
Also probably worth putting alignment marks on the copper layer (not silkscreen as alignment can be poor)

blogger
 
Posts: 43
Joined: Tue Nov 24, 2009 5:59 am

Re: BGA Requirements

Post by blogger »

Sounds like Analog's gyros.
Good luck.

IHeartEngineering
 
Posts: 12
Joined: Sun Aug 28, 2011 4:36 pm

Re: BGA Requirements

Post by IHeartEngineering »

I can now report that it is possible to hand place BGA parts if you use a stencil to apply solder paste. I'm not convinced you can do it without a stencil.
We have managed to achieve a 100% success rate with a sample set of two boards. ;)
pbrd-01.jpg
pbrd-01.jpg (232.45 KiB) Viewed 3614 times
If anyone is interested I can post a photo of our stencil setup.

Does anyone have a good technique for low volume underfill for BGA parts?

Rochey
 
Posts: 23
Joined: Thu Nov 03, 2011 2:35 pm

Re: BGA Requirements

Post by Rochey »

Please post the stencil setup :)

thanks!

Rochey

IHeartEngineering
 
Posts: 12
Joined: Sun Aug 28, 2011 4:36 pm

Re: BGA Requirements

Post by IHeartEngineering »

The jig is a bunch of 'scrap' boards blue taped down to an anti-static mat with a bluetape hinge to hold the stencil in place.
The stencil alignment was checked with a microscope. This is probably the easiest solution that provides the minimum quality required.
ballin-01.jpg
ballin-01.jpg (230.67 KiB) Viewed 3590 times
ballin-02.jpg
ballin-02.jpg (253.75 KiB) Viewed 3590 times
ballin-03.jpg
ballin-03.jpg (260.64 KiB) Viewed 3590 times

IHeartEngineering
 
Posts: 12
Joined: Sun Aug 28, 2011 4:36 pm

Re: BGA Requirements

Post by IHeartEngineering »

ballin-04.jpg
ballin-04.jpg (188.38 KiB) Viewed 3590 times

IHeartEngineering
 
Posts: 12
Joined: Sun Aug 28, 2011 4:36 pm

Re: BGA Requirements

Post by IHeartEngineering »

Has anyone reballed a BGA component?
Tips or tricks?

Locked
Please be positive and constructive with your questions and comments.

Return to “SMT (Surface Mount Tech)”