Electronics Forum: bga's (Page 525 of 546)

how to prenvent flux risidue in the blind vias.

Electronics Forum | Mon Feb 19 22:56:20 EST 2007 | davef

Russ We agree with your comments on plugging from one side only. But... We believe that it IS possible to trap process chemicals [technically, not flux] in a blind [or any other] via. This can be done by plating the via closed, rather than pluggi

LGA36 6.5 x 3.5 mm

Electronics Forum | Sat Mar 24 05:25:07 EDT 2007 | mika

Thanks aj, Ohh I wish that there was a way to post a picture in this forum or a possibility to attach the datasheet... Which BTW does not have any recommendation of "how to". This package does not have the "center thermal pad" like a QFN or MLF pack

Pick & place

Electronics Forum | Mon Mar 26 13:49:16 EDT 2007 | grantp

Hi, I don't know anyone who uses Mancorp, and apart from this forum have never heard of them. I guess the big problem I faced when getting into SMT is trying to find a machine that could do what we wanted at a good cost. I originally purchased MYD

Pros/Cons of Gold immersion boards(solderability)

Electronics Forum | Thu May 10 19:19:41 EDT 2007 | rgduval

Wayne, I haven't seen anything indicating that Gold Immersion is necessary for lead free... However, it is my companies preferred finish for lead free assemblies. We've taken this stance for the following reasons: 1. Better solder quality on th

CSP rework station advice needed

Electronics Forum | Thu May 17 21:50:29 EDT 2007 | jeremyl

Hi All. We are a tiny startup company developing an IC in a flip-chip CSP package. We find ourselves in need of being able to remove and replace (ie rework) our chip on a characterization board. The board will not be big and the chip is very small

Reflow Profile Design

Electronics Forum | Fri Jun 15 11:05:17 EDT 2007 | grantp

Hi, This is a little embarrassing asking this question, as I think I am profiling our oven incorrectly. I have been using the profile based on the solder paste specification, however we have been getting a large BGA chip coming more unreliable, and

What is the best way to remove OSP coatings.

Electronics Forum | Tue Sep 11 22:52:18 EDT 2007 | davef

Here are some options for removing OSP coatings from pads of the BGA substrates. * Leave the substrates in storage for 13-14 months. Shelf life of OSP coating is ~12 months, depending on the product. * Wash the substrates in your aqueous washer. Ea

via under a smd pad ?

Electronics Forum | Fri Nov 23 16:32:05 EST 2007 | davef

There a several things you can do to prevent the solder wicking down the hole with the current design, and that's where you should focus. Cost goes up as you go down the list, but in neither case do you need to respin the board, have solder starvatio

Paste Expiration

Electronics Forum | Wed Feb 20 10:04:15 EST 2008 | slthomas

Yeah, it blows, but basically we toss it when it quits printing. We've never seen any visible quality issues we could attribute to recycling paste like this so we keep doing it. When we start doing BGA and X-raying stuff we'll take a closer look at w

Solder wetting to ENIG pads

Electronics Forum | Tue May 13 08:26:29 EDT 2008 | davef

First, on your reflow temperature comment: The 183*C focus for reflow recipes for tin-lead solder is a falicy. If you held a recipe for tin-lead solder at 183*C peak, it would never reflow. Recipes for tin-lead solder need to be at liquidus plus 20*C


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