Electronics Forum | Wed Feb 23 21:24:42 EST 2000 | Dave F
Chris: Whatever way you decide to define your pads, use the same type on the component and the board. Non-solder mask defined pad advantages: � No point-of-stress concentration at edge mask and solder ball � No CTE mismatch at edge mask and solder
Electronics Forum | Wed Oct 29 22:41:42 EST 2003 | msimkin
Our design team have got a problem. We need to either drill out 6 vias/pads for a BGA site, or remove the solder balls form the BGA before they are palced. ( std eutectic) Has anyone used a vendor to remove balls from BGA (0.75mm piutch, ball size ap
Electronics Forum | Tue Jun 26 21:36:48 EDT 2007 | davef
While your peak temperature measurement is probably correct, you probably ripped the pads from the board long before reaching that temperature. By using a steep temperature ramp, you are causing the corners of the BGA to curl away from the board and
Electronics Forum | Sun Dec 06 21:31:47 EST 2009 | rajeshwara
Attached is the BGA BALL soldered underneath reflow profile , plz check and advice.
Electronics Forum | Wed Jan 31 05:23:37 EST 2007 | pbarton
Barry, We do not see much in the way of solder splatter or solder balling. We have removed some parts but in the process of doing so we remove any useful evidence really. Quite a lot of the solderable portion of the part is on the underside. Like
Electronics Forum | Thu Jun 12 11:49:56 EDT 2014 | patel_daxa29
No, is will not create random solder balls. I have experience doing this(When we had a big via in middle of filter cap which was sucking all solder ,leaving insufficient solder for a joint).I calculated volume of via hole to determine the expansion o
Electronics Forum | Mon May 10 16:37:01 EDT 2004 | davef
First some definitions, the two main types for solder masking near BGA pads are: 1 Pad, Non-Solder Mask Defined. In circuit board design, pads with spacing that does not allow solder (usually bumps) on the pads to contact the adjacent solder mask. [
Electronics Forum | Thu Apr 15 12:58:59 EDT 1999 | Chrys Shea
| | Can someone explain the difference between solder "fines" and solder balls? Is there an official specification where "fines" are defined? What is the spec for "fines"? | | | | I consider "fines" individual unmelted metal spheres that are foun
Electronics Forum | Mon Feb 25 21:09:48 EST 2002 | davef
You are correct about a TCE [CTE] mismatch issues in ceramic packages. The coefficient of thermal expansion [ppm/�C] of major ceramic package elements are: * Silicon - 3 * Standard 92% alumina ceramic � 6.5 * FR4 board � 18-20 Several points are: *
Electronics Forum | Thu Mar 30 21:46:56 EST 2000 | Dave F
Reg: This is copy / paste from draft version of IPC 7095 ( issued May 1999 ) ... 7.3 Assembly accept/reject criteria 7.3.1 Voids in solder joint a. Sources of Voids There can be voids in solder balls, or at the solder joints to the BGA, or at the so
.gif)
