Electronics Forum | Thu Oct 26 14:40:12 EDT 2000 | ptvianc
Hello: I have not seen a published formula for calculating the package weight that can be secured by molten solder. I have seen forumlas printed for tombstoning. From that aspect, we developed the following rule-of-thumb for first-order estimates:
Electronics Forum | Thu Jan 27 14:49:53 EST 2000 | Glenn Robertson
Tuan - One of the reasons I suggested pre-tinning (aside from the negative effects of Gold on appearance and reliability) is the known slower wetting of Sn/Ag and Sn/Cu alloys as compared to Sn/Pb. If you don't have to be Lead-free, the high Lead
Electronics Forum | Wed Dec 08 10:10:41 EST 1999 | John Thorup
Hi Dave I think you just provided the key to understanding the problem. By your description you are talking about a CBGA (ceramic). These typically have balls composed of 10/90 Sn/Pb which melts at a higher temperature than the 62/36/2 Sn/Pb/Ag (or
Electronics Forum | Tue Aug 17 14:08:50 EDT 1999 | Glenn Robertson
| We have a design on which there is an ASIC that will not be produced anymore in the future. As we want to make this design over the next 10 years we are evaluating the possibility to buy the necessary ASICs for the next 10 years. This will give us
Electronics Forum | Thu Apr 22 16:07:36 EDT 1999 | Rick
| | Do solders exist that are both lead-free and low-temperature (e.g. 100-170 Celsius range)? If so, who supplies these materials? Any websites or contact information would be most helpful. | | | | Also, I am not an expert on soldering, so any
Electronics Forum | Thu Apr 15 08:21:47 EDT 1999 | Terry Keen
| We process both tin/lead plated boards and gold plated boards in our surface mount group. I have used Sn62/Pb36/Ag2 solder paste on all gold plated boards to help prevent gold scavaging. To reduce the amount of different solder pastes we have to
Electronics Forum | Thu Apr 15 09:45:34 EDT 1999 | Terry Keen
| | We process both tin/lead plated boards and gold plated boards in our surface mount group. I have used Sn62/Pb36/Ag2 solder paste on all gold plated boards to help prevent gold scavaging. To reduce the amount of different solder pastes we have t
Electronics Forum | Mon Jan 13 17:50:54 EST 2003 | jonfox
I was looking for some good documentation that could nail down some pros/cons of voids, but haven't found any. The biggest issue is if you are going to temp cycle the chips/PCB after assembly. Depending on the cycle, the situation of the test, it c
Electronics Forum | Wed May 07 09:21:46 EDT 2003 | davef
Here's some papers: * �Voiding Of Lead-Free Soldering At Microvia�; Dr. Hyoryoon Jo, B. Nieman, and Dr. N.C. Lee Indium Corporation of America; SMTA International; 09/22/2002 * �Solder Joint Formation With Sn-Ag-Cu And Sn-Pb Solder Balls And Pastes�;
Electronics Forum | Sat Jun 21 00:37:20 EDT 2003 | nifhail
Most of the capacitors & resistors supplier have implemented Leadfree finished on their components and like it or not, most of the PCBA house already using them in their process. I just got a notice from my component supplier telling me that they wil