Electronics Forum | Tue Mar 24 13:21:16 EST 1998 | Earl Moon
| Should I use thermals or direct connects on | vias from BGA pads to power planes. The via is | connected to the BGA pad via a short 8mil trace. Thermals are safest. However, I have had no problems using direct connects provided parameters are capab
Electronics Forum | Mon Sep 22 02:15:09 EDT 2003 | chrissieneale
We were having void problems with heat transfer down the via's (24 layer boards, shed loads of planes). So we drew the via away from the centre into a teardrop pad. Void's gone!
Electronics Forum | Thu Jul 20 23:41:55 EDT 2017 | heros_electronics
Below is an email that I copy and pasted from my customer's engineer about his concerns with the issue of the chips not reflowing (which is why I was asking about X-ray the chips to make sure they reflowed): Can you let me know your thoughts on his
Electronics Forum | Thu Aug 12 17:15:56 EDT 1999 | Jim Blankenhorn
| I am currently involved with designing a pcb which will use 225 pin bga,s | The problem with this design is that the components will dissipate a lot of heat and the design we have come up with is | use the middle 6 or 7 rows of balls as the ground
Electronics Forum | Fri Aug 13 04:12:41 EDT 1999 | ray hare
| | I am currently involved with designing a pcb which will use 225 pin bga,s | | The problem with this design is that the components will dissipate a lot of heat and the design we have come up with is | | use the middle 6 or 7 rows of balls as the
Electronics Forum | Thu Jun 04 12:22:12 EDT 1998 | John Allan
| | | Hello: | | | BACKGROUD: SMT components soldered on the top-side of boards that also require wave soldering have the potential to reflow during wave soldering. Reflowing these components during wave soldering is not good. It can cause cold jo
Electronics Forum | Thu Jun 04 08:32:21 EDT 1998 | Dave F
| | Hello: | | BACKGROUD: SMT components soldered on the top-side of boards that also require wave soldering have the potential to reflow during wave soldering. Reflowing these components during wave soldering is not good. It can cause cold joints
Electronics Forum | Mon Jul 26 18:01:30 EDT 1999 | Earl Moon
| Presently protos of micro-bgas (80i/o) pitch .030/.031 | 12BGA per assembly | | The board is a (.062, 4 layers) FR-4 using Dry film | Pads .014inch | Vias within footprint .020inch | Vias to be filled by bottom side(solder side) only .030in dia. F
Electronics Forum | Thu Jun 10 16:42:11 EDT 2010 | daxman
Hi Muarty, We've had a lot of experience with QFN's now. Several years ago we started testing various design methods of the via arrays as well as paste apertures to cover the arrays. There has been some time that has passed now since these packages
Electronics Forum | Thu Jun 25 08:30:38 EDT 1998 | Earl Moon
| I have a single-sided board with test vias that pass through the board. The test vias are pasted and reflowed with the SMT components on the top side. When the boards are wavesoldered, the solder coverage on the vias is spotty. Some will sold
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