Electronics Forum | Fri Jan 14 17:09:21 EST 2005 | Bob R.
Whether or not conformal coating creates a reliability problem if it bridges the gap between the board and bottom of the part depends on the properties of the coating. A low modulus coating is fine, but one thats modulus increases at colder temperat
Electronics Forum | Mon Aug 14 13:51:37 EDT 2023 | calebcsmt
I'm actually currently in the process of discussing with stencil MFG regarding the apertures and reduction to see if perhaps it was not optimal for this fine pitch QFN, as just as you mentioned, we have similar products with similar QFNs that do not
Electronics Forum | Mon Jul 30 11:19:00 EDT 2001 | hinerman
A flexible array support system is superior in the following categories discussed in the 'tooling classes' thread. -High Flexibility -Effective on a variety of products -Low operator intervention -Conforms to PCB, so it is both accurate and repeatab
Electronics Forum | Tue Jun 08 17:52:53 EDT 1999 | Chrys Shea
| | | Hi,my master | | | How to iron out such soldering bridge with below conditions: | | | 1.The component(Harness)lead pitch is 2.0mm,the lead length is 3.2mm. | | | 2.PCB width is 1.6mm.Pad size is 1.65mm.Its a single copper PCB | | | 3.using s
Electronics Forum | Tue Nov 27 08:47:24 EST 2007 | ratsalad
The letter below was dated December 13, 2006 from Kester's Senior Market Development Engineer. I guess since then they have moved production back to Mexico. We no longer use EM907 as our primary Pb-free paste so I haven't seen any containers in a w
Electronics Forum | Tue Dec 03 18:51:57 EST 2019 | kylehunter
Hi all, We are having a confusing defect with one of our client's boards. It is a large board, 30" x 12". The client supplies the LEDs, they are cheap overseas diodes, and it is not uncommon to have reels with the packaging torn. We have w
Electronics Forum | Fri Aug 20 03:19:22 EDT 1999 | PeterB
| | | | | | One of the DFM suggestions I've seen is to remove the solder mask web, i.e. the mask between pads on 20-mil QFP devices. The rational is that if the mask is thicker than the pad the mask can prevent the stencil from making intimate conta
Electronics Forum | Thu Nov 29 15:08:56 EST 2007 | jaimebc
Shy, You mentioned that you are using "dog bone" apertures for your chip components? It doesn't make sense to me. I thought that the "dog bone" was used for fine pitch devices, to keep the solder away from the center and avoid bridging. It doesn't
Electronics Forum | Tue Jun 08 17:31:15 EDT 2010 | whitewing
For protos and very short runs I already use a polyester stencil + pizza oven process which is fine except for the placement time and tedium. I'm partly trying to bridge the gap between that and stuff that needs subbing out due to quantity, and partl
Electronics Forum | Tue Jun 08 15:04:06 EDT 1999 | JohnW
| | | Hi,my master | | | How to iron out such soldering bridge with below conditions: | | | 1.The component(Harness)lead pitch is 2.0mm,the lead length is 3.2mm. | | | 2.PCB width is 1.6mm.Pad size is 1.65mm.Its a single copper PCB | | | 3.using s
.gif)
