Electronics Forum | Tue Jan 25 07:49:17 EST 2005 | davef
On "Solder beading seemed to be a problem", consider revisiting the thermal recipe used for reflow. The PTH barrel may not be getting warm enough. On "Component not being designed to pin in paste work, with no proper standoffs", consider: * Using a
Electronics Forum | Thu Feb 17 14:39:39 EST 2005 | JB
We have PCB's that have been poorly designed and do not have enough support. A quick fix, so they don't bow in the oven, is to set them on a stronger frame, before reflow, from a panel that has been singulated. Single or double sided? Hope I inte
Electronics Forum | Mon Feb 28 09:21:08 EST 2005 | Dave G
UIC has a nozzle specifically designed for 0603's. (UIC P/N 46937042) That's what I've been using with better results than the 08mpf. Even the 08 will overhang the part some. We place 0603's on pretty tight centers so I need a nozzle that wouldn't ov
Electronics Forum | Fri Feb 25 10:46:50 EST 2005 | John S
We are developing a new product, and some of the designers are proposing QFN packages. These look like leadless QFP's. We don't currently use anything like this, but we operate in a high reliability automotive market. Can anyone provide advice/com
Electronics Forum | Mon Feb 28 06:06:04 EST 2005 | Guest
I'm looking for recommendations on pad and stencil design for products with 0.5 mm pitch BGA's. The latest info that I found in the archives of this forum dated more than a year ago. It didn't give me much confidence that assembly of such components
Electronics Forum | Fri Mar 04 10:04:14 EST 2005 | jbrower
We use Alpha UP-78 (Older paste formula) and it works well for what we do. We standardized our stencils at 5mil with a 10% reduction on IC apetures and a home plate design on passive components. Additionally we use laser cut electro-polished stenci
Electronics Forum | Mon Mar 07 11:20:10 EST 2005 | mrduckmann2000
Russ, I tried to get a screen for glue but the design engineer who laid this board out made up his own rules. The 0402 pads are to close for a proper dot size.....per the stencil house. That is why I am going the solder mask route. I would rather
Electronics Forum | Mon Mar 07 08:22:09 EST 2005 | davef
Via in pad can have any size hole, but you're correct. The larger the hole, the more solder that is scavenged from the solder connection. We believe that a proper via in pad design will either: * Move the via to the edge of the pad and cover the vi
Electronics Forum | Tue Mar 22 12:04:31 EST 2005 | John S
Thanks for the advice. In this scenario we are designing our own product. Currently we are building at a prototype level with no appreciable wait between reflow passes. The part in question is a 64 pin QFP. We use a BTU VIP 98 with edge conveyor.
Electronics Forum | Mon Apr 18 09:52:36 EDT 2005 | pjc
FormFlex and the GridLok system will not work on a semi-automatic printer. They were designed for fully automatic machines. The print table is very shallow on the DEK 248, SMTechs and MPM SPM, UP100 and MicroFlex. DEK should have magnetic base suppor
