Electronics Forum | Thu Sep 17 15:21:50 EDT 2020 | lpbro
For height, I start +-2mil usually. For 3mil stencils, my lower limit starts at 1.5mil, upper is 5. If the area is chem ethed, I normally add .5 to the stencil height. My default volume is 60 - 160%. Then print specs are adjusted till I see fit, then
Electronics Forum | Fri Mar 02 00:21:38 EST 2007 | AMS
Hello, I havea 0.4mm pitch TQFP with heat transfer pad on the bottom side of component. I will appreciate any suggestions with regards to: 1) stencil thickness (Rest of components on board are 0603 passives and few 40 mil pitch IC's) 2) Stencil
Electronics Forum | Wed Mar 02 02:37:52 EST 2022 | davef
None of the IPC standards care how boards are soldered
Electronics Forum | Tue Mar 01 16:36:43 EST 2022 | joshsvoboda
We are fairly new to selective soldering. I would like to find out if there is an IPC PCB design standard to allow for selective soldering.
Electronics Forum | Wed Mar 02 12:39:02 EST 2022 | stephendo
Go with the machine manufacturer's recommendations. And remember there are no hard and fast keep out areas. You can go a little tighter than they suggest but it is risky.
Electronics Forum | Wed Mar 02 18:23:57 EST 2022 | proceng1
In my experience, take whatever the manufacturer tells you the minimum keep away area is and double that for standard use. I'm not saying it can't do what they say, but no matter how precise the software, the motor control, the lead screws and rails
Electronics Forum | Thu May 23 12:11:40 EDT 2002 | pjc
One thing I have done in your situation is ask the customer if they have any older design boards that are similar in thermal mass or if they have any from proto work, etc.... Otherwise find/make a board of similar thermal mass as best you can.
Electronics Forum | Thu Aug 25 10:32:03 EDT 2005 | davef
IPC-2221A, Generic Standard on Printed Board Design, the base document that covers all generic requirements for printed board design, regardless of materials. From there, the designer can choose the appropriate sectional standard for a specific techn
Electronics Forum | Mon Jun 28 10:17:44 EDT 2004 | davef
People like flat surfaces for placing and reflowing certain components, like fine pitch devices. Some board suppliers can supply HASL that is flat and well controlled from an amount of material stand-point. Unlike OSP, HASL has a wonderful shelf-li
Electronics Forum | Fri Oct 04 11:46:31 EDT 2002 | mzaboogie
Hi Dave, No we are placing these parts on hard boards. Thank God! Thanks Chris
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