Electronics Forum | Tue Nov 30 21:23:55 EST 1999 | cklau
hello; When we are doing component land pattern design , one thing will always be in our mind; that is the basic criteria or common land pattern design guideline for reflow and flow solder assemblies. For basic fomula in calculating resistors are:
Electronics Forum | Wed Dec 01 22:34:32 EST 1999 | Dave F
Mark: Ralph Woodgate is a "god" of solderability control programs. We have: � Been attending his seminars for, maybe 8 to 10 years ... who keeps track when you�ve been breathin� fumes that long? � Three different editions of his "Handbook Of Machi
Electronics Forum | Tue Nov 30 16:50:20 EST 1999 | Dave F
Greg: It depends on the specifics of the flux you are using. You didn�t say. Generally, using a: � "No-clean flux" should create no flux entrapment problems for most applications. � RMA with 25% or more solids as a "no-clean" should create no flu
Electronics Forum | Thu Nov 25 21:43:49 EST 1999 | cklau
Via is normally a plated thru holes in (0.63 to 1.0 mm (0.025" to 0.040") diameter lands , which unless properly treated they must be located away from the component lands to prevent the solder migration off the component land during reflow soldering
Electronics Forum | Thu Nov 18 10:56:16 EST 1999 | Dave F
Jacky: There�re major four factors that affect the reliability of a solder connection. 1 Design of the connection including the shape and height of the lead and the type and amount of solder. 2 Dissolution of base metals into the solder connection.
Electronics Forum | Fri Nov 26 06:18:18 EST 1999 | stefano bolleri
Jeff & Ted, we have used a dispensing system too and yes, I agree, we are not too happy with the results. Not at the point that it doesn't work, though. I think our problem basicly is that we have selected an entry-level dipensing system. We are app
Electronics Forum | Fri Nov 26 09:13:10 EST 1999 | Wolfgang Busko
Jeff, Ted, Stefano What Stefano is saying sounds reasonable. With entry-level systems its always a struggle to get sufficient results. The operators golden hand is needed. Better controlled advanced dispensing systems should do the work, unluckily I
Electronics Forum | Mon Nov 15 21:35:50 EST 1999 | Dave F
Bob Bob: Fortunately, you found this before you built-up a lot of product. Some thoughs and other drivel: 1 Use IPC-TM-650, Method 2.4.8 for copper peel with a Instron machine. Typical pad peel strength requirement for FR-4, 2 oz. copper is: 6 l
Electronics Forum | Tue Nov 16 09:44:18 EST 1999 | - bobar
Ken, The technology you are referring to is also known as return-to-web. This panelization method involves a hard tooled perimeter die and a press equipped with an air cushion. The PCB circuit is punched out and then inserted or "pushed" back into
Electronics Forum | Mon Nov 22 11:16:04 EST 1999 | Boca
Chris, Some ramblings- Your choice depends on factors like which defects you're looking for, bugdet, quality inspection philosophy, high or low mix environment, sample sizes or 100%, and so on. Are you going to test 100% of the product coming off t
