Electronics Forum: process (Page 1004 of 1146)

Re: Wave soldering smt components

Electronics Forum | Fri Dec 17 03:38:53 EST 1999 | cklau

Hello Guys; I "ll like to add some comment on Mr John message , see below.. "Be sure that the components to be used on the bottom can take the maximum heat of the wave and the delta T of entering the wave."-John The required preheat temp , that i

Re: un-tested assembled circuit reject rates

Electronics Forum | Wed Dec 08 02:07:25 EST 1999 | Scott Cook

Tim, What Brian writes is all true. However, let em put it into a sales / marketing perspective..... The REAL issue in your situation is: Who is responsible for the failures which WILL result in shipping untested product? Typically, your customer

Re: Noclean soldering to gold

Electronics Forum | Mon Dec 06 03:54:57 EST 1999 | Chris May

Hi Russ, I have a similar situation. I have been told that this can be caused by the nickel, over which the gold is plated, can result in suspect joints, embrittlement etc. Some joints can even be weak and broken without much force on some of my boa

Re: Noclean soldering to gold

Electronics Forum | Mon Dec 06 05:18:53 EST 1999 | Wolfgang Busko

Hi Russ, assuming that only your flux changed and the PCB-finish stayed the same it seems to me that the solderability of that finish is somehow poor. About Ni/Au it can be said that the solderconnection is made between Ni and Sn. The Au-finish is ju

Re: Help With Justification

Electronics Forum | Thu Dec 02 11:14:49 EST 1999 | Dave F

Michela: Here's an outline for you to fill in the blanks: Policy Purpose Applicability Definitions Applicable Documents 1 Justification Of Spending 1.1 Request Preparation 1.2 Request Content 1.2.1 Summary Section 1.2.2 Capital Appropriation Reques

Re: Land patterns for 0612 and 0508 capacitors

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:

Re: Via Sizes

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

Re: Test the solder point

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.

Re: PCB panelization method

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

Re: Dull Solder

Electronics Forum | Fri Nov 12 10:00:42 EST 1999 | Dave F

Edmund, following-on from Wolfy: Back in the old days, anyone who could spell "sodder" considered "bright and shiny connections" GOOD and "dull and grainy connections" BAD. Now, "dull and grainy" connections can be either GOOD or BAD, depending on


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