Electronics Forum | Thu Sep 06 11:56:24 EDT 2007 | gmoritz
> x/y position of that lead does > > not change as the head rotates." > Heh-heh. You'd think so, wouldn't you? > Have you observed this with a magnifying glass? Heh-heh yourself. I (think) I know better than to think that it would withstand tha
Electronics Forum | Tue Sep 11 12:45:01 EDT 2007 | rgduval
Both questions will depend upon the IC specifications. Check the manufacturers recommendations for temperature specification, as well as reflow profiling. As a general rule, we don't like to rework a component more than 2 times after initial reflow
Electronics Forum | Tue Sep 18 12:10:39 EDT 2007 | wailiang81
Hi, good day to all. This is my 1st question post in this forum. Hope able to share some knowledge here. As we know QFP area like 0.4mm pitch was a very critical area to control especially those PCB using silkscreen printing process manufactured. Onc
Electronics Forum | Thu Sep 20 15:02:36 EDT 2007 | pjc
You do not always need test points designed on the board. Any ICT supplier will consult with you on that and after looking at your designs. Teradyne offers new and refurb'd systems for ICT, analog only or w/ Vectorless testing to ensure ICs have a co
Electronics Forum | Fri Sep 28 16:49:48 EDT 2007 | davef
good * No IMC => bad Intermetallic growths are diffusion limited, and therefore the thickness of the intermetallic is given by: z^2 = (Do)(t)exp[-Q/RT] Where Do (m^2 s-1) is the diffusion coefficient, T(�K) is the temperature, Q (J mol-1) is the act
Electronics Forum | Thu Oct 25 07:54:57 EDT 2007 | hussman
It's all by feel and looks. Too many variables to tell you exact number of times. Most profile boards are set up to perform initial profile and then repeatability at a set period after that. So changing boards will alter the t-couple and skew your
Electronics Forum | Tue Oct 30 06:20:58 EDT 2007 | aj
Hi All, I would appreciate some advise with regard to Leadfree settings for a 5 zone reflow oven. I have a 35mm square BGA 672 pin on board. I am struggling to get the Delta T down to 2 degrees C . I have 5 Thermocuples drilled up from the bottom a
Electronics Forum | Mon Nov 12 09:22:41 EST 2007 | devajj
BTW, The surrounded QFN fine pitch terminals > should have the normal aperture reduction of 7 % > in case of RoHS Senju solder paste. This works > for our Telecom customer. > > The vias in the > ground pad will be somewhat filled with solder >
Electronics Forum | Sat Nov 17 10:24:17 EST 2007 | etienne
Hi, I can give my opinion in this topic since I worked with both machines. To say the truth, I would recommend neither machine. First of all, operating software is much quite the same for both machines. The TP9 is true that has a larger footprint ov
Electronics Forum | Wed Nov 21 09:19:09 EST 2007 | Paul M.
Need some opinions from you fine folks. We are building assemblies 90% SMT, 10% TH. Fine pitch and BGA devices, etc. The customer is complaining about cold solder joints (SMT) after about 1 year of use, scattered thru-out the assembly, not consistan
