Electronics Forum: stencil (Page 411 of 540)

Can we hide extra long pad with solder mask ?

Electronics Forum | Fri Nov 09 11:22:43 EST 2001 | denis

We are a contract manufacturer and we do business with a big company. There is a mistake in the design of the PCBs they are supplying: the pads are too long (under the component) and sometimes we get short circuit we cannot see. Changing the design w

Non-wettig on chip cap.

Electronics Forum | Fri Dec 07 08:32:56 EST 2001 | scottdavies

I have used Multicore MP-100 and Heraeus F380 pastes for a while, and experienced very few dry joint problems. May be worth checking if the pad size and/or spacing are to the correct specification for the components. Check the date codes on the comp

Lumpy joints

Electronics Forum | Mon Dec 17 11:20:12 EST 2001 | slthomas

Well, I was able to convince them we had a serious problem on the poorly reflowed boards without spending 2k on off- site analysis. Now all we have to do is sort out the ones that flowed well but had solder balls (looks like a damaged stencil prob

Shear Test Results

Electronics Forum | Mon Dec 17 07:34:07 EST 2001 | Adam

Dear Colleagues Does anyone know or care to share any information as to typical torque values ( N/cm ) for components that have been placed using screen printing surface mount adhesive, using a plastic stencil ? Are there any industry set shear test

SMD solder joint calculation

Electronics Forum | Wed Jan 16 20:06:09 EST 2002 | davef

No, not as such. Consider: * Using the IPC calculator [free at http://www.ipc.org]. It allows you to consider / assess the amount of solder when designing pads. * Reviewing IPC-7525 - Stencil Design Guidelines. It gives general aperture guidelines.

Wave Soldering Thick PCB's

Electronics Forum | Mon Jan 28 00:48:21 EST 2002 | peterson

Being in the backplane biz, we too, encounter similar problems...especially when our customer reads the IPC as Biblical (you will achieve 75% fill or be turned into a pillar of salt). Anyway, recently, one of our process engineers suggested paste-hol

Solder Paste Inspection System.

Electronics Forum | Tue Mar 12 11:20:08 EST 2002 | BTaylor

I agree with davef on most subjects including this one , we have used a microscope and an experienced inspector for years and done just fine. Recently due to customer demands we an acquired an ASC 3-D inspection station, and it works great it told us

Cpk Variables Control for Paste Printing

Electronics Forum | Tue Mar 19 00:14:47 EST 2002 | ianchan

Hi Guys, Can anyone help us out here, please? We need to know what formulae (other than Length(L)xBreath(B)xheight(Z)), is used to determine what volume of paste is required for 20mils pitch leadless chip carrier (LCC28), for the paste printing pro

BCC Technology --- Placement, Rework, Reflow

Electronics Forum | Sun Mar 24 23:11:36 EST 2002 | sy_koh

I am looking technology for BCC package. The preliminary datasheet from customer show that it had rectangular flat pad on the joint. The smallest pitch is 0.6mm having 96 I/Os. I am currently putting BGA, uBGA, CSP and CBGA onto PCBs usinf no-clean

Solder paste for RF boards

Electronics Forum | Mon Apr 15 21:27:16 EDT 2002 | djarvis

Everything we do is RF and have had no problems in the last 7 years with - Indium NC-SMQ92J, Sn63 Pb 37, 90.25% Metal, -325+500 mesh. Stencils are always 0.005" thick. However I will qualify that by adding we are an OEM and each new product may requi

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