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ICT bare board

Views: 3867

tanemmirt

#48320

ICT bare board | 12 March, 2007

i designed a new product; i want to produce it in china, so they requested the ICT to be done; i have 03 questions if some one can help me on: 1� is it mondatory to test all components and paths in the PCBA; and check all soldering joints? 2� testing the pathes will be done in final assembly or on the naked board? 3�do we have to create a VIAs for each testing points , or the ICT tester can do it over the component pin?

thanks a lot for your help

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#48324

ICT bare board | 12 March, 2007

It sounds like you may be thinking of two different test methodologies.

What is required? Bare-bard testing, to verify pcb fabrication? Or populated board testing, to verify manufacturing?

If it's bare board testing, the fab house should advise availability/need of test points/vias for testing. Considering it's not populated, I'd suspect that the bed of nails fixture designed for the board should be able to use pads as test targets. Bare board electrical testing ensures opens/shorts on the bare pcb from the pcb fab house.

If you're looking for populated board testing, you're into a whole different realm of test targets, and net availability.

A good rule of thumb in in-circuit testing is to test 100% of all available nets on the board, or to at least design the fixture to do this.

cheers ..rob

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#48325

ICT bare board | 12 March, 2007

Q1.� is it mondatory to test all components and paths in the PCBA; and check all soldering joints? A1. Nothing is mandatory. You do ICT to prove some component functionality and check manufacturing process. ICT test coverage is driven by factors including availability of test pads, access to test pads, and type of component being tested. Test coverage is counter balanced by the cost of test that is primarily driven by complexity of the test fixture and the test program, and maybe machine test time [duration]. Using test pads is better practice.

Q2.� testing the pathes will be done in final assembly or on the naked board? A2. Testing of traces and interlayer connections is done most often on the bare board by probing pads. Commonly, In-Circuit Test [ICT] is a manufacturing defects analysis performed after completing all soldering and component attach.

Q3.� do we have to create a VIAs for each testing points , or the ICT tester can do it over the component pin? A3. It�s not a good idea to probe component pads, because the force of the probe making contact could damage the solder connection.

Consider using design for test assessment software to help you determine test pad location.

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tanemmirt

#48354

ICT bare board | 13 March, 2007

thanks a lot robqd3 and davef for your assistance,just a littel question concerning testing soldering joints, is it enough to ask the producer to test all my soldring joints without modifying any thing in the ciruit (( adding vias etc...)) if i have to add some thing, is it for all components ? the ICT machine is the concord T323. if some one has encontred an example of ICT request ,can i get a look oer it? your help is appriciated

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tanemmirt

#48357

ICT bare board | 13 March, 2007

thanks a lot robqd3 and davef for your assistance,just a littel question concerning testing soldering joints, is it enough to ask the producer to test all my soldring joints without modifying any thing in the ciruit (( adding vias etc...)) if i have to add some thing, is it for all components ? the ICT machine is the concord T323. if some one has encontred an example of ICT request ,can i get a look oer it? your help is appriciated

reply »

#48383

ICT bare board | 13 March, 2007

Try this: http://www.accutroninc.com/download/ict.pdf

We have no relationship, nor receive benefit from the company referenced above.

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tanemmirt

#48466

ICT bare board | 17 March, 2007

thanks davef, your help was really segnificant.

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