Inquiry about QC Testing (In Line Sampling)

Hi, Guys. I really need your help. Can anyone here help me to identify in existing standards such as automotive and jedec and others if our existing QC Testing test process is a requirement?

Here is our Test process flow overview :

Step 1: Lot preparation and Work Place readiness.
Step 2 : Lot Track In. This step enters to the system the details of lot ID that is for test.
Step 3 : Class Testing. All IC will be electrically tested.
Step 4 : QC Testing (In Line Sampling). This is done every end of class testing. Where in number of samples will be tested again using QC program.
Step 5 : Count reconciliation. Counting of Bin 1 and rejects.

Hope that someone will reply asap.

Thanks.

Hi,

as you have not further specified which types of products you want to test, and how it is done and documented in detail, it is difficult for me to provide specific suggestions.

Well, as far as I know no standard defines a specific testing procedure, because there is no one-fit-all solution. The "good practice" rule applies instead, this means "state of the art".

Some ideas:

• Liaise with your R&D department and ask them, how they performed testing during development - maybe they even have some scientific literature about it
• Do some research on your own
• Maybe IEEE Xplore?
• Apply statistical test design (e.g. to define min sample size & frequency)
• Analyze your process to identify the steps which are critical for the resulting quality / waste and target your testing activities based on these facts
• Write a testing procedure and clear test spcifications
• Document and analyze your test results

Best regards

I am assuming that you are questioning whether or not the binning process must be QC tested? In other words your in-process test, bins ICs by some criteria (speed, voltage, etc.) and then QC takes a sample of the bin(s) to determine if the ICs were binned correctly?

If this is your question it is a pretty specific question. someone who is closer to this industry right now will have to answer it...

in the meantime, perhaps if we knew why you were questioning whether or not this is 'required' by some standard we could provide more general help...

Hi, Bev D. You captured the background correctly. I am questioning our current test process flow because I am seeing high gain in our productivity if this will be removed. Now I need your help if there will be a violation on standards if this will be removed, or if there is a standard that mandates to perform QC testing on all IC devices during electrical testing.

Hope that someone will extend help on this.

Winrich Germann said:

Hi,

as you have not further specified which types of products you want to test, and how it is done and documented in detail, it is difficult for me to provide specific suggestions.

Well, as far as I know no standard defines a specific testing procedure, because there is no one-fit-all solution. The "good practice" rule applies instead, this means "state of the art".


Some ideas:

• Liaise with your R&D department and ask them, how they performed testing during development - maybe they even have some scientific literature about it
• Do some research on your own
• Maybe IEEE Xplore?
• Apply statistical test design (e.g. to define min sample size & frequency)
• Analyze your process to identify the steps which are critical for the resulting quality / waste and target your testing activities based on these facts
• Write a testing procedure and clear test spcifications
• Document and analyze your test results

Best regards

Click to expand...

Hi, thanks for your inputs. Yes after I determine the standard requirement, then I will work with the R&D experts.

I have been removed from IC testing long enough to no longer remember the standards so someone else will have to answer that specific question.

Some practical advice regarding the removal of the QC testing: QC testing - in this application - is typically a simple repeat of the original binning testing. If your original test program has good repeatability AND the mechanism for allocating the bin is effective then the QC testing will be redundant. the QC testing should pass every time. if it doesn't, you either have a poor repeatability test or your binning mechanism is flawed (sends the IC to wrong location or incorrectly marks it or whatever). From a practical standpoint this is where I would start..

Thanks so much Bev D. The challenge here is that there are some devices that encounters unit failure after QC Testing. But these QC samples are already a tested good units. I am seeing factors in our testing handlers and testers like its set up integrity.

The good thing here is : 65% of encountered QC failures are invalid functional rejects upon isolation.

Hello,
The automotive standard TS16949, does not specify how you should conduct in-process QC testing. You need to define the appropriate QC controls to address all of the identified failure modes and reduce the risk to as low as reasonably possible. If your process is in control PpK 1.67 for example the extent of QC sampling test may be reduced. Hope this helps.

Hi Luv d 4um, thank you. But I red the TS16949 and browsed it and it does not require in line QC sampling during class testing of IC devices. Please correct me if I am wrong.

You are absolutely correct. TS does not tell you how to do things. It tells you that you need to control the process(8.2.3) and Product (8.2.4). Your control plan should define in-line QC sampling during class testing of IC device. If you are shipping to a specific OEM there are customer specific requirements that may require in-line QC sampling during testing of IC device.