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Topic: OLED test jig (Read 6548 times) previous topic - next topic

OLED test jig

Hi All,

My first post here ;)

I bought some OLED screens like below picture.
[attachment=1]
It uses some flex pcb connector, 31 pins at 1mm pitch.
[attachment=0]
I'm hoping to use them in my upcoming projects. But I need to test first and I do not want to solder onto the connectors unless on the final PCB.
I'm considering 31pin PFC connector but the seller told me it doesn't fit (which I doubt).
Can someone suggest how I can make a test jig for this type of screen? Or post a picture?
I'm pretty sure there should be something they use in the factory. I just need to build a light duty version.

Thanks

Bob

Re: OLED test jig

Reply #1
Hi & welcome to DP!

If the PFC connector doesn't fit I can think of two alternatives.

Use pogopins. You probably have to use two sets of them where one set is connecting to all even pads from one direction and another set to the odd-numbered pads from the other direction. But it will be hard to get it all lined up properly.

And the pogopins might destroy the rather delicate flex pcb.

Another method would be a pcb with pads at the same spacing as the display and the use one of those zebra-strip connectors that could be found in calculators connecting the lcd to the pcb. It's a piece of rubber with a lot of alternating conductive and non-conductive parts in black and white.

You would need something that clamps down onto the flexpcb and keeps it steady at the zebra connector.

But I would seriously recommend "sacrificing" one of your displays and solder it up properly to a breakout for testing. Making a temporary non-destructive test connector for them would probably be more expensive than thel oled itself.

Re: OLED test jig

Reply #2
Hi masteng,

Thanks for the quick reply/suggestion.

I pulled out a rubber stripe from an old LCD screen, which is pink in color, not really zebra type. I measure the resistance across both sides and get 100-200ohm resistance. Guess this will cause problem on my screen as not all the signals are digital, some pins are for bypass capacitors and some are for bias voltage.

So it seems like pogopin is better choice. But I'm not familiar with them. Are those used for the nail bed for PCB testing? If it is I can easily get some from a friend :D
As you suggest to line up the pins in two lines, what is the purpose? Is it to prevent the pins to short each other or for balancing?

Thanks

Re: OLED test jig

Reply #3
I think that the oled might work even with the zebra 100 ohm resistance in the connector. If you have a suitable pcb to mate it with already you might give it a quick test and see how it turns out. but if it's not working you'll have a hard time to figure out whether the connector is the culprit or the firmware :-)


pogopins are commonly used for pcb testing beds, so your friend will probably have suitable models for your need.  Yes, the suggestion to connect from two angles was for getting the spacing between the pogopins increased to 2 mm c/c - that is probably still tight enough to be unconfortable.

Re: OLED test jig

Reply #4
As matseng says i would just solder them to a pcb and go from there. If you have a hotair you could easily unsolder them and reuse. Make sure you keep then contact strip straigh and dont wobble the flex pcb too much. Hotair would soften the kapton. I've managed to solder/unsolder an tft (same flex) for about 5 times.

Re: OLED test jig

Reply #5
For 80 bucks you can get a rig that does exactly what you want. They even have demos for this exact purpose at the stand in SEG market.

website of 'my' guy is www.szjt998.com
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OLED test jig

Reply #6
[quote author="ian"]For 80 bucks you can get a rig that does exactly what you want. They even have demos for this exact purpose at the stand in SEG market.

website of 'my' guy is http://www.szjt998.com[/quote]

Hi Ian, saw your twitted picture of the rig yesterday. Ya that's the thing I needed, although a little overkill for just 20+ screens.
I just got 100 #000 pogo pins from my friend, which are specified as minimal testing gap of 0.9mm. Am going to build a custom jig for this.

Btw I'm not able to access the website u gave :(

Re: OLED test jig

Reply #7
Hi,
As suggested by matseng and Ian I made a poorman's oled test jig using pogo pins.
Details at http://www.ba0sh1.com/oled-test-jig/

[attachment=0]

Re: OLED test jig

Reply #8
Nice work! Thanks for sharing, we'll post it up.
Got a question? Please ask in the forum for the fastest answers.