How to prevent the LED wrong polarity when insertion on the production line?

P

psriphum

Do anyone have an idea to prevent the LED wrong polarity when insert LED to the PCB in the production line?

Please help!!!
 
A

achorste

I would presume you'd be looking at some kind of poke yoke setup - is there any way of changing the configuration of the LCD to only fit one way round or could you use colour coding of the tips to aid the operators?

Sorry, my experience isn't in electronics, but there's my tuppence :)
 

Miner

Forum Moderator
Leader
Admin
Do anyone have an idea to prevent the LED wrong polarity when insert LED to the PCB in the production line?

Please help!!!
Automated or manual assembly? Yes, automated assembly can insert with wrong polarity also. If automated assembly, how are the LEDs packaged and presented to the pickup device (i.e., tape and reel, magazine, etc.).
 
M

MIREGMGR

LEDs typically are manufactured with mechanical/dimensional differences between the leads, and often with a mechanical asymmetry or keying feature to the base of the overmold.

Automated handling from tape should never get them wrong, if properly engineered. Manual handling can involve mistakes, but a post-insertion visual check can be done based on LED features.

When the lens/overmold is transparent, it's also possible to observe orientation by looking at the internal structure. This can be done on an automated basis with video and pattern recognition, or manually either with direct optical magnification or with video.
 
P

psriphum

All guys,

Thank you so much for all ideas and suggestion.

Yes, I'm looking for the poka yoke. LED that we're using on production floor, they were packed in the bag and its body is transparent.

Even it easily to see the internal structure which totally differnt between Anode and Cathode. We still found the problem.:confused:

so I hope I can solve the problem but I need more time to think about it.

DO anyone have an idea??????
 

Steve Prevette

Deming Disciple
Leader
Super Moderator
Are you talking surface mount LED's, or the bigger LED which does have two different lenght leads?
 
P

psriphum

Hi,

This is the manual mount and it is the through hole part which its lead length is the same.
:confused:
 
Last edited by a moderator:
C

Cesium54

Hi,

This is the manual mount and it is the through hole part which its lead length is the same.
:confused:

We hand install LED's in our units, and they have always come with one lead shorter than the other, and it's negative (minus length). The legs are also different in that the Negative lead is straight while the Positive is bent at a 90º angle twice. We have also seen the Negative side have a flat area to indicate polarity.
You may have to install a simple diode tester at the solder station to avoid this issue. A little time up front saves a lot of rework time later.

Hope this helps.
 
Top Bottom