IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
1–10 of 14 posts
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#2Luckily never been bitten by component orientation issues. But every time I get a PCB assembled at JLCPCB with WS2812b or WS2816b LEDS they always email me to confirm LED orientation. I'm assuming customers have messed this up frequently enough to require a customer ACK.
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#3Luckily never been bitten by component orientation issues. But every time I get a PCB assembled at JLCPCB with WS2812b or WS2816b LEDS they always email me to confirm LED orientation. I'm assuming customers have messed this up frequently enough to require a customer ACK.
They will send this email for all LEDs and generally all polarized components (capacitors, diodes, etc.)
JLC is also extremely unique because they offer the component orientation configuration GUI. This GUI's output is likely used for PNP tape orientation configuration as well.
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#4Why is this posted here? It's old, and it's not terribly relevant, though it's not useless.
For anything larger than 2 pins, pin 1 at upper left and pin 1 at lower left are both quite common. Components are also reeled more or less randomly. (There are some patterns, but you'll be better served by pretending there aren't.)
Put that all together and it means... it's all a cluster and gets manual intervention for every build. You can't automate it, but you can automate the intervention (that's what JLCPCB has done to enable scaling to lower volumes).
Just pick "lower left" or "upper left" for your library and stick to it. That's the best you can realistically do.
Also, LEDs are terrible and everyone hates them.
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#5[deleted]
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#6Luckily never been bitten by component orientation issues. But every time I get a PCB assembled at JLCPCB with WS2812b or WS2816b LEDS they always email me to confirm LED orientation. I'm assuming customers have messed this up frequently enough to require a customer ACK.
ws2812 family is a mess. The pin 1 is not the pin which has the corner mark and pinout varies between specific packages and variations.
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#7Luckily never been bitten by component orientation issues. But every time I get a PCB assembled at JLCPCB with WS2812b or WS2816b LEDS they always email me to confirm LED orientation. I'm assuming customers have messed this up frequently enough to require a customer ACK.
ws2812 family is a mess. The pin 1 is not the pin which has the corner mark and pinout varies between specific packages and variations.
What an awful set of things to do!
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#8Earlier quoted context omitted.
ws2812 family is a mess. The pin 1 is not the pin which has the corner mark and pinout varies between specific packages and variations.
What an awful set of things to do!
All LEDs are like this. It's horrible. The only good thing about it is that every professional in the entire industry has come to expect that if it's an LED, something somewhere will be wrong with it.
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#9Why is this posted here? It's old, and it's not terribly relevant, though it's not useless. For anything larger than 2 pins, pin 1 at upper left and pin 1 at lower left are both quite common. Components are also reeled more or less randomly. (There are some patterns, but you'll be better served by pretending there aren't.) Put that all together and it means... it's all a cluster and gets manual intervention for every…
(I'm the OP) I got interested in PCBA, one thing lead to another, and I ended up posting this document which hopefully can provoke some good discussions :-)
I was also specifically interested in how critical the manual intervention seems to be - and how accepted it is. What are the barriers to automating this completely?
If the assembly fab had access to the schematic (I know a lot of people wouldn't want to share the schematic, but if we suppose that's not a problem), would that clarify most situations?
Is 100% automation possible at all?
Re: IPC-7351B Electronic Component Zero Orientation [pdf] (2010)
#10Earlier quoted context omitted.
What an awful set of things to do!
All LEDs are like this. It's horrible. The only good thing about it is that every professional in the entire industry has come to expect that if it's an LED, something somewhere will be wrong with it.
By all LEDs do you mean addressable and other multipin LEDs? Never seen anything weird with classic 5mm/3mm. The flat side+leg length is quite reliable. 0805/1206 smd LEDs also seem mostly fine.