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LINEAR VOLT REG Polarity diagonally opposite

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#55910

LINEAR VOLT REG Polarity diagonally opposite | 8 August, 2008

On a specific shop order we face the trouble of wrong polarity for LINEAR VOLT REG. This is happened b/c components were situated diagonally opposite way in the reels. Here are suppier details: ST MICROELECTRONICS P/N: L5973D013TR

Can we leave baords as it is if there is no impact? Is there any impact of diagonally opposite polarity?

Thanks

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#55919

LINEAR VOLT REG Polarity diagonally opposite | 9 August, 2008

From the sound of things, the part has the correct polarity. More correctly, your placement program has the part rotated 180*. It's not uncommon to receive parts from a supplier that are rotated from order to order. Consider revising your first piece inspection process to respond to this situation.

If we were your boss and we found that you knew it was wrong and left it, it had a HUGE impact. You'd be on-line at the unemplyment office.

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#55921

LINEAR VOLT REG Polarity diagonally opposite | 9 August, 2008

Thanks for reply

Thats in my mind to remind Process team to modify MPI. We already having some trouble with other components and my eyes were focused on specific problems +what was specifiewd in MPI to be see closely.

Do you think we need to revise program or MPI (Inspection Procedure?)I think its Program right.

So can you please make a more detail analysis and tell me can we accept board in the same condition if there is no technical impact of 180 degree apart polarity.

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#55931

LINEAR VOLT REG Polarity diagonally opposite | 11 August, 2008

Your MPI (Inspection Procedure) is certainly flawed. Your MPI should have caught this on the first board your produced, before it was reflowed.

For help convincing yourself the part is rotated 180*, your choices are: * Get the pin-out of the component. Find Vcc on the component. Find Vcc on the board using the schematic. Determine which pad of the pads for this component that has Vcc on it. Compare the two. * Ask the designer of the board.

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#55937

LINEAR VOLT REG Polarity diagonally opposite | 11 August, 2008

Well first 6 out of 180 were right and acceptable RTI result was supplied too late, I was busy on inspection and the technician was out of RTI station.

I have deatiled data sheet (17 pages) with all facts and figures, will I forward it to you?

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#55945

LINEAR VOLT REG Polarity diagonally opposite | 11 August, 2008

So, how did you get some parts going one way and other parts going another way? It would be highly unusual to receive a reel packaged that way.

No, don't send the data sheet. We can see that Vcc is on pin 8 of the part. What pin of this component does Vcc connect to on the board?

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