Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


COMPONENT DROP DURING SECOND SIDE REFLOW

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#78686

COMPONENT DROP DURING SECOND SIDE REFLOW | 14 August, 2017

Dear ALL,

what might be reasons for component drop during second side reflow soldering in PCB( OCCURS NOT FREQUENTLY- 100 BOARDS ONCE )??

your valuable comments are welcome!!!

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#78743

COMPONENT DROP DURING SECOND SIDE REFLOW | 24 August, 2017

We often do double sided SMT assembly, never had issues with smaller components. However, we apply glue to heavier components like inductors, SD card sockets etc.

For this purpose, we have a glue dispensing machine inline after the solder paste printer.

AS per my understanding, when the total effect of surface tension of the solder paste on the component leads is lower than the weight / gravitational pull, the component will fall.

Imagine a small water drop on a water tap, it does not fall down unless it gets bigger in size (surface tension less than gravity)

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#78746

COMPONENT DROP DURING SECOND SIDE REFLOW | 25 August, 2017

Thank you so much for your valuable feedback . Root cause was found that amount of solder paste printed on board is uneven. Uneven solder paste printing was Due to misalign of backup support pins in PRINTER. Problem was rectified after changing backup support pins .

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#78752

COMPONENT DROP DURING SECOND SIDE REFLOW | 26 August, 2017

Luckly u found the root cause :) Don't you use SPI or some inspection machine?

To prevent the trouble can happen next time, in my opinion, U shoud have inspection tool or Stencil design change to increase amount of solder.

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#78755

COMPONENT DROP DURING SECOND SIDE REFLOW | 26 August, 2017

Thank you for your Feedback

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