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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


PCB lamination issues

Views: 1504

M.Haris

#47543

PCB lamination issues | 11 February, 2007

1. After reflow some boards start producing bumps/bubbles which damage the internal layers causeing PCBs failed in Electrical-testing. How can I eradicate this problem from my assembling process?

2. If SMT components are mounted on non-rigid FLEX PCBs, how it can be soldered?

3.Reflow oven Spec. says that to put PCBs in these temperatures for preheat, activation and reflow zone but these temperatures are not in the range (doesn�t mingle) of my solder paste temperatures so when I put my temperatures according to oven then soldering is good but if I put temperature according to solder paste specification it is not. Is that effect on my soldering process?

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#47568

PCB lamination issues | 12 February, 2007

Q1. After reflow some boards start producing bumps/bubbles which damage the internal layers causeing PCBs failed in Electrical-testing. How can I eradicate this problem from my assembling process? A1. Find a proper board supplier.

Q2. If SMT components are mounted on non-rigid FLEX PCBs, how it can be soldered? A2. Use a reflow oven. This may require a fixture to hold the flex flat.

Q3. Reflow oven Spec. says that to put PCBs in these temperatures for preheat, activation and reflow zone but these temperatures are not in the range (doesn�t mingle) of my solder paste temperatures so when I put my temperatures according to oven then soldering is good but if I put temperature according to solder paste specification it is not. Is that effect on my soldering process? A3. What ever works is the proper way to determine the proper temperatures in a reflow oven. Oven manufacturer and paste fabricators suggestions are guidelines that help get you in the vicinity of the proper temperatures.

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