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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Questions about SMT Process Control

MM

#29953

Questions about SMT Process Control | 9 August, 2004

Hello, I'd like to consult somebody here about how to do the inspection of solderablity of a PWB. what is the root cause about the cold soldering in SMT.

reply »

#29955

Questions about SMT Process Control | 9 August, 2004

Do a search on COLD SOLDER and see if this answers some questions first.

reply »

George

#30012

Questions about SMT Process Control | 12 August, 2004

The #1 cause of cold-solder is less heat.

reply »

#30015

Questions about SMT Process Control | 13 August, 2004

Solderability standards are: * IPC EIA J-STD-002B - Solderability Tests for Component Leads, Terminations, Lugs, Terminals and Wires * IPC EIA J-STD-003A - Solderability Tests for Printed Boards

Not intending to insult you, but terms used to describe solder connections are often specific. �Cold solder� is very uncommon in SMT solder connections. It is more closely related to wave soldering and hand soldering. Generally cold solder connections are caused by: * Solder temperature: too high, too low * Conveyor speed: too high, too low * Contamination of solderable surfaces.

We would like to help you understand your problem better. So, it would help if you told us more about your situation. For instance: * Appearance of your defective solder connection. * Process [ie, paste, reflow profile, conveyor, etc.]. * Component [ie, type, termination finish, etc.] and board [ie, solderability protection, solder mask type, thickness, etc.] * Distribution [ie, new / old problem, one / many products, location on board, etc.] of your defective solder connection.

reply »

Robert Ack

#30213

Questions about SMT Process Control | 24 August, 2004

Sometimes cold solder can manifest if out of date solder paste is used. Stock rotation is one way of preventing this from happening. Also, leaving pcb's out for too long before being placed in an oven can also cause the flux to evaporate which will also cause this to occur.

reply »

Solder Paste Inspection

SMT equipment