Posted by Henry on May 06, 03 at 22:51:06:
In Reply to: MONEY is right...another term is; CHEAP or QUICK & DIRTY posted by Ben on May 05, 03 at 14:20:09:
I blame management.
Whether it's cold solder joints, or poor mounting/vibration - it's not a new problem. My '85, with the circuit mounted behind the dash (under the steering column), had the same amateurishly designed board, solder joints that failed (for whichever reason), and a big power transistor that had to press against its heat sink, yet had no means of support other than the solder on its three leads.
GM has known since '85 that its wiper circuits are poorly designed and fabricated. Management has chosen to do nothing about it, so I blame them, not the vendor, for the problem.
Henry
: Have designed stuff for military and NASA, including ruggized with conformal coating & potting the whole dang thing inside the enclosure to combat vibration.
: The type of cracks eyeballed seem more cold solder joints than vibration induced. The size of some of the electrical leads would have broken the trace bond to FR4 (if FR4...most likely lesser material) or broken the lead themselves. Tale tail is the dull surface and can see that the molten metal had cooled too fast and froze while still in crystalline state.
: Have also eyeballed several from dealers parts counter before "buying" one...decided not to after seeing all to fimilar cold solder joints. Told the parts manager, but don't know if he believed me and just put back into stock or tried going up the GM ladder...
: Knock on wood, but did the resolder several years ago and it's still good to go...
: Good solderig practices for this level of product is not rocket science (pun intended). From what can see, looks like too short time in solder wave...if wave soldered...if pot soldered, again, too short time in solder pot...both then cooled down to fast. Antoher potential is poor quality flux, not enough flux, or oxidation on the leads (poor storage conditions, allowed moisture to oxidize the leads). Most likely because the larger sized leads are the main problem (heat sink to the initial solder blob).
: Then if there is the level of vibration Old ASE Pro states, then it exacerbates the cold solder joints. Plus poor design to have an assembly with that much force(s) onto the PCB...or allow the connector to float along with the PCB...