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broken components

Views: 2305

#58902

broken components | 26 May, 2009

hi, i am proccess eng solder wave process.I have problem with a PCB.There have ceramic SMD capacitor, SMD thermistor and SMD inductor 1uH.After reflow all is OK, but after SW these components are broken???The pin is separated from the body???the question is "what is the reason".If I make hand soldering the components are OK?

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#58903

broken components | 26 May, 2009

Is the components on the top or on the bottom of the pcb?

Have you checked whether the temperature on pcb are too high when it pass through SW that it exceeds the limit that the components can take? Do check with the component manufacture for the technical data sheet of the component. And it depends on what flux you used to set a minimum temperature on the pcb, so if the flux require a higher burn off temperature that damage the component, you might need to find another alternative to fit the SMD part after wave or hand solder the thru hole part(depends which are more loaded).

Before loading pcb thru wave, it is always better to acquire a correct profile for the pcb to avoid any damage cause to board and components. Heating ramp should not exceed 4dg Celsius/sec and cooling ramp should not exceed 5dg Celsius/sec.

Regards, xin xi

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#58909

broken components | 27 May, 2009

all components ar on the top side...

regards

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#58910

broken components | 27 May, 2009

Have you tried profiling the board with temperature label or profiler thru wave?

I reckon your pre-heat temperature might be too high either on top or bottom and cause the component to expand unevenly.

Regards, xinxi

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#58912

broken components | 27 May, 2009

Please describe the break in the components. Attaching pictures would be helpful.

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#58939

broken components | 29 May, 2009

The problem could be that the preheat temp of the PCB is too low on entering the bath.Also look at moisture ingression of components.Have a look at solder Assit at http://www.shanelo.co.za

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#58946

broken components | 29 May, 2009

It would help to see pictures, but I suspect the parts are seeing excessive strain when snapped into or removed from the pallet.

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