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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Components Solder Short

Views: 1314


CKH

#42868

Components Solder Short | 21 July, 2006

Hi Folk,

what is the possible cause for the components (e.g ICs) to be Solder shorted? I know that one of the cause is the solder paste height is too thicked. Could anyone advise me on then possible root cause and solution(to minimize the rate of solder short) to this.

Thks & Warmest Rdgs CKH

reply »


RDR

#42877

Components Solder Short | 21 July, 2006

Thinner stencil

Russ

reply »

#42879

Components Solder Short | 21 July, 2006

hot/cold slump, print misregistration

reply »

Chunks

#42881

Components Solder Short | 21 July, 2006

Paste too thick. Paste not aligned on pad. Part not aligned on pads. Part leads not straight. Oven profile. Paste slump from warm board. Operator before oven thinks they can place IC better than placement machine - so plays IC hockey with part. Oven conveyor not smooth.

reply »

#42909

Components Solder Short | 24 July, 2006

- Dirty stencil transfering paste from the stencil bottom. - Stencil opening (Pad Hole) to pad ratio incorrect - too large -misaligned stencil

reply »

#42910

Components Solder Short | 24 July, 2006

It could be an over-zealous operator moving the IC with tweezers before reflow oven.

Have a splendid day!

-Samir

reply »

#42915

Components Solder Short | 24 July, 2006

Set-down height to low, iow, parts getting squashed too deeply into the paste.

No mask between pads on fine pitch.

Pads too wide for the pitch.

reply »

PCB contract manufacturer

SMT Equipment