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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


0603 Tombstoning

Michael Parker

#4860

0603 Tombstoning | 23 February, 2000

I have experienced tombstone with one brand of 0603 capacitor. Swapping in another brand (actually two different brands to date) has stopped the tombstone. I have measured the parts (length, width and height). There does not appear to be any appreciable difference. All other process parameters remain the same. (reflow profile, x, y, z placement). Any ideas where to look next?

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CFraser

#4861

Re: 0603 Tombstoning | 23 February, 2000

What machine are you using to place the components? I assume that you have checked placement prior to the refow process?

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Jason Nipper

#4862

Re: 0603 Tombstoning | 23 February, 2000

Hi Mike,

I have had problems in the past that were very difficult to determine the source of. Our tombstoning issues were caused by the plating on the part itself. If your smd placement, x-y positioning and placement pressure is not an issue, and you have checked your profile, then your issue could could be contaimination on the leads of the component or just poor plating all together. Are your pads contaiminated or oxidized? Do you use OSP or HASL on your boards?

Jason

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K

#4863

Re: 0603 Tombstoning | 23 February, 2000

Michael: I would agree with Jason. It seems your analysis has pointed you to one specific brand of part. I've also seen this phenomenon. The part was Palladium plated and when we switched to a nickel/tin plated part, the problem went away. Some of the plating materials used will be a challenge to solder to & give varying results. Also, open a line of communication with the supplier of the part that's tombstoning. Tell them what's up & ask for their help. It is to their best interest to do what they can. If they won't help......move on to another.

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#4864

Re: 0603 Tombstoning | 23 February, 2000

Mike: I'm with you. The only variable is the component. Look for corrosion, uneven plating, or crud on one of the end-caps. Good luck. Dave F

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RDR

#4865

Re: 0603 Tombstoning | 24 February, 2000

I have seen this before, our problem was palladium termination of this component. We could not change suppliers so we use a "reverse homeplate" stencil design to put the majority of paste directly underneath the solder terminations of the component. This reduced our DPMO tremendously. If palladium is your problem and you have to use it you may want to try a 2% silver paste

Russ

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Michael Parker

#4866

Re: 0603 Tombstoning | 24 February, 2000

Thanks to all who responded. I am tending to believe oxidation is the root cause. I will be contacting the supplier to get definitive answer.

Mike

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