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Component Skew during Reflow Process

Views: 6278

#83111

Component Skew during Reflow Process | 1 August, 2019

hi Team,

observed component skew during reflow process.

Inductor location. I have attached the image for the same.

Please provide your valuable feedback.

Attached are the images for the same.

Its SAC305 alloy , R0L1 flux chemistry.

Regards, Ameen

Attachments:

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#83122

Component Skew during Reflow Process | 1 August, 2019

I noticed that your solder mask registration is off some.

Does it cover a significant portion of any of the pads for these parts?

If so, is it possible that the surface tension of the solder at liquidus is enough to skew the part when the solder is pulled from the solder mask to the pad?

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#83125

Component Skew during Reflow Process | 1 August, 2019

if the inductors were your only problem. My mom wouldn't be pleased with the V30200C dual voltage rectifier just below the inductors

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#83128

Component Skew during Reflow Process | 1 August, 2019

Looks like you have too much solder, looks like is balling out of the side of your pads.

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#83135

Component Skew during Reflow Process | 1 August, 2019

Hi ALL,

Thanks for your valuable inputs. Will go through the suggestions and come back.

Regards, Ameen

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#83137

Component Skew during Reflow Process | 2 August, 2019

Hi All,

Any method to check any vibration in reflow oven.

Regards, Ameen

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#83143

Component Skew during Reflow Process | 2 August, 2019

While I agree there is "too much solder" on this board, I don't think that is the sole explanation of what's going on here.

I don't think the pads on the board match up well with the terminations on the components.

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#83335

Component Skew during Reflow Process | 22 August, 2019

I have to agree with Dave here. Can you compare the datasheet pad recommendations to your design ? It may help to show the forum a picture of the bare PCB pad design along with a pic of the bottom terminations on the part.

What Stencil thickness are you using here ?

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#83347

Component Skew during Reflow Process | 23 August, 2019

Hi ,

We are using 5 mil thickness. Sure will very the PAD with component data sheet recommendation.

Regards, Ameen

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#83684

Component Skew during Reflow Process | 5 November, 2019

Hi Ameen,

Did you fix it? I had the exact same problem with the same type of coil , check the images , LF solder SAC305, we have adjusted the solder apertures to the minimum solder required to have a strong joint enough to break the pad from the board in a push test, we have shifted the placement in opposite direction of the movement, reduced the oven chain speed to reduce vibration and of course all new set points for temperatures just to ensure the PCB gets hotter that the components using the bottom oven blowers with higher power that top side blowers to reduce turbulence, we can not used glue nor tape because is a high runner and still affected around 5% of produced due this problem.

Attachments:

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#83918

Component Skew during Reflow Process | 11 December, 2019

Dear Javi,

Thanks for the feedback and review.

Sorry i was bit busy.

Yes the issue is minimised, but not eliminated. We have tried with reducing the vibration source in chain conveyor of oven.

Our board is having parts very next to each other. Offset placement is not feasible.

Customer requirement is to have solder fillet evidence at edge. Reducing for solder paste. We have not tried.

Regards, Ameen

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#83924

Component Skew during Reflow Process | 11 December, 2019

Dear Ameen,

We have proved to the customer than the solder fillet obtained after the solder reduction is enoug by bracking some parts and obtainig more than 200 Newtons before and after, the problem has deminish but not yet solved , next step is reduce the solder mask window to block the shifting space, proposal sent to the customer for a respin.

Attachments:

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#83933

Component Skew during Reflow Process | 12 December, 2019

Dear Javi,

Thanks for such a detailed study and idea.

Will try to prove it to customer. And let you know.

Ours is high mix low volume EMS.

We may get this PCBA back in next month. Will try to implement all your suggestions.

Thanks once again.

Regards, Ameen

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