BGA component keep having solder bridge after reflow oven

Thread Starter

JohnT86

Joined Aug 26, 2021
6
Hello all,

Would like to get some help with this issues. My company is building this PCBA that has a couple of BGA on it. One BGA is having solder bridge issue, and another one keep having solder void. We are using Indium 6.6HF (lead free clean solder), running a Heller 1707 MK III series with 7 zones reflow oven. The stencil is .003 mil thick. Attach is the profile that we use. Any help/tip would great.

Thank you All
 

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Thread Starter

JohnT86

Joined Aug 26, 2021
6
The design are from the customer. Our company job is to install all the component, test and ship it back to the customer.
 

Papabravo

Joined Feb 24, 2006
16,938
The design are from the customer. Our company job is to install all the component, test and ship it back to the customer.
Oh dear. That can be a problem, if the PCB layout was not done by someone intimately familiar with the assembly process. There could be a board fault that is unfixable.
 

Thread Starter

JohnT86

Joined Aug 26, 2021
6
We have manufactured pcba with bga before and rarely get these issues or we are able to fix the issues right away. We are unable to solve this one at the moment. Any tip? Thanks
 

Papabravo

Joined Feb 24, 2006
16,938
We have manufactured pcba with bga before and rarely get these issues or we are able to fix the issues right away. We are unable to solve this one at the moment. Any tip? Thanks
For the solder bridge I would look at the solder mask and/or the paste application for a fault that allows the solder to flow between the balls, or between a ball and an adjacent track. The void is trickier but if the result is consistent it suggests a layout or component fault. If your only job is assembly, did anybody check the board fabrication films before the boards were fabricated? Did you have any hand in the board fabrication process or were the boards just handed to you?
 

Thread Starter

JohnT86

Joined Aug 26, 2021
6
Hi Papabravo,

No we did not have any hand on the board design, we were sent all the files and we out source to one of our board manufacture company. On our next run, we are going to look at the solder paste application like you mention before we run it through our pick and place machine. We are also looking into getting an addon to our oven that will have hydrogen at the end of it.

Thank You for all the reply.
 

Papabravo

Joined Feb 24, 2006
16,938
Hi Papabravo,

No we did not have any hand on the board design, we were sent all the files and we out source to one of our board manufacture company. On our next run, we are going to look at the solder paste application like you mention before we run it through our pick and place machine. We are also looking into getting an addon to our oven that will have hydrogen at the end of it.

Thank You for all the reply.
I'm sorry for you difficulties and hope you can come to a speedy resolution.
 

BobaMosfet

Joined Jul 1, 2009
1,878
Hello all,

Would like to get some help with this issues. My company is building this PCBA that has a couple of BGA on it. One BGA is having solder bridge issue, and another one keep having solder void. We are using Indium 6.6HF (lead free clean solder), running a Heller 1707 MK III series with 7 zones reflow oven. The stencil is .003 mil thick. Attach is the profile that we use. Any help/tip would great.

Thank you All
Use more flux, if possible.
 

AlbertHall

Joined Jun 4, 2014
11,524
Where I used to work was a repair facility and we had a machine for removing and replacing BGAs. There was one chip which they couldn't get work after replacing it. I got the job of fixing this problem. I tried all sorts of profile - fast slow, hot cooler, in many combinations and none of them worked. We bought a camera that used a narrow prism to ook underneath BGA chips and this was a revelation. These chips showed one two kinds of bad soldering. The first one was where the chip was too low at the corners and so the solder had sqished sideways and shorted the connections. The second kind had the corner connections well made but on the middle ones there was a gap between the balls on the chip and the pads on the board.

I came to the conlusion that either the board was bowing downward or the chip bowing up. We sent some boards and chips to the machine manufacturer and they couldn't do it either. We just gave up trying to replace these chips.
 

Thread Starter

JohnT86

Joined Aug 26, 2021
6
BobaMosfet- We have try that too. We got these flux pen where we add flux through out the PCB and then we add the solder paste over it. IT does help with other component but not these BGA.

AlbertHall- We feel the same way here. Given us to much problem.

Ty all
 

BobaMosfet

Joined Jul 1, 2009
1,878
BobaMosfet- We have try that too. We got these flux pen where we add flux through out the PCB and then we add the solder paste over it. IT does help with other component but not these BGA.

AlbertHall- We feel the same way here. Given us to much problem.

Ty all
Have you tried a liquid flux- Just put a puddle all over the BGA foot-print. No bridging should occur unless there are contaminants, which the flux should help eliminate. Different solder? Different temperature? -- I can see how frustrating this is with a BGA.
 

Thread Starter

JohnT86

Joined Aug 26, 2021
6
No we haven't try that. We thought that it may not mix well with the solder paste and make it to liquid causing the BGA to move around. But we will look into that if we can't find a way to resolve it.
 
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