We are working to upgrade our BGA Rework Systems to place BGA's up to 150mm in size. We are encountering an issue that I wanted to pose to this group.
When we get above 50mm in chip size, which is the field of view for the vision systems Prism, the pads at the upper edges of the BGA start to skew or go off on the vertical alignment, (up and down). The larger the chip, the more the skew. We found it odd that only the vertical alignment would be off and not the horizontal alignment, (left & right)
I am trying to figure out if a mechanical adjustment is off, or if the prism needs to be larger. Our vision systems are robotic and can move to center the balls around the outer perimeter of the BGA in the center of the cameras vision. So it does not make sense to me why we are getting a skew when we are able to center the camera on the pad and ball that we are aligning.
Would like to hear what you think.
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