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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


AXI and AOI

Mike J

#20618

AXI and AOI | 8 July, 2002

HI, We are looking into expanding our current x-ray inspection from manually inspection one panel per lot to 100% automated inspection for all of our BGA and CSP builds. We have 100% manual inspection at the end of our SMT lines and we are considering looking into the combo AOI and AXI systems.

What key items to I need to look at when comparing the systems from the different suppliers?

Has anyone gone through this analysis and would be willing to share those results?

Thanks, Mike

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CAL

#20622

AXI and AOI | 8 July, 2002

Hi Mike- Just a few things to help me understand: What is the need to goto 100% inspection? Contract calls for it, had a high fall out, or high rel ?? Is the current inspection not meeting your needs? Cal

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Mike J

#20626

AXI and AOI | 9 July, 2002

Cal, Our parent company is a FAB and they are about to release a new generation of parts. Usually the die is qualified in a simple TSOP form factor. This time the first product quals will take place in the BGA and CSP from factors rather than the typical TSOP version.

We are the SMT arm of the company and help out in the qualification process. Our current x-ray system is capable, but inspection routine is not programmable. To qualify this new part we are required to do 100% inspection to start out.

Mike

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#20627

AXI and AOI | 9 July, 2002

When you look at the capabilities of Combo machines they tend to sacrifice performance when compared to separate X-ray and AOI machines, meaning they don't do either the X-ray or AOI operations as well as a machine that was designed to do only one. Also, 100% automatic in-line 2D or 3D X-ray should be re-considered for cost issues. Cost in dollars and cost to run the process. Anyone that "needs" 100% 3D X-ray that is not mandated by a customer or dictated by a product such as life-medical, aerospace, etc...in my opinion, has no confidence in, or control of thier process. There are some very capable manual X-ray machines out there today, and you may already have one, that run 2D but have axis manipulators that simulate true 3D, meaning you can rotate the board or X-ray gun so you can X-ray around a BGA part. An MXI machine is an effective tool to validate a new process concerning solder joints and is great for checking solder joints on a sampling or audit basis. AOI is best for finding incorrect, missing, missoriented and missplaced components on the board pre or post reflow. There are table top and in-line machines on the market. In-line is best if you want real-time feedback of placement errors before reflow, where it makes the most sense to effect repairs and take corrective action to your process. Even the most advanced AOI systems out there have problems picking up post solder errors such as insufficent fillets and do you no good on leadless devices. Pre-reflow AOI machines tend to be lower cost. Have you considered an in-line 3D solderpaste measurement system? These systems tend to be fairly inexpensive and provide valuable data to the process engineer. It is a great tool to tune and control your printing process. And printing is a very critical step and one that Operators can easiliy screw up. When used effectively, a combination of 100% in-line solderpaste measurement, in-line pre-reflow AOI and post solder MXI gives you all the tools to control your process. When the solderpaste is measured and the board is AOI'd you can send it into the oven with complete confidence!

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Solder Paste Inspection