I am looking into solder paste inspection systems. I have used a solder paste height inspection system in the past. We have derived less than usefull information from this system as it will only measure the pad that was taught. I have seen it pass the pad that was taught on a board that had a solder skip in the printing process at another location. I am seeing systems that will do height and coverage. Can anybody comment on their experiences good or bad? Any recommedations on models?
It really depends on several things. Is solder paste inspection driven from the customer? Do you have a lot of time and bodies to do solder paste inspection? Does it add value to your process?
If you answered �Yes� to any of the above, then you are stuck doing this. In reality, this kind of inspection is a dog and pony show. Measuring 10 bricks of paste out of 3,000 does not mean a thing, except that those 10 spots will solder correctly (assuming the measurements where within range). As you stated earlier, you can have skips on a board that will pass this so called quality check point. This makes this step a dog and pony show. It may look good to a customer, but anyone close to the real process knows better. It does generate a lot of data, which someone should be collecting and using. If not, again it�s a waste of time.
To be honest, I have never seen a system like this make an impact that affected decision making of any kind. I would suggest buying a screen printer that has 2D capability. Most top line screen printers can do 100% 2D inspection. At a minimum get an older machine with 2D inspection and then have it inspect your suspect areas. At least you will be inspecting these area 100% of the time. Do you really need to measure the height? Unless scavenging can occur, I would suggest a 2D system on a screen printer.
I agree. I have tried to educate management as to the real benifits of height measurement. Our President attended a CEO meeting of some sort and was told that solder paste height measurement will solve all of the worlds problems. She then inquired as to why we were not measuring everything as we already had the equipment. Anyways, that's an uphill battle. So, our current system is down (burnt the laser out) It will cost over 1K for the part ($.35 laser diode) that can only be replaced by a trained monkey at a premium rate. At this point I am not inclined to repair this system. As I had mentioned, I have seen some systems that do coverage as well as height. I was wondering if anyone had any input as to these systems. It would cost us about 100K to retrofit 2-D on our DEK's so I was hoping that I could find something that would get me by at a lower cost.
OUCH! The ol' boss went to a seminar clich� eh? That�s a killer. Especially if it�s salesperson driven (which most are). Almost as bad as when they pick up Circuits Assembly or Assembly Magazine.
OK so you�re stuck doing this process. I would invest in the trained monkey with the $0.35 diode. There are a few good machines out there to do solder paste inspection, but if you�re going to spend the money, why not look at solder joints after the oven? There are several machines that will look at component ID as well as solder joint quality. But these machines cost $150K (US) and up. We use YesTech and are pretty happy with it. That coupled with our 2D on our MPMs, life is good.
Back in the mid 90s I used an SVS 3D solder paste inspection system. We used it as a stand along unit but it was an inline model. We would bring printed PCBs off the Dek 265 solder printers and check every 5 or 10 printed panels. They almost always passed the test requirements. When they did fail, and it was not often that this would happen, it was almost always due to a machine issue. Particularly it was often due to a clamping issue with those razor sharp Dek edge clamps getting dinged. The PCB did not sit flat against the stencil when the edge clamps had dings in them. There were a few products that we printed using old manual or semi auto printers. These often failed at 3D inspection.
I agree that simple height measurement is not very helpful. We had a Cyberoptics LSM once. It helped a bit with the manual printer setup before metal squeegee blades were introduced.
I know 3D inspection has come a long way and prices have dropped. I feel you are better off putting the money into a new printer with 2D inspection. With 2D on the printer, you can stop the problem at the source and even correct it. I am not absolutely sure but I think some 2D systems will initiate an under stencil wipe when 2D inspection failures occur. With metal squeegee blades and automatic printers, height of paste is usually met if length and width of the printed solder brick is in spec.
My experience has been very different from the other responders. We put an in-line system in place about 3 months ago and the results have been pretty eye-opening. We were astounded to see how many prints were actually bad once we started inspecting them. The machine inspects every brick on the board, and compares it to specifications you provide for length, width, height, profile, shorting, etc. Defects are indicated on a display via color code. The operator or engineer can examine each brick individually for its defect characteristics to understand root cause. The 3-D has helped us improve yields significantly by finding defects, but by also helping us fine tune our printing process. We plan in adding a machine to our other two lines.
We looked into the same issues last year, and we decided on a Koh Young 3020 (table-top) that is running Koh Young 3030 (In-line) software.
Our decision was based on a 1-year research process that included data from both our customers that were using systems paste inspection systems at the time, as well as talking with the different representatives and manufacturers.
Best 3D system we purchased and have been running for over a year now is the Koh young. Best Gage R and R, easiest programming, easiest user interface and best defect detection. We used to run an MVP Supra in 3D but had issues with software glitches causing us to rethink. (Linus based system)
In approximately one month I am installing 2D at our DEK print station. We are going with the basic (cheap) software options and 2D camera. After it is up and running we will determine if it is indeed useful.
At that point we will decide on the advanced software. This software for advanced stencil and advanced board detection are $10,000 each. So you see why we are opting for the basic software first.
The basic software gives you area solder "present" detection as well as stencil aperture blockage of any degree.
If you want solder alignment (never a problem at my place) or solder bridging you need advanced board software. If you want stencil smearage detection you need advanced stencil software. None of these last two options seem worthwhile to me as the basic functions would most likely fail for other related issues to the print.
However if you want/need solder volume analysis you need both advanced stencil and board software.