A.O.I recommendation

I think I have everyone beat. I work for a small Contract Manufacturer, and we are trying to grow our business. We generally have two or 3 different jobs running at the same time and up to 10 different jobs running in a day. So we needed to find a machine that was extremely simple to program and was extremely flexible. Since we don�t do final test or IC testing we really rely upon the optical inspection to make sure the parts are where they need to be. I am head of the mechanical assembly area and director of quality and the only degreed engineer on site, we have 3 other guys with technical degrees here also. I was tasked with finding the right AOI machine for our business, with emphasis on solder joint detection. There has to be about 20 different AOI machines on the market divided into 2 categories. All the machines that are listed we demo'd. The first are the strictly algorithm based. These are the Agilent, Omron, Landrix (Teradyne) machines. What these machines are really set up for is there ability to handle larger dedicated runs, i.e. in the 1000 piece or more runs. Agilent is almost on the borderline of these machines. They have tried to really simplify the programming process. But there is still considerably more that goes into programming then the image based system. They are also considerably slower due to the amount of calculations they do on each inspection. The other two you really need to have a semi-dedicated line to run. There is some serious programming that needs to happen on these two.

The second set was the imaged based systems. The N'Spec, YesTech, and the Mirtec. These machines are very similar in their ability to perform absence/presence, skew, identify parts. Where the line became fuzzier was the ability to do solder inspection. All 3 of these machines claim to do solder inspection, and all have similar claims on how they do it. They all are using the two different lights and a technique of taking photos with both and then doing a subtraction algorithm to compare the images they get an image of reflection. We went to a place that had a 4 YesTech machines and they were not using the solder inspection. Which we though was fishy, since he was a "power user". The programming interface was good and very quick. (We had them program one of our simple boards, it was a 7 component board on a 10 by 10 tray of boards. We used this tray as a gage at each of the sites to compare the programming. Not to mention it was worth it to see what the reaction of the operators and engineers was when you asked them to program it for you.) And how it did reporting was very good also. The thing that left us very uneasy was the fact that the machines they had had multiple cameras but they were only using one and the fact they were not using the solder inspection. The thing that killed the N'Spec was it was Apple based and since I also do some of the IT stuff here I did not feel comfortable enough with this fact, trying to deal with the software interface, since you have to convert to MS protocol to save to the network, maybe not as big of a deal as I think but I would rather save direct to the server then try to do a conversion first. I think this may have been just as good and maybe even have an edge but the whole Apple thing is a severe detractor in my book. We ended up going with the Mirtec. When we went to the site the engineer that took us through the machine was great. The interface for programming was even better then the YesTech especially the ability to drag and drop components from the library into locations on the board.

After we had demo�d the machines at various customer sites and spoken to people who had each of the different machines. We narrowed it down to the Mirtec and the Agilent machines. We took a trip to see an Agilent Machine with a run of our parts, had to go there because the machine is quite large. We wanted to see how the machine would handle the programming, and after 2 hours there they were still taking us through their set-up and interface and had not programmed a part. Mirtec came to our site set up in about 20 minutes and was off and programming. By the end of the day 3 of us had learned the interface and all knew how to run/program the machine, including an operator. We had also run 2 lots of boards, which had gone through final inspection, and found 5 solder defects and 3 placement defects out of about 150 boards. These defects were so slight that the human eye with magnification wouldn�t have picked it up. Our owner placed an order for 2 that day. The only problem that we have to this point is our ability to program, no fault of the machine or software, but we are getting better, we went with medium to low settings for most of the criteria and are slowly bumping it up, this is just learning curve stuff, since we have only had the machines for about 3 months, most customers ask for class 2 but are expecting class 3. The other issue we had was the operator was not doing due diligence to inspecting the issued flagged by the machine and letting stuff go that shouldn�t have left here. The machine did a good job with the reporting tools to show us this.

You really need to identify your need and make sure you get the best machine for it. If you have a dedicatied line spend the extra and go for the agilent or other machines. If you need flexibilty and ease of use stay image based. I bet even on some dedicated lines the imaged based will most likely be better then some of the more expensive algorithm based machines. Not to mention ROI is easier to justify for 70,000 then 140,000 and up. Sorry if this is fragmented or doesn�t make sense in parts, just tried to spend minimal time to convey what I had found.

Fred Fagundes ffagundes@vrindustries.com www.vrindustries.com

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I have been working with the Yestech system in my facility after evaluating the Mirtec. The yestech system has far less false calls and better defect coverage based on the test vehicles I ran. The YTV-1000 out performed the Mirtec in defect detection / program and set up time.

Our quality department and operator are really happy.

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We have 3 inline Yestech systems in our facility. One system being used pre reflow for paste inspection and the other two for parts and solder. The systems work great for paste inspection (Better than what the sales guy told us). They are also very good for the final inspection. We are doing 100% inspection now and we have found a good point on where our false calls are close to 0%. We evaluated Mirtec before buying these systems and discovered that the sales guy and engineer were not being fare and were changing the scores really low to apparent low false call rate. This is something that Yestech was not doing. We bought Yestech and after 6 months we are very satisfied with the machines and support.

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> Although I am sure that some of the postings here > are legitimate, it is obvious that many of them > have been written by AOI manufacturers or > suppliers. This forum is meant to be a > communication channel for process engineers, not > salesmen. Please save your sales material for > the trade magazines. > > I have several years of > experience with optical inspection. In my > experience, the best way to ensure that you are > getting the best system for your application is > to put the system to the test with your own > board. Most AOI manufacturers would be happy to > run a demo with your assembly. Have them program > your board in front of you so you know how long > it will take and how complicated the program > creation process will be. Also, prepare a few > boards with a variety of defects and test the > system's capabilities. Do not let the vendor > know which components are defective as it is easy > for a vendor to change the parameters to catch > those defects. Do not believe everything that > you read, have them prove the system�s > capability. > > Steve

what do you think for schneider and koch system

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I agree with steve. With so many vendors advertising to be the best, it is critical to have a "real time" demonstration on your product. Take a few good boards and a few defect boards along with the necessary data to the demo. Don't allow any programming before your demonstration so that you can see the entire process required to create a machine program.

Both Yestech and Mirtec advertise similar capabilities and were within our budget. However, after attending real time demos on both systems, our choice was Yestech. Their program time was very fast and required virtually no fine tuning before running the defect boards. They were able to find all of our known defects and actually found 2 that we weren't even aware of. We are currently investigating methods for product tracking (ie. barcodes) and liked the flexibility of the Yestech to adapt to whatever method we choose. They also include software updates in the base price of their machines.

Hope this helps with your AOI search...

B.T.

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