SMT vs TH

We use both technologies and each comes with a mixed bag. What is the driving force behind your desire to convert? Is it just bad chips or something else? It sounds like you are having quality issues with your vendor and you would be good to address that issue first. That said, if you are purchasing parts out of the back of someones van (gray market), then I will assume some of the parts you are using are obsolete (and are just outright defective). If that's the case, convincing management shouldn't be to hard if they want to stay in business. They would have to redesign the pth product anyway so you might as well convert over to SMT. Cost will always be a concern, so you may want to see if they would be open to having a contract manufacturer build the boards for you.

Convincing management for the need for change can sometimes be daunting but it will come when it reflects on the bottom line. There are many advantages to going with SMT that I am sure you are aware. A smaller footprint being the biggest advantage. Is your company still designing new products with PTH technology? It may be they just don't want to spend the money on a new line. We converted out of necessity. PTH parts are getting harder to find, and when you do find them, especially the older parts, you pay tooth and nail for it. So many of your SMT parts will be cheaper. I don't know anything about your PTH line, but setup, depending on what system you are using can be a disadvantage with SMT. Our setup ranges from 2-4 hours per changeover. We don't have any change over time on our PTH line. Mainly because there are enough slots available for the components we use. What we loose in setup time we gain in speed. SMT is much more accurate in placing parts and much faster. Our SMT can place 20K/hour compared with 3-4K for our PTH. Mostly, when you convert or design new products using SMT, the product will have greater longevity than using PTH(Be careful, though, even SMT has many components that are at end-of-life). You will have more options for cross-referencing parts as well. SMT components are more reliable simply because they are newer. We have purchased many PTH parts that supposedly were brand new but didn't work per the spec sheet (counterfeiting could be an issue, but I cannot confirm this and have no personal experience with it).

With SMT, you get new problems. Solderability can sometimes be an issue. You get lifted leads which can be difficult to detect; therefore, if you can convince management to purchase an SMT line, have them throw in a good AOI system as well. It is well worth the money and will reduce rework and decrease repair time. Tombstoning is another issue you will see with SMT as well as insufficient solder. So there are many new defects thrown into the pot when you convert to SMT. But the conversion is well worth the trouble. But your company will have to decide what's best for themselves. In order for companies to be competitive, they have to invest in capital. That's a fact.

To sum up: 1)The speed of the AOIs should be a major selling point to management. There are much faster system out there than what we use. 2)Parts availability is another. Conversion out of necessity. 3)A smaller footprint should be a good point. Who doesn't want a more compact product that uses less power? 4)The added reliability of SMT components.

Good luck!

Reese

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