Time to fab some boards.

OldDogBlog post 15

In this post I will discuss producing the first prototype boards that I planned on using at the World Maker Faire.

Up to this point the process has been about deciding what to create starting from a blank sheet of paper and progressing up through having a circuit board designed and ready to fabricate. Back in OldDogBlog #10 I mentioned a company in Texas, MacroFab, that I was considering to build my boards. They can handle 5 mil trace/space with no upcharge and can assemble boards with BGAs on them. They also specialize in small quantity production runs without charging a massive amount per board.

I learned about MacroFab when I stumbled across their podcast one day and continue to be a regular listener. You can find their website here: https://macrofab.com/ and their podcast here: https://macrofab.com/blog/podcast/

I used their online tools to upload my design files and bill-of-materials (BOM) for the parts on the board. They have a list of “house parts” that they guarantee to be in stock and provide them at reduced cost. I used the house parts whenever I could to help keep my costs lower.

If you have a company fabricate and assemble the boards (called “stuffing the board” in the old days) bear in mind that they will need to purchase small quantities of parts. In order to run the parts through their automated pick-and-place machines, they will need to order components on cut tape and have tape leaders attached. Companies like Digi-Key and Mouser will do that if you order a Digi-Reel or Mouse Reel of components. However, this has an upcharge associated with it.

Therefore, when you see the parts costs for assembly, they will seem higher than if you just purchased cut-tape parts yourself. This is one reason why small quantity production has higher per-board cost compared to building larger quantities.

Once I uploaded all the information and placed my order, MacroFab came back with a question regarding the drill file and whether or not some holes were to be plated or not. These types of questions are common as the company wants to ensure they are interpreting your design correctly. They want you to be happy with the end product.

I placed an order for a whopping three assembled boards at a little over $53 per board. That was a bargain in my book since I didn’t have to fuss with trying to install the BGA part by hand. Better to let the automated tools handle that!

I didn’t need the boards in any particular hurry so I opted not to expedite the order. The boards arrived on my doorstep about three weeks after I placed the order. Not bad.

Next up – oooohhhhh…..aaaaaahhhhhh……


Tom Burke