Methods For Prototype PCBs
2013-11-18 by <palciatore@...>
A recent thread that was a thinly disguised ad has brought back to my mind the basic reason why I joined this group and several others. I have been mostly lurking on all of these boards trying to pick up the answers that I need.
I have made PCBs at home decades before the present and the process was relatively painless and inexpensive. These were the days before PCs, Gerber files, and the internet. I took a sheet of drafting media and pasted on pads and tape to form the layout. I took that manual drawing to a place with a copy camera and got a high contrast negative made from it. Then that negative was used with a sensitized board to make a board. Today this process is no longer possible. Places with copy cameras are no longer in every or even any city. The drafting aids are hard to impossible to find. Etc. so be it. Life moves on.
So I am looking for a new way to make prototype boards, preferably in quantities of one. And that is why I am here. But it seems to me that every present day alternative has it's own problems and pitfalls. And when I move from prototype to a production run, most or all of the effort I put out for the prototype board is not applicable for a larger order because I must use another supplier.
There are on-line places who specialize in small orders and who supply software for your use, but they are not mutually compatible and they do not have good pricing for orders of one to three boards as well as for larger orders like 50 or more boards. One place may be good for three prototype boards but then they charge too much for larger orders. Another may have nice prices for larger orders but they will soak you if you need two or more prototype orders to develop the design. And if you have to use two or more services you will have to do all the work of laying out the board over for each one. It seems like you are going to pay many hundreds of dollars to develop a working design.
If you use home methods to make the prototype boards you are up against another set of problems. From the conversations here and on other boards, there are problems with almost every present-day, home process. You can not just directly print a negative or positive because the density of most printers is not sufficient to guarantee no holes or light spots in it. If you use toner transfer that also has problems. Modify a printer to print directly on the copper? Well, it is not supposed to work, but some say that it does. Etc., etc., etc.
I am presently working on two projects and need to make or have made some prototype boards. One can use perf-board and point-to-point wiring but the other uses small surface mount parts and needs a foil heat sync and two layers so it will probably require a real PCB for even the first prototype. It may need three or more revisions before it is complete. I am really puzzling over that one. I am up to several hundred dollars if I have the prototype boards made by others. But I would still need several hundred dollars of printer and other supplies if I do it at home.
Back to the other thread. That company was heavily criticized for posting a "free" ad here. So, they are trying to advertise an inexpensive way to get a few boards made and the general thought is that this is a bad thing. From their point of view, the alternative is to use PAID ads. And who pays for those ads? They do. Or is it, "They do?" Actually, ad costs are factored in to the price of the goods or services so it is the customer who pays. I know this because I am constantly looking for ways to advertise my own creations without making them too expensive for anybody to buy. As a customer of these services, I do NOT object to an OCCASIONAL free ad if it helps to keep their prices down. Frankly, I think boards like this one should allow occasional free ads that are RELATED to the main topic of conversation. By "occasional" I do not mean daily or even weekly, slick messages that are obviously created by a professional creator. I mean monthly or less and just a message with one or two sentences describing the services available. Am I out of line here? I think that would be a valuable service to all the members here. I mean, am I the only one who spends as much time reading the ads in magazines as in reading the articles. Heck, some printed magazines that you pay $5 to $10 a copy for have degenerated to publishing articles that are thinly disguised advertisements for a product.
I have made PCBs at home decades before the present and the process was relatively painless and inexpensive. These were the days before PCs, Gerber files, and the internet. I took a sheet of drafting media and pasted on pads and tape to form the layout. I took that manual drawing to a place with a copy camera and got a high contrast negative made from it. Then that negative was used with a sensitized board to make a board. Today this process is no longer possible. Places with copy cameras are no longer in every or even any city. The drafting aids are hard to impossible to find. Etc. so be it. Life moves on.
So I am looking for a new way to make prototype boards, preferably in quantities of one. And that is why I am here. But it seems to me that every present day alternative has it's own problems and pitfalls. And when I move from prototype to a production run, most or all of the effort I put out for the prototype board is not applicable for a larger order because I must use another supplier.
There are on-line places who specialize in small orders and who supply software for your use, but they are not mutually compatible and they do not have good pricing for orders of one to three boards as well as for larger orders like 50 or more boards. One place may be good for three prototype boards but then they charge too much for larger orders. Another may have nice prices for larger orders but they will soak you if you need two or more prototype orders to develop the design. And if you have to use two or more services you will have to do all the work of laying out the board over for each one. It seems like you are going to pay many hundreds of dollars to develop a working design.
If you use home methods to make the prototype boards you are up against another set of problems. From the conversations here and on other boards, there are problems with almost every present-day, home process. You can not just directly print a negative or positive because the density of most printers is not sufficient to guarantee no holes or light spots in it. If you use toner transfer that also has problems. Modify a printer to print directly on the copper? Well, it is not supposed to work, but some say that it does. Etc., etc., etc.
I am presently working on two projects and need to make or have made some prototype boards. One can use perf-board and point-to-point wiring but the other uses small surface mount parts and needs a foil heat sync and two layers so it will probably require a real PCB for even the first prototype. It may need three or more revisions before it is complete. I am really puzzling over that one. I am up to several hundred dollars if I have the prototype boards made by others. But I would still need several hundred dollars of printer and other supplies if I do it at home.
Back to the other thread. That company was heavily criticized for posting a "free" ad here. So, they are trying to advertise an inexpensive way to get a few boards made and the general thought is that this is a bad thing. From their point of view, the alternative is to use PAID ads. And who pays for those ads? They do. Or is it, "They do?" Actually, ad costs are factored in to the price of the goods or services so it is the customer who pays. I know this because I am constantly looking for ways to advertise my own creations without making them too expensive for anybody to buy. As a customer of these services, I do NOT object to an OCCASIONAL free ad if it helps to keep their prices down. Frankly, I think boards like this one should allow occasional free ads that are RELATED to the main topic of conversation. By "occasional" I do not mean daily or even weekly, slick messages that are obviously created by a professional creator. I mean monthly or less and just a message with one or two sentences describing the services available. Am I out of line here? I think that would be a valuable service to all the members here. I mean, am I the only one who spends as much time reading the ads in magazines as in reading the articles. Heck, some printed magazines that you pay $5 to $10 a copy for have degenerated to publishing articles that are thinly disguised advertisements for a product.