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From my days in the Silicon Valley in California, the biggest thing I
remember about PCB costs weren't related directly to the size or thickness, they were quantity.... I've had quite a number of double sided PCBs fabricated, along with numerous multilayer ones, and the overriding issue with cost was the "non-recurring costs " of generation of the masks, tooling and setup needed to convert the supplied circuit trace films to finished boards. Once the fixed costs are covered, the individual costs of each board weren't usually all that high, if you had enough volume. As a simple example, a small jumper board of about 2.5" square, double sided 60 mil thick and only about 75 holes, with soldermask cost about a buck each at a quantity of 200. At a quantity of 500, the price was something like sixty cents each... Of course, this was the sort of thing that a hundred pieces would be a near lifetime supply, and at a quantity 100, the price was about 1.75 each.... Such is the problem of amortizing the fixed and setup costs over a relatively small quantity. So, any price that you get quoted on a per square inch basis will have to carry some serious disclaimers or additional explanation of the fixed and setup costs incurred in making the first board, along with price breaks for quantity.... The best thing to do is to contact some places that do engineering prototype quantity work, and see what they say. You can usually get a decent price quote by providing the outside dimensions, basic construction (thickness, number of layers and copper weight (thickness) along with things like number of holes, how many different sizes of holes involved, whether they are plated through, and whether you want a bare board, solder plating on the exposed copper and such things as solder mask and legend (the exact term for legend, the lettering on one or more sides of the board doesn't come to me at this moment,)) and, of course, the quantity of the run you want made. Of course, tolerance is also important.... If you need ultra-precise registration between layers, that will tend to cost more than an alternate board with a looser tolerance... It seems like a lot of information, but once you get used to it, it's not so bad. Of course, if the relative amount of circuitry on opposite sides of the board isn't somewhat equal, (called copper-balancing) the board may have a tendency to warp during manufacture, or even warp or curl with changes in temperature, particularly if one side uses a thick (heavy) copper and the other lighter weight copper. This is especially important if you intend to wave solder the PCB during assembly or other manufacturing processes.... Of course, yet another variable in the cost issue is where the PCB manufacturer is and what sort of volume they deal with. If you're looking for quick turn shops, there are (or at least used to be) a lot of them around the Silicon Valley area. However, if you're expecting to find someone in Podunk WA, KS, OH, FL or similar locations away from high-tech development, you may be looking at higher prices unless they are "hungry". Good Luck -_Rick AH7H basketball_jones wrote: Hello, I am working on a PCB-based antenna, with copper on both sides. Believe it or not, the hardest part is figuring out how much the PCB material would cost. Does anyone have any PCB costing numbers for FR4, FR408, Nelco 40013, Rogers 4003, any other material? I understand that thickness plays a major part in the cost so if possible please include the board thickness with the cost number (I am currently thinking of using 20mils thick PCB). It would probably be easiest if the cost was in units of US$ per sq. inch or sq. cm. Many thanks. |