How to Use a Pin Count to Estimate the Scope of a PCB Design

It should be noted that this method is only for quoting PCB design, or PCB layout, not product development, overall electronics project design, schematic capture or manufacturing. If you need a quote for any of these, please contact us.

If you get stuck on how to estimate any of these three quantities, but have a netlist generated from your schematic, send the netlist as an attachment to an email and we will quote from that.

1. "Component lead count" (or " Pin Count ," it's name from pre-SMT days) is a count of all of the component leads (or pins), whether connected to nets or not and including mounting hardware, as estimated from the schematic hard copy or bill of materials. This is the best, simplest method of estimating the size and scope of the printed circuit design job. If you have only a hand-sketch for a schematic, then this is the only method that makes sense for this simple method. If you have no schematic yet, then a ball-park quote on component lead count is still your best method.

   With a pin count plus predicted overall dimensions of a board, we can estimate the number of hours it would take to design the PCB. We do that by inserting this data into a spreadsheet that was developed from time studies.

   A manual component lead count can take some time for a very large schematic.
   If you already have captured your schematic in Altium Designer, you can use it to extract a Protel netlist. Then you can use Notepad++ to count the hyphens ("-"). More detail on how to do this is below.   Most CAE software is not set up to generate a component lead count automatically.   But they can usually generate the following data, which we can quote from:

2. "Node Count" or "Connected Pin Count"   A node is a pin or lead which will have at least one wire connected to it. To get a node count automatically, extract the netlist as a Protel-format (choose Protel, not Protel2) netlist. This file will include a parts section as well as a nets sections. In the nets section, which starts with a parentheses, that is a (, count the hyphens (-). I use my text editor to count these for me. I select the nets section, and have the editor automatically count the hyphens in the selection. An alternative could be to extract a format netlist and count the dots (periods, ".") in the nets section.

We need the X- and Y-Dimensions to obtain an aspect ratio and area for estimating density. If this is not determined, give us the maximum dimensions which you can easily tolerate. If the board has an irregular shape, do your best in giving us a simplified rectangular equivalent in shape and area of the sum total of portions of the board available for component placement. If you have no idea yet, then allow yourself enough room by adding up the sum total of the rectangular area taken up by each component (including its leads, and you'll need the component "spec sheets" for this) and doubling that. This will give you enough room for the components and routes without having to go to over four layers (except for BGA designs) and without needing to put components on both sides of the board.

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Altium Designer can be used with Notepad++ to get a pin count. When you create the Protel netlist, you can have Alitum Designer project parameters be set to include "one-pin unnamed nets." Thus, the "netlist" for counting pins includes the nodes of unconnected pins, giving you a pin count when you do this:  In Notepad++, Select the nets section, and have the editor automatically count the dashes in the selection. This won't include any mounting hardware or mounting holes of connectors which are not specifically included in the schematic's symbols, so you would add those in to get the total correct component lead count.

— John Walt Childers, IPC-CID

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