The Specification

The Specification is the customer's instructions to the designer describing the features the new product should have. A specification starts out as ideas and a wish list, and then gradually gets nailed down to something more formal and explicit. It is a good idea to have a list of "reasons why" and "how it's done" to explain the specification, but keep these separate from the main document.

Specifications given by the customers are specially designed to cater to their individual needs. For instance, a PCB for a camera or radio would differ from that of a computer motherboard or a factory machine. But the customers’ design need not be the "gospel truth". Remember, the design given by the customers are merely a representation of their needs, but can be improved upon by engineers specializing in PCB design.

Program Specification

Usage of computer programs eases the design procedures. Testing and debugging is also done with the help of specially written/coded programs. However, each PCB design requires its own functional program, as circuits are complex and differ from one another. Test software for a radio’s PCB cannot be used to test and debug a PCB circuit for an electronic washing machine!

The specification for the electronic product being designed will usually also be the specification for the programming required. There is a lot of overlap between the hardware and software components, and it is often easier to specify the two together. In some instances a designer will trade off hardware against software, and so reduce the cost of the final product by implementing a function as code instead of in components.

The program specification will require the writer to go into substantial detail about how the product actually operates, and how it is used. To design a good user interface (if interaction with an operator is required by the product) requires a thorough knowledge of the products operation, and substantial experience with existing products, controls and menus.

A thorough program specification leads straight into Flow charts and timing diagrams, which are components of Program Design. This leads to documentation of the software and hardware in a detailed manner so that when the completed PCB package is sent to the customer, it is more comprehensive to the user. If an error were to occur, trouble-shooting could be easily done.

Of course, good PCB design circuits are produced by quality equipment with high precision, accuracy and sensitivity. For example, according to PCC Circuits Inc, a customers’ typical usage requirement for the drilled hole diameter is minimum 0.0135 inch to 0.025 inch. PCC Inc presently has the drilling capability of up to 0.010 inch!

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