Difference between revisions of "Printed circuit board"

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(Most PCBs now surface-mount)
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A '''printed circuit board''' (often abbreviated as '''PCB''') is a technology used for cost-effective production of multiple instances of a module.
 
A '''printed circuit board''' (often abbreviated as '''PCB''') is a technology used for cost-effective production of multiple instances of a module.
  
A thin fiberglass sheet has holes drilled in it, where the leads from components will be placed. It is then coated with a thin layer of copper; next, a pattern of 'resist' is applied, outlining a series of 'traces' which will connect together the components placed on the board. (This resist is usually printed on the board, hence the name.) The board is then placed in a chemical bath which dissolves the copper where it is not protected by the etch, leaving the traces.
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A thin fiberglass sheet is coated with a thin layer of copper; next, a pattern of 'resist' is applied, outlining a series of 'traces' which will connect together the components placed on the board. (This resist is usually printed on the board, hence the name.) The board is then placed in a chemical bath which dissolves the copper where it is not protected by the etch, leaving the traces.
  
 
The first PCB's were single or double-sided. Later, techniques for producing so-called 'multi-layered PCBs' were deveioped; a number of thin PCBs were created, and then glued together; this allowed the production of complex circuits which could not be 'routed' with only two surfaces.
 
The first PCB's were single or double-sided. Later, techniques for producing so-called 'multi-layered PCBs' were deveioped; a number of thin PCBs were created, and then glued together; this allowed the production of complex circuits which could not be 'routed' with only two surfaces.
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When PCBs were first used, they had holes drilled in them, where the leads from components would be inserted. Most components are now designed to be surface-mounted, so the PCB layout has pads for them to be soldered to.
  
 
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Revision as of 00:11, 8 July 2017

A printed circuit board (often abbreviated as PCB) is a technology used for cost-effective production of multiple instances of a module.

A thin fiberglass sheet is coated with a thin layer of copper; next, a pattern of 'resist' is applied, outlining a series of 'traces' which will connect together the components placed on the board. (This resist is usually printed on the board, hence the name.) The board is then placed in a chemical bath which dissolves the copper where it is not protected by the etch, leaving the traces.

The first PCB's were single or double-sided. Later, techniques for producing so-called 'multi-layered PCBs' were deveioped; a number of thin PCBs were created, and then glued together; this allowed the production of complex circuits which could not be 'routed' with only two surfaces.

When PCBs were first used, they had holes drilled in them, where the leads from components would be inserted. Most components are now designed to be surface-mounted, so the PCB layout has pads for them to be soldered to.