How to Assemble Circuit Boards at Home
Printed circuit boards are thin, rugged plastic boards that have a copper foil pattern bonded to them. The foil forms connections between electronic parts and makes a circuit. Whether you've etched and drilled your own circuit board or you purchased one as part of a kit, assemble it by placing parts and soldering them to the board. In addition to putting the parts in the right locations, some require careful orientation before you can solder them.
Things You'll Need
- Scotch-Brite pad
- Sink
- Soft towel
- Antistatic wrist strap
- Parts checklist
- Pencil
- 30-watt soldering iron
- Electronics solder
- Electronic parts
- Diagonal wire cutters
Instructions
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1
Inspect the circuit board. If the copper layer is not bright and shiny but appears oxidized, scrub it under cold running water with a Scotch-Brite pad, then dry it with a soft, lint-free towel.
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2
Connect the antistatic wrist strap's grounding wire to a reliable earth ground such as the center screw on an AC outlet plate or a metal conduit pipe. Put the strap on your wrist.
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3
Review the parts checklist. Note the different kinds of parts planned for the board, including integrated circuits, transistors, resistors and connectors.
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4
Take the first resistor on the checklist and bend its leads 90 degrees relative to the body, so they are both pointing in the same direction. Find the resistor's number on the component side of the board, which may be silk screened with white lettering.
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5
Insert the leads through the board and spread them out slightly to keep the part from falling out. Touch the tip of the hot soldering iron to the joint between the lead and pad, then touch the end of the solder to the hot joint and let a small amount of solder flow onto the joint.
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Remove the iron and wait a moment to let the joint cool. Solder the other lead in the same manner. Clip the excess leads with the diagonal wire cutters. Check the resistor off on the checklist.
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7
In the same manner, solder all remaining resistors to the board.
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8
Take a diode or capacitor and note its orientation on the board. Some capacitors have a positive and negative side and all diodes have a cathode and anode that must match an orientation mark on the board. Bend the component's leads, place it in its correct orientation and solder it to the board. Clip off any excess leads. Check it off on the checklist.
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9
Take a transistor and note its orientation. These parts have three leads, collector, emitter and base or source, drain and gate. You don't need to bend the leads before you place these parts. Orient the transistor, place it and solder it to the board. Trim lead excess and check it off the checklist.
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10
Take an integrated circuit, if your project has one, and align it to the board. The integrated circuit has a notch or other orientation mark. Slip all the circuit's pins through the corresponding holes in the board. Hold the circuit in place and solder two pins at opposite corners of the integrated circuit to keep it from falling out. Solder the remaining pins, doing a few at a time and allowing a minute for the circuit to cool before doing more. Integrated circuit leads are short, so you don't need to trim them. Check the integrated circuit off the checklist.
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Insert connecting wires to their correct locations on the board, solder them, trim the excess and check them off the checklist.
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Tips & Warnings
Circuit boards that have a shiny plating do not need cleaning before soldering.
References
- Photo Credit Jupiterimages/Photos.com/Getty Images
