Printed Circuit Boards
Written by a world-renowned electronics expert, this reader-friendly guide helps engineers and technicians solve issues in PCB layout, fabrication, assembly, and testing.
TABLE OF CONTENTS Printed Circuit Boards
13.8: Hand Soldering
13.8 Hand Soldering
Even though mass soldering techniques have become popular due to economic reasons, hand soldering still has a great relevance. In small and medium scale manufacturing facilities, hand soldering is still practised. Even otherwise, if joints are faulty and require re-work, and repair and touch-up, hand soldering is resorted to. Good soldering skill is essential for operators undertaking manual soldering as well as for field service technicians who undertake repairs at customer sites.
13.8.1 Hand Soldering Requirements
The most important requirement for hand soldering, besides a skilled trained operator working with a proper ESD-controlled, clean workstation, is a good quality and temperature-controlled soldering iron with a suitable, clean and fine bit which is properly earthed.
Making good soldered joints is a skilled task, which requires proper tools, a high level of cleanliness and an ESD-controlled workplace.
Quality solder joints can only be achieved under clean conditions. Boards, component leads, and soldering equipment must be carefully cleaned both before and after the soldering operation. Beside others, two main parameters must be controlled to achieve repeatable quality joints. These are:
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Temperature: The metal to be joined and solder need a temperature range from 215 C to 250 C. The setting temperature depends upon the equipment used as well as of the shape of the tip and is approximately 50 C higher.
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Time of heat application: There is a minimum and maximum time limit, ranging between 2-4 seconds.
The temperature must be correct for the flux to be activated...
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