File name p29.pdfRepair tips 104S CM23 GSIII 29
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0. Warning solder the component on one side. Ensure that the component is
positioned correctly on the solder lands (see Fig. 8.2A).
All ICs and many other semi-conductors are susceptible to - Next complete the soldering of the terminals of the component (see
electrostatic discharges (ESD). Careless handling during repair can Fiq. 8.2B).
reduce life drastically. When repairing, make sure that you are
connected with the same potential as the mass of the unit via a wrist
wrap with resistance. Keep components and tools also at the same
potential ! MOUNTING
e.g. A PAIR OF TWEEZERS
1. Servicing of SMDs (Surface Mounted Devices)
1.1 General cautions on handling and storage A
- Oxidation on the terminals of SMDs results in poor soldering. Do not
handle SMDs with bare hands.
- Avoid using storage places that are sensitive to oxidation such as
SOLDER
places with sulphur or chlorine gas, direct sunlight, high 0.5 - 0.8 mm
temperatures or a high degree of humidity. The capacitance or SOLDERING
PRESURE
resistance value of the SMDs may be affected by this. IRON
- Rough handling of circuit boards containing SMDs may cause
damage to the components as well as the circuit boards. Circuit
boards containing SMDs should never be bent or flexed. Different SOLDERING TIME SOLDER
circuit board materials expand and contract at different rates when < 3 sec/side 0.5 - 0.8 mm B
PRESURE
heated or cooled and the components and/or solder connections SOLDERING
may be damaged due to the stress. Never rub or scrape chip IRON
components as this may cause the value of the component to
change. Similarly, do not slide the circuit board across any 2. Caution when attaching SMDs
surface. |