2.6.3 Legend Marking, Stencil Method
| Printed Board Type: R/F/W/C | Skill Level: Intermediate | Conformance Level: High | Rev.: D | Rev. Date: Jul 7, 2000 |
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Outline
This method can be used to add, change or replace legend and markings on printed boards or printed board assemblies. This method uses epoxy ink and a brush or roller technique. A stencil is used to outline the characters.
Procedure
Damaged Legend
Figure 1: Replace legend using a stencil.
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| 1. |
Clean the area.
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| 2. |
Scrape off any remaining character or legend
with a knife and clean the area.
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Caution
Abrasion operations can generate
electrostatic charges. |
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| 3. |
Select the appropriate stencil
or have a stencil made up (See Figure 1). |
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| 4. |
Mix the epoxy ink. White is the
most common color. Spread a thin even coating of
the epoxy ink on the ink plate or on a smooth surface. |
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| 5. |
Position the stencil on the circuit
board surface and hold in place firmly |
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| 6. |
Roll or brush the ink onto the
stencil. Do not smudge characters or apply excess
ink. |
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| 7. |
Cure the epoxy ink per the manufacturer's
instructions. |
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Figure 2: Completed legend repair.
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Evaluation |
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| 1. |
Visual examination for proper characters,
positioning and legibility. |
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