2.6.3 Legend Marking, Stencil Method
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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.
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Tools and Materials
Cleaner
Color Agent/Epoxy
Ink
Ink Roller
Ink Plate
Microscope
Oven
Knife
Stencil
Wipes
Procedure 2.6.3 Legend/Marking, Stencil
Method
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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