2.6.2 Legend Marking, Hand Lettering Method

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 pen to hand letter the legends on the printed board surface.

Minimum Skill Level - Intermediate
Recommended for technicians with skills in basic soldering and component rework, but may be inexperienced in general repair/rework procedures.

Conformance Level - High
This procedure most closely duplicates the physical characteristics of the original, and most probably complies with all the functional, environmental and serviceability factors.

Acceptability References
IPC-A-600 2.0	Externally Observable Characteristics
IPC-A-610 8.0	Marking
Procedure References
1.0	Foreword
2.1	Handling Electronic Assemblies
2.2	Cleaning
2.5	Baking And Preheating
2.7	Epoxy Mixing and Handling
IPC7721 2.6.2	Legend/Marking, Hand Lettering Method

Tools and Materials

Cleaner
General purpose cleaner for removing contamination.

Cleaning Brushes
Disposable brushes for use with solvents for cleaning and application of coatings.

Color Agents
Use to tint the color of epoxy used for solder mask repair or circuit base board repair.

Circuit Bond Epoxy
Clear, superior strength epoxy in two-compartment plastic packages.
Shelf life 6 months, no refund or exchange.

Knife with #16 Blades
A must-have tool for precise cutting, scraping and trimming.

Microscope
Precision microscope with stand and lighting for work and inspection.

Mixing Picks
Unique mixing sticks have a paddle shape on one and sharp pick on the opposite end.

Oven
General purpose oven for drying, baking and curing epoxies.

Wipes
Nonabrasive, low-linting wipes for cleanup.

Images and Figures

2.6.2 Legend Marking, Hand Lettering Method

Damaged Legend

Figure 1: Apply legend using a wood stick dipped in epoxy ink.

Figure 2: Completed legend repair.

Procedure

Clean the area.
Scrape off any remaining character or legend with a knife and clean the area.

Caution
Abrasion operations can generate electrostatic charges.
Mix the epoxy ink. White is the most common color.
Sharpen a wood stick and dip the pointed end into the epoxy ink. Hand letter the legend or markings as needed.
Cure the epoxy ink per the manufacturer's instructions.

Evaluation

Visual examination for proper characters, positioning and legibility.

Procedure for reference only.