Upgrade of manual coating glue application specifications: refined processes help electronic manufacturing quality leap

With the continuous expansion of electronic equipment application scenarios, coating, as a key material for circuit board protection, has become the focus of industry attention for its standardization and accuracy of manual glue application. Recently, a number of electronic manufacturing companies jointly revised and released a new version of the "Manual Coating Glue Application Specifications", emphasizing the optimization of details in the entire process from pretreatment to curing to improve product protection performance and production efficiency. 

**1. Pretreatment: "Double Insurance" of Cleaning and Masking**

Before gluing, the flux residue, oil stains and dust on the surface of the circuit board must be thoroughly removed. It is recommended to bake at 60℃ for 10-20 minutes to remove moisture. For sensitive areas such as sockets, pins, LEDs, etc., the specifications require the use of tooling protective covers or anti-static adhesive tape to ensure that functional parts are free of paint contamination

**2. Preparation process: viscosity control and defoaming management**

Adjust the dilution ratio according to the type of coating (such as acrylic acid, polyurethane), and let it stand for 2 hours after mixing to eliminate bubbles. The wet film thickness needs to be controlled within the range of 0.1-0.3mm by a special tester to ensure the uniformity of the coating.

**3. Manual sizing: innovation of techniques and tools**

During operation, use an anti-static natural fiber brush and apply at a uniform speed in the same direction to avoid uneven thickness caused by cross-brushing. Key areas (such as radiator pins and solder joints) need to be repainted twice. After coating, the circuit board needs to be placed horizontally and the distance between the boards should be kept at 1cm to promote the natural leveling of the paint film.

**4. Curing and environmental monitoring**

The room temperature curing time is shortened to 24 hours, and the heating curing (60℃) can be accelerated to 2-4 hours. The ambient humidity is strictly controlled at 45%-75%, and the temperature range is 15-30℃ to prevent the paint film from turning white or bubbles.

**5. Quality inspection and rework: double guarantee mechanism**

After curing, the coating integrity is tested by ultraviolet light. If missing coating or bubbles are found, local repainting is required. When rework, use a special solvent or hot air gun to remove the old paint film. Violent scraping and damaging the circuit are strictly prohibited.

**6. Industry applications and future trends**

The new version of the specification has been piloted in consumer electronics, automotive electronics and other fields. The technical director of an automotive electronics company said: "Manual gluing is irreplaceable in small-batch, high-precision scenarios, but it must strictly follow standardized processes. For example, the popularization of anti-static brushes has increased the uniformity of the coating by 30%."

With the coordinated optimization of automated equipment and manual processes, the conformal coating gluing technology is iterating towards a more efficient and lower-cost "smart manual" mode, providing a solid guarantee for the reliability of electronic equipment in extreme environments.