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1. Causes and avoidance of white powdery substances in and around the quick-drying adhesive

Reason: Instant dry glue whitening (or white fog) refers to the process of bonding, the instant dry glue overflows or is not fully cured, the cyanoacrylate monomer in the instant dry glue will volatilize and react with the moisture in the surrounding environment, curing into small particles fall around the bonding surface, leaving a white powdering residue.

Avoid: (1) Use the appropriate amount of glue. (2) Strengthen the ventilation of the environment (3) Package the quick-drying glue after curing completely (4) Use low-volatile quick-drying glue

2. the two-component epoxy adhesive curing surface is poor or local non-curing reasons and avoid methods

Reasons: mainly measuring or mixing device failure, production personnel operating error. The resin components are deposited for a long time and cannot be fully stirred before use, resulting in the imbalance between the actual ratio of resin and curing agent. The curing agent component is stored open for a long time, and the moisture absorption fails. In the high humidity season, the potting parts did not enter the curing process in time, and the surface of the objects was hygroscopic.

Avoid methods: (1) the resin and curing agent components must be strictly proportioning in accordance with the requirements of the instruction manual. (2) If the packing component is placed for a long time, it is necessary to fully mix the packing evenly before mixing to avoid the problem of inconsistent actual proportions. (3) When storing the curing agent group, be sure to pay attention to waterproof and moisture-proof to avoid the failure of the curing agent. (4) Ensure that the surface of the bonded substrate is clean.

3. How to choose moisture-cured silica gel for electronic devices

Moisture-cured silica gel is condensed by absorbing water in the air and releasing small molecular by-products. According to the types of small molecule by-products can be divided into: Deoxime, deacid, dealcohol, deacetone, deamine and other different types, due to deoxime, deacid, deamine type silica gel released small molecules for oxime, acid, amine and other corrosive gases usually cause corrosion on electronic devices, affecting long-term reliability, so electronic devices with moisture curing silica gel usually choose deacetone, dealcohol this neutral gas silica gel. Avoid possible risks.

4. The problem of sticky surface after curing of photocuring adhesive

Sticky surface problems after curing of photocuring adhesives often occur in acrylate type glue applications. The main reason is that the oxygen in the air is the inhibitor of the double bond crosslinking reaction of acrylate type glue, and the surface of the glue is exposed to the oxygen of the air, resulting in insufficient curing. The usual solution is to create an oxygen-free environment by filling with nitrogen or vacuuming to avoid the effects of oxygen inhibition, or to accelerate the surface curing of the colloid by increasing the intensity of the photocuring UVC band.