Instant adhesives (cyanoacrylate adhesives) do indeed have typical applications in TWS earphones, primarily for magnetic fixing, rapid shell positioning, and small component bonding. Their core advantages are fast curing speed and short positioning time, effectively improving assembly efficiency.
However, there are numerous adhesive points inside TWS earphones, and the performance requirements of the adhesive vary significantly depending on the location. Instant Adhesive are just one option; the table below will help you understand this more clearly:
Applications | Recommended Adhesive Types | Core functions and features |
Magnet mounting | Instant-drying adhesive (cyanoacrylate) | Typical products such as Xihe 1203S have extremely fast curing speed (initial curing in 10-90 seconds) and strong adhesion. |
Housing bonding/sealing | PUR hot melt adhesive (PUR 6503N) | It exhibits high initial strength, good toughness, and resistance to high temperature and humidity, making it suitable for bonding and waterproofing of load-bearing structural components. |
Speaker sealing | Specialty adhesive (low modulus) | Low modulus and low VOC are required to ensure that acoustic performance is not affected. |
Solder joint protection | UV adhesive (e.g., acrylic UV adhesive) | It cures quickly, has shock and moisture resistance, and protects precision solder joints. |
SMT automatic glue dispenser SEC-DH600L
Second Intelligent high precision smt automatic Inline dispensing machine apply epoxy resin to the bottom of the PCB board for underfill
Second Intelligent smt automatic glue dispenser automation SEC-DH600L has the following advantages:
● CCD visual programming precise positioning, visual correction, improve programming efficiency and dispensing accuracy;
● Chinese and English operating system, the software interface layout is clear, the operation is simple, easy to learn and understand;
● Support visual inspection, integrated control of dispensing and visual inspection, multi-purpose machine, effective control of dispensing yield;
● It can be equipped with a lin e laser scanner for 3D path guidance and flexible dispensing;
● The software can support a variety of dispensing systems and functional module applications, such as automatic needle alignment, automatic
height measurement, dispensing weighing compensation, five-axis linkage and other functions, which can effectively overcome the difficulties of
various dispensing processes and help improve quality;
Ι.Precautions for Using Super Glue
Using super glue in precision, small-space electronic products like TWS earphones presents several unique challenges:
Appearance Risks: Avoid “Whitening”: Volatile substances from ordinary super glue can leave a white, hazy residue (whitening) on the surface of precision parts, affecting appearance. Therefore, when using super glue for earphone shells and other exterior components, low-whitening, low-odor super glues should be preferred.
Material Compatibility: Plastic Bonding: TWS earphones extensively use PC, ABS, and other plastic shells. When bonding these “low-energy surface” plastics, ordinary super glue may not provide sufficient adhesion. A matching primer is usually required to pre-treat the bonding surfaces to achieve a strong bond.
Biocompatibility: Skin Contact Safety: The earphone insert will be in prolonged contact with the skin, so the allergenicity of the adhesive ingredients must be considered. Some suppliers have launched products free of specific allergens (such as IBOA-free), which is crucial information to verify when selecting materials.
Ⅱ.Process challenge: How to accurately apply the adhesive
Precise Adhesive Application Choosing the right adhesive is not enough; precise application is also crucial, posing a significant challenge in TWS earphone assembly.
● Extremely High Dispensing Precision Requirements: The internal space of TWS earphones is extremely compact, resulting in complex and irregular dispensing paths. For example, filling extremely narrow gaps (approximately 0.25mm wide) with adhesive often requires controlling the amount of adhesive applied within ±3%, while there is virtually no tolerance for excess or insufficient adhesive.
● Automation is the Mainstream:To meet these stringent requirements, the current mainstream solution is to use high-precision dispensing equipment equipped with a CCD vision positioning system. This automatically identifies the product’s position and performs precise dispensing in minute gaps, achieving a positional accuracy of 0.01mm, which is difficult to achieve manually.
In general:
Fast-drying adhesives in TWS earphones primarily address the issue of “fast adhesion,” making them ideal for rapid shaping processes such as magnet fixation. However, for parts that need to withstand stress and provide sealing and waterproofing, engineers typically choose more specialized adhesives such as PUR hot melt adhesives or UV adhesives. The entire dispensing process places very high demands on the precision and consistency of the equipment.
Second Intelligent has played an important role in theresearch, development, manufacturing, pre-sales and after-sales services of fluid dispensing robot, potting and coating solutions which range from various types of automatic fluid dispensing, potting, two-component potting machines and coating machines with desktop, free-standing, inline or cobot combined systems, and widely used in global electrical, electronics, home appliances, automobile, telecom, pharmaceutical, automotive electronics, semiconductor, aerospace, LED and more.
