With the popularity of keyless entry systems (PEPS) in new energy and high-end fuel vehicles, door handles have been upgraded from traditional mechanical handles to intelligent components that integrate coils, micro switches, and antenna modules.
These sensing coils are responsible for implementing key functions such as touch recognition, proximity sensing, and vehicle owner authentication, and their stability directly determines user experience and vehicle safety.
Due to the long-term exposure of the door handle to the outdoors, its internal antenna coil needs to face:
The damp heat cycle caused by long-term exposure to sunlight and rain
Cold and hot shock under temperature difference between winter and summer (-40~125 ℃)
Structural fatigue caused by frequent pulling
Difficulty in sealing due to narrow cavities and complex structures
Therefore, the sealing of the internal coil of the door handle must be selected
A special material system with low dielectric, low stress, temperature stability, moderate fluidity, and adhesive properties.
Requirement analysis of sealing materials
Based on the structural characteristics of the car door handle antenna coil and the reliability requirements of the vehicle manufacturer, the core indicators for selecting adhesive are as follows:
Temperature resistance performance (-40~125 ℃)
Ensure that there is no cracking, detachment, or water leakage under severe thermal shock.
Low dielectric constant (key!)
Avoid affecting the signal resonance and transmission rate of the coil.
Low hardness, low stress system
Reduce stress concentration on the shell and components during thermal expansion and contraction processes.
Good adhesion strength (PA66+GF, PC, metal)
Ensure that the sealing body does not detach from the shell to prevent water leakage or structural looseness.
Controllable liquidity
It is necessary to permeate the internal exhaust of the coil without being too thin to permeate excessively.
Fast curing speed, improving production line efficiency
The door handle usually needs to be glued in stages, so the curing time is crucial.
In response to the above requirements, Yilian provides two preferred material systems for car door handles:
SIPC 1823 (Organic Silicon System)
PUR 1670 (polyurethane system)
Yilian Material Solution
Scheme A: SIPC 1823- Low dielectric flexible silicone sealant
System type: two-component addition molding silicone
Hardness: A ≈ 35 (soft and does not damage the coil)
Dielectric constant: low, with minimal impact on antenna signals
Temperature resistance: -40 ℃~125 ℃
Adhesive adaptability: suitable for PA66+GF shell PCB、 coil
Core advantages of SIPC 1823
① Extremely low dielectric constant, does not interfere with signals
For sensitive components such as door handle antennas, low dielectric materials can ensure normal signal radiation without causing attenuation or frequency drift.
② Flexible and low stress structure, enhanced resistance to thermal shock
The softness of A35 can effectively absorb the thermal stress of the shell and coil,
No cracking, warping, or peeling during cycling at -40~125 ℃.
③ Excellent permeability, conducive to exhaust and secondary sealing
The coil structure is complex, and the silicone system is more likely to penetrate the gaps and release bubbles.
④ Meet automotive grade reliability requirements
Waterproof and moisture-proof
Excellent insulation performance
Resistant to yellowing and aging
Suitable for long-term outdoor exposure conditions.
Plan B: PUR 1670- Rapid curing low dielectric polyurethane adhesive sealant
System type: two-component polyurethane (100:33 ratio)
Hardness: A ≈ 65 (higher structural support)
Low dielectric constant
Curing characteristics: sensitive to moisture, environmental control should be taken into account
The application value of PUR 1670
① Higher hardness provides structural support for shell bonding
PUR 1670 is harder than 1823 and is suitable for combined applications of coil potting and shell bonding.
② Fast curing speed, suitable for high cycle production lines
The curing speed advantage of polyurethane is obvious, which can improve efficiency in production.
③ Low dielectric constant, suitable for antenna electronics
It will not affect the communication signal of the door handle antenna.
④ Caution for use: Sensitive to moisture
Proper humidity control is required for sealing and storage to ensure curing effect and appearance quality.
Complete recommended application scenarios
In order to balance structural adhesion and coil performance, the following combination scheme is recommended:
Coil sealing: SIPC 1823 (preferred recommendation)
Extremely low dielectric
A35 low hardness
Temperature resistance -40~125 ℃
High insulation, low stress
Moderate liquidity, permeable coil
Shell bonding: PUR 1670
A65 provides structural strength
The bonding effect of PA66+GF is stable
fast curing
Low dielectric ensures signal safety
The collaborative use of two systems can balance signal integrity, structural strength, and environmental reliability.
Tags: PEPS antenna potting · PUR1670 · SIPC1823 · Low dielectric potting adhesive · Organic silicone potting adhesive · Automotive electronic sealing · Automotive door handle potting · Automotive grade potting material · Door handle coil potting
