Conductive adhesives for automotive cameras
Silver conductive adhesive is used to ground the metal housing to the circuit board in automotive camera modules, providing EMI shielding for rearview cameras, surround-view cameras and ADAS cameras.
Modern cars are a harsh electromagnetic environment: electric motors, inverters, ignition systems and dozens of control units all operate at the same time. Cameras transmit high-speed video signals over coaxial or differential cables, which are highly sensitive to interference. Good grounding of the shielding housing is a must.
Noise entering the video signal path can cause horizontal lines, flickering or dropped frames. For ADAS cameras, these faults directly affect lane and pedestrian detection, which is why automakers' electromagnetic compatibility standards are extremely strict.
Why use conductive adhesive instead of soldering or springs
- No high soldering temperatures, safe for the sensor and lens.
- Bonds around the entire perimeter, providing more uniform shielding than point contacts.
- Better vibration resistance than mechanical spring contacts.
- Also serves as a mechanical fixing.
Comparison of conductive adhesive types
| Type | Volume resistivity | Curing | Notes |
|---|---|---|---|
| Silver-filled epoxy | 0.0001–0.0005 Ω·cm | 120–150°C, 30 minutes | Strong adhesion, most common |
| Low-temperature cure epoxy | 0.0005–0.002 Ω·cm | 80°C, 60 minutes | Safe for modules with lenses already mounted |
| Silver-filled silicone | 0.001–0.005 Ω·cm | 150°C | Elastic, good thermal cycling resistance |
| Nickel–graphite filled adhesive | 0.01–0.1 Ω·cm | Room temperature or heat | Low cost, basic grounding |
Automotive reliability testing
Automotive cameras must pass a series of tests according to the automaker's standards, typically including hundreds of thermal shock cycles from -40°C to 105°C, damp heat at 85°C/85% RH for 1,000 hours, random vibration and salt spray testing. After each step, the contact resistance of the adhesive joint is measured again, and the increase usually must not exceed 20%.
Metal housing surface
Aluminum housings have a natural oxide layer that increases contact resistance. Use nickel-plated or tin-plated housings, or apply a conductive conversion coating before dispensing the adhesive.
The dispensing process also needs tight control: silver-filled adhesives tend to settle if left standing for long, so the syringe should be stirred or rolled according to instructions before being loaded onto the machine.
AMS supplies conductive adhesives for automotive camera modules along with PPAP support documentation. Contact AMS Vietnam for advice.
