Fingerprint Sensors
Application information
Recent market information from IHS and Yole anticipating gradual transition to 3D image sensing …
Capacitive FPS technology not suitable for Under Glass (UG) or Under Display (UD)
Optical and Ultrasonic FPS being pursued for improved security and better fit for full screen smart phone
Mobile FPS market impacted by 3D Face ID success
Integrating FPS in Smart Cards
Requirements:
- Fast (UV) and or low temperature cure
- Thin bond line control
- Low stress, low warpage
- Good and stable electrical properties
“Capacitive Sensing” = A low RF signal is injected into the finger, then read by the pixels on the silicon acting like antenna
Successful use of Henkel’s Adhesive Films for Glass Sensor Attach in HVM
Glass Attach to Sensor Die
Key Requirements
- ▪ High adhesion
- ▪ Low temperature cure
- ▪ Low moisture absorption
- ▪ Thin bond line control
Recommended LOCTITE Products (links)
▪ ABLESTIK QMI 536NB Low warpage, low temperature cure
▪ ABLESTIK ABP 2035SC(R) High adhesion, low temperature cure
▪ ABLESTIK ABP 6892 Low stress for ultra-thin glass, low temperature cure
▪ ECCOBOND OGR-150THTG Low viscosity, UV and low temperature cure
▪ LOCTITE NCA 2280LV High viscosity, UV and low temperature cure
▪ ABLESTIK ATB 120U, 140U Low modulus FILM adhesives, oven and skip cure
Sensor & Controller Die Attach to FR4 or Ceramic
Key Requirements
- ▪ High adhesion
- ▪ Low temperature cure
- ▪ Low warpage
Recommended LOCTITE Products
- ▪ ABLESTIK QMI 536NB Low warpage, low temperature cure
- ▪ ABLESTIK ABP 2035SC(R) High adhesion, low temperature cure
- ▪ ABLESTIK ATB F125E High modulus FILM adhesive, temperature cure
Flip Chip Underfill for Reinforcement
Key Requirements
▪ Good flow ability
▪ Flexible product to absorb stress
▪ High adhesion
▪ High reliability
Recommended LOCTITE Products
▪ ECCOBOND UF 3811 High Tg, low CTE, rework-able, room temperature capillary flow, relatively low temperature cure (~10min @ 130°C or 1hr @ 100°C)
▪ ECCOBOND E1216M Anhydride-free, fast flow, snap curable capillary underfill
▪ LOCTITE NCP 5209 Medium viscosity, high Tg (by thermal compression bonding)
Electrically Conductive Adhesives (ECA) for Bezel Attach
Key Requirements
▪ Good and stable electrical connection
with metal bezel (same like solder)
▪ Fast and low temperature cure
▪ High adhesion to metal
Recommended LOCTITE Products
▪ ECCOBOND CE3103WLV High viscosity, fast thermal cure
▪ ABLESTIK ABP 2032S High adhesion, low temperature cure
▪ ABLESTIK 2030SC(R) Low stress, low temperature cure
Gap Filling Adhesives to Attach Bezel Ring to Glass
Key Requirements
▪ Good adhesion
▪ Good gap fill capability
▪ UV with second cure system
▪ Good moisture resistance
▪ Low bleed
Recommended LOCTITE Products
▪ ECCOBOND DS 3318LVT Transparent, UV and LED cure
▪ LOCTITE PC40-UMF Transparent, UV and moisture cure
Encapsulants for Wire Bond Protection
Key Requirements
▪ Low temperature cure
▪ Suitable modulus
▪ Passing reliability
Recommended LOCTITE Products
▪ ABLESTIK QMI 536NB Low warpage, low temperature cure
▪ ABLESTIK 8387B Fast and low temperature cure
▪ ECCOBOND FP 4654 Low stress (13ppm CTE), jet-able, excellent thermal stability
▪ ECCOBOND UF 3811 High Tg, low CTE, rework-able, room temperature capillary flow,
relatively low temperature cure (~10min @ 130°C or 1hr @ 100°C)