APPLICATION NOTES SAW DEVICES GLOSSARY OF TERMS ENVIRONMENTAL AND MECHANICAL SPECIFICATIONS Nominal frequency (Fn): The nominal values of the center frequency F0 and is used as the reference frequency of related standard. Unit of nominal frequency is in MHz. Shock (Drop test): Natural drop on a hardwood board at 1.0m, 3 times. The specimens shall meet the electrical specifications. Insertion Loss (IL): The logarithmic ratio of the power delivered to the load impedance before the filter is inserted to the power delivered to the load impedance after the filter is inserted. Unit of Insertion loss in is dB. Pass Bandwidth (BWp): The frequency interval in which the relative attenuation (the attenuation from the minimum insertion loss) is equal to the specified value 3dB. Stop Bandwidth (BWr): The frequency interval in which the relative attenuation (the attenuation from the minimum insertion loss) is equal to the specified value of "A" dB. Group Delay Ripple (GDR): The difference between the maximum and minimum value of the group delay in the specified range of the pass band. Unit in μs. Pass band Ripple (AR): The difference between the minimum peak attenuation and the maximum peak attenuation within a pass band. Unit is in dB. Terminating Impedance (Zt): Impedance presented to the filter by the source or by the load. Vibration: Frequency with an amplitude of 1.5mm sweeping between 10Hz to 55Hz within 1 minute for 2 hours minimum on each axis on three (3) mutually perpendicular axes. The specimens shall meet the electrical specifications. Resistance to solder heat: Immerse the leads or terminals in soldering bath at 245° ±5°C for 5 ±0.5 s. 75% or more of the immersed surface shall be covered with solder. Temperature characteristics: Specimens shall be measured within -40°C to +85°C temperature range. The specimens shall meet the electrical specifications. Dry heat (aging test): Te mperature 125°C ±2°C for 250 hours. The specimens shall meet the electrical specifications. Cold resistance: Te mperature - 40°C ±3°C. Duration 96 hours. The specimens shall meet the electrical specifications. Thermal shock: Heat cycle conditions -55°C (30 minutes), 25°C (5 minutes), +85°C (30 minutes) for 5 cycles. The specimens shall meet the electrical specifications. EQUIVALENT LC MODEL SAW RESONATOR HANDLING PRECAUTIONS 1. Use the SAW product within its maximum ratings. 2. Never apply voltage higher than the maximum rating since high level voltage could accelerate deterioration of the SAW characteristics. 3. The shield grounding condition should be determined so that electrical coupling between input and output may be minimized before using the device. Coupling between input and output will cause ripples in the pass band amplitude and group delay. 4. Storage temperature shall not exceed 85°C. 5. Be careful when using ultrasonic cleaning SAW products since device material and construction is sensitive to ultrasonic vibration. 6. Do not apply sudden or excessive thermal or mechanical shock to the SAW products since it could worsen or deteriorate the SAW characteristics. TEST CIRCUIT SAW RESONATOR ABRACON IS ISO 9001 / QS 9000 CERTIFIED Abracon Corporation. 30332 Esperanza, Rancho Santa Margarita, California 92688 Ph 949.546.8000 | Fx 949.546.8001 | www.abracon.com | [email protected] APPLICATION NOTES SAW DEVICES Definition of SAW: Surface Acoustic Wave (SAW) is a wave propagating along the surface of an elastic substrate. Frequency of SAW is: V F= Where V is the velocity of SAW ( ~ 3,100m/s) Is the IDT period. Frequency range of SAW products is 10MHz to 3GHz. SAW filters characteristics: SAW filter is an integrated, passive device with bandpass filter characteristics. Operation is based on the interference of mechanical surface waves. Input/Output transducers are formed on a piezoelectric material. SAW filters advantages: Reduced size and weight. High reliability and ruggedness. No tuning or readjustment. Mass production capable. SAW filters fundamentals: SAW devices consist of two transducers with interdigital transducers of thin metal electrodes deposited on a piezoelectric substrate such as quartz or lithium tantalite. One of these acts as the device input and converts signal voltage variations into mechanical surface acoustic waves. The other IDT is used as an output receiver to convert mechanical SAW vibrations back into output voltages. Such energy conversions require the Interdigital transducers to be used in conjunction with elastic surfaces that SAW filters manufacturing process: Wafer (LiTaO3 or LiNbO3, or SiO2) Al deposit (sputtering) 0.15µ to 1.5µ Photoresist (PR coating) Exposure Develop Al etching (Wet etching) PR removal QC check + Probing (F0, IL) Sieving (Scribing) QC check (chips, cracks) Mounting Ag/UV bond Wire bonding Seam sealing Marking Final tests and inspections SAW filter parameters: Nominal frequency Fn (MHz) Pass Bandwidth 3dB BWp (MHz) Stop Bandwidth BWr (MHz) Insertion Loss IL (dB) Pass Band Ripple AR (dB) Group Delay GD (µs) Temperature coefficient TC (ppm/K) Te rmination Impedance (ohms) Operating temperature range T (°C) are also piezoelectric ones. SAW No. 1 2 3 4 devices structure: Parts list Materials Lid FeNiCo Ceramic base Al2O3 Chip (Die) LT, LN, SiO2 Wire Al, Au ABRACON IS ISO 9001 / QS 9000 CERTIFIED Abracon Corporation. 30332 Esperanza, Rancho Santa Margarita, California 92688 Ph 949.546.8000 | Fx 949.546.8001 | www.abracon.com | [email protected] APPLICATION NOTES SAW DEVICES • Mobile Phones With the growth of wireless communications, SAW devices have become a critical component for electronics manufacturers. For 2002, Abracon is pleased to announce the addition of SAW Resonators and SAW Filters to our Frequency Control product line. With high volume off-shore manufacturing, Leading technology and Superior engineering resources in design and process manufacturing, Abracon would like to be your preferred supplier for SAW devices. Our experienced engineering team can • Automotive support your SAW application from the initial Electronics design through production. Custom designs are available utilizing high technology mask designs, wafer fabrication, assembly and complete reliability testing. For immediate assistance, Please contact Abracon Corporation or send an email to: [email protected] Applications for Commercial Communications: • Remote Keyless Entry • Fiber Optics • LAN Systems • Cable TV, Set-top box • Digital Audio/Video Broadcasting (DAB)/(DVB) • Digital Satellite Systems Applications for Consumer Communications: • Mobile Phones • Pagers • Wireless Lan Systems • Remote Keyless Entry (RKE) • Security Systems • Wireless Communications • Garage Door Opener Products offered: RF SAW filters (0.1GHz ~ 2GHz) IF SAW filters (10MHz ~ 500MHz) SAW resonators one port or two ports (200MHz ~ 600MHz) ABRACON IS ISO 9001 / QS 9000 CERTIFIED Abracon Corporation. 30332 Esperanza, Rancho Santa Margarita, California 92688 Ph 949.546.8000 | Fx 949.546.8001 | www.abracon.com | [email protected]