PRECAUTIONS TO BE TAKEN WHEN USING MULTILAYER PIEZOELECTRIC ACTUATORS (Please read these precautions before using our products) 1. Before using our products or designing a system using our products, read the precautions and specifications (such as level of quality) for the products you intend to use on the last page of this manual. 2. The main failures with multilayer piezoelectric actuators are deterioration of insulation resistance, short-circuit, and open-circuit. Before using the products, design systems carefully to ensure redundancy, prevention of the spread of fire, and prevention of faulty operation allowing for the occurrence of failures. 3. Use the products after checking the working conditions and rated performance of each of the multilayer piezoelectric actuator series. Selection of AE series (a resin-coated type) or ASB, ASL series (a metalsealed type) should be based on the intended working temperature and humidity. ISO 9001 ISO 14001 JQA JQA JQA-0366 JQA-E-90094 CONTENTS Resin coated type multilayer piezoelectric acutuators AE series ......................... 5 Metal sealed type multilayer piezoelectric actuatoes ASB series (85C rated), ASL series (150C rated)....................................................... 9 Reliability .......................................................................................................................... 13 Use guide .......................................................................................................................... 15 Precautions to be taken ................................................................................................. 16 Inquiries Multilayer Piezoelectric Actuators Vol.01 3 NEC TOKIN's multilayer piezoelectric actuators are available in three series. Resin-coated type General-purpose 85C rated AE series Metal cased type High-power General-purpose 85C rated ASB series 150C rated ASL series *AE series is resin-coated products. Therefore we recommend metallic case type, ASB or ASL series in high humidity condition. NEC TOKIN's multilayer piezoelectric actuators were produced by our unique element structure technology using ceramic materials with high electrostrictive factors developed by NEC TOKIN. Features Special ceramics developed by NEC TOKIN are used in piezoelectric ceramic elements. As compared with conventional actuator elements, NEC TOKIN's multilayer piezoelectric actuators have the following advantages: Advantages over electromagnetic actuators Superior response High resolution for positioning Low power consumption No electromagnetic noise Advantages over bimorph piezoelectric actuators High energy conversion efficiency (around 7 times the energy conversion efficiency of the bimorph type actuator), and low power consumption Large generated force Stable displacement, and reduced shift and creep phenomena Higher response speed (more than 100 times the response speed of the bimorph piezoelectric actuator) Advantages over stacked piezoelectric actuators Compact (less than 1/10 the specific ratio of the stacked piezoelectric actuator) Low drive voltage, and ease of use Inexpensive Insulator Internal electrode External electrode Ceramic Structure of NEC TOKIN's Multilayer Piezoelectric Actuator 4 Multilayer Piezoelectric Actuators Vol.01 Resin coated type multilayer piezoelectric actuators AE Series Outline Features Large generated force: 3,500 N/cm2 (typ.) High-speed response: Driving up to about 1/3 of selfresonant frequency (in several ten kHz) is possible. Accurate positioning: Controllable in nm. Low power consumption: Can be retained at the leakage current (100 A or less). Very small size: 1/10 or less of conventional multilayer actuators Multilayer piezoelectric actuators are ceramic elements for converting electrical energy into mechanical energy such as displacement or force by utilizing the piezoelectric longitudinal effect. NEC TOKIN's multilayer piezoelectric actuators are produced based on our unique element structure design by making use of originally developed piezoelectric ceramic materials with high electrostrictive factors. Compared to conventional piezoelectric actuators, they are smaller in size but can generate higher displacement and force at low voltages. Especially, the resin-coated AE series actuators feature compact size and wide variety in shape for use in ultra-fine positioning mechanisms and drive sources for various applications. Applications Printer/magnetic head position adjustment, mirror/ prism positioning, linear motors, pumps, vibration, valve drive, manipulators, etc. Numbering system Example: AE 0505 D16 XXX Additional code (optional) Nominal displacement: Indicated by two digits in micrometers [m] in succession to D Example: D16 = 16 m Cross sectional dimensions: Unit: Millimeters [mm] Example: 0505 = 5 mm 5 mm Series name: AE = Resin-coated type Multilayer Piezoelectric Actuators Vol.01 5 Standard Parts List Displacement [m] Generated force Resonance frequency Capacitance Insulation resistance Overall length Maximum driving voltage Recommended driving voltage [N] [kHz] [F] [M] min. [mm] Model AE0203D04 4.6 1.5 3.0 1.5 200 261 0.09 100 5 AE0203D08 9.1 1.5 6.1 1.5 200 138 0.18 100 10 AE0203D16 17.4 2.0 11.6 2.0 200 69 0.35 50 20 AE0203D44H40 42.0 6.6 28.0 6.6 200 34 0.82 20 40 AE0505D08 9.1 1.5 6.1 1.5 850 138 0.75 50 10 AE0505D16 17.4 2.0 11.6 2.0 850 69 1.4 10 20 AE0505D44H40 42.0 6.6 28.0 6.6 850 34 3.4 5 40 AE1010D16 18.4 3.5 12.3 3.5 3,500 69 5.4 5 20 AE1010D44H40 42.0 6.6 28.0 6.6 3,500 34 13.6 2 40 AE1414D16 18.4 3.5 12.3 3.5 7,000 69 10.8 2 20 AE2525D15 15.6 2.0 10.1 2.0 20,000 69 30.5 0.4 20 Performance Item Standard Operating temperature range Conditions When applied with a DC voltage: Ambient temperature -25 to +85C When driven by an AC voltage: Ambient temperature + Temperature rise due to generated heat Maximum driving voltage 150VDC Recommended driving voltage 100VDC Displacement See the standard parts list Generated force (compression resistance) See the standard parts list Capacitance See the standard parts list Capacitance allowance +/-20 % Dissipation factor 3.5 to 5.0% Insulation resistance See the standard parts list Resonance frequency See the standard parts list Tensile strength 1/10 of generated force Typical value of the element under our test conditions Young's modulus 4.41010N/m2 Typical value of the element under our test conditions The force required for restricting the displacement to 0 when the maximum driving voltage is applied. f=1kHz Value obtained in 1 minute at 150 VDC With both ends of element in free state Typical value of the element under our test conditions Temperature cycle test Displacement: Initial value 20% Room temperature (3 min) Capacitance: Initial value 30% -25C (30 min.) tan: Less than initial rated value Room temperature (3 min) Insulation resistance: 1 M or more +85C (30 min) Appearance: No noticeable defect Repetition of 10 cycles of the above Outer Dimensions Unit : mm Model H 1A007 (+) T1 W1 AE0203D04 20.1 30.1 AE0203D08 20.1 AE0203D16 20.1 AE0203D44H40 AE0505D08 H * T2 W2 50.1 3.5max. 4.5max. 100 30.1 100.1 3.5max. 4.5max. 100 30.1 200.1 3.5max. 4.5max. 100 20.1 30.1 400.1 3.5max. 4.5max. 100 50.1 50.1 100.1 6.5max. 6.5max. 100 AE0505D16 50.1 50.1 200.1 6.5max. 6.5max. 100 50.1 50.1 400.1 6.5max. 6.5max. 100 100.1 100.1 200.1 11.5max. 11.5max. 100 (-) W1 T1 AE0505D44H40 W2 T2 AE1010D16 AE1010D44H40 Note: Factory-shipped polarization : Red lead wire = (+), white lead wire = (-) 6 Multilayer Piezoelectric Actuators Vol.01 100.1 100.1 400.1 11.5max. 11.5max. 100 AE1414D16 14.20.1 14.20.1 200.1 15.7max. 15.7max. 100 AE2525D15 25.10.1 25.10.1 200.1 26.6max. 26.6max. 100 *Length of lead wire Wire diameter Model Number d* D* r* AE0203D08 0.3 0.5 100 AE0203D16 0.3 0.5 100 d = Diameter of lead wire AE0505D08 0.3 0.5 100 D = Outer diameter including the thickness of coating AE0505D16 0.5 0.8 100 AE1010D16 0.5 0.8 100 AE1414D16 0.5 0.8 100 D d R R= Length of lead wire * Typ. Special Design Parts Non-standard parts may be manufactured on order. With regard to the generated displacement and generated force, use the guideline below with the performance of the standard parts as the reference. Displacement: Roughly proportional to the element length Generated force: Roughly proportional to the sectional area of the element Please contact us for further details. Characteristic Data 100 50 Unpolarized 0 Generated displacement (m) Measured temperature : 23C (with use of unpolarized element) AE0505D16 40 Generated displacement (m) Voltage (V) 150 30 20 10 Measured temperature : 23C (with use of unpolarized element) AE0505D16 30 0 50 100 Voltage (V) 150 20 10 Fig. 2 Voltage vs generated displacement characteristics Unpolarized 0 0 20 40 60 80 100 Time (sec) Fig. 1 Voltage and generated displacement vs time characteristics Multilayer Piezoelectric Actuators Vol.01 7 AE0203D08 (measuring 2x3x10mm element) Ihys Generated displacement (m) 20 20 Measured temperature : 255C (with use of polarized element) AE0505D16 Generated displacement (m) 10 150 VDC 500 16 12 0 10 I150 6 I (residual displacement) 4 Ihys -50 0 50 100 150 200 Temperature (C) Generated force (N) Fig. 4 Temperature characteristics of generated displacement 0V, open element -10 I 75 150 Drive voltage (V) 8 0 1000 I150 I + I150 14 2 F0 0 18 0V, shorted element -20 Fig. 3 Generated Force vs Generated Displacement Characteristics DC 75V superimposed on SIN waveform (150V) AE0505D16 AE0505D16 After passage of 5 min 100 80 Heat generation T (C) 1 kHz 500 Hz Heat generation T (C) 70 60 80 Amplitude of a.c. 40 V DC bias 100 V 50 V 150 V 75 V Symbol 20 V 60 40 20 50 200 Hz 40 10 100 1000 AC frequency (Hz) 30 Fig. 6 Heat generation vs frequency characteristics 100 Hz 20 50 Hz 10 0 100 200 300 Time (sec) Fig. 5 Heat development characteristics 8 Multilayer Piezoelectric Actuators Vol.01 Metal sealed type multilayer piezoelectric actuators ASB Series (85C rated), ASL series (150C rated) Outline Features High reliability: Realization of MTTF = 36,000 hours (at 85C and 100 V) Easier installation n equipment thanks to the built-in pre-load mechanism and mounting attachment Minimum mechanical abrasion Large generated force: 800 N Accurate positioning: Controllable in nm Multilayer piezoelectric actuators convert electrical energy into mechanical energy such as displacement or force by making use of the piezoelectric longitudinal effect. NEC TOKIN's multilayer piezoelectric actuators are produced based on our unique element structure design by making use of originally developed piezoelectric ceramic materials with high electrostrictive factors. Compared to conventional piezoelectric actuators, they are smaller in size but can generate higher displacements and forces at low voltages. Especially, the metal sealed ASB/ASL series actuators are much less influenced by ambient humidity because of insulation from the atmosphere. As a result, long service life and high performance never experienced in the past have been attained to allow use in various applications such as semiconductor device production equipment and optical communication equipment requiring high reliability. Applications Fine adjustment of various X-Y tables steppers, mirror/prism positioning, linear motors, fluid flow control valve drive, vibration, manipulators, etc. Numbering system Example: AS B 170 C 801 N P 0 New design No. Sequentially numbered starting from 0 Configuration of drive block P = Plane Configuration of mount N = Female thread type F = Flange type Generated force Unit: Newton [N] The first two digits are effective numerals. The last digit is an exponent of 10. Example: 801 = 800 N = 80 kgf Maximum drive voltage C = 150 V Nominal displacement Unit: Micrometers (m) The first two digits are effective numerals. The last digit is an exponent of 10. Example: 170 = 17 m Construction of housing and B = Bellows ((pre-load), maximum operating temperature: 85C operating temperature range L = Bellows (pre-load), maximum operating temperature: 150C Series name AS = Encapsulated in metal case Multilayer Piezoelectric Actuators Vol.01 9 Standard Parts List * ASB series Generated force Resonance frequency Capacitance Insulation resistance Maximum driving voltage Displacement [m] Recommended driving voltage [N] [kHz] [F] [M] min. ASB170C801*P0 17.0 3 12.0 3 800 14 1.5 30 ASB340C801*P0 34.0 6 24.0 6 800 12 3.0 15 Model ASB510C801*P0 51.0 9 36.0 9 800 10 4.5 10 ASB680C801*P0 68.0 12 48.0 12 800 8 6.0 5 * ASL series Generated force Resonance frequency Capacitance Insulation resistance Maximum driving voltage Displacement [m] Recommended driving voltage [N] [kHz] [F] [M] min. ASL170C801*P0 17.0 3 12.0 3 800 14 1.12 30 ASL340C801*P0 34.0 6 24.0 6 800 12 2.23 15 ASL510C801*P0 51.0 9 36.0 9 800 10 3.35 10 ASL680C801*P0 68.0 12 48.0 12 800 8 4.47 5 Model Performance Item Operating temperature range Standard When applied with DC voltage: Ambient temperature ASL : -40 to +150C When driven by pulse: Ambient temperature + Rise by generated heat Maximum driving voltage 150VDC Recommended driving voltage 100VDC Displacement See the standard parts list Generated force (compression resistance) See the standard parts list Capacitance See the standard parts list Capacitance tolerance +/- 20 % Dissipation factor 3.5 to 5.0% Insulation resistance See the standard parts list Resonance frequency See the standard parts list Airtightness 1 10-8 atm cc/sec or less Displacement: Initial value 30% Capacitance: Initial value 30% Temperature cycle test Conditions ASB : -25 to +85C tan : Less than initial rated value Insulation resistance: 1 M or more Appearance: No noticeable defect The force required for restricting the displacement to 0 when the maximum driving voltage is applied. f=1kHz Value obtained in 1 minute at 150 VDC With both ends of element in free state Typical value of the element under our test conditions ASB ASL Room temperature (3 min) Room temperature (3 min) -25C (30 min) -40C (30 min) Room temperature (3 min) Room temperature (3 min) +85C (30 min) +150C (30 min) Repetition of 10 cycles of the above Displacement: Initial value 30% Capacitance: Initial value 30% High-temperature shelf test Temperature tan : Less than initial rated value Insulation resistance: 1 M or more ASB: 852C ASL: 1502C Time 1,00048 h Appearance: No noticeable defect Displacement: Initial value 30% Capacitance: Initial value 30% Solvent resistance test tan : Less than initial rated value Insulation resistance: 1 M or more Appearance: No noticeable defect Solvent: Isopropyl alcohol Temperature: 235C Time: Immersion for 1 min Mark: Easily legible Displacement: Initial value 30% Capacitance: Initial value 30% Heat resistance test tan : Less than initial rated value Temperature: 1503C Insulation resistance: 1 M or more Time: 964 h Appearance: No noticeable defect Mark: Easily legible 10 Multilayer Piezoelectric Actuators Vol.01 Outer Dimensions (Common to ASB and ASL Series) Flange type Female thread type TOP VIEW TOP VIEW 17 19.60.5 17 Enlarged cross-section of section A (4/1) 11.50.5 4- 3.5 Section A Enlarged cross-section of section A (4/1) 11.50.5 Details of mark Mark ASB001A Section A Product code Details of mark Mark 2A001 Manufacturing lot No. L0.5 2.50.2 L0.5 13010 [mm] 2 Product code 2A001 Manufacturing lot No. 13010 2.50.2 [mm] 2 190.5 90.2 ASB007A 130.5 19.60.5 3.00.2 P.C.D.28 17 45 M4 screw of min. 3 deep Prepared hole of max. 5 deep Part name L AS*170C801NP0 38.4 AS*340C801NP0 45 Part name L AS*170C801FP0 32.4 58.4 AS*340C801FP0 52.4 AS*510C801NP0 78.4 AS*510C801FP0 72.4 AS*680C801NP0 98.4 AS*680C801FP0 92.4 350.5 BOTTOM VIEW BOTTOM VIEW Characteristic Data * ASB series Voltage vs Displacement Drive frequency vs Displacement Compression load vs Displacement 70 60 70 ASB680C801*P0 60 Crest value of voltage 150V (SIN waveform) DC bias : 75V ASB510C801*P0 50 80 B6 AS 60 20 30 20 ASB170C801*P0 10 0 50 100 Displacement (m) Displacement (m) Displacement (m) ASB340C801*P0 AS B5 10 C8 01 *P 0 0 30 40 *P 40 50 01 ASB510C801 *P0 C8 50 Applied voltage 150VDC AS B3 40 C8 01 *P 0 ASB 170C 801* P0 0 200 ASB340C801*P0 30 20 ASB170C801*P0 10 10 150 40 400 600 800 DC voltage (V) Generated force (N) Temperature vs Displacement DC bias vs Capacitance 0 10 1000 100 1000 Drive frequency (Hz) Temperature vs Insulation resistance 60 5 ASB340C801*P0 30 20 4 Insulation resistance () 40 ASB510C801*P0 3 ASB340C801*P0 2 ASB170C801*P0 ASB170C801*P0 10 20 40 Temperature (C) 60 80 0 10 108 ASB510C801*P0 7 10 106 1 0 ASB170C801*P0 9 Capacitance (F) Displacement (m) ASB510C801*P0 -20 1010 Measured frequency : 1kHz 50 0 Measured voltage : 150VDC 6 Applied voltage 150VDC 50 100 DC bias voltage (V) 150 -25 -15 -5 5 25 45 65 85 105 125 Temperature (C) Multilayer Piezoelectric Actuators Vol.01 11 * ASL series Temperature vs. Capacitance Temperature vs.Displacement 60 2500 2000 Capacitance (nF) Displacement(m) 50 ASB510C801*** 40 30 ASL510C801*** 20 ASB Type 1500 1000 ASL Type 500 10 0 0 -40 -20 0 20 80 100 40 60 Temperature(C) 120 140 160 -40 -20 0 20 40 60 80 100 120 140 160 SAMPLE:5x5x20mm Temperature (C) Shall be added as required in the same way as for the ASB series in the future Application Examples DC servo motor Y-direction drive frame Control circuit Piezoelectric actuator Piezoelectric actuator Drive table Bypath Diaphragm Flexible supporting rod Y Drive table X X-Y slide surface Base PTFE slider (Tuning method: Air gap) Piezo Actuator Air Gap Alignment Fixture Single Mode Fiber Mirror 12 Multilayer Piezoelectric Actuators Vol.01 Glass Ferrule Reliability Majority of failure mode of multilayer piezoelectric actuators is the short circuit due to degraded insulation. Though the cause of degradation of insulation has not been clarified perfectly, it has been found that the failure rate varies greatly between statistic uses (DC voltage application) and dynamic uses (pulse voltage application). Since it has been found that the influence of humidity is great in addition to the ambient temperature as in the case of other general electronic parts, the metal sealed type featuring high reliability by elimination of the influence of the atmosphere has been added in the product line. This section describes the reliability guidelines for static and dynamic uses for each of the resin-coated and metal sealed types. Reliability of our multilayer piezoelectric actuators is represented by MTTF (mean time to failure) on assumption of static uses. Though the number of repetitions is considered to be used to represent the reliability in the case of dynamic uses, the accurate relationship between the indicator and cause has not been obtained because of various influential causes and the mutual action between them. For the present, therefore, only the obtained data and our concept are described. (1) Resin-coated Type (AE Series) a. DC voltage application The acceleration factor has been obtained empirically for each of the drive voltage, ambient temperature and relative humidity based on many experimental result data. The MTTFr in an actual application is estimated using equation (1) below with MTTFs observed under accelerated condition as the reference value. MTTF r=MTTF sA vA hA t * * * (1) MTTF r : Estimated value MTTF s : Reference value (=500h) * * * Typical value as of the year 1990 A v : Acceleration factor for drive voltage= 150 3.2 V r : Actual voltage (V) Vr A h : Acceleration factor for relative humidity= 90 4.9 H r : Actual relative humidity (RH%) Hr A t : Acceleration factor for ambient temperature=1.5 40-Tr 10 T r : Actual ambient temperature(C) [Example] The following calculation is made for the case of use at 25C, 60% RH and 100 V: MTTF r =500 150 100 3.2 90 60 4.9 1.5 40-25 10 =5003.667.291.84 24,500h (2.8years) b. Pulse voltage application When this element is driven by a pulse voltage, temperature rise occurs as a result of heating due to dielectric loss of ceramics. Therefore, the element is not likely to be influenced by the humidity, thus extending the service life greatly. Since this effect is affected by the element shape, pulse waveform and frequency, it cannot be calculated by an equation as in the case of DC voltage application. It has been seen that no failure occurred after application of 0 to 150-V rectangular pulse wave at 500 Hz to the AE0203D08 for 500 hours (equivalent to 900 million pulses). On the other hand, physical damage due to ringing phenomenon due to element fixing method and voltage rising speed may arise, so attention should be paid. Please refer to the separately printed "Guide to Multilayer Actuator" for more detailed data. Multilayer Piezoelectric Actuators Vol.01 13 (2) Metal Sealed Type (ASB/ASL Series) a. DC voltage application MTTFr of the metal sealed type under the actual operating conditions is calculated/estimated from the reference MTTFs and the acceleration factor as in the case of the resin-coated type. However since the internal element is sealed from the atmosphere, it is not influenced by the atmospheric humidity. Therefore, equation (2) below is used. MTTF r =MTTF sA vA t * * * (2) MTTF r : Estimated value MTTF s : Reference value (=36,000h) * * * Typical value as of 1990 A v : Acceleration factor for drive voltage= 100 2 V r : Actual operating voltage (V) Vr A t :Acceleration factor for ambient temperature=1.5 85-Tr 10 T r : Actual operating temperature (C) [Example] The following calculation is made for use at 25(c and 150 V: MTTF r=36,000 100 2 150 85-25 10 1.5 =36,0000.4411.3 179,000h (20.4years) b. Pulse voltage application Estimation by an equation is extremely difficult because of the influence of the pulse waveform, frequency, etc. in addition to the voltage and ambient temperature as in the case of the resin-coated type. It has been seen that no failure occurred under the following conditions up to 1,000 hours (equivalent to 100 million pulses) in the case of the ASB170C801NP0: [Conditions for evaluation] Temperature: 852C Humidity: 90 to 95% RH Load: 200 N to 500 N (20 kgf to 50 kgf) Drive voltage waveform: Rectangular wave, 30 Hz, 0 V to 100 V, duty ratio at 30% 14 Multilayer Piezoelectric Actuators Vol.01 Guide to Use Fixing Method: Carefully prevent any bending, twisting or tensile force from being applied to this product. Reference: Guide for tolerance of twisting and tension Reference value Remarks -1 Twisting force 310 N*m or less For an actuator which generates a force of 800 N Tension 50 N or less (compression resistance) Install the actuator so that the center axis of generated displacement is aligned with the center axis of the load. a. Resin-coated type * Epoxy-based adhesives are usable for bonding. Select a type featuring high rigidity and minimum thickness so that the generation force and displace ment would not be spoiled. * When thermosetting resin is used, perform polarizing treatment (see the caution section) again after setting. * This type is weak to a tensile force because of its structure and may be broken when applied with tension. Use in the state constantly applied with compression is effective in preventing any mechanical damage. The pressure applied to this element should be kept at 20 to 50% of the force generated by this element (compression resistance). * Install the element so that the axis of generated displacement is vertical to the mounting surface. b. Metal sealed type * Select the mounting bracket (female thread type or flange type) according to the mounting method, and install the element utilizing the bracket. * Fix the element securely so as not to damp the generated force or displacement. * Connect the driven item at the displacement generating end after securing the mounting portion so as to avoid unnecessary stress application at the time of installation. * Though this product is designed to apply a compressive force to the internal element by the metal case, avoid any usage causing application of bending, twisting or tension at the time of driving. Driving Method: Connect the red lead wire to the positive (+) terminal of the power supply. Also prevent reverse voltage application. Basically the voltage controls the aimed displacement and generated force. In driving, however, it is also necessary to take ringing due to the resonance or hysteresis of the element itself into consideration. In pulse driving, it is further necessary to pay sufficient attention to heat generation due to dielectric loss, charge/discharge current due to the capacitive component and the power output impedance as well. Please refer to the separately printed Guide for Use of Multilayer Piezoelectric Actuators". Multilayer Piezoelectric Actuators Vol.01 15 Precautions Connect the red lead wire to the positive (+) terminal of the power supply. Carefully avoid electric shock since a high voltage is in use. Never apply an excessive tension to a lead wire. Do not handle the product by picking up or moving the lead wire. Do not disassemble the case of the metal sealed type. Machining of the actuator element and replacement of the lead wire are prohibited. Do not handle the resin-coated type (AE series) with bare hands. Otherwise, the reliability of the element would be degraded. Do not wash resin-coated type (AE series) by organic solvant. Avoid excessive physical shock resulting from, for example, dropping. Otherwise, the internal piezoelectric ceramic element may be damaged. If exposed to high temperatures above 100C or for use after long storage (for more than three months), the actuator should be used after being polarized using the following circuit configuration and conditions shown below. R1 S V PA R2 Protective resistor R1 = 1 k Protective resistor R2 = 1 k Polarizing conditions: DC voltage application 0 V 1500.2 V (to be retained for 10 seconds) 0 Do not apply voltage exceeding MAX. driving voltage value to the actuator. Otherwise, degraded reliability or mechanical fracture may arise. Do not use the actuator in a high concentration of highly inflammable gas. Otherwise, ignition may occur. Use the actuator so as not to cause bending, twisting or tension. Furthermore, align the center axis of displacement of the actuator with the center axis of the mechanical load. Drive the actuator at an initial speed exceeding three times the resonance cycle to prevent damage caused by ringing. Store the resin-coated type (AE series) preferably in a dry atmosphere (desirably below 40% RH) at ordinary temperatures (-5 to +40C). Store actuators where there is no vibration. 16 Multilayer Piezoelectric Actuators Vol.01 Multilayer Piezoelectric Actuators Vol.01 17 18 Multilayer Piezoelectric Actuators Vol.01 When using our products, the following precautions should be taken. (1) Safety designing of an apparatus or a system allowing for failures of electronic components used in the system In general, failures will occur in electronic components at a certain probability. NEC TOKIN makes every effort to improve the quality and reliability of electronic component products. However, it is impossible to completely eliminate the probability of failures. Therefore, when using NEC TOKIN's electronic component products, systems should be carefully designed to ensure redundancy in the event of an accident which would result in injury or death, fire, or social damage, to ensure the prevention of the spread of fire, and the prevention of faulty operation. (Please refer to precautions to be taken when using multilayer piezoelectric actuators for the details of failures.) (2) Quality level of various kinds of parts, and equipment in which the parts can be utilized Electronic components have a standard quality level unless otherwise specified. NEC TOKIN classifies the level of quality of electronic component products into three levels, in order from a lower level, a standard quality level, a special quality level, and a custom quality level in which a customer individually specifies a quality assurance program. Each of the quality levels has recommended applications. If a user wants to use the electronic parts having a standard quality level in applications other than the applications specified for the standard quality level, they should always consult a member of our company's sales staff before using the electronic parts. Standard quality level : Computers, office automation equipment, communications equipment, measuring instruments, AV equipment, household electrical appliances, machine tools, personal equipment, industrial robots Special quality level : Transportation equipment (automobiles, railways, shipping, or the like), traffic signals, disaster prevention/crime prevention systems, a variety of safety devices, and medical equipment which is not directly intended for life-support purposes Custom quality level : Equipment for airplanes, aerospace equipment, nuclear power control systems, and medical equipment, apparatus or system for life-support purposes Unless otherwise shown, the quality level of NEC TOKIN's electronic component products included in documents such as catalogues, data sheets or data books is the standard quality level. (3) This manual is subject to change without notice. The contents of this manual are based on data which is correct as of September 2004, and they may be changed without notice. If our products are used for mass-production design, please cousult with a member of our company's sales staff by way of precaution. (4) Reprinting and copying of this manual without prior written permission from NEC TOKIN Corporation are not permitted. (5) Industrial property problems In the event any problems associated with industrial property of a third party arising as a result of the use of our products, NEC TOKIN assumes no responsibility for problems other than problems directly associated with the constitution and manufacturing method of the products. (6) Should any of these products come under the category of strategic goods or services (according to Japan's foreign trade and foreign exchange regulations), the sender must obtain an export license from the Japanese Government before said products can be exported outside Japan.