Quality Information www.vishay.com Vishay Semiconductors Quality Information Corporate Quality Policy Our goal is to exceed the quality expectations of our customers. This commitment starts with top management and extends through the entire organization. It is achieved through innovation, technical excellence, and continuous improvement. 18348 Fig. 1 - Vishay Quality Policy Rev. 1.8, 25-Jan-16 1 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors VISHAY INTERTECHNOLOGY, INC. ENVIRONMENTAL, HEALTH, AND SAFETY POLICY Vishay Intertechnology, Inc. is committed to conducting its worldwide operations in a socially responsible and ethical manner to protect the environment, and ensure the safety and health of our employees, to conduct their daily activities in an environmentally responsible manner. Protection of the Environment: conduct our business operation in a manner that protects the environmental quality of the communities in which our facilities are located. Reduce risks involved with storage and use of hazardous materials. The company is also committed to continual improvement of its environmental performance. Compliance with Environmental, Health and Safety Laws, and Regulations: comply with all relevant environmental, health and safety laws, and regulations in every location. Maintain a system that provides timely updates of regulatory change. Cooperate fully with governmental agencies in meeting applicable requirements. Energy, Resource Conservation, and Pollution Control: strive to minimize energy and material consumption in the design of products and processes, and in the operation of our facilities. Promote the recycling of materials, including hazardous wastes, whenever possible. Minimize the generation of hazardous and non-hazardous wastes at our facilities to prevent or eliminate pollution. Manage and dispose of wastes safely and responsibly. World Class Excellence • 2016 • • • 2000 • • • • 1995 • • • • 1990 Think Automotive Quality Zero Defect Strategy Integrated Management System Design for Six Sigma ISO / TS 16949 ISO 14000 QS 9000 / VDA 6.1 EFQM Approach ISO 9000 Advanced Quality Tools Cost of Quality Empowered Improvement Team 17275 Fig. 2 - Vishay Quality Road Map QUALITY SYSTEM VISHAY CORPORATE QUALITY Vishay Corporate Quality defines and implements the Vishay quality policy at a corporate level. It acts to harmonize the quality systems of the constituent division and to implement Total Quality Management throughout the company worldwide. QUALITY PROGRAM At the heart of the quality process is the Vishay worldwide quality program. This program, which has been in place since the early 90’s, is specifically designed to meet rapidly increasing customer quality demands now and in the future. Vishay Zero Defect Program • Exceeding quality expectations of our customers • Commitment from top management through entire organization • Newest and most effective procedures and tools - Design, manufacturing, and testing - Management procedures (e.g. SPC, TQM) • Continuous decreasing numbers for AOQ and failure rate • Detailed failure analysis using 8D methodology • Continuous improvement of quality performance of parts and technology Vishay Corporate Quality implements the Quality Policy and translates its requirements for use throughout the worldwide organization. Vishay Quality has defined a roadmap with specific targets along the way. The major target is to achieve world-class excellence throughout Vishay worldwide. Rev. 1.8, 25-Jan-16 2 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors QUALITY GOALS AND METHODS The goals are straightforward: customer satisfaction through continuous improvement towards zero defects in every area of our operation. We are committed to meet our customers’ requirements in terms of quality and service. In order to achieve this, we build excellence into our products from concept to delivery and beyond. • Design-in Quality Quality must be designed into products. Vishay uses optimized design rules based on statistical information. This is refined using electrical, thermal, and mechanical simulation together with techniques such as FMEA, QFD, and DOE. 18349 • Built-in Quality Quality is built into all Vishay products by using qualified materials, suppliers, and processes. Fundamental to this is the use of SPC techniques by both Vishay and its suppliers. The use of these techniques, as well as tracking critical processes, reduces variability, optimizing the process with respect to the specification. The target is defect prevention and continuous improvement. The procedures used are based upon these standards and laid down in an approved and controlled quality manual. BUSINESS EXCELLENCE Total quality management is a management system combining the resources of all employees, customers, and suppliers in order to achieve total customer satisfaction. The fundamental elements of this system are: • Qualification All new products are qualified before release by submitting them to a series of mechanical, electrical, and environmental tests. The same procedure is used for new or changed processes or packages. • Management commitment • EFQM assessment methodology • Employee involvement teams (EITs) • Supplier development and partnership • Monitoring A selection of the same or similar tests used for qualification is also used to monitor the short- and long-term reliability of the product. • Quality tools • Training • Quality system • SPC (Statistical Process Control) SPC is an essential part of all Vishay process control. It has been established for many years and is used as a tool for the continuous improvement of processes by measuring, controlling, and reducing variability. • Design for Six Sigma • Think Automotive Quality program • Zero defect All Vishay employees from the senior management downwards are trained in understanding and use of TQM. Every employee plays its own part in the continuous improvement process which is fundamental to TQM and our corporate commitment to exceed customers’ expectations in all areas including design, technology, manufacturing, human resources, marketing, and finance. Everyone is involved in fulfilling this goal. The management believes that this can only be achieved by employee empowerment. • Vishay Quality System All Vishay’s facilities worldwide are approved to ISO 9000. In addition, depending on their activities, some Vishay companies are approved to recognized international and industry standards such as ISO / TS 16949. • Each subsidiary goal is to fulfill the particular requirements of customers. The Optoelectronic divisions of Vishay Semiconductor GmbH are certified according to ISO / TS 16949. The Vishay corporate core values • Leadership by example • Employee empowerment • Continuous improvement • Total customer satisfaction are the very essence of the Vishay Quality Movement process. Rev. 1.8, 25-Jan-16 3 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors • Training • Gauge Repeatability and Reproducibility (GR and R) Vishay maintains that it can only realize its aims if the employees are well trained. It therefore invests heavily in courses to provide all employees with the knowledge they need to facilitate continuous improvement. A training profile has been established for all employees with emphasis being placed on total quality leadership. Our long-term aim is to continuously improve our training so as to keep ahead of projected changes in business and technology. This technique is used to determine equipment’s suitability for purpose. It is used to make certain that all equipment is capable of functioning to the required accuracy and repeatability. All new equipment is approved before use by this technique. • Quality Function Deployment (QFD) QFD is a method for translating customer requirements into recognizable requirements for Vishay’s marketing, design, research, manufacturing, and sales (including after-sales). QFD is a process, which brings together the life cycle of a product from its conception, through design, manufacture, distribution, and use until it has served its expected life. TQM TOOLS As part of its search for excellence, Vishay employs many different techniques and tools. The most important of them are: • Auditing QUALITY SERVICE As well as third party auditing employed for approval by ISO 9000 and customers, Vishay carries out its own internal and external auditing. There is a common auditing procedure for suppliers and sub-contractors between the Vishay entities. This procedure is also used for inter-company auditing between the facilities within Vishay. It is based on the “Continuous Improvement” concept with heavy emphasis on the use of SPC and other statistical tools for the control and reduction of variability. Vishay believes that quality of service is equally as important as the technical ability of its products to meet their required performance and reliability. Our objectives therefore include: Internal audits are carried out on a routine basis. They include audits of satellite facilities (i.e., sales offices, warehousing etc.). Audits are also used widely to determine attitudes and expectations both within and outside the company. • A partnership with our customers • On-time delivery • Short response time to customers’ requests • Rapid and informed technical support • Fast handling of complaints 18351 18352 • Failure Mode and Effect Analysis (FMEA) • Customer Quality FMEA is a technique for analyzing the possible methods of failure and their effect upon the performance / reliability of the product / process. Process FMEAs are performed for all processes. In addition, product FMEAs are performed on all critical or customer products. Complaints fall mainly into two categories: • Logistical • Technical Vishay has a procedure detailing the handling of complaints. Initially complaints are forwarded to the appropriate sales office where in-depth information describing the problem, using the Vishay customer analysis request (CAR), is of considerable help in giving a fast and accurate response. If it is necessary to send back the product for logistical reasons, the sales office issues a returned material authorization (RMA) number. • Design of Experiments (DOE) There is a series of tools that may be used for the statistical design of experiments. It consists of a formalized procedure for optimizing and analyzing experiments in a controlled manner. Taguchi and factorial experiment design are included in this. They provide a major advantage in determining the most important input parameters, making the experiment more efficient and promoting common understanding among team members of the methods and principles used. Rev. 1.8, 25-Jan-16 On receipt of the goods in good condition, credit is automatically issued. 4 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors If there is a technical reason for complaint, a sample together with the CAR is sent to the sales office for forwarding to the failure analysis department of the supplying facility. The device’s receipt will be acknowledged and a report issued on completion of the analysis. The cycle time for this analysis has set targets and is constantly monitored in order to improve the response time. Failure analysis normally consists of electrical testing, functional testing, mechanical analysis (including X-ray), decapsulation, visual analysis and electrical probing. Other specialized techniques (i.e. LCD, thermal imaging, SEM, acoustic microscopy) may be used if necessary. If the analysis uncovers a quality problem, a corrective action report (CAR) in 8D format will be issued. Any subsequent returns are handled with the RMA procedure. 21112 Customer notifies Vishay sales office of a complaint and sales obtains the necessary information about return using attached form (CAR) Complaint regarding comercial aspects like wrong product, stock rotation wrong quantity Complaint regarding technical aspects like out of spec, wrong label, packaging Samples to be sent by the customer to the Vishay location in charge 8D report to be sent to the customer with Vishay reference number Entitled to return / replacement products No End of return procedure Yes 22539 Sales assign RMA for customer product return Complaint and Return Procedure Rev. 1.8, 25-Jan-16 5 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors 22209 Corrective Action Request Form Rev. 1.8, 25-Jan-16 6 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Vishay 8D Form Rev. 1.8, 25-Jan-16 7 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Vishay 8D Form Rev. 1.8, 25-Jan-16 8 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Change Notification RELIABILITY AND QUALIFICATION All product and process changes are controlled and released via ATP (approval of technical product and process changes). This requires the approval of the relevant departments. In the case of a major change, the change is forwarded to customers via sales / marketing before implementation. Where specific agreements are in place, the change will not be implemented unless approved by the customer. Qualification is used as a means of verifying that a new product or process meets specified reliability requirements. This is also used to verify and release changes to products or processes including new materials, packages, and manufacturing locations. At the same time it provides a means to obtain information on the performance and reliability of new products and technologies. QUALITY AND RELIABILITY • Wafer process / technology qualification • Package qualification • Product / device qualification The actual qualification procedure depends on which of these (or combinations of these) are to be qualified. Normally there are three categories of qualification in order of degree of qualification and testing required. There are three types of qualification and release: ASSURANCE PROGRAM Though both quality and reliability are designed into all Vishay products, three basic programs must assure them: • Average outgoing quality (AOQ) - 100 % testing is followed by sample testing to measure the defect level of the shipped product. This defect level (AOQ) is measured in ppm (parts per million) For the qualification there are two different standards. For Commodity and Industrial products the Vishay internal standard is used. For Vishay Automotive Grade parts, the qualification is done according to AEC-Q101. • Reliability qualification program - to assure that the design, process, or change is reliable Accelerated testing is normally used in order to produce results fast. The stress level employed depends upon the failure mode investigated. The stress test is set so that the level used gives the maximum acceleration without introducing any new or untypical failure mode. • Reliability monitoring program - to measure and assure that there is no decrease in the reliability of the product The tests used consist of a set of the following: • High temperature life test (static) • High temperature life test (dynamic) • HTRB (high temperature reverse bias) • Humidity 85/85 (with or without bias) • Temperature cycling • High-temperature storage • Low-temperature storage • Marking permanency • Lead integrity • Solderability • Resistance to solder heat • Mechanical shock (not plastic packages) • Vibration (not plastic packages) • ESD characterization SMD devices only are subjected to pre-conditioning to simulate board assembly techniques using the methods defined in standard J-STD-020D before being subjected to stresses. 18357 AOQ PROGRAM Before leaving the factory, all products are sampled after 100 % testing to ensure that they meet a minimum quality level and to measure the level of defects. The results are accumulated and expressed in ppm (parts per million). They are the measure of the average number of potentially failed parts in deliveries over a period of time. The sample size used is determined by AQL or LTPD tables depending upon the product. No rejects are allowed in the sample. The AOQ value is calculated monthly using the method defined in standard JEDEC® 16: 6 AOQ = p x LAR x 10 (ppm) where: Normally, the endpoint tests are related to the datasheet or to specified parameters. Additionally, they may include: number of devices rejected p = -------------------------------------------------------------------------------total number of devices tested = lot acceptance rate: number of lots rejected LAR = 1 – ------------------------------------------------------------number of lots tested • • • • • The AOQ values are recorded separately with regard to electrical and mechanical (visual) rejects by product type and package. Rev. 1.8, 25-Jan-16 9 Destructive physical analysis X-ray Delamination testing using scanning acoustic microscope Thermal imaging Thermal and electrical resistance analysis Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Qualification procedure Wafer process qualification Package qualification Device type qualification Monitoring Process change qualification 18358 A summary of the reliability test results combined with process flows and technological data will be prepared when the device has passed the Vishay qualification tests. The summary is named QualPack. For Vishay Automotive Grade devices also additional information according to the PPAP requirements will be provided on request. 22212 Example of the QualPack Rev. 1.8, 25-Jan-16 10 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors RELIABILTY MONITORING AND WEAR-OUT MTTF, MTBF The monitoring program consists of short-term monitoring to provide fast feedback on a regular basis in case of a reduction in reliability and to measure the early-life failure rate (EFR). At the same time, long-term monitoring is used to determinate the long-term steady-state failure rate (LFR). The tests used are a subset from those used for qualification and consist of: MTTF (mean time to failure) applies to parts that will be thrown away on failing. MTBF (mean time between failures) applies to parts or equipment that is going to be repaired. MTTF is the inverse failure rate. 1 MTTF = -- So R(t) becomes to: • Life tests • Humidity tests R (t) = e • Temperature-cycling tests = e t - ---------------MTTF After a certain time, t will be equal to MTTF, R(t) becomes: The actual tests used depend on the product tested. R (t) = e Depending on the assembly volume a yearly monitoring and wear-out test plan is created. -1 = 0.37 If a large number of units are considered, only 37 % of their operation times will be longer than MTTF figure. Wear-out data are very important in optoelectronic device. Failure rate λ - t The failure rate () during the constant (random) failure period is determined from life-test data. The failure rate is calculated from the formula: r r = ------------------------------------------- = ---C fi x ti + N x t Useful life where = failure rate (h-1) 21140 Early failure period Constant failure rate period r = number of observed failures Wear-out failure period fi = failure number ti = time to defect Fig. 3 - Bathtub Curve N = good sample size The lifetime distribution curve is shown on fig. 3. This curve is also known as the “bath-tub curve” because of its shape. There are three basic sections: t = entire operating time C = number of components x h The result is expressed in either • Early-life failures (infant mortality) • Operating-life failures (random failures) a) % per 1000 component hours by multiplying by 105 • Wear-out failures or in Out of that data degradation curves can be made. These curves show the long time behavior of the different devices. b) FITs by multiplying by 109 (1 FIT = 10-9 h -1) Example 1: determination of failure rate 500 devices were operated over a period of 2000 h (t) with: 1 failure (f1) after 1000 h (t1) The failure rate of the given example can be calculated as follows: 1 = -------------------------------------------------------------------------- 1 x 1000 h + 499 x 2000 h Some typical curves are attached in this report. RELIABILITY PRINCIPLES Reliability is the probability that a part works operated, under specific conditions, performs properly for a given period of time. –6 –1 = 1.001 x 10 h F(t) + R(t) = 1 or R(t) = 1 - F(t) That means that this sample has an average failure rate of 0.1 %/1000 h or 1001 FIT where: R(t) = probability of survival F(t) = probability of failure F(t) = 1 - e-t Example 2: the failure rate of the population Using example 1 with a failure rate of 1001 FIT and 1 failure: 2/2 at 60 % confidence is 2.02 where = instantaneous failure rate t = time thus, 2.02 pop = ---------------------------5- = 2022 FIT 9.99 x 10 This means that the failure rate of the population will not exceed 2022 FIT with a probability of 60 %. R(t) = e-t Rev. 1.8, 25-Jan-16 11 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Observed failure rates as measured above are for the specific lot of devices tested. If the predicted failure rate for the total population is required, statistical confidence factors have to be applied. The confidence factors can be obtained from “chi square” (2) charts. Normally, these charts show the value of (2/2) rather than 2. The failure rate is calculated by dividing the 2/2 factor by the number of component hours. 2 pop = ----------------C 2 The values for 2/2 are given in table 1 18362 ACTIVATION ENERGY TABLE 1 - 2/2 CHART Provided the stress testing does not introduce a failure mode, which would not occur in practice, this method gives an acceptable method for predicting reliability using short test periods compared to the life of the device. It is necessary to know the activation energy of the failure mode occurring during the accelerated testing. This can be determined by experiment. In practice, it is unusual to find a failure or if there is, it is a random failure mode. For this reason an average activation energy is normally used for this calculation. Though activation energies can vary between 0.3 eV and 2.2 eV, under the conditions of use, activation energies of between 0.6 eV and 0.9 eV are used depending upon the technology. CONFIDENCE LEVEL NUMBER OF FAILURES 60 % 90 % 0 0.92 2.31 1 2.02 3.89 2 3.08 5.30 3 4.17 6.70 4 5.24 8.00 5 6.25 9.25 6 7.27 10.55 • Accelerated Stress Testing In order to be able to assure long operating life with a reasonable confidence, Vishay carries out accelerated testing on all its products. The normal accelerating factor is the temperature of operation. Most failure mechanisms of semiconductors are dependent upon temperature. This temperature dependence is best described by the Arrhenius equation. 0.8 eV 0.7 eV Acceleration Factor T2 = T1 x e 1000 EA 1 1 ------ x ----- – ----- T1 T2 k where k EA T1 T2 T 1 T 2 = Boltzmann’s constant 8.63 x 10-5 eV/K = activation energy (eV) = operation temperature (K) = stress temperature (K) = operation failure rate = stress-test failure rate 0.6 eV 100 0.5 eV 10 1 55 18361 75 95 115 135 155 Temperature (°C) Fig. 4 - Acceleration Factor for different Activation Energies Normalized to T = 55 °C Using this equation, it is possible from the stress test results to predict what would happen in use at the normal temperature of operation. Rev. 1.8, 25-Jan-16 12 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors ACTIVATION ENERGIES FOR COMMON FAILURE MECHANISMS • Climatic Tests Models Temperature cycling failure rate The inverse power law is used to model fatigue failures of materials that are subjected to thermal cycling. For the purpose of accelerated testing, this model relationship is called Coffin-Manson relationship, and can be expressed as follows: The activation energies for some of the major semiconductor failure mechanisms are given in the table below. These are estimates taken from published literature. TABLE 2 - ACTIVATION ENERGIES FOR COMMON FAILURE MECHANISM T stress M A F = -------------------- T use FAILURE MECHANISM ACTIVATION ENERGY Mechanical wire shorts 0.3 to 0.4 Diffusion and bulk defects 0.3 to 0.4 AF Tuse Oxide defects 0.3 to 0.4 Tstress = temp. range under stress operation Top-to-bottom metal short where: 0.5 M = acceleration factor = temp. range under normal operation = constant characteristic of the failure mechanism Electro migration 0.4 to 1.2 Electrolytic corrosion 0.8 to 1.0 TABLE 3 - COFFIN - MANSON EXPONENT M Gold-aluminum intermetallics 0.8 to 2.0 FAILURE MECHANISM M Gold-aluminum bond degradation 1.0 to 2.2 Al wire bond failure Intermetallic bond fracture Au wire bond heel crack Chip-out bond failure 3.5 4.0 5.1 7.1 Ionic contamination 1.02 Alloy pitting 1.77 Failure rates are quoted at an operating temperature of 55 °C and 60 % confidence using an activation energy (EA) of 0.8 eV for optoelectronic devices. For instance: T use = 15 °C/60 °C = 45 °C T stress = -25 °C/100 °C = 125 °C Example 3: conversion to 55 °C In Example 2, the life test was out at 125 °C so to transform to an operating temperature of 55 °C. T1 = 273 + 55 = 328 K T1 = 273 + 125 = 398 K Acceleration factor = 3 125 °C A F = ------------------ 21 45 °C Relative Humidity failure rate Moisture effect modeling is based upon the Howard-Pecht-Peck model using the acceleration factor of the equation shown below: T (423 K) ----------2- = ----------------- = 144 T (328 K) 1 thus 423 K 2022 328 K = -------------------- = ------------144 144 RH stress A F = --------------------- RH use = 14 FIT (at 55 °C with a confidence of 60 %) C xe E 1 1 -----A- --------- – ------------ k T use T stress where: This figure can be re-calculated for any operating / junction temperature using this method. RHstress = relative humidity during test RHuse = relative humidity during operation • EFR (Early Life Failure Rate) Tstress = temperature during test This is defined as the proportion of failures that will occur during the warranty period of the system for which they were designed. In order to standardize this period, Vishay uses 1000 operation hours as the reference period. This is the figure also used by the automotive industry; it equates to one year in the life of an automobile. In order to estimate this figure, Vishay normally operates a sample of devices for 48 h or 168 h under the accelerated conditions detailed above. The Arrhenius law is then used as before to calculate the failure rate at 55 °C with a confidence level of 60 %. This figure is multiplied by 1000 to give the failures in 1000 h and by 106 to give a failure in ppm. All EFR figures are quoted in ppm (parts per million). Tuse = temperature during operation EA = activation energy k = Boltzmann constant C = material constant For instance: RHstress = 85 %, RHuse = 92 % Tstress = 85 °C, Tuse = 40 °C 0.8 1 1 ---------------------------------------- – ---------- -5 8.617 x 10 313 358 85 % RH 3 A F = ------------------------ x e 92 % RH A F 33 The value of EFR and LFR is also depending on the amount of new products brought to market in the period. If a lot of new products are released the EFR and the LFR value can also be increased in that period due to increased rejects. Rev. 1.8, 25-Jan-16 13 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors This example shows how to transform test conditions into environmental or into another test conditions. This equation is applicable for devices subjected to temperature humidity bias (THB) testing. These include the use of: • Earthen wrist straps and benches • Conductive floors • Protective clothing Using these acceleration factors the useful lifetime can be calculated. Applying the acceleration factor once more, useful lifetime for the moisture effect model for parts subjected to THB can be estimated by the following equation: Useful life years • Controlled humidity It also lays down the methods for routinely checking these and other items such as the earthen of machines. A semiconductor device is only completely protected when enclosed in a «Faraday Cage». This is a completely closed conductive container (i.e., sealed conductive bag or box). A F x test hours = ---------------------------------------hours per year with: test hours = 1000 hours per year = 8760 Most packaging material (i.e. tubes) used for semiconductors is now manufactured from anti-static material or anti-static-coated material. This does not mean that the devices are completely protected from ESD, only that the packing will not generate ESD. Devices are completely protected only when surrounded on all sides by a conductive package. AF 118 (40 °C / 60 % RH) 118 x 1000 Useful life years = ------------------------------ 13.5 years 8760 This means that operation in 40 °C / 60 % RH environment is good for around 13 years, calculated out of the 85 °C / 85 % RH 1000 h humidity stress test. It should also be remembered that devices can equally as easily be damaged by discharge from a high voltage to ground as vice-versa. HANDLING FOR QUALITY Testing for ESD resistance is part of the qualification procedure. The methods used are detailed in MIL-STD-883 Method 3015.7 (human body model) and EOS/ESD-S5.1-1993 (machine model) specification. Also testing according to the CDM (charged coupled device model) is part of the advanced qualification procedure. • Electrostatic Discharge (ESD) Precautions Electrostatic discharge is defined as the high voltage, which is generated when two dissimilar materials move in contact with one another. This may be by rubbing (i.e. walking on a carpet) or by hot air or gas passing over an insulated object. Sometimes, ESD is easily detectable as when a person is discharged to ground. • Soldering All products are tested to ascertain their ability to withstand the industry standard soldering conditions after storage. In general, these conditions are as follows: Electronic devices may be irreversibly damaged when subjected to this discharge. They can also be damaged if they are charged to a high voltage and then discharged to ground. • Wave soldering: Double-wave soldering according to CECC 00802 Damage due to ESD may occur at any point in the process of manufacture and use of the device. ESD is a particular problem if the humidity is low (< 40 %) which is very common in non-humidified but air-conditioned buildings. ESD is not just generated by the human body but can also occur with ungrounded machinery. • Reflow soldering: according to JEDEC STD 20D Note • Certain components may have limitations due to their construction • Dry pack ESD may cause a device to fail immediately or damage a device so that it will fail later. Whether this happens or not, usually depends on the energy available in the ESD pulse. When being stored, certain types of device packages can absorb moisture, which is released during the soldering operations, thus causing damage to the device. The so-called “popcorn” effect is such an example. To prevent this, surface mount devices (SMD) are evaluated during qualification, using a test consisting of moisture followed by soldering simulation (pre-conditioning) and then subjected to various stress tests. In table 4 - Moisture Sensitivity Levels - the six different levels, the floor life conditions as well as the soak requirements belonging to these levels are described. Any device which is found to deteriorate under these conditions is packaged in “dry pack”. All ESD-sensitive Vishay products are protected by means of • Protection structures on chip • ESD protection measures during handling and shipping Vishay has laid down procedures, which detail the methods to be used for protection against ESD. These measures meet or exceed the standards for ESD-protective and preventative measures. Rev. 1.8, 25-Jan-16 The dry-packed devices are packed generally according to IPC JEDEC STD 33 “Handling, Packing, Shipping and use of Moisture / Reflow Sensitive Surface Mount Devices”, IPC-SM-786 “Recommended Procedures for Handling of Moisture Sensitive Plastic IC Packages”. 14 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Following some general recommendations: • Shelf life in the packaging at < 40 °C and 90 % RH is 12 months • After opening, the devices should be handled according to the specifications mentioned on the dry-pack label • If the exposure or storage time is exceeded, the devices should be baked: - Low-temperature baking - 192 h at 40 °C and 5 % RH - High-temperature baking - 24 h at 125 °C TABLE 4 - MOISTURE SENSITIVITY LEVELS FLOOR LIFE SOAK REQUIREMENTS LEVEL CONDITIONS TIME TIME (h) CONDITIONS 1 30 °C / 90 % RH Unlimited 168 85 °C / 85 % RH 2 30 °C / 60 % RH 1 year 168 85 °C / 60 % RH 2a 30 °C / 60 % RH 4 weeks 696 30 °C / 60 % RH X Y Z 3 30 °C / 60 % RH 168 h 24 168 192 30 °C / 60 % RH 4 30 °C / 60 % RH 72 h 24 72 96 30 °C / 60 % RH 5 30 °C / 60 % RH 48 h 24 48 72 30 °C / 60 % RH 5a 30 °C / 60 % RH 24 h 24 24 48 30 °C / 60 % RH 6 30 °C / 60 % RH 6h 0 6 6 30 °C / 60 % RH X = Default value of Semiconductor manufacturer’s exposure time (MET) between bake and bag plus the maximum time allowed out of the bag at the distributor’s facility. The actual times may be used rather than the default times, but they must be used if they exceed the default times. Y = Floor life of package after it is removed from dry pack bag. Z = Total soak time for evaluation (X + Y). Note • There are two possible floor lives and soak times in level 5. The correct floor life will be determined by the manufacturer and will be noted on the dry pack bag label per JEP 113. “Symbol and Labels for Moisture Sensitive Devices”. Rev. 1.8, 25-Jan-16 15 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors QUALITY AND RELIABILITY DATA Average Outgoing Quality (AOQ) AOQ IRDC AOQ Visibles AOQ el. 3 AOQ el. 4 AOQ mech. AOQ mech. 3 ppm ppm 2 2 1 1 0 0 2011 22213 2012 2013 2014 2011 22870 2013 2014 AOQ Couplers AOQ IR Receiver 4 2012 1.0 AOQ el. AOQ el. AOQ mech. AOQ mech. ppm ppm 3 2 0.5 1 0 2011 22214 2012 2013 AOQ Sensors 0 2014 22871 2011 2012 2013 2014 AOQ el. 8 AOQ mech. 7 ppm 6 5 4 3 2 1 0 22869 2011 Rev. 1.8, 25-Jan-16 2012 2013 2014 16 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Early Failure Rate (EFR) 40 35 30 ppm ppm EFR Visibles 45 EFR IRDC 450 400 350 300 250 200 150 100 50 0 25 20 15 10 5 0 2011 2012 2013 2014 2011 22218 2012 2013 2014 22873 EFR Couplers EFR IR Receiver 35 10 30 8 20 ppm ppm 25 15 6 4 10 2 5 0 0 2011 2012 2013 2014 2011 22219 2012 2013 2014 22874 EFR Sensors 20 ppm 15 10 5 0 2011 2012 2013 2014 22872 Rev. 1.8, 25-Jan-16 17 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 Quality Information www.vishay.com Vishay Semiconductors Latent Failure Rate (LFR) LFR IRDC LFR IRDC 24 20 20 16 16 FIT FIT 24 12 12 8 8 4 4 0 0 2011 2012 2013 2014 2011 22223 2012 2013 2014 22876 LFR IR Receiver 4 4 FIT 3 FIT LFR Couplers 5 2 1 3 2 1 0 0 2011 2012 2013 2014 2011 2012 2013 2014 22877 22224 LFR Sensors 16 14 12 FIT 10 8 6 4 2 0 2011 2012 2013 2014 22875 Rev. 1.8, 25-Jan-16 18 Document Number: 80077 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000