Quality control and environmental activities
CHAPTER 14
1 Quality control 1-1 Quality control system 1-2 Product reliability 1-3 For your safety
2 Environmental activities
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Quality control and environmental activities
Opto-semiconductor products from Hamamatsu Photonics are used in a wide range of fields including medical diagnosis, measurement, industrial instrumentation, automobiles, information equipment, general electronics, and academic research. As their product applications expand, demands for even higher product quality and reliability are increasing. To meet these marketplace demands, we are actively taking measures to improve product quality levels.
[Figure 1-1] Quality assurance chart Division Sales Design, Quality Customer manager development Manufacture Inspection control Purchasing Shipment Supplier Quality manual, division procedures, document control
Quality system
Quality control
Education, training Quality objectives
Quality policy Marketing research
Catalog product proposal
Product commercialization review New product needs
Custom products
Design plan Product design Design review
Approval
Prototype Design verification Pilot first sample, first product manufacturing
Practical test
1-1
Sales/equipment/human resource planning
Business policy
Design
1.
Inspection
Reliability test
OK Design validation
Quality control system
OK
Standard procedures, initial production control planning Product authorization
The Solid State Division employs the ISO 9001 Quality Management System to standardize quality. In this system, items that are basic requirements are formalized in a “Quality Manual” and rules for design, materials, manufacture, inspection, shipping, and equipment management are placed in document form as “Standards” to create a consistent quality assurance system. Figure 1-1 shows a quality assurance chart.
Production
Purchasing Supplier registration Material registration
Material manufacture
Incoming
Subcontracting
Receiving inspection OK No Good Production Calibration Inspection
OK Product storage
Complaint
Delivery
Shipment
Complaint
Reception
Acceptance Customer satisfaction
Answer
Confirmation Root cause investigation, recurrence prevention Report
Customer satisfaction report
Management review
Quality standardization
Production planning
Nonconforming product control
Improvement
Our policy at the Solid State Division of Hamamatsu Photonics is to “take responsibility as an opto-semiconductor manufacturer to establish a quality control system that provides products the customer needs and to contribute to the progress of industry and science.” To achieve this policy, we are making continuous efforts to supply products that are even better, cheaper, faster, and gentle on the earth to satisfy customers.
Receive order
Order
Quality policy
Corrective/preventive action Internal quality audits ISO committee ISO promotion meeting QC meeting PQC meeting Evaluation of the quality objectives KOTHC032EC
Design and development On the basis of the requirements from our customers and marketplace, we start investigating the possibility of production in terms of a new or custom-order product’s functions, reliability, cost, and so forth.
(1) Input to design and development We verify the requirements of our customers and marketplace; outline the functions, performance, applicable regulations, and the like; and document the information.
2
(2) Output from design and development
Process management
The designers outline appropriate information regarding the input requirements, purchasing, and production as well as safety and environmental requirements and create an output document.
(3) Design review The output from design and development is reviewed to determine whether the input requirements can be satisfied.
(4) Design and development verification The output from design and development is inspected to ensure that the input requirements can be satisfied. This is conducted in the prototype stage of product development.
(5) Design and development validity verification The validity of design and development is verified to ensure that the product meets the requirements of the intended application. This includes reliability tests. This is conducted in the mass production stage of product development.
(6) Product authorization Meetings to discuss design (e.g., product specifications), process (manufacturing and inspection), product (reliability), and purchasing (subcontractors and suppliers) are held, and then the product is authorized.
The production process is supervised based on QC process charts and work standards to ensure that quality and reliability are at levels planned in the product design. Main production processes for opto-semiconductors include oxidation, photolithography, ion implantation, diffusion, electrode-forming, and etching in the front end process (wafer process), as well as wafer dicing, die bonding, wire bonding, and sealing in the back end process (assembly process). To verify that the products meet the required specifications, Hamamatsu performs process inspections and product inspections that check the product electrical/optical characteristics and external appearance. The inspection items, methods, and test criteria are established in the product specifications. Destructive testing and lot evaluations are done by product sampling inspections. Control to prevent contamination of light receiving/emitting surfaces is essential for opto-semiconductor products. The packing process requires use of special packing materials and techniques to safeguard light receiving/emitting surfaces from contamination as well as countermeasures to vibration, impact, temperature/humidity, and electrostatic charges. Table 1-1 shows a QC process chart example. Evaluation is made on statistical process control (SPC) using control charts and the like to determine whether a process is stable or is in a controlled state as well as process capabilities. If the control chart indicates an abnormal tendency or if the process capabilities are insufficient, the cause of the problem is investigated and fed back to maintain and improve the relevant process.
[Table 1-1] QC process chart example (part of process) Process
Control item
Method Document
No. Symbol 1 1-1 1-2
4-2 1-3
Work name
Device/condition, item Measuring device, sample Sample size, frequency
Material acceptance Wafer Resistivity, thickness Appearance Lead frame Dimensions Appearance Plating thickness Mold resin Characteristics
Record
Check Visual check Microscope Visual check Thickness gauge Check
Each time All wafers 1 frame/lot 1 frame/lot 3 frames/lot When materials are delivered
Acceptance inspection sheet Purchasing specification Work procedure Acceptance inspection sheet Inspection procedure
Check
Each time
Run sheet Work logbook
Visual check
All wafers
Work procedure Wafer process Manufacturing specification
Thickness gauge Check
1 wafer/lot Each time
Run sheet Work logbook
Microscope Microscope
3 wafers/carrier 3 wafers/carrier
Work procedure Wafer process Manufacturing specification
Purchasing specification
4-4 2 2-1
2-2
Wafer process Oxidation furnace Oxidation Temperature, time Wafer appearance 1 Color, uniformity Wafer appearance 2 SiO2 thickness Photolithographic work Photomask Wafer appearance 3 Pattern condition Pattern accuracy, pattern defect
3
Dealing with process errors
Product identification and traceability
Figure 1-2 shows a system chart for error handling. [Figure 1-2] System chart for error handling Fault finder
Trouble report
Close
Corrective Supervisor Quality control action dept.
Purchasing
Supplier
Confirm details at location and on items No
Action needed?
Yes Where problem occurred?
In-house process
Recurrence prevention check
Close
Progress/ countermeasure check
Trouble investigation request form
Confirmation
Not in-house process
• In-house Corrective action instruction Supplier
Example
S1234 3A 001 Confirmation
Corrective action instruction Corrective action
Corrective action
Serial number Production month (alphabetical order... Jan: A, Feb: B, Dec: L) Production year (last digit of year) Type number
Confirmation
Purchasing management KOTHC0029EA
When a problem occurs in the production process, which might cause defects that exceed preset process standards or might adversely affect the product quality, then the problematic lot is immediately identified and separated from other semi-finished parts. At the same time, the cause of the problem is investigated, and the corrective action that should be taken is decided. Along with confirming the corrective action was effective, we take measures to prevent the problem from reoccurring.
Equipment and work environment management The work environment in the manufacturing process greatly affects product quality and reliability of optosemiconductor products. Cleanliness, temperature, and humidity in particular must be strictly controlled. Optosemiconductors are produced in clean rooms where cleanliness is controlled at a high level. To maintain and control the cleanliness level in clean rooms, strict control standards are established for factors such as cleanliness, entry/exit methods, work clothing, carry-in items, and work procedures. Damage caused by electrostatic discharge (ESD) can be a serious problem as process geometry shrink and diverse packages become available, so electrostatic countermeasures are enforced. The department dealing with products requiring ESD countermeasures sets up special areas that must comply with ESD control standards and gives workers instructions in equipment and work site supervision, work clothing, and handling methods. Production equipment is verified after modifications or expansions and also given regular maintenance. Specific methods for making start-up and periodic equipment inspections are established to perform preventive maintenance, and constant efforts are made to prevent quality problems and keep stable production. 4
To establish traceability for determining the production lot and material lot for the individual products delivered to our customers, records of each process contain columns for entering used materials, devices, and production information. These records are stored securely as product history information. When necessary, as shown in the following example, the type number, production year and month, production serial number, and so on are indicated on the product.
Purchasing management of parts and materials has a large effect on product quality, so we use a system that judges and then registers both the suppliers and the parts and materials for purchasing. We carry out an inspection of the suppliers to check compliance with the quality system, environment system, green purchasing policy, business continuity capability, and other factors. We then register those suppliers who meet our standards and also make new and periodic supplier audits mainly by the purchasing, quality control, and design departments. The semiconductor wafers, electrode materials, chemicals, gases, and the like used to produce opto-semiconductor products must be of high purity and high quality. The metal and ceramic materials, printed circuit boards, and mold resin used for packages must be of high precision and high quality. These types of purchased items undergo strict individual testing and are then registered before they can be used in our products. An incoming inspection of those purchased items is then made based on the required specifications to verify their quality. After acceptance, these purchased items are stored in properly controlled locations that meet storage conditions specified in the design standards, and a high level of purchased item quality is maintained [Figure 1-3].
[Figure 1-3] Purchasing control chart
Purchasing, subcontracting, and change control
Purchasing information
Supplier registration
Design
Quality control
Outsourcing application
[Figure 1-4] Measuring equipment traceability
Purchasing/subcontractor management
Supplier
New supplier application
New supplier
A
Site investigation
Rank Other than A Supplier registration Request for decision (internal memo)
Material registration application Purchasing specifications and the like Preliminary survey sheet for environmental controlled substances Acceptance inspection standards
Confirmation of contents
Material registration
Delivery specifications and drawings QC process chart Estimate SDS
National standard Public calibration laboratory
AIST, NIST*
Corporation calibration laboratory
Japan Electric Meters Inspection Corporation
Other calibration laboratory
Measuring equipment manufacturer
Private calibration laboratory
Product management Standards division
Measuring equipment standards, calibrator
Solid State Division Calibrator Quality control
Calibrator
Solid State Division Measuring Manufacturing dept. equipment
Measuring equipment Inspection equipment, standard element
RoHS substances analysis report High-risk material registration application
Customer
Purchasing request
Order form
Material, subcontracting
Products
Products
* AIST: National Institute of Advanced Industrial Science and Technology (Japan) NIST: National Institute of Standards and Technology (U.S.) KOTHC0033EB
Acceptance inspection
Invoice Inspection sheet
Judgment No Good Fault investigation request
Cause investigation
Examination, acceptance
Solution response Material special acceptance control form
Investigation, answer
Response Material change or cancellation B
Rank
Evaluation
S∙A Basic business contract Quality assurance agreement QC check sheet supplier environmental investigation report Monthly purchasing report
Acceptance
No Good
Improvement plan
→
Calibration
Amount of annual business
Organization chart Quality assurance system chart ISO registration certificate
Site investigation
Site investigation report Evaluation
Measuring equipment (source meter)
Initial product, special acceptance form
Site investigation plan, result report Supplier evaluation report
Standard (calibrator)
Material special acceptance application Material change application
Investigation, answer
Material change or cancellation application
[Figure 1-5] Measuring equipment inspection example (for photodiode)
Periodic inspection Inspection equipment made by Hamamatsu (photodiode measuring device)
Standard element (photodiode)
→ ← Start-up inspection
Improvement activities KOTHC0039EC
Measurement management
[Figure 1-6] Calibration certificate example of calibrator
To perform product inspection accurately, a system (traceability) to ensure the accuracy of measuring equipment is implemented. Calibrators for calibrating the measuring equipment are traceable to national standards through measuring equipment manufacturers, public organizations, or standard equipment in Hamamatsu Product Management Division. In addition, inspection equipment and standard elements are traceable to measuring equipment [Figure 1-4]. Furthermore, in addition to calibration, start-up inspections and periodic inspections are made to detect and prevent degradation in accuracy and malfunction in measuring equipment and inspection equipment.
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[Figure 1-8] Complaint action chart
Change control Changes such as in designs, purchased items, production methods, and equipment are made in order to improve product quality, function, reliability, and productivity. Change planning is first drawn up, the job schedule from change setup to completion is clarified, and the planning is then finalized at a change conference attended by all related departments including quality control. Finally, the change is decided after evaluating the effects on quality, reliability, productivity, etc. Changes requiring the customer’s approval in advance are implemented after obtaining the customer’s consent. Initial production control is performed as needed and a final check made of all effects caused by the change [Figure 1-7].
Customer
Sales
Complaint
Reception Information confirmation Returned product action form
First report
Report
Sales
Quality control
Contents confirmed Returned product action ledger recorded Put on the article card Quality judgment/correlativity investigation/making first report No
HPK responsible
Yes Minor
Quality influence report of products
Report
Directions Critical, major
Customer complaint level
Complaint ac tion meeting “Critical” & “Major”: needed “Minor”: if necessary Specific within the range of object/enclosure Inspection under the reproducibility conditions Examination and confirmation of correspondence (survey result and nonconforming circumstances)
[Figure 1-7] Change control chart Customer
Correspondence section, Division manager, related section Quality control the responsibility (design, manufacture) of a management
Examination and confirmation of correspondence (cause and reproducibility)
Section initiating change
Related sections
Plan of applicable products disposed/ countermeasures implemented
Change proposal
Nonconforming products investigation report (8D report) Change meeting
Change planning form
Not needed Needed
Approval
Customer confirmation
Change proposal
Change meeting
OK
Design verification/validation
Confirmation
Change application
Customer evaluation
Investigation report
No Good
Change application
Report
Approval/agreement Applicable products disposed/ countermeasures implemented Returned product action ledger recorded
Confirmation
Not needed
Needed Corrective & preventive action indicating form
Issue of change Needed Customer agreement application form Not needed
Corrective & preventive action Follow-up No Good
Confirmation of customer’s change decision
Close
Change implementation
First sample control/initial production control
Follow-up
Close KOTHC0026EB
Complaint handling At Hamamatsu we work to speedily resolve customer complaints by way of our complaint handling system. The contents of the complaint are first checked, and an investigation made to find the cause. Besides notifying the customer of these results, we also use them as feedback in the design and production processes to prevent a recurrence of the trouble. If we decide, based on those investigation results, that the quality control system must be overhauled, then corrective action is taken and results from that action are verified [Figure 1-8].
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Approval
Instruction and training
Revised standards
First sample confirmation
OK
KOTHC0028ED
Change decision
Customer confirmation
Corrective/ preventive action
The Solid State Division provides worker instruction and training as an active promotion to maintain and improve product quality as well as upgrade employee skills. Employee skills are periodically reviewed, and instruction/training plans are then drawn up and performed as needed. When a particular job requires obtaining qualifications, then those are clearly specified, and a system is then set up to certify employees who meet the requirements of the job. The types of instruction span many areas including new employee education, on-the-job training, and safety and health instruction. Positive efforts are also made to collect information outside our company in order to upgrade employee knowledge and skills.
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(3) Reliability testing
Product reliability
Reliability (1) Definition of reliability In the Glossary of Terms Used in Reliability of JIS, reliability is defined as “the capability of an item to perform a required function under specified conditions for a specified period of time.” We define the term as “the capability to withstand operation under the customer’s usage environment over the warranty period (or longer than the warranty period).”
(2) Failure region of opto-semiconductor products The failure region of opto-semiconductor product can be divided into initial failure, random failure, and wear-out failure. The curve indicating the change in each failure rate over time is called a bathtub curve. [Figure 1-9] Bathtub curve example
We make reliability tests to verify that a product meets the specified reliability requirements. In reliability testing for product authorization, long-term stress tests are performed to verify that wear-out failures do not occur under the assumed usage environment and within the assumed usage period. Reliability tests are performed by selecting typical products from among a group of structurally similar products. If needed, this testing is performed individually. For a portion of mass-produced products, to verify that the quality set at the development stage is maintained even after mass production, mass-produced products are sampled and subjected to reliability tests once a year. Reliability test methods conform to JIS, JEITA, IEC, MIL standards, and the like. Some products are also tested according to their product application. For example, optical communication devices are tested according to the Telcordia GR-468 standards. Products including automotive devices are also subjected to testing specified by the customer. Table 1-2 shows typical reliability tests.
Failure rate
(4) Lifetime prediction
Initial failure
Random failure
Wear-out failure data obtained through reliability testing can be used to determine the cumulative failure rate over time. By taking into account logarithmic-normal-distribution, Weibull-distribution, and acceleration factor of reliability testing, one can calculate the activation energy that leads to specific wear-out failures and predict the length of time to reach the cumulative failure rate reference (wear-out failure lifetime).
Wear-out failure
[Figure 1-10] Failure rate prediction using Weibull plot 90
Time KOTHB0013EA
Initial failure
Initial failures occur at a relatively early period after starting the use of a product. It is caused by a design or manufacturing defect, incompatible usage environment, and so on. Initial failure rate decreases as time passes. Screening inspections before shipment can eliminate devices exhibiting initial failures and thereby improve the initial failure rate in the market place. •
Cumulative failure rate (%)
•
50
Predicted failure rate
Acceleration test failure rate
10
× Acceleration factor 1
0.1 100
1000
10000
100000
Random failure Time (h)
As the name suggests, random failures occur randomly after the initial failure period but before the wear-out failure period. Failures occur sporadically, and the failure rate is nearly constant but never zero. •
Wear-out failure
Wear-out failures increase as time passes due to fatigue, wear, deterioration, and so on. Examples of wear-out failures in opto-semiconductor products are electromigration, wire breakage due to repetitive temperature changes, and sensitivity deterioration due to ultraviolet light and X-ray exposure.
KOTHB0014EA
Failure analysis Failure analysis is a way of investigating the cause of failure and the mechanism that leads to the failure by researching the failure that occurred in the manufacturing process, marketplace, etc. The facts that are revealed through this activity are fed back to design and manufacturing to prevent the same failure from reoccurring [Figure 1-11].
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[Figure 1-11] Flow chart of typical failure analysis
Failure analysis examples
Failure occurrence
(1) Leakage between terminals Side face observation: reaction areas verified with an IR-OBIRCH microscope
Collection of failure data
Verification of the failure phenomenon Electrical characteristics measurement: semiconductor parameter analyzer and the like Appearance observation: optical microscope and the like Determination of failure location Light emission observation: emission microscope OBIRCH observation: IR-OBIRCH microscope Front side observation: optical microscope and the like Determination of the root cause and mechanism of problem (estimation) Cross section observation: focused ion beam Front side peeling observation: electron microscope and the like Elemental analysis: EDX and the like Feedback KOTHC0066EA
[Table 1-2] Reliability test examples Test item
Life test
Test condition examples
Maximum storage temperature Tstg max., 1000 hours EIAJ ED-4701/200 201
Low-temperature storage
Minimum storage temperature Tstg min., 1000 hours
EIAJ ED-4701/200 202
High-temperature & high-humidity storage
85 °C, 85%, 1000 hours
EIAJ ED-4701/100 103
High-temperature operation
Maximum operating temperature Topr max., operating conditions: EIAJ ED-4701/100 101 depends on individual specs, test time: 1000 hours
Low-temperature operation
Minimum operating temperature Topr min., operating conditions: EIAJ ED-4701/100 101 depends on individual specs, test time: 1000 hours
High-temperature & high-humidity operation
85 °C, 85%, operating conditions: depends on individual EIAJ ED-4701/100 102 specs, test time: 1000 hours
Unsaturated steam pressurization
120 °C, 85%, 170 kPa, 96 hours
Temperature cycle
Maximum storage temperature Tstg max., 30 minutes, minimum EIAJ ED-4701/100 105 storage temperature Tstg min., 30 minutes, 100 cycles
X-ray irradiation
Output tube voltage: 100 kV, 1 million roentgen
UV light irradiation
Terminal strength
Hg light
253.7 nm, 1000 hours
D2 light
200 nm to 400 nm, 1000 hours
Pulling
A load is imposed for 10 seconds.
Twisting
A lead is bent 90° and rotated.
Bending
A lead is bent 90° with a load applied, and is then bent back.
-
EIAJ ED-4701/400 401
100 Hz to 2000 Hz, acceleration: 200 m/s2 sweep time (100 Hz to 2000 Hz to 100 Hz): 4 minutes EIAJ ED-4701/400 403 sweep direction: 3 directions of X, Y and Z, 4 times each
Shock
Maximum acceleration: 15000 m/s2, pulse width: 0.5 ms shock direction: 4 directions of X1, (X2), Y1, Y2, Z1, (Z2), EIAJ ED-4701/400 404 3 times each Accelerated aging Steam, 4 hours Lead free
Soldering by hand: 245 °C, 2 seconds Reflow: 225 °C or higher (235 °C peak), 20 seconds
Other than surface 260 °C, 10 seconds mount type Resistance to soldering heat
Surface mount type
Preprocess: JEDEC Level 5a (30 °C, 60%, 48 hours) to Level 1 (85 °C, 85%, 168 hours) Lead free: solder heating process, 3 times, 235 °C or higher (240 °C peak), 30 seconds
EIAJ ED-4701/300 303 JIS C60068-2-58 EIAJ ED-4701/300 302
JEDEC J-STD-020
C=100 pF, R=1.5 kΩ, applied voltage: ±1 kV, number of times: 1
EIAJ ED-4701/300 304
Thermal shock
100 °C to 0 °C, 10 times
EIAJ ED-4701/300 307
Transportation temperature cycle
-40 °C to +70 °C, 5 times
JIS C60721-3-2
Resistance to solvents
Solvent type: isopropyl alcohol, dipping time: 5 minutes, rubbing: 5 strokes in both directions
EIAJ ED-4701/500 501
Electrostatic breakdown
Note: Please contact us for information on reliability test for individual products.
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EIAJ ED-4701/100 103
Vibration
Strength Solderability test
Other
Test standards
High-temperature storage
Cross section observation: cracks verified in the TSV insulation film (electron microscope; cross section polisher) Crack
Crack
→ Feedback: insulation film modification, structural improvement
(2) IC short circuit Back side observation: abnormal signals verified with an IR-OBIRCH microscope
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For your safety
Handling precautions Products must be stored and used under the conditions specified in the delivery specification sheets. If these conditions are not met, problems such as oxidation and contamination of leads and packages absorbing moisture may occur. When using our products in your products, be sure to agree to the delivery specification sheet. Depending on the product, precautions specific to the product may be present in addition to general precautions. As such details are provided in the operation manual supplied with the product, be sure to read it. Table 1-3 shows an example of the handling precautions of opto-semiconductor products.
Examples of problems that have occurred due to inappropriate handling (1) Examples of problems caused by external force Front side observation (after film peeling): foreign substance verified in the abnormal signal area with an optical microscope
Cross section observation: foreign substance shorting the terminals is discovered (focused ion beam; Fe·Cr detected from the foreign substance through elemental analysis)
Damage to metal wiring Examples in which the metal wiring on a bare chip is damaged due to physical contact
Damage to sensor package An example in which an inappropriate heatsink coupling (e.g., improper viscosity or nonuniform grease or screws tightened too strong) causes excessive load to be applied to the sensor’s heat dissipation section and damages the bonded area of the ceramic and heat dissipating sections Ceramic area
Heat dissipation area
→ Feedback: complete particle control, inspection method enhancement
Cracked chip caused by external force An example in which a strong external force applied to the scintillator on the chip cracks the chip
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Damage to the image sensor scintillator An example in which the surface of the scintillator on a chip is damaged due to physical contact with a jig or other tool, causing adverse effects on the captured image
Scintillator damage
(2) Examples of problems caused by the environment Resin peeling caused by moisture absorption An example in which the resin peels off the chip surface due to moisture absorption by the package resin during soldering, causing degradation in sensitivity due to the increased reflectance from the photosensitive area surface caused by the peeling
Captured image
Broken cable of a sensor with a cable An example in which the cable breaks due to long-term use and repeated bending
Sensitivity degradation caused by blemishes on the package surface An example in which the sensitivity degrades due to the reduced light transmittance caused by soot adhering to the package surface of a photosensor used to monitor the flames in a boiler
X-ray photo of the circled area
[Table 1-3] Handling precaution examples Type
Metal, ceramic plastic package product
Bare chip
Unsealed product
10
Handling precautions
Product examples
Electrical and optical characteristics may deteriorate if dust, contamination, or scratches are on the product. When handling the product, remember to work in a clean place, not apply strong friction to the window material, and use tweezers and/or gloves. Standard Si photodiode Product deterioration is especially faster at high temperature and humidity than at normal Photo IC temperature and humidity. Avoid storage or usage in an unnecessary high temperature and humidity environment. Storage conditions Unopened product: temperature: 15 °C to 35 °C, humidity: 45% to 75%, up to 3 months Opened product: temperature: 15 °C to 35 °C, humidity: 5% or less, up to 20 days Open the bag and mount the product in a clean room (class 10000 or better). Chip product Be careful not to physically damage or contaminate the chip, and exercise extreme caution when handling. Evaluate and verify the effects of your mounting method and packaging material on the reliability. Storage conditions Unopened product: temperature: 15 °C to 35 °C, humidity: 45% to 75%, up to 3 months Opened product: temperature: 15 °C to 35 °C, storage in a low-humidity desiccator (no condensation), up to 3 months Open the bag and mount the product in a clean room (class 10000 or better). Windowless product Be careful not to physically damage or contaminate the chip, and exercise extreme caution when handling. Do not make contact with wiring. As a general rule, use an air blower to remove contamination. Pay attention to contamination and condensation when sealing or bonding a scintillator. When soldering, pay attention to the solder iron tip temperature, soldering time, and splashing flux.
TE-cooled type
Pay attention to prevent wiring errors to thermoelectric coolers or thermistors as errors can damage the devices. Do not use the devices at current or power exceeding their ratings. Product with built-in Use heatsink with sufficient heat dissipation capacity for cooling. Keep the thermal resistance thermoelectric cooler between the element and heatsink as small as possible (use heat dissipation sheets or silicon grease).
Electrostatic sensitive type
Apply measures to workplace and facilities according to the extent of deterioration that may occur. Such measures include using a conductive mat and grounding the equipment. Compound semiconductor When handling the product, apply measures according to the extent of deterioration that may occur. Image sensor Such measures include using an ionizer to remove static electricity and wearing a grounded wrist strap.
For UV light and X-ray measurement
Avoid unnecessary exposure to UV light or X-rays as long-term exposure to them cause Radiation detector deterioration (e.g., increased dark current and sensitivity deterioration) in the product X-ray image sensor characteristics. Flat panel sensor
Sensitivity degradation caused by high-energy UV light An example in which the sensitivity of the light incident area degrades as a result of KrF excimer laser striking and damaging the Shottky film
2.
Environmental activities
Environmental idea
[Figure 1-12] Sensitivity uniformity (Schottky type photodiode) 160
Recognizing that living in harmony with the global environment is a critical issue for mankind, the Solid State Division of Hamamatsu Photonics conducts business with consideration to environmental conservation, and works to create new scientific fields and new industries and to show the road to true human health through research into photonics technology and extending its application.
Before UV light irradiation 140
Environmental policy Output current (nA)
120
The Solid State Division is conducting environmental activities in compliance with the following environmental policy.
100 After UV light irradiation
80 60 40 20 0 0
2
4
6
8
10
12
Position (mm) KrF excimer laser (λ=248 nm) irradiation area KGPDB0081EA
Establish an environmental management system to promote conservation of the earth’s environment by setting up and maintaining an internal organization for environmental protection. Assess the impact on the environment by our activities, products and services, set environmental objectives and goals, review our environmental preservation activities through environmental audits, and constantly improve our environmental management. Comply with environmental regulations and other requirements we have accepted and impose our own voluntary standards as necessary, to reduce the burden on the environment. Take preventative measures for curbing environmental pollution, save energy and resources, reduce waste, and ensure correct usage of chemical substances. Strive to raise the understanding of the environmental policy and the awareness of environmental issues among all our employees through education and an in-house publication about the environment.
Standardizing environmental management The Solid State Division is implementing the ISO 14001 Environmental Management System and making continuous improvements to provide proper environmental management and reduce environmental risks.
Environmental auditing To maintain and improve our environment management system, we carry out external audits conducted by certification bodies and internal audits conducted by the Solid State Division on a regular basis.
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Activities to reduce environmental risks The Solid State Division constantly makes improvements that takes into account the burden on the living environment including the atmosphere, water quality, and noise and strives to prevent environmental pollution.
[Figure 2-2] Infrared detectors used in greenhouse gases observing satellite “Ibuki” (a) InGaAs PIN photodiode
(b) InGaAs linear image sensor
Emergency response training The Solid State Division furnishes manuals for handling accidents and disasters and regularly performs emergency training according to each department’s business operation.
Environmental impact of business activities We assess the impact on the environment by our business activities and engages to reduce greenhouse gas, drainage, waste, and other burden placed on the environment.
(2) Environmentally conscious products As part of our global environmental conservation efforts and reduction of burden on the environment, we apply environmental measures on the products, develop new products and new technologies, and promote the sales of environmentally conscious products.
Example: CCD area image sensor S12071
We work to make our products more compact, power efficient, long lasting, energy efficient, and so on according to their applications so that the burden placed on the environment is reduced.
With CCD area image sensor S12071, dark current noise has been suppressed to 1/20 of that in previous products. This has allowed the cooling temperature of the built-in thermoelectric cooler to be increased, which has reduced the power consumption to 1/7 of that in previous products. Moreover, the incorporation of new packaging technology has significantly increased the air tightness and moisture proof reliability and prolonged the service life of the product.
(1) Products contributing to the environment
[Figure 2-3] CCD area image sensor S12071
Addressing environmental issues through products
Hamamatsu manufactures products that contribute to environmental measurement of atmosphere, water quality, and the like, content analysis of environmental management substances, and energy reduction of ordinary electric equipment.
Example: Infrared detectors Infrared detectors are used to measure the absorption peak specific to a gas in order to measure its type and concentration. Our products are used in the greenhouse gases observing satellite “Ibuki” (GOSAT).
[Figure 2-4] Power consumption of built-in thermoelectric cooler
[Figure 2-1] Greenhouse gases observing satellite “Ibuki” Power consumption (W)
8.2
1/7
1.2
(Courtesy of JAXA)
Previous product (Td=-10 °C)
Improved product S12071 (Td=0 °C) KMPDB0396EA
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Conforming to regulations regarding the chemicals contained in our products Hamamatsu Photonics has established an “Environmental Control Substance Management Standard” to control the chemical substances contained in products. We are actively engaged in complying with the EU RoHS directives and regulations on chemical substances contained in products.
(1) Chemical substances regulated by RoHS For each product, we control the amount of substances that are specified in IEC62474 including the six substances (lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyl, and polybrominated diphenyl ether) regulated by RoHS directives. Judgment on whether a product will comply with RoHS directives is clearly specified in the quotation sheet when drawing up an estimate.
(2) Waste reduction, separation, and recycling From the standpoint of reducing the burden on the environment and using resources effectively, the Solid State Division is promoting 3Rs (reduce, reuse, and recycle) and proper treatment as its fundamental policies and is engaged in activities under the slogan “Zero Emission.” In addition, to enforce separation of waste produced, a waste separation database has been established and is running on our company’s intranet.
(3) Energy saving and reduction of carbon-dioxide emissions We at the Solid State Division are expanding our energy saving activities in an aim to reduce the energy used by business operations by at least 1% per unit of sales compared to the previous year. In order to prevent global warming, we are also actively working to reduce the greenhouse gases, such as non-energy source carbon-dioxide, that are used in the manufacturing process .
(2) Management of high-risk materials When there is possibility that a material may contain an environmental management substance, we determine that material as a high-risk material and inspect it using an X-ray fluorescence analyzer during the acceptance test.
Green purchasing To comply with environmental regulations on products and minimize the burden on the environment, we at the Solid State Division have established green procurement policies and chemical substance management standards, and are promoting procurement activities that give priority to materials with a smaller load on the environment.
Working toward global environmental conservation At the Solid State Division we conduct environmental activities for global environmental conservation.
(1) Management of chemical substance usage quantity If chemical substances are not properly managed, environmental pollution can result and may cause adverse effects on human health and ecosystem. At the Solid State Division we accurately monitor and strictly control the emission levels of chemical substance into the atmosphere and water and the amount of movement of waste and so forth.
Examples · Management of usage quantity of chemical substances subject to the PRTR Law · Collection of SDS information and disclosure within our company · Activities to reduce VOC emissions
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