Key Steps for Quality Control in Lithium Battery Enterprises
The requirements for batteries in terminal products are "safer, higher capacity, faster charging, higher power, and longer lifespan", so battery production enterprises must have better quality control and quality assurance systems.
Establishment of quality system
Establishment of system documents: According to ISO requirements, system documents are divided into first level document quality manual, second level document quality control procedure, third level document SOP, and fourth level document inspection record inspection guide. Different industries need to have a complete set of fourth level documents. After a good quality system is established, each department of the company operates according to the quality system. It's not like asking the boss or manager to make decisions on everything. If there are any imperfections in the quality system, it can be gradually improved. The quality system document is a live document that requires continuous review and improvement.
After the establishment of system documents, QA engineers or system engineers regularly conduct system audits of the company's system documents. When a company first establishes system documents, it usually conducts a quarterly audit to identify and improve any discrepancies in the operation of the system documents among various departments in a timely manner; Mature systems generally undergo a system document review every six months or even once a year to ensure that the system documents are well executed in various departments. If there is no good execution, timely detection or correction can be made to ensure the good operation of the company's quality system.
Supplier Quality Management
The main materials of batteries include: positive electrode materials. Negative electrode material, word elimination, aluminum foil, diaphragm. Electrolyte. Shell (National Type Film
Aluminum shell, ear, equipment, etc., each of which has varying degrees of impact on the final performance, quality, and cost of the battery. Different suppliers and batches of materials may have significant differences, which requires supplier management. The quality, cost, delivery time, research and development capabilities, reaction speed, and strategic positioning of suppliers are all indicators for evaluating suppliers, and quality management is one of the most important assessment KPs for supplier management
There is an important concept in supplier quality management, Win Win, which is to provide reasonable profit margins for suppliers. Only by earning money can they ensure quality. Simply bargaining can lead to suppliers reducing quality or cutting corners in personnel training and testing methods. So when quoting from suppliers, they should list material costs, manufacturing costs, management costs, and reasonable profit margins.
Regular supplier audits and on-site process control are very important. In European and American companies or Apple companies, there are many engineers responsible for supplier management. Process monitoring ensures that the quality control of supply barrels is carried out in accordance with our quality requirements. From new product development to sample production to mass production and shipment of finished products, each supply curve is regularly monitored by on-site personnel for quality. When the supplier's product is delivered to the next supplier, the next supplier will conduct IQC incoming inspection. If any material defects are found, we need to provide timely feedback. We use the 8D logic to find Root Cause and closed-loop control to close this issue. Even the mistakes made by this product or similar products in the 8D logic will be prevented and improved in similar products or processes, and thoroughly improved in other products or processes, Avoid making the same mistake.
This is what we are talking about supplier management, ensuring good management of suppliers, monitoring of supplier processes, ensuring that supplier incoming materials meet requirements, and promptly correcting any issues. Ensure that the supplier's materials meet the company's quality requirements.
Process quality control
1. Establishment of SOP and SIP files.
For each process, a standard guide book should be drafted clearly, which will cover the standard operating procedures and precautions. If there are projects that significantly affect product quality (CTQ), exclamation marks and asterisks should be used to indicate that employees cannot operate in violation of regulations. Misoperation can cause serious defects in the product. The homework inspection guide book has a clear definition of the sampling frequency, inspection methods, and inspection instruments used for inspection, Train inspectors to inspect according to our homework inspection instructions, ensuring that the inspection methods are correct and not misjudged, and also for KPI KPOV and input/output should be identified, and the impact of predecessors on certain processes on output should be controlled. DOE should be used to optimize equipment and process parameters. Control the input and output of the machine, and control the output of key products.
2. MSA measurement system.
To ensure that the inspection can truly reflect product performance, it is necessary to ensure that the inspection system GR&R (repeatability and reproducibility of measurement system errors) meets the requirements. When MSA GR&R<10% is a good measurement system, and 10% -30% measurement errors are too large, the measurement system needs to be improved, otherwise it cannot be used for product inspection. For example, measuring instruments such as battery weighing, electrode weighing, and ingredient weighing must be strictly calibrated.
3. CTQ
All input and output parameters that affect product quality must be identified within the process. For these CTQ projects, special monitoring should be carried out, including input parameters, such as alarms or machine equipment design. For real-time monitoring, if the process capability parameter CPK value can reach 1.33, sampling can be used. Therefore, the identification of CTQ is very important. For the parameters of CTQ in the process, SPC process statistics technology should be used to monitor whether the process input and output parameters are controlled, SPC can reflect whether the process is stable or not. If there is any abnormality, it will be reflected in the SPC control chart. The cause can be investigated in advance and preventive measures can be taken to avoid uncontrolled production process. If there are any abnormalities in SPC, they should be handled in a timely manner, and any problems encountered in the process should be resolved in a timely manner to ensure that the process is controlled and stable production.
4. Process control anti fooling system (shop floor control)
For key parameters, in process control, existing MES should be used for some monitoring. If the previous station tested for defects, the defects should be selected or intercepted at the next station. When employees make operational errors on the production line, there will be a system to prevent defective products from flowing to the next process or customers' hands. This system must be in place when conducting PFMEA or controlling key characteristics of products, otherwise suppliers will not be allowed to produce. The process control foolproof system is a necessary condition for Apple to audit suppliers, and without this system, one cannot become an Apple supplier.
5. Product traceability system
If there are abnormalities in production or customer complaints, it is convenient to recall the product, quickly determine the scope of product impact, facilitate traceability and isolation of the product, and facilitate quality investigation. The traceability system should at least achieve the traceability of human-machine materials and production time, including the characteristic parameters of key processes, operators, machine equipment numbers, material batch numbers, production time, CTQ, etc., all of which should have a system to facilitate investigation.
The process control foolproof system and product traceability system are two hard conditions for supplier management and quality management. Without either system, Apple will not provide them with a project. Currently, domestic enterprises are doing very poorly in these two areas. Without these two systems, many quality problems cannot be traced and investigated.
6. Employee self inspection and re inspection
To provide training for employees, each employee must clarify which are defective products, which are good products, which are qualified, and which are not. They must undergo training, certification, and assessment before they can start work. When defective products are found during the production process, employees will isolate the defective products and prevent them from flowing to the next station or even the customer's hands
7. IPQC inspection
IPQC is like a police officer in a factory, who conducts regular inspections on the mechanical equipment parameters of the production line, the operator's operating techniques, the operator's compliance with the operation flow, the CTQ parameters, and the input/output parameters of the equipment according to the sampling plan. The inspections may occur every 2 hours or every 4 hours based on the stability of the product process. When making the process control plan, the inspection frequency, sampling frequency, and The inspection method is clearly defined.
8. Preservation of process quality records
For the input/output key process parameters of each process, detailed quality records must be kept to ensure that there is sufficient quality record proof to prove that your product meets the Spec and the process is controlled when abnormalities are found on the client or process. When quality disputes or customer complaints occur, process quality records serve as strong evidence to prove that your process control is under control, abnormal issues are special, not batch issues, and production control meets quality requirements.
9. Monitoring and improvement of qualification rate
There should be data to record the qualification rate of each process in the production process, and control the yield of the process based on the company's continuous improvement or the yield target of the process. For projects that do not meet the standards or have high defect rates, data should be collected and analyzed using Plato to achieve continuous improvement. Plato is the principle of 28. According to statistical quality analysis, 20% of projects often result in 80% of defects. Conversely, when we use Plato's analysis, 80% of defects are often caused by the first two and three items. Therefore, we will focus our energy and resources on the first two and three items of 80% defects, and focus on improving them. The advantage of Plato is that for process defects, process analysis is not generalized, but targeted, This is the application of Plato.
10. Cycle time and UPH monitoring and improvement
What are the benefits of these two? When Cycle time is used for analysis and modification, your delivery cycle, WIP operation, or WIP inventory will be reduced, which can shorten your delivery time, shorten the production cycle of the product, and quickly respond to customer delivery. The improvement of UPH lies in improving and increasing the production capacity of the equipment.
11. Preventive maintenance of mechanical equipment
When the mechanical equipment is purchased, the equipment management personnel should develop a detailed maintenance plan based on the equipment operation manual, and develop equipment inspection and maintenance work instructions. Clearly list the maintenance methods, frequency, and replacement cycle of spare parts, conduct equipment maintenance visits, and ensure that the equipment is in good operating condition. The maintenance of equipment is similar to the maintenance of cars, and preventive maintenance should be carried out on production equipment. It cannot be repaired until it is broken, otherwise it will cause a significant loss to the lifespan of the equipment and the utilization of spare parts.
Quality Management of Finished Products (OQC)
One important aspect of finished product quality management is the sampling plan. According to different quality requirements, the sampling plan table needs to develop different sampling plans, sampling frequency, and sampling quantity. After determining the sampling items, measure the system and MSA (ability of inspection and testing equipment) GR&R needs to be evaluated. If the instruments, equipment, or measurement system do not meet the requirements, registration changes need to be made. The next step is the training and assessment of inspection personnel. Inspection personnel must pass the training and assessment before they can start work. If the inspection standards and requirements are not grasped correctly, misoperation of measurement equipment will affect the fairness of product inspection. If unqualified products are found during finished product inspection, a Action Plan should be in place. When defective products are found, they should be promptly handled through the Material Review Board (MRB), either downgraded for acceptance, reworked, or scrapped. A clear action plan should be in place to handle them in a timely manner.
ORT reliability testing management of products
ORT testing is very important. Sample testing is conducted on product performance, such as high temperature, high humidity, impact and other testing projects. Different ORT testing projects are developed according to different industry regulations. After some extreme testing and simulation of customer usage extreme conditions, the product meets the requirements, and any defects can be detected and improved in a timely manner.
The management of ORT is also important, including your sampling plan, number and frequency of tests, testing items, measurement system, training and assessment of testing personnel. Regarding the Reaction Plan for ORT defects, testers should promptly report any defects to their superiors, conduct timely evaluations, conduct defect analysis, and take improvement measures.
Key Steps for Quality Control in Lithium Battery Enterprises
The requirements for batteries in terminal products are "safer, higher capacity, faster charging, higher power, and longer lifespan", so battery production enterprises must have better quality control and quality assurance systems.
Establishment of quality system
Establishment of system documents: According to ISO requirements, system documents are divided into first level document quality manual, second level document quality control procedure, third level document SOP, and fourth level document inspection record inspection guide. Different industries need to have a complete set of fourth level documents. After a good quality system is established, each department of the company operates according to the quality system. It's not like asking the boss or manager to make decisions on everything. If there are any imperfections in the quality system, it can be gradually improved. The quality system document is a live document that requires continuous review and improvement.
After the establishment of system documents, QA engineers or system engineers regularly conduct system audits of the company's system documents. When a company first establishes system documents, it usually conducts a quarterly audit to identify and improve any discrepancies in the operation of the system documents among various departments in a timely manner; Mature systems generally undergo a system document review every six months or even once a year to ensure that the system documents are well executed in various departments. If there is no good execution, timely detection or correction can be made to ensure the good operation of the company's quality system.
Supplier Quality Management
The main materials of batteries include: positive electrode materials. Negative electrode material, word elimination, aluminum foil, diaphragm. Electrolyte. Shell (National Type Film
Aluminum shell, ear, equipment, etc., each of which has varying degrees of impact on the final performance, quality, and cost of the battery. Different suppliers and batches of materials may have significant differences, which requires supplier management. The quality, cost, delivery time, research and development capabilities, reaction speed, and strategic positioning of suppliers are all indicators for evaluating suppliers, and quality management is one of the most important assessment KPs for supplier management
There is an important concept in supplier quality management, Win Win, which is to provide reasonable profit margins for suppliers. Only by earning money can they ensure quality. Simply bargaining can lead to suppliers reducing quality or cutting corners in personnel training and testing methods. So when quoting from suppliers, they should list material costs, manufacturing costs, management costs, and reasonable profit margins.
Regular supplier audits and on-site process control are very important. In European and American companies or Apple companies, there are many engineers responsible for supplier management. Process monitoring ensures that the quality control of supply barrels is carried out in accordance with our quality requirements. From new product development to sample production to mass production and shipment of finished products, each supply curve is regularly monitored by on-site personnel for quality. When the supplier's product is delivered to the next supplier, the next supplier will conduct IQC incoming inspection. If any material defects are found, we need to provide timely feedback. We use the 8D logic to find Root Cause and closed-loop control to close this issue. Even the mistakes made by this product or similar products in the 8D logic will be prevented and improved in similar products or processes, and thoroughly improved in other products or processes, Avoid making the same mistake.
This is what we are talking about supplier management, ensuring good management of suppliers, monitoring of supplier processes, ensuring that supplier incoming materials meet requirements, and promptly correcting any issues. Ensure that the supplier's materials meet the company's quality requirements.
Process quality control
1. Establishment of SOP and SIP files.
For each process, a standard guide book should be drafted clearly, which will cover the standard operating procedures and precautions. If there are projects that significantly affect product quality (CTQ), exclamation marks and asterisks should be used to indicate that employees cannot operate in violation of regulations. Misoperation can cause serious defects in the product. The homework inspection guide book has a clear definition of the sampling frequency, inspection methods, and inspection instruments used for inspection, Train inspectors to inspect according to our homework inspection instructions, ensuring that the inspection methods are correct and not misjudged, and also for KPI KPOV and input/output should be identified, and the impact of predecessors on certain processes on output should be controlled. DOE should be used to optimize equipment and process parameters. Control the input and output of the machine, and control the output of key products.
2. MSA measurement system.
To ensure that the inspection can truly reflect product performance, it is necessary to ensure that the inspection system GR&R (repeatability and reproducibility of measurement system errors) meets the requirements. When MSA GR&R<10% is a good measurement system, and 10% -30% measurement errors are too large, the measurement system needs to be improved, otherwise it cannot be used for product inspection. For example, measuring instruments such as battery weighing, electrode weighing, and ingredient weighing must be strictly calibrated.
3. CTQ
All input and output parameters that affect product quality must be identified within the process. For these CTQ projects, special monitoring should be carried out, including input parameters, such as alarms or machine equipment design. For real-time monitoring, if the process capability parameter CPK value can reach 1.33, sampling can be used. Therefore, the identification of CTQ is very important. For the parameters of CTQ in the process, SPC process statistics technology should be used to monitor whether the process input and output parameters are controlled, SPC can reflect whether the process is stable or not. If there is any abnormality, it will be reflected in the SPC control chart. The cause can be investigated in advance and preventive measures can be taken to avoid uncontrolled production process. If there are any abnormalities in SPC, they should be handled in a timely manner, and any problems encountered in the process should be resolved in a timely manner to ensure that the process is controlled and stable production.
4. Process control anti fooling system (shop floor control)
For key parameters, in process control, existing MES should be used for some monitoring. If the previous station tested for defects, the defects should be selected or intercepted at the next station. When employees make operational errors on the production line, there will be a system to prevent defective products from flowing to the next process or customers' hands. This system must be in place when conducting PFMEA or controlling key characteristics of products, otherwise suppliers will not be allowed to produce. The process control foolproof system is a necessary condition for Apple to audit suppliers, and without this system, one cannot become an Apple supplier.
5. Product traceability system
If there are abnormalities in production or customer complaints, it is convenient to recall the product, quickly determine the scope of product impact, facilitate traceability and isolation of the product, and facilitate quality investigation. The traceability system should at least achieve the traceability of human-machine materials and production time, including the characteristic parameters of key processes, operators, machine equipment numbers, material batch numbers, production time, CTQ, etc., all of which should have a system to facilitate investigation.
The process control foolproof system and product traceability system are two hard conditions for supplier management and quality management. Without either system, Apple will not provide them with a project. Currently, domestic enterprises are doing very poorly in these two areas. Without these two systems, many quality problems cannot be traced and investigated.
6. Employee self inspection and re inspection
To provide training for employees, each employee must clarify which are defective products, which are good products, which are qualified, and which are not. They must undergo training, certification, and assessment before they can start work. When defective products are found during the production process, employees will isolate the defective products and prevent them from flowing to the next station or even the customer's hands
7. IPQC inspection
IPQC is like a police officer in a factory, who conducts regular inspections on the mechanical equipment parameters of the production line, the operator's operating techniques, the operator's compliance with the operation flow, the CTQ parameters, and the input/output parameters of the equipment according to the sampling plan. The inspections may occur every 2 hours or every 4 hours based on the stability of the product process. When making the process control plan, the inspection frequency, sampling frequency, and The inspection method is clearly defined.
8. Preservation of process quality records
For the input/output key process parameters of each process, detailed quality records must be kept to ensure that there is sufficient quality record proof to prove that your product meets the Spec and the process is controlled when abnormalities are found on the client or process. When quality disputes or customer complaints occur, process quality records serve as strong evidence to prove that your process control is under control, abnormal issues are special, not batch issues, and production control meets quality requirements.
9. Monitoring and improvement of qualification rate
There should be data to record the qualification rate of each process in the production process, and control the yield of the process based on the company's continuous improvement or the yield target of the process. For projects that do not meet the standards or have high defect rates, data should be collected and analyzed using Plato to achieve continuous improvement. Plato is the principle of 28. According to statistical quality analysis, 20% of projects often result in 80% of defects. Conversely, when we use Plato's analysis, 80% of defects are often caused by the first two and three items. Therefore, we will focus our energy and resources on the first two and three items of 80% defects, and focus on improving them. The advantage of Plato is that for process defects, process analysis is not generalized, but targeted, This is the application of Plato.
10. Cycle time and UPH monitoring and improvement
What are the benefits of these two? When Cycle time is used for analysis and modification, your delivery cycle, WIP operation, or WIP inventory will be reduced, which can shorten your delivery time, shorten the production cycle of the product, and quickly respond to customer delivery. The improvement of UPH lies in improving and increasing the production capacity of the equipment.
11. Preventive maintenance of mechanical equipment
When the mechanical equipment is purchased, the equipment management personnel should develop a detailed maintenance plan based on the equipment operation manual, and develop equipment inspection and maintenance work instructions. Clearly list the maintenance methods, frequency, and replacement cycle of spare parts, conduct equipment maintenance visits, and ensure that the equipment is in good operating condition. The maintenance of equipment is similar to the maintenance of cars, and preventive maintenance should be carried out on production equipment. It cannot be repaired until it is broken, otherwise it will cause a significant loss to the lifespan of the equipment and the utilization of spare parts.
Quality Management of Finished Products (OQC)
One important aspect of finished product quality management is the sampling plan. According to different quality requirements, the sampling plan table needs to develop different sampling plans, sampling frequency, and sampling quantity. After determining the sampling items, measure the system and MSA (ability of inspection and testing equipment) GR&R needs to be evaluated. If the instruments, equipment, or measurement system do not meet the requirements, registration changes need to be made. The next step is the training and assessment of inspection personnel. Inspection personnel must pass the training and assessment before they can start work. If the inspection standards and requirements are not grasped correctly, misoperation of measurement equipment will affect the fairness of product inspection. If unqualified products are found during finished product inspection, a Action Plan should be in place. When defective products are found, they should be promptly handled through the Material Review Board (MRB), either downgraded for acceptance, reworked, or scrapped. A clear action plan should be in place to handle them in a timely manner.
ORT reliability testing management of products
ORT testing is very important. Sample testing is conducted on product performance, such as high temperature, high humidity, impact and other testing projects. Different ORT testing projects are developed according to different industry regulations. After some extreme testing and simulation of customer usage extreme conditions, the product meets the requirements, and any defects can be detected and improved in a timely manner.
The management of ORT is also important, including your sampling plan, number and frequency of tests, testing items, measurement system, training and assessment of testing personnel. Regarding the Reaction Plan for ORT defects, testers should promptly report any defects to their superiors, conduct timely evaluations, conduct defect analysis, and take improvement measures.
