Objective Identification of Causes for Product Failure Certification

Product Specification

Failure analysis of polymer materials
·Efficient and objective identification of causes to solve product failure problems
Failure analysis of polymer materials. Failure may occur at various stages of the product life cycle, involving product R&D design, incoming material inspection, processing and assembly, test screening, storage environment, customer use and other links. confirms the failure mode, analyzes the failure mechanism, clarifies the failure cause, and finally gives preventive measures to reduce or avoid the recurrence of failure by analyzing samples of process waste, early failure, test failure, pilot failure and field failure.

Service background
Failure analysis of polymer materials is of great significance to the production and use of products. Failure may occur at various stages of the product life cycle, involving product R&D design, incoming material inspection, processing and assembly, test screening, storage environment, customer use and other links.

By analyzing samples of process waste, early failure, test failure, pilot failure and field failure, confirm the failure mode, analyze the failure mechanism, clarifies the failure cause, and finally gives preventive measures to reduce or avoid the recurrence of failure.

Failure analysis services rely on hundreds of cutting-edge analytical instruments in professional laboratories, supplemented by the extensive experience of technical experts in polymer materials and failure analysis, to ensure that the analysis results are fair, professional and objective, so as to help customers improve product quality and improve technical processes.

Failure analysis objects
Plastics Rubber Natural latex Adhesives
Unknowns Metal materials and parts Automotive parts Composite materials
Coatings Oils
Fine chemicals
Inorganic substances
PCB Electronic components
Welding products
LED products
Service content
Failure analysis of polymer materials generally includes steps such as failure background investigation, analysis scheme design, result analysis and discussion. During the analysis process, we will fully communicate with customers to ensure the accuracy of the results.

1. Use comprehensive and diversified analysis and testing methods to directly explore the most important and most likely causes of failure:

1. Design a unique analysis plan based on the characteristics of failure and the characteristics of the product.

2. Comprehensively use various analysis and testing methods, including but not limited to microscopic morphology analysis, component analysis, performance analysis and reproducibility testing.
3. Comprehensively compare and analyze failed products, infer the causes of failure or eliminate factors that may affect failure.
4. Provide improvement measures and suggestions to reduce or avoid the recurrence of failure.

2. Specific process of service:

1. Failure background investigation: product failure phenomenon, failure environment, failure stage (design debugging, pilot test, early failure, mid-term failure, etc.), failure ratio, failure history data, etc.

2. Non-destructive analysis: X-ray fluoroscopy, ultrasonic scanning, electrical performance test, morphology inspection, local component analysis, etc.

3. Destructive analysis: unsealing inspection, profile analysis, probe test, focused ion beam analysis, thermal performance test, body composition test, mechanical performance test, etc.

4. Use condition analysis: comprehensive analysis of structural analysis, mechanical analysis, thermal analysis, environmental conditions, constraint conditions, etc.

5. Simulation verification experiment: design simulation experiment based on the failure mechanism obtained by analysis to verify the failure mechanism.

6. Give the cause of product failure and provide improvement suggestions or solutions.

Common reasons for product failure
1. Change of raw material supplier or quality control problem of raw material supplier, resulting in batch product failure caused by differences between raw material batches.
2. Temperature/humidity changes and seasonal changes, resulting in product failure during production or use.
3. Process problems in the production process, resulting in product failure.

Common product failure modes
1. Deformation, breakage, cracking, wear, shedding, delamination, blistering;
2. Blooming, oiling, powdering, precipitation, foreign matter;
3. Corrosion, powdering, aging, discoloration, etc.

Failure case
Case 1 - Cracking
1. Background introduction
The customer's product is a black plastic frame of a mobile phone component. The material is a blend of PC and glass fiber. The surface is coated with primer and light-cured varnish. The frame cracked about 2 months after production.

2. Solution and verification
Based on the customer's samples and cracking conditions, the failure analysis team proposed a verification solution:
(1) Material analysis: Based on the comparison of the failed sample, normal sample and pellets, confirm whether the cracking is caused by material changes.
(2) Fracture analysis: Analyze the cross section of the failed sample to find the cause of failure from the microstructure.
(3) Ash analysis: According to the glass fiber and unknown particles found in the cross section, the ash content of the sample is measured to confirm the glass fiber content.
(4) Physical property analysis: Analyze the melt mass flow rate of the sample to confirm whether there is a possibility of degradation.

3. Results and conclusions
(1) PC has a large number of uniform micropores and a significantly increased melt mass flow rate. The surface PC is likely to be degraded, resulting in reduced strength.
(2) Glass fiber is added to PC for reinforcement, but the bonding between glass fiber and PC is poor, resulting in PC being unable to effectively cover the glass fiber to improve strength.
(3) The fracture source of the failed sample is at the corner of the structure, where the stress is more concentrated. Since the strength is not enough to resist this stress concentration, microcracks appear after a long period of action and then the cracks spread, causing the sample to crack.
(4) There is no significant difference in the main components between the failed sample, the normal sample and the pellets; however, there is a significant difference in the components of the reinforcing components. Compared with the raw materials, the finished product after injection molding not only has glass fiber, but also has a significantly increased TiO2 content, but the increase of this component has little correlation with the spraying process.

4. Analysis and suggestions
(1) The moisture content of the pellets needs to be strictly controlled during PC injection molding, and the pellets must be fully dried before they can be used for injection molding.
(2) Improve the bonding between glass fiber and PC.
(3) Anneal the product after injection molding to reduce residual internal stress.

Case 2 - Corrosion
1. Background introduction
The customer's sample is a PCB electronic device, which is encapsulated with a two-component epoxy adhesive. For cost considerations, the customer wants to introduce a second cheaper supplier. It turns out that the two-component epoxy adhesive provided by the supplier caused serious via corrosion on the surface of the PCB board. The customer wants to find the cause of the corrosion and entrusts SGS to conduct a failure analysis investigation.

2. Solution and Verification
 proposed a general technical solution and conducted verification in response to the customer's problem:
(1) Analysis of the composition of epoxy adhesive used for normal and failed parts.
(2) Analysis of the surface morphology and surface composition of failed electronic devices.
(3) GC-MS analysis of two-component epoxy adhesive cured parts.

3. Results and Conclusions
(1) The surface morphology and composition analysis of the corrosion site also revealed obvious information about modified amine curing agents at the corrosion site, which can be inferred to be caused by amine curing agent corrosion.
(2) The two-component epoxy adhesive of the new supplier's product has a low degree of crosslinking after curing. At the same time, a large number of small molecular amine substances were detected, and the amine curing agent is easy to migrate, which will cause corrosion when in contact with the circuit board.
(3) The aromatic solvent oil in the two-component formula of the new supplier is more different from the original supplier's formula. The aromatic solvent oil has a swelling effect on the cured parts, making it easier for small molecular substances to migrate.

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