Electrostatic Discharge (ESD) in electronic production is a silent threat that causes irreversible damage to products. OEMs and CEMs must implement comprehensive strategies to mitigate the impact of ESD in the Surface Mount Technology (SMT) production environment to prevent costly downtime, financial losses, and damage to their reputation.
What is ESD?
The static electricity shock we experience when flipping a light switch or touching metal is a minor inconvenience compared to the effects of the permanent damage ESD can cause to electronic products during assembly. ESD is the sudden flow of electricity between two electrically charged objects caused by contact, an electrical short, or dielectric breakdown.
Five tips for minimising ESD
As electronic devices become faster and smaller, their sensitivity to ESD increases and it’s even more critical than ever to establish an ESD-controlled STM production environment. ESD is preventable during the assembly process with ESD systems that ground operators, and equipment to eliminate static electricity, protect components and ensure consistent, reliable production and electronic products.
1. Proper Grounding and Bonding
All conductive surfaces and objects, such as workstations, tools, and equipment must be connected to a low-impedance ground connection. Workers should wear wrist straps that connect to the ground while handling sensitive components. Install conductive flooring or anti-static mats to minimise static build-up. Workstations should have static-dissipative surfaces, made from materials like conductive rubber or laminate. Regular checks and maintenance of these tools are necessary to ensure their effectiveness.
2. Controlled Environment
The manufacturing environment should be free from static-generating materials like untreated plastics. Maintain the humidity level between 30-70% to reduce static electricity, and the temperature should be controlled within the range of 18-30Ā°C. Install ESD-safe flooring, walls, ceilings, and work surfaces to create a static-free environment.
3. ESD Awareness and Training
Educate employees about the dangers of electrostatic discharge, and its impact, on the manufacturing process. Conduct regular training sessions and workshops to reinforce best practices and ensure everyone follows the ESD control guidelines effectively.
4.Ā Use of Ionizers and ESD-Protected Storage
Ionizers can neutralise static charges on surfaces where grounding is impossible. Different types of ionisers (DC, AC, and pulsed DC) can be used based on the specific needs of the workstation. Additionally, use ESD-protected storage solutions, like conductive bags, bins, and containers to transport and store components and prevent static build-up.
5. PCB Handling Equipment
Manual handling of PCBs during production increases the chance of having ESD issues. Automated board loaders and unloaders on an SMT line are advantageous because they minimise PCB handling. Nutek board handling machines are all earthed, dissipating any potential build-up of static electricity.
*** The above information serves as a guideline. Due to the complexity of the ESD system in SMT environments, Hawker Richardson recommends consulting the S20.20 Standard and utilising the services of an experienced provider. Contact our team, and we will connect you with trusted experts.
Resources:
The S20.20 Standard can be obtained from the EOS/ESD Association
Sources:
