Chip-on-Board (COB) & Chip-on-Flex (COF) Assembly Services
Direct Die Attachment for Rigid and Flexible Substrates
Chip-on-Board (COB) and Chip-on-Flex (COF) are advanced microelectronic assembly techniques where bare die are directly attached and electrically connected to printed circuit boards (PCBs) or flexible circuits. This direct attachment approach eliminates traditional package overhead and enables smaller, lighter, and higher-performance solutions for modern electronic designs.
QP Technologies offers COB and COF assembly on substrates up to 5″ × 8″ and larger, providing a flexible and precise platform for complex assemblies.
Direct Mounting & Electrical Interconnection
In COB and COF assembly, die are mounted directly onto the target substrate, rigid PCB for COB or flexible circuit for COF, using die-attach adhesives or surface mount technology. Shorter interconnection paths improve electrical performance and thermal dissipation, while reducing overall package size and cost.
Our COB/COF services include:
- High-precision die attach
- Wire bonding and ribbon bonding
- Passive component integration prior to die mounting
- Encapsulation and protective coatings
- Custom fixture design to support unique form factors
Rigid & Flexible Substrate Assembly
❖ Rigid PCB (COB)
- Direct die attach on printed circuit boards
- Precision wire bonding
- Encapsulation options including glob top, overmold, frame and lid
- Ideal for devices where size, performance density, and mechanical stability matter
❖ Flexible Circuit (COF)
- Direct die placement and electrical integration on flexible substrates
- Flex circuits accommodate bending and dynamic form factors
- Optimal for sensors, wearable electronics, medical devices, and RFID applications
Chip-on-Flex assemblies leverage the benefits of flexible circuits while maintaining robust electrical interconnects and high integration density.
Component Integration & Substrate Support
Before die attachment, QP Technologies can populate the substrate with required surface mount and discrete components using automated SMT processes. This includes:
- Passive networks
- Diodes and transistors
- Connectors
- Integrated circuits
This pre-assembly ensures a streamlined production flow and maximizes design flexibility.
Custom Fixture Design & Engineering Support
To support unique form factors or challenging assemblies, QP Technologies provides in-house design and fabrication of custom fixtures. These fixtures:
- Aid in accurate die placement
- Facilitate repeatable bonding
- Reduce setup time
- Support prototype and low-volume production flows
Custom fixture development also accelerates lead times for new designs.
Quality Assurance & Reliability
COB and COF assemblies are verified through industry-standard inspection and testing procedures, including:
- Automated optical inspection (AOI)
- Bond integrity verification
- Surface finish and coverage evaluation
- Process traceability documentation
Collectively, these steps ensure assemblies meet your performance, reliability, and manufacturing specifications.
Integration with Other Advanced Assembly Services
This COB/COF service integrates seamlessly with QP Technologies’ broader advanced assembly offerings, including:
- Multi-Chip Module (MCM) & System-in-Package (SiP)
- Flip Chip Assembly
- Stacked Die Assembly
- Chiplet Integration
- Surface Mount Technology (SMT)
These capabilities allow you to build hybrid and system-level assemblies when required.
Request a COB/COF Assembly Consultation
To discuss your Chip-on-Board or Chip-on-Flex assembly requirements, including substrate type, die dimensions, and performance goals, contact QP Technologies with your design files and BOM.