Topline Circuit provides professional flex and rigid-flex PCB assembly services for your complex electronic projects. Our experienced team specializes in flexible circuit board assembly, ensuring high-quality results for applications requiring bendable, lightweight, and space-saving solutions.
Assembly Capabilities for Flex & Rigid-Flex PCBs
| Assembly Capability | Description & Key Applications |
|---|---|
| Surface Mount Technology (SMT) | Components are mounted directly onto the PCB surface. It is the standard method for high-density, modern electronic assemblies. |
| Through-Hole Technology (THT) | Component pins are inserted into drilled holes and soldered. It provides strong mechanical bonds, often used in military, aerospace, and heavy-power applications. |
| Flip Chip | The silicon chip is inverted and connected directly to the substrate bumps. It offers shorter electrical paths and is used in high-performance, compact designs. |
| Selective Soldering | A programmable machine solders specific through-hole components by controlling pre-heat, flux, and solder time, protecting surrounding heat-sensitive parts. |
| Press Fit | Creates a gas-tight connection between the PCB and plated through-hole without soldering. Ideal for high-current connectors and aerospace applications. |
| Automatic Optical Inspection (AOI) | Uses high-resolution cameras to detect component presence, orientation, solder joint quality, and alignment defects during or after the reflow process. |
| X-Ray Inspection | Verifies hidden solder joints beneath components like BGAs and QFNs, ensuring internal structural integrity and precise alignment. |
| In-Circuit Testing (ICT) | Uses a custom fixture to electrically test individual component values, circuit continuity, and functionality on populated boards in mass production. |
| Flying Probe Testing | Uses movable probes to check circuit continuity and opens/shorts without a custom fixture. Highly cost-effective for prototype and low-volume runs. |
| Conformal Coating | Applies a protective chemical layer (e.g., acrylic, silicone) to the assembled PCB to shield against moisture, dust, chemicals, and extreme environments. |
| Mechanical Assembly / Box Build | Integrates populated PCBs into final enclosures with cables, displays, and mechanical parts, delivering a complete, ready-to-use electronic product. |
| Reballing | The process of replacing or renewing the solder balls on BGA components, enabling the repair, testing, or reuse of high-value integrated circuits. |

Technical Specifications
Flexible PCB Assembly:
- Minimum trace/space: 0.075mm/0.075mm
- Minimum hole size: 0.1mm
- Board thickness: 0.1mm – 3.2mm
- Copper weight: 0.5oz – 2oz
- Surface finishes: ENIG, Immersion Silver, OSP, Gold Plating
Rigid-Flex Assembly:
- Layer count: 2-38 layers
- Bend radius: As per design requirements
- Component mounting: SMT and through-hole
- Testing: Flying probe, fixture testing
Applications
Our Assembly Capabilities include rigorous quality control measures:
- Medical Devices: Wearable health monitors, surgical instruments
- Aerospace & Defense: Avionics, communication systems
- Consumer Electronics: Smartphones, wearables, cameras
- Automotive: Dashboard displays, sensors, control modules
- Industrial Equipment: Robotics, automation systems
- Telecommunications: 5G devices, networking equipment
Component Sourcing and Procurement Models
When planning a PCBA processing project, buyers must decide how components and materials will be sourced. Topline Circuit supports multiple procurement models to align with your supply chain strategy and project requirements.
Full Turnkey Assembly In a full turnkey model, the manufacturer takes full responsibility for sourcing all components and PCB materials based on the approved Bill of Materials (BOM). This approach centralizes supply chain management, reduces coordination overhead, and helps mitigate the risk of production delays caused by component shortages. It is particularly suitable for projects requiring strict traceability and integrated quality control from fabrication through final assembly.
Consigned and Partial Assembly For buyers who prefer to maintain direct control over their component inventory, consigned assembly services are available. In this model, the customer purchases and ships the components to the assembly facility. Partial consignment is also supported, allowing buyers to source critical or long-lead-time components themselves while the manufacturer procures standard passive parts and PCB materials. Buyers choosing this route must ensure that all components meet the required IPC standards and are properly packaged to prevent moisture or ESD damage during transit.
Quality Assurance
- 100% AOI (Automated Optical Inspection)
- X-ray inspection for BGA and hidden joints
- Functional testing and burn-in testing
- Flex testing for dynamic applications
- IPC-A-610 Class 2/3 compliance
- Complete traceability and documentation
Ready to start your flex or rigid-flex PCB assembly project? Contact our engineering team for:
- Free DFM (Design for Manufacturability) review
- Quick quote within 24 hours
- Technical consultation and support
To request a quotation, please send your Gerber files, BOM, assembly drawings, and quantity requirements to sales@toplinecircuit.com