Topfast is a trusted professional PCB manufacturing and PCBA assembly service provider. We have over ten years of experience in the industry. We provide cost-effective, high-quality solutions for consumer electronics, industrial equipment, medical devices, and research projects. We offer one-stop services ranging from PCB prototyping to mass production.
Q1: What kind of company is Topfast?
Topfast is a trusted professional PCB manufacturing and PCBA assembly service provider. We are committed to providing top-notch solutions for consumer electronics, industrial equipment, medical devices, and more. With years of industry experience, we are your go-to experts for quality and value. We offer end-to-end services from PCB prototyping to mass production, including turnkey assembly, component procurement, and multiple testing options. We are dedicated to precision, reliability, and customer satisfaction.
Q2: Is there a minimum order quantity (MOQ) for PCB assembly orders?
Generally, we do not impose a minimum order quantity for PCB assembly orders. Whether for prototypes or small to medium-volume production, we are ready to assist.
Q3: Can you assemble PCBs not manufactured by Topfast?
Currently, we do not offer assembly services for PCBs produced by other manufacturers. To ensure end-to-end quality control, improve production efficiency, and optimize costs, we recommend using our integrated “Fabrication + Assembly” service model.
Q4: What files are required for a PCBA order?
To ensure smooth production, please provide the following files:
- Gerber files (must include silkscreen, copper, and solder paste layers)
- Centroid file (Pick and Place/XY data)
- Stückliste (BOM)
Providing additional files such as assembly drawings, special instructions, or project images is also recommended to prevent misunderstandings and improve assembly accuracy.
Q5: What is a Centroid File?
A centroid file, also known as a Pick and Place or XY file, is used for programming automated assembly equipment. It should include:
- Reference designator
- X and Y coordinates (location)
- Rotation
- Board side (Top/Bottom)
Only surface-mount devices (SMDs) should be included. Some CAD tools generate this file automatically, while others require manual export. Providing an accurate file helps ensure placement precision.
Q6: How should consigned or kitted components be packaged and labeled?
Please mark each package with:
- Line item number (as in the BOM)
- Manufacturer or customer part number
- Menge
Please also include a detailed packing list to facilitate efficient receipt and inspection.
Q7: What are the requirements for excess components in consigned/kitted orders?
To avoid production interruptions, we recommend providing extra components as follows:
- Resistors, capacitors, diodes (0603, 0805, 1206, 2225, SOT, SOD, MELF): Minimum 50 pcs, plus an additional 30 pcs
- Small components (0201, 0402, miniMelf, etc.): Minimum 100 pcs, plus an additional 50 pcs
- High-value components (ICs, BGAs, QFPs, connectors, etc.): We suggest providing 1–5 extra pieces
If you would like unused components returned, please inform us in advance.
Q8: Do you offer component sourcing services?
Yes, we provide “partial turnkey” services: you may supply some components, and we will procure the rest. If components are out of stock or substitutions are needed, we will promptly seek your confirmation to ensure all selections meet design requirements.
Q9: Do you support BGA assembly? Are there any specific requirements?
We support various packages, including 0.25mm fine-pitch BGAs, and provide X-ray inspection to ensure quality. For BGA pad design, please note:
- Vias near pads must be tented (covered with solder mask)
- Vias in pads must be filled with resin
This ensures soldering reliability and prevents defects such as voids or short circuits.
Q10: How are unused components handled after order completion?
After order fulfillment, unused components can be:
- Returned along with the assembled boards
- Stored in our warehouse for future orders
Please specify your preference when placing the order.
Q11: How is the total cost of PCBA services calculated?
We offer an online real-time quoting tool that covers basic engineering costs, stencil fees, and labor. Turnkey orders also include component costs, with transparent pricing and no hidden fees.
Q12: When does the production lead time officially start?
The production cycle begins only after the following conditions are met:
- All PCBs and components are ready
- All required files have been provided (Gerber, BOM, centroid file, etc.)
We will confirm promptly and proceed with production.
Q13: Are the components compliant with RoHS standards?
Yes, by default, we provide RoHS-compliant lead-free assembly services. We also support leaded processes upon request.
Q14: When is panelization required?
If a single board is smaller than 50mm x 100mm, or if the board shape is non-rectangular (e.g., circular or irregular), panelization is necessary to facilitate production and assembly. We will generate the panelization design and corresponding stencil.
Q15: Why are breakaway rails required?
If the edge-to-copper clearance is less than 3.5mm, or if panelization is used for easier assembly, breakaway rails must be added along the longer edges of the board. This ensures stable handling and processing by SMT equipment. The rails can be easily removed after assembly.
Q16: What should I do if I receive defective boards?
Please contact us immediately. We will evaluate the issue and offer repair, rework, or remanufacturing as needed. In some cases, we may request the return of defective boards for analysis. We are committed to resolving all issues to your satisfaction.
Q17: What standards do you follow for assembly?
We adhere to the IPC-A-610 Class 2 standard, ensuring that products meet industrial requirements for reliability and longevity.
Q18: What is the lead time for turnkey orders?
The lead time for turnkey orders depends largely on component procurement. During this period, we proceed with PCB fabrication and stencil preparation. We provide daily email updates on component status to minimize overall delivery time.
Q19: How should I provide special instructions?
You may specify special requirements via email or include a readme document with your order to ensure accurate execution.
Q20: What types of testing services do you offer?
We provide:
- Visual inspection
- Automatisierte optische Inspektion (AOI)
- X-Ray inspection (for BGAs and fine-pitch components)
- Functional testing (requires customer-provided test specifications)
Q21: Do you offer IC programming and functional testing?
Yes, we support IC programming (a hex file is required) and functional testing (a test program and hardware are required).
Q22: Do you offer conformal coating services?
We provide conformal coating services. For more details, please contact: Sales@topfast.com.
Q23: What factors affect the cost of PCB assembly?
Key factors include:
- Single or double-sided assembly
- Number and type of components
- Process complexity (e.g., BGAs, fine-pitch components)
- Testing requirements (AOI, X-Ray, functional testing)
- Coating, packaging, and shipping methods