PCB Assembly Design for Testing (DFT) & Manufacturability (DFM)

At Fuchuangke Technology, we understand that high quality PCB assembly means getting it manufactured and assembled right at the first time upon the right Gerber files, BOM and other files. We always do our best to build your PCB boards at the lowest possible cost and quickest possible delivery time, but PCBA quality and functionality remain our highest priorities at all times. This attitude is the reason that our PCB assembly process includes multiple approaches of testing, including E-test, Solder Paste Inspection, Visual Inspection, AOI, X-ray, and First Article Inspection for components soldered onto the bare PCBs.

DFM Validation for PCB Assembly

We offer DFM validation for PCB assembly with the support of experienced engineers and prescribed guidelines. We are one of the few electronic contract manufacturers to give a free design for manufacturability (DFM) validation for every PCB assembly project. Therefore, global customers contact us to avail this benefit. DFM validation enables to detect errors at the initial stage, which helps to avoid PCB assembly production delays and expensive mistakes.

PCB Assembly DFM Advantages

Early DFM validation helps to save considerable time. DFM validation for printed circuit board is comprehensive process which includes

• Detecting inaccurate footprint for components
• Inappropriate parts spacing
• First pin indication
• Part to part spacing
• Part to edge spacing
• Footprint corroboration
• Verification of bill of material (BOM) with PCB board
• Cathode mark for diode
• Component polarity, etc.

We have main objective of design for manufacturing is to improve the product quality, cost and delivery. Using precise DFM procedures enables to have desired quality, reduction in turnaround time and product cost by carefully selecting the appropriate parts for the application. It has been observed that minute mistakes lead to heavy losses to the majority of the customers, so it is desired to have DFM validation at a very beginning stage. DFM validation at the right time enables to correct mistakes at the early state before committing it to PCB and assembly manufacturing. This in turn saves customers from the hassles of rework and lead to further reduction in PCB assembly cost.

We have employed experienced engineers who are well-versed with prescribed standards of DFM validation. Our PCB assembly team ensures accurate DFM check and strives to deliver quality end product. DFM validation enables consumers to have superior quality circuit board assembly.

PCB Assembly Design for Testing

All of these testing approaches are included by default when applicable, but our customers also request additional testing at their customized requirements. These optional testing approaches are known as In-Circuit Testing (ICT) and Functional Testing (FCT), and both are conducted after PCB assembly to check for the desired functionality of your printed circuit board assemblies (PCBAs) by our testing engineers. The cost and time requirements of the ICT and FCT procedures is largely dependent upon the specifics of the PCB assembly project in question, and there are a few strategies that you can employ to make these procedures more efficient. Design for Testing (DFT) is what we use to describe the optimization of a project for efficient ICT and FCT, and this article aims to give our customers a basic overview of best practices in DFT when it comes to PCB assembly projects.

DFT for Functional Circuit Testing

FCT is a black-box approach that target the overall output or functionality of your PCBs, meaning that the complexity of the test depends mainly upon your test procedure, rather than the minutia of the circuit board itself. When you request FCT for your project, during the quoting stage of the process, we will ask you to submit a written testing procedure, which is analyzed to determine cost and time consumption requirements. Some simple FCT procedures, which are the most efficient test procedures, have only a few steps like below,

• Power supply set-up
• Turn on the power supply
• Required message to be displayed on a display, or a certain set of LEDs to flash or turn on

Some customers will include LEDs in their design whose only purpose is to identify correct operating voltages at specific points on the circuit board. While this strategy does take some space on the PCB, it can mean that your project can be verified by a simple FCT procedure, rather than a more in-depth ICT check.

DFT for In-Circuit Testing

ICT is a white-box approach, where our testing engineers monitor individual voltage and current levels on a finished PCB, possibly even performing step-by-step program execution on the circuit board’s firmware. This method is much more in-depth than FCT, and normally requires considerably more in terms of both time and cost, but it is very effective at pinpointing any potential issues on a circuit board, down to a single component.

ICT is the most efficient in Prototype PCB assembly projects since the lower quantities of these order volumes mean that the greater time requirement of ICT is not multiplied overmuch by a large number of circuit boards. That being said, it is possible to optimize your testing method to ICT by designing a testing fixture. A PCBA testing fixture allows for us to test your PCB assemblies quickly, by simply pressing them down one-by-one on a collection of test pins, similar to Bed of Nails PCB Testing for bare PCBs, rather than meticulously probing with a DMM or oscilloscope. It should be noted that your need not actually design a mechanical fixture, but simply indicate to us in a drawing which pads should be tested and what their electrical characteristics should be at a given point in time. Where probing is necessary, the process can be made more efficient by the inclusion of test points on the PCB assembly for easy connection to our test equipment.

We have engaged a professional service team to address all issues. We carefully evaluate Gerber, bill of material (BOM) files for DFM and DFT check. You can easily communicate with our team through multiple available channels, including email, online form and attachments. Please tell us know your concerns and we will response you with an appropriate solution.

Quick Quote

Click the Quick Quote buttons below, you can turn to the different PCB quote pages. Just fill in the PCB specifications, upload Gerber files, BOM, Assembly Drawing and Pick-and-Place file, you will get quick quote of PCB board and PCB Assembly.

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