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One of the most overlooked areas of PCB Assembly is pre-delivery prep. This is a bit strange, as getting your boards manufactured correctly and back on time is crucial to your project being on schedule.
However, many people leave all the PCB assembly prep action until after questions about good documentation and test plans for manufacturing documentation that you can rely on through your board build process.
Why does this happen? There could be several reasons, but we think the main reason is that you don't know what to do, so you leave everything until the last minute, then everything goes wrong.
Alternatively - maybe you are a little more proactive than most but still unsure what's required - you put together a great package, but then some things still go wrong and again seem to be out of everybody's control. The net result is that everyone loses their patience and starts blaming everyone else for "handling it poorly." Here's a checklist of twelve things you should do before shipping your prototype boards.
PCB assembly includes all the processes from when the bare PCBs are received from the manufacturer to when they are shipped back to the customer.
With so much that can go wrong, miscommunication, and mistakes, it's essential to have a checklist of things to do before you start production. Some items on this checklist may seem obvious, but it's easy for them to slip through the cracks if you're not careful!
Assemble your design file according to specifications and make sure it includes any special instructions from your PCB manufacturer (if applicable).
If you're using a 3rd party service provider for your fabrication, check their documentation (or ask them directly) to see whether they require anything else.
This might seem obvious, but it's imperative to ensure that all your parts are accounted for when you send off your design files. A great way to do this is to count out all of the components (or at least sort them into groups) when you're assembling your prototype board.
Doing so will help ensure that the manufacturer will know exactly what was supposed to be included in your order if anything goes wrong with shipping or assembly.
It can also help prevent mistakes like accidentally ordering more resistors than capacitors or vice versa—and accidentally ordering two entirely different kinds of capacitors altogether.
It's easy to forget to include the Gerber files for the entire board instead of just one part. When ordering boards, you can select a panelized version of your PCB, which will allow you to order several smaller boards on a single panel.
The only problem is that if you don't also order the Gerber files for the entire board, it will be challenging to make changes and re-order a new set of boards if something goes wrong with your first batch.
If you're ordering a PCB online and your service provider doesn't offer an option of uploading an archive with all of your files, you can use a free tool like WinZip to unzip all of your files to do so in separate folders. You can then upload each folder separately, which will give you access to the full Gerber set for your project.
Nothing is worse than realizing that the silkscreen is wrong after the boards are already being soldered. Make sure all of your text is readable, and all of your graphics are clear and easy to read.
Don't forget any part numbers or revision numbers, and make sure they're spelled correctly and are consistent with any other documentation you might have on hand.
Double-check the silk layer colors and make sure the images are crisp and legible; if there's an error, it is time to fix it before manufacturing begins. Remember: save yourself some money by catching this problem early!
It's always good practice to have a Bill of Materials (BOM) included, even if you're ordering just one prototype board. The BOM helps us ensure we have everything set up correctly and that no components are left out.
It also helps us check that we're making the correct number of each part, so we don't accidentally send you 20 resistors when you only want 10.
It's also an excellent way for us to help you if something goes wrong: if there's an issue with your design, we can tell you precisely what pins are connected to which parts, which can help you figure out what went wrong.
Insurance is an agreement between two entities that if one party suffers a loss due to an event covered by the insurance policy (such as damage or destruction), the other party will provide compensation for their loss. This can be done through cash payment, replacement of damaged property, or both.
At this point, you've built your circuit board, assembled all of the components, and tested it to ensure it's working correctly. Now you're ready to send it off to a PCB assembly house, but before you do, you should take some time to research shipping insurance, which may or may not be provided by the assembly house.
While it might not seem like something you need at first, shipping insurance is an excellent idea for various reasons. Most importantly, it can cover both your goods and your prototypes if they are lost or destroyed in transit.
Choose a company that offers services that fit your needs. For example, are you looking for a manufacturer with quick turnaround times?
Is cost vital to you? Do you need prototypes shipped across the country or internationally? Be sure the manufacturer has all of the services that you need—any extra services they offer are simply icing on the cake!
Before choosing a company, understand precisely how prototype boards are made? Are bare boards sent to you and then soldered by hand, or do you have a pick-and-place machine that places components automatically?
Will your designer be able to create schematics easily using software such as Eagle CAD? Are there restrictions on how many layers of traces or how many components can be placed on a board? Make sure your PCB manufacturer offers double-sided boards and extra layers of boards.
Give Your Manufacturer All the Files They Need
Ensure all required Gerber files and drill files are included in your order—the manufacturer often specifies the design rules and drill sizes for your board. Before uploading Gerber files, be sure that each layer's colors correspond to the color of the solder mask on top of it (silver for unconnected pads or solder mask and green for copper). Include an image of the board layout in case there's any confusion about assembling it.
Before you place your order, make sure your components are in stock. You don't want to wait weeks for a replacement to arrive from the manufacturer only to find that the parts you need are no longer available.
If a particular component is in high demand, you may consider sourcing it elsewhere. If you're using a PCB assembly service, they'll let you know if the parts aren't immediately available and do their best to give you an estimated timeframe for when they will be in stock again.
After you've assembled your prototype PCBs, they're ready to be placed into their final packaging. But before that can happen, there are a few tasks you must complete first. Before assembling your board, you should have already selected your white labeling method. Here are some of the factors to consider when deciding on a type of white labeling for your PCBs:
When choosing a white labeling method, it's essential to know the 3-meter length of the boards to calculate precisely how much space each type will take up and what size label sheets will fit in the box with them. If you're using a service like PCBWay, this information should be readily available.
If you're doing your printing with an inkjet printer (which is likely), then select a paper stock based on the inkjet-printing requirements listed in the manufacturer's datasheet.
If you need specialty mounting holes (like larger or smaller diameter holes or blind/buried holes), then make sure those requirements are known and fulfilled before sending them out for assembly.
If you need a PCB assembled, you're most likely designing a circuit board with LEDs. And if you're planning a circuit board with LEDs on it, you're most likely building a prototype of something. When it comes to PCB assembly, one of the first things people think about is how they'll be marking their LED locations.
The truth is, LED placement is one of the essential steps in your design process because how you mark your LEDs can drastically affect how easy or difficult your PCB will be to build. You must choose your LED colors and placements carefully, or you'll have a complex prototype for your manufacturer to assemble.
The font is one of the first things to consider when designing your circuit board. It would help if you chose an option that is easy to read and understand for both you and any potential customers who may need to interpret the schematic later on.
For example, if there are multiple ground connections between two points, it's easier for someone to see that they all route back to one point if the text reads "Ground" rather than "GND" or "VSS.
Before you ship your boards off to be assembled, there are a few things that you need to do first. This checklist will ensure that your PCB assembly house has all of the information they need to build your prototype boards from start to finish.
In addition, it's a good idea to make sure the parts fit correctly, the Gerber files and drill files have been generated correctly, and the design meets industry standards.
Follow these twelve simple steps, and you'll have a quality, high-performing prototype on your hands. We hope that this checklist will give you some peace of mind when it's time to send your boards for manufacturing.