If you need to manufacture several prototypes which require PCB assembly, it doesn’t make sense to buy pricey equipment. As an alternative, you might wish to subcontract the production to a reliable vendor. A lot of vendors will offer both PCB production and assembly. I will show you what to look out for when choosing a vendor. I will also give some pointers on which services modern vendors offer.
Often you will find a quotation system on contract manufacturer websites. Using this system, you can get an instant quote for your board or assembly. This will help you save time when comparing various manufacturers. This quote system should allow you to enter all of the board data. Such data include board thickness, material and any special manufacturing requirements like milling. This will help you avoid any surprises in case of surcharges for particular manufacturing requirements.
If you manufacture a small volume of boards, the cost customarily will be higher per board than the cost when manufacturing a higher quantity. This is a result of the board manufacture and assembly setup expense which is generally fixed. A few manufacturers will employ a system where they combine boards from several clients. Using this method the setup cost will be distributed amongst several customers. When you are still in the design phase of your product, you do not want to spin a large number of boards initially. As soon as you refine your design you may gradually wish to increase the board quantity.
If you are using a low-cost board manufacturing service then your alternatives in regard to material and thickness will be restricted. Generally you will have a choice of normal materials and board thicknesses. This is to help the supplier combine your production with the production for other customers. Additionally, lead time plays a big role in determining cost. A longer lead time allows the manufacturer more freedom in slotting your production. When you enter your data in the instant quote section, you will see that the production cost will differ depending on the lead time. If you can wait then cost will be lowest. If you are in a rush then you will have to pay extra to be moved ahead of the line.
Ensure that your contract manufacturer will support the file format for manufacture that you offer. The most common format for PCB manufacture is the Gerber format but a few vendors will also accept board files from common PCB software products. If you pick a vendor which also provides circuit board design services then you can rest assured that there won’t be any lengthy delays in case your board files have a problem that needs to be corrected.
Make certain that your supplier can handle the package type of each part on your board if you plan on outsourcing the PCB assembly. You should get a list of which types of components your vendor can mount online. Some vendors may not be capable to mount particular BGA or chip-scale packages. It is best to get in touch with your vendor ahead of time to avoid problems down the road.
A number of manufacturers will have stock of commonly used parts which you can pull from as opposed to purchasing each part yourself. When using your vendor’s stock, you have to make certain you indicate which parts you are consigning. You can usually specify this in your bill of materials. The BOM which you upload to your vendor’s website must include this data.
If you plan to purchase the SMT stencil from the same vendor, you should order it right away when buying the circuit boards to avoid any PCB assembly delays.
To make certain that your circuit boards will function, make certain that your vendor is quality certified and offers the tests and board inspection methods that are required. Please note, however, that certain tests, such as ICT testing requires additional time and cost to prepare suitable test fixtures.
