In PCB assembly there are usually 5 procedures that are followed every time: paste, pick and place, cook, inspect and test. Here is a brief overview of the entire PCB assembly process undertaken as soon as the manufacturer has everything it needs to begin the run.
Begin by applying solder paste to the empty board. This can be accomplished in a number of ways, but it usually involves the placement of a solder screen over the board. A solder screen is generated from the files supplied by the board designer, with holes where each component will be on the board. Paste is then applied through these holes directly on to the surface in a precise manner, which ensures that when the solder pads of each component are added later in the process, there will be enough paste on that spot to bond to the pad and temporarily attach the component to the board.
Get more information on PCB assembly
Once the solder paste has been laid on the board, the next procedure is to actually place each component on the board surface with a method known as "pick and place." In this stage, machines have been programmed with PCB design specifications and they know which components to grab from the dispenser and where to place them on the PCB. The solder paste will keep each component stuck to the board until it is permanently attached in the next stage.
Once all components are in place, the board is ready to be "cooked." This involves putting the PCB through an oven, heating the board just enough to permanently attach the components while not causing any damage. Other processes can be used if the components are too delicate to be soldered in this way.
After that has been completed, it is time to inspect the board to make sure it meets all design specs. This is usually done automatically via yet another machine which tests each connection and verifies the location of each component. A few of these machines have the ability to determine any errors caused by wrong components chosen by the pick and place machine.
Learn more about PCB assembly
The last step in the PCB assembly process is the board testing. This is sometimes called the burn-in process, in which the PCB is inserted into the device for which it was created, such as a computer, and the computer is run for a certain amount of time to determine whether the board is fully functional.
No comments:
Post a Comment