PCB Designer
The success of a circuit board assembly depends on several factors. One of the most important is component availability, which ensures that the board’s assembly vendor has the requisite components on hand when it comes time to build the boards. If any of the components required by a design aren’t available, it can throw off the whole production process, undermining the value of quick-turn PCB manufacturing. Fortunately, there are steps that can be taken to avoid these kinds of delays. Read on to discover five critical DFA norms every PCB designer should know.
When a pcb design assembly is designed with assembly in mind, electrical engineers take several factors into consideration. For example, they choose the right package size for the components, avoiding unnecessarily small packages. This saves space on the board and also helps to avoid rework later in the process.
Next, they use an etching process to cut the copper traces on each layer of the PCB. After this, they print out a photoresist mask on the inner layer and a solder mask on the outer layer. Technicians then place the layers together and align them with a machine known as an automated optical inspection (AOI) device. This step verifies that the inner and outer layers are devoid of any defects.
Five Critical DFANorms Every PCB Designer Should Know
In the last step of preparation, a chemical bath fuses all the different layers together. Then, it’s time for the plated copper stage. The entire panel is bathed in copper, including the drilled holes that were used for the component leads earlier on. The copper is deposited in the same way that it was etched and imaged on the earlier steps, and a thin layer of tin covers the exposed fiberglass substrate for the outer layer.
Once the board is plated, it’s ready for the next step: component placement. This is where the actual parts go on the PCB. There are two main ways that this can be done: surface mount technology (SMT), where the components are mounted directly on the top and bottom of the board, or through-hole technology (THT/PTH), where the leads pass through plated holes in the circuit board and are soldered to pads on the other side.
During this step, it’s vital that the BOM is correct. Otherwise, errors can occur during placement that can lead to a variety of issues, such as component shifting. This occurs when the pads for two components are not commensurate in size, so they don’t mate properly during assembly. Fortunately, PCB designers can mitigate this issue by communicating with the electrical engineer and choosing larger components whenever possible. This will help to eliminate many common assembly mistakes, such as oversized capacitors and resistors.
