Having been involved in the printed circuit board (PCB) world for nearly four decades, I continue to see the same drawing mistakes. When declaring PCB tolerances in any given design, the PCB designer must take into consideration the manufacturing of the board itself. In this blog post, we will review some of the issues we commonly see in PCB designs that are not allowing the proper tolerances for the routing, drilling, and plating processes.
At the conclusion of our webinar, How PCB Design Choices Affect Overall Cost from Your PCB Fabricator, we had several questions submitted to our presenter, Ed McMahon, CEO at Epec. We have compiled these questions into a readable format on our blog.
Many applications today send signals between two devices to provide data or to perform a specific function. These signals may consist of radio frequencies (RF) or microwave frequencies. Typically found in the communication industry, RF/microwaves are common for satellites, radar, and navigational systems. Yet, they can also be found in smaller applications, such as garage door openers, security key card terminals, wireless alarm systems, and handheld warehouse inventory scanners.
After an engineer has finished their circuit design for a printed circuit board (PCB), the next step is to enter the schematic details into a computer-based schematic capture program such as Altium, Eagle, or OrCAD. The finished printed circuit board will provide the physical assembly and interconnection platform for the various electronic components required by the schematic.
There was a time when the PCB manufacturing industry included a fair number of bucket shops, so called because much of their processing was done in small portable tubs filled with etchants, solvents, and other mysterious solutions. They cranked out very basic, low-cost, low-complexity PCBs, using equipment and methods that were questionable at best. Their business and environmental practices were often similarly questionable.
Design for Manufacturing (DFM) is critical to the success of your PCB order. Features that make your circuit board difficult to build add cost to your product and can increase the scrap rate. If you have designed a PCB that is more complex than usual, it is useful to submit files to your fabricator for review before placing your order so you will have some time to address any issues that might delay production.
At the conclusion of our recent webinar – Match Your High-Tech PCB Design To Your Supplies Capabilities – we had a number of questions for our presenter, PCB Field Applications Engineer Al Wright. We decided to compile these into a readable format on our blog.
In simple terms, cable assemblies are comprised of two primary elements: the conductor and the connector. Rightfully so, the conductor’s sole purpose is to pass current at a given voltage, while the connectors job is to affix the cable assembly securely to a mating interconnect.
Ordinarily you may not want your PCB (printed circuit board) manufacturer to adjust your data files, but there are occasions when that may be the easiest way to achieve a particular result. For instance, you may need to have some, but not all, vias of a particular size plugged so that the assembly solder will not wick through to the other side of the board. Or perhaps a few trace pairs need to run at a specified impedance, while the impedance for all the other traces of the same width is non-critical.
The design of a multi-layer PCB (printed circuit boards) can be very complicated. The fact that a design even needs to use more than two layers implies that the required number of circuits will not fit onto just a top and a bottom surface. Even in cases where the circuitry does fit onto two external layers with no problem, the PCB designer may decide to add power and ground planes internally in order to correct a performance shortcoming.