Bittele’s Circuit Design Tips for Ease of Manufacturing and Assembly

When you collaborate with your PCB Fabrication and PCB Assembly service provider, you can expect your PCB project to be finished more quickly, more accurately, and at a lower overall cost. Though this truth is widely recognized, some PCB designers understandably prioritize collaboration only during the PCB Manufacturing and PCB Assembly Process, overlooking the fact that collaboration is equally important during the PCB Design Process. This article is intended to address that imbalance, giving Bittele’s clients some insight into the design choices that can significantly affect their Complete PCB Assembly projects.

Essential PCB Design Rules

The first thing to keep in mind during your design is that the specifications for your PCB must match up with Bittele’s Essential PCB Design Rules. We recommend that you set your CAD layout software to work on these same design rules to make sure your PCBs will always be within our capabilities. Any violations will be caught by our DFM Check process, before PCB Fabrication begins, but these violations will have to be addressed before production can proceed, which often leads to delays and sometimes additional cost.

Documentation Control

A well-planned system for managing updates of your PCB Design Files throughout the design process can help immensely in avoiding issues that often occur at the quotation stage of the project. We commonly see contradictions between a client’s Gerber Files, Bill of Materials (BOM), and associated drawings, which normally mean that the project must be placed on hold while files are updated. To help with documentation clarity, we also offer a guide to Eliminating Ambiguity in PCB Designs.

Standardization

Bittele provides a number of Standard PCB Options that we offer for no additional cost. These options range from PCB Solder Mask and Silkscreen specifications to Inspection and Testing Methods such as Automated Optical Inspection (AOI) and Electrical Testing. When you choose these options, you can rest assured that our production team is well acquainted with their production, and can accomplish the manufacturing efficiently and effectively. Unique special requirements are sometimes necessary for a design, but you should expect these additional options to require some additional cost and lead time.

Standardization also extends to the parts you choose for PCB Assembly. Simply put: the greater the number of unique Component Packages in a given BOM, the greater the time requirement for Bittele’s DFM Check prior to PCB Fabrication and PCB Assembly. The DFM Check includes a comparison of each land pattern in the PCB layout against the datasheet Part Footprint for each part in the BOM. This comparison necessarily becomes more onerous as the number of unique packages is increased. If the DFM Check process does discover footprint-to-land pattern mismatches, the necessary design revisions will also be more quickly completed when fewer unique land patterns exist across the design.

Minimize Complex Parts

Complex PCB Components are sometimes required for a complex product, but it is important to understand the additional considerations that must be made for these components in order to better plan and budget for a product during the design phase. Packages with no external leads, such as BGA, LGA, QFN, CSP, FLIP-CHIP, and POP require X-Ray Inspection during the final quality check on the assembled boards. This verification process incurs some extra PCB Assembly Cost and lead time compared to QFP-style packages. Rework is also much more difficult for these types of parts, which makes the entire assembly process much less forgiving. The very fine-pitch versions of these packages will sometimes require complex processes as well.

Minimize Complex Processes

Certain actions in the PCB production process require more time and attention on the manufacturer’s part, and ultimately result in a more costly and time-consuming project cycle. In some cases, these processes are required for a particular project, but at the same time, PCB designers should understand the considerations required by some of these complex processes. If your design includes Via in Pad filling, Heavy Copper, Blind / Buried Vias, Wire Bonding, or Conformal Coating, Bittele recommends that you look into our resources on these topics to determine how they might affect the overall timeline for your project

Minimize Number of Drill Sizes

The slowest operation in drilling is the tool exchange. Usually the boards are drilled at very high RPM values, up to 60-80.000 rpm. To change the tool, the machine has to stop the spindle, and we must wait until the tool stops rotating. Once the drill action has stopped, the machine must move to the drilling rack, replace the old tool, pick up the new tool, move back to board drill position, drive the spindle again, and wait for the RPM value to reach the set point for the new tool. Each tool change takes approximately the same time as drilling 100-200 holes. Try to minimize the number of drill tools as much as possible. It is best to standardize any holes with diameter differences of only a few mils, if the change will pass your required tolerances.

If you still find yourself with any questions about the efficiency of your PCB project with Bittele, or to send in your PCB Design Files to get started today, please feel free to Contact Us any time! You can reach us over email at sales@7pcb.com, or call us toll-free at 1-888-812-1949.

Bittele is a full-service provider of low-cost Canada-Based PCB Assembly solutions. In business since 2003, we have established ourselves as a leader in the PCB production industry, and we offer a variety of tailored solutions to meet your specific needs.