I certainly would not classify myself as absent-minded, but when I first began designing circuit boards, I would often draw them out before building them with a software design tool. By doing this, I could easily make changes if something was omitted or incorrect. I have long since abandoned this step, as software tools have become more robust, especially with improvements in identifying errors such as unrouted nets, etc. Nevertheless, complex designs can motivate me to revert to the comfort of a drawing, as I keenly remember having designs with omissions. That is probably because on those few occasions that I did leave something out, it was indeed indispensable.
Drawing a circuit board design
A similar feeling of dread can be experienced while sending your contract manufacturer (CM) an incomplete manufacturing file package. Just as the software package you use affects your design product, the manufacturing file impacts your CM’s ability to build your boards. It may be assumed, rightly, that during prototyping the design will go through multiple modifications. However, for each pass through the iteration cycle, your board must be manufacturable. And manufacturing begins with and requires an accurate quote. First, let’s take a look at the quoting process, then what is necessary for your CM to generate a prototype PCB quote that does not require the all too common back and forth before accuracy is achieved.
The Prototype PCB Quote Process
Prior to embarking on a PCB development project with a CM, obtaining a quote is invaluable for comparing and evaluating different fabrication and assembly services providers. Not only does this establish expectations for deliverables and costs, but it should also serve to illustrate that your CM has a complete understanding of your design specifications, including any board specializations. Unfortunately, this is too often not the case, and instead of an efficient PCB quote process, there are sometimes extensive delays. The most common reasons for these delays are listed below.
Typical Reasons for Prototype PCB Quote Delays
- Manufacturing file package in the wrong format
The lack of a standard manufacturing file format provides an opportunity for designers and CMs to have differing preferences. When this occurs, you either have to go with the pseudo-standard Geber file format or rely on a conversion to your CM’s designated format. In the former case, there is a possibility of errors that may result in delays with your quote.
- Inconsistency between manufacturing package files
Over the last couple of decades, as PCB manufacturing equipment and processes have evolved, the potential for errors when the manufacturing package includes multiple files has become more apparent. In response, other formats, such as IPC 2581, have emerged that are more accurate. Support for this transition to a single file format is growing in the industry.
- BOM components not available
Another issue that can prevent your CM from creating your quote is the inability to source, and therefore price, all of your BOM’s components. An inaccurate or incomplete electronics component list will lead to delays and possibly additional development costs.
- Board complexity
Another reason for not being able to get a quote quickly is that your PCB layout is very complex and requires a pre-quote DFM review to ensure that it adheres to your CM’s DFM rules and guidelines. It is imperative that your design is within the tolerances of your CM’s equipment and processes.
- Quality and traceability requirements for manufacturing not specified
Depending upon the type of board, there may be various regulations and standards that impact the PCB manufacturing process, including IPC classification level. Additional regulatory requirements that may require special certification, such as for ITAR compliance, may also be needed. If this information is absent from your design specification, it can cause delays and additional costs, especially if additional board spins are needed.
The reasons listed above are typical culprits for prototype PCB quote delays. However, it can be extended to include any errors or omissions that would hinder your CM in building boards that completely incorporate your design requirements and meet the thresholds for manufacturability. Now, let’s take a look at ways to avoid these quote delays.
How to Avoid Prototype PCB Quote Delays
As the first step before your boards can be made, which may also dictate your choice for PCB manufacturing, the need for an accurate quote is obvious. And for critical system designs, such as aerospace and medical devices, finding a capable and qualified CM is paramount. Therefore, you should follow a reliable regimen as given below for obtaining a prototype PCB quote that is accurate and free from delays that can adversely affect your overall PCB development.
Ways to Avoid Prototype PCB Quote Delays
- Ensure your PCB design software can export your design in a format that your CM can use.
- Use a single file manufacturing package format, (IPC 2581, ODB++) if possible.
- Source all components and verify availability before including them in your design.
- Acquire and incorporate your CM’s DFM into your DRC before design and perform DFM checks often.
- Beware of and include all regulatory requirements for your design in your manufacturing file.
By following the suggestions above, you can achieve a fast and efficient prototype PCB quote process experience.
|Tempo‘s Custom PCB Manufacturing Service
Tempo Automation is the industry leader in producing fast, high-quality PCBs for prototyping and low volume production. This is possible due to the use of our customized quote tool that enables us to verify the accuracy of your BOM and the availability of components quickly. In most cases, we can return an accurate quote to you within hours and complete boards within as little as three days.
And to help you get started, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium Designer or Cadence Allegro user, you can simply add these files to your PCB design software. For Mentor Pads or other design packages, we furnish DRC information in other CAD formats and Excel.