Design Tips for Lowering Costs of Fab and Assembly


Reading time ( words)

This is the million-dollar question of every project: How can I cut the cost of the PCB? 

There are about a thousand answers to this question. I may be exaggerating a little bit, but not much, especially when you consider that there are about 4218 different ways a PCB could fail. That’s a lot, but fortunately you really need to have a significant combination of these failures before it makes the boards unusable.

That said, there are a few simple guidelines that everyone can follow to reduce costs. I talk about them in my IPC CID and CID+ courses. Designers, fabricators, and assemblers talk about them in a variety of articles. Some professionals who have published some great articles on cost-saving strategies include Tara Dunn, Happy Holden, Chris Church, Kella Knack, Judy Warner, Julie Ellis, Lars Wallin, and many, many others.

It’s not as simple as saying, “Just cut down the layer count” or “Just use smaller parts and traces.” Here’s another: “Just use standard FR-4 material.” Then there’s, “Just don’t use blind and buried vias.”

These will certainly work if you make them happen, but they are not always the go-to answers on how to reduce costs. I’ve actually reduced the cost of some boards by doing the opposite of what you would normally think you should do. Here are some examples:

  • Adding layers: This cut the cost of the board because I could increase the size and spacing of the traces. I was able to add an extra GND layer for shielding and better electrical performance. I had less fallout, less bow and twist, and easier manufacturing; thus, I cut the final costs.
  • Using larger components: When only one component on the board had pin spacing less than 0.5 mm, it didn’t save any space at all. This part needed a special paste mask and we had to have extra spacing for the masking. Replacing it with a larger package saved us space on the board and cost less in manufacturing.
  • Using higher-temp materials: This helped the board to withstand the stresses of manufacturing. It cut down on stress failures and fallout, thus cutting the overall costs.
  • Using blind and through-vias: This improved breakout from fine-pitch parts. It wasn’t as expensive as using blind, buried, and through-vias; it improved power connectivity, and saved space on the board.
  • Split one board into two boards: I modularized high-power, larger-pitch circuits and low-power, small-pitch circuits. The electrical requirements for these are different and become cost-adders for manufacturing when combined. Creating two boards, one with thick copper and larger features, the other with thin copper and smaller features, allowed each to be easily created at less overall cost.

So, here’s my take on how to reduce your costs:

Planning Ahead

This is one of the most important jobs of the program manager (PM). You’d be surprised how many DFM issues start with the PM. So, how does the PM influence the costs?

To read this entire article, which appeared in the August 2022 issue of Design007 Magazine, click here.

Share




Suggested Items

Material Conservation: The PCB Designer's Role

09/01/2022 | I-Connect007 Editorial Team
During these times of supply chain uncertainty, many product developers are considering new ways to conserve materials—from laminates to components, layer reduction, and everything in between. Barry Matties and Happy Holden recently spoke with Alun Morgan, president of EIPC and technology ambassador for Ventec, about material conservation strategies for today’s PCB designers and design engineers. Alun explained why this may be the perfect time to educate PCB designers about conserving materials: When a model is broken, the people involved are much more open to new ideas.

Designing for Material Conservation Means Changing Attitudes

08/29/2022 | I-Connect007 Editorial Team
It makes a lot of sense: During times when the supply chain is stretched to the breaking point—and the last few years certainly qualify—what if PCB designers created boards that used fewer components and less laminate? Do PCBs still have to be 0.062" thick? Why not reduce layer count while they’re at it? Andy Shaughnessy and Nolan Johnson spoke with I-Connect007 columnist Dana Korf about the idea of designing a PCB with material conservation in mind. Is it a great new idea, or are we opening a whole new can of worms and a separate group of problems?

Webinar Review: Thermal Integrity of High-Performance PCB Design

08/01/2022 | Andy Shaughnessy, Design007 Magazine
Electrical and mechanical engineers may be working on the same product development teams, but they speak different languages, and they have completely different objectives. As a result, these folks almost never use the same software tools. But Cadence’s new Celsius Thermal Solver is an exception to the rule. In a new CadenceTECHTALK webinar, “How Static and Dynamic IR Drop Analysis Can Help PCB Designs and Challenges,” product manager Melika Roshandell and SerDes SI/PI engineer Karthik Mahesh Rao explain how the EE and ME can both use the Celsius Thermal Solver to achieve their disparate objectives.



Copyright © 2022 I-Connect007. All rights reserved.