Connect the Dots: Design Tips For Layout

As a PCB manufacturer, we receive hundreds of PCB layouts represented in Gerber format every week. As you might expect, they’re not all created equal. Some of the layouts check every box and roll straight into manufacturing, while others need work before they can be sent to the production floor.

We affectionately refer to these layouts on occasion as Etch-A-Sketch designs, meaning that they did not adhere to best practices nor pay close attention to detail during the layout phase. And yes, sometimes these designs really do look like they were created on a toy from the ‘70s and not in a CAD tool. We recognize there are many good reasons for not-quite-ready-for-prime time designs to be submitted, such as:

• A designer lacking layout experience
• Looming deadlines and rushed design processes
• A lack of attention to the details
• A need for something to test in a hurry

Often, these issues create delays and issues with yield or reliability. They can be avoided before they cause problems with your budget and production schedule. Here are some best practices for doing so. Use the Tools in Your CAD Program You can represent a feature in your design by almost any means you’d like, but adhering to a few best practices leveraging the many useful functions in your CAD design tools can help eliminate confusion for your PCB manufacturer. For example, you can represent slots as overlapping drilled holes in your design. It is a common practice, but it creates two potential issues for the manufacturer:

1. If left as is, it can create broken drill bits impacting yields and quality of the product.

2. The other possibility is that the tooler corrects the issue during manufacturing, which is a very inefficient process. Most software for PCB layout offers the capability to make a slot and have it contained on the drill layer of the Gerber files.

Most software for PCB layout offers the capability to make a slot and have it contained on the drill layer of the Gerber files.

To read this entire column, which appeared in the January 2020 issue of Design007 Magazine, click here.

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2020

Connect the Dots: Design Tips For Layout

02-06-2020

As a PCB manufacturer, we receive hundreds of PCB layouts represented in Gerber format every week. As you might expect, they’re not all created equal. Some of the layouts check every box and roll straight into manufacturing, while others need work before they can be sent to the production floor.

View Story

Connect the Dots: A Penny for Your Thoughts on Copper

01-22-2020

You're probably thinking: “Bob can’t possibly write an entire article dedicated to the use of copper in PCBs.” To that, Bob says, “Hold my beer.”

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2019

Connect the Dots: Design Tips For Layout

02-06-2020

As a PCB manufacturer, we receive hundreds of PCB layouts represented in Gerber format every week. As you might expect, they’re not all created equal. Some of the layouts check every box and roll straight into manufacturing, while others need work before they can be sent to the production floor.

View Story

Connect the Dots: A Penny for Your Thoughts on Copper

01-22-2020

You're probably thinking: “Bob can’t possibly write an entire article dedicated to the use of copper in PCBs.” To that, Bob says, “Hold my beer.”

View Story
Back

2018

Connect the Dots: Six Tips to Ensure Parts Fit on Your Board

12-12-2018

One of the most frustrating mismatches with alternative through-hole parts occurs when the land pattern matches, but the pin size is off. If hole sizes are too tight, pins may not fit through the holes, or if they do go into the holes, they may not solder well. Solder will need to flow through the gap between the pin and the hole barrel. If there is not enough space to allow enough solder mass to flow through the hole, the circuit board will absorb heat from the molten solder and cause the solder to solidify partway up the hole. This is called a cold solder joint and can result in a premature failure of your circuit.

View Story

Connect the Dots: New Landing Design to Reduce Thermal Pad Failure

11-16-2018

You’ve finally finished your design. All the traces are correct and the IC landings are to the manufacturer’s specifications. A short run of test boards performs perfectly. For best results, you select a reputable domestic board house for production and a quality assembly shop to do the soldering. When the finished boards arrive, everything looks great. You’re in high spirits and congratulate yourself on a job well done. Then the reports start coming in.

View Story
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2017

Connect the Dots: Six Tips to Ensure Parts Fit on Your Board

12-12-2018

One of the most frustrating mismatches with alternative through-hole parts occurs when the land pattern matches, but the pin size is off. If hole sizes are too tight, pins may not fit through the holes, or if they do go into the holes, they may not solder well. Solder will need to flow through the gap between the pin and the hole barrel. If there is not enough space to allow enough solder mass to flow through the hole, the circuit board will absorb heat from the molten solder and cause the solder to solidify partway up the hole. This is called a cold solder joint and can result in a premature failure of your circuit.

View Story

Connect the Dots: New Landing Design to Reduce Thermal Pad Failure

11-16-2018

You’ve finally finished your design. All the traces are correct and the IC landings are to the manufacturer’s specifications. A short run of test boards performs perfectly. For best results, you select a reputable domestic board house for production and a quality assembly shop to do the soldering. When the finished boards arrive, everything looks great. You’re in high spirits and congratulate yourself on a job well done. Then the reports start coming in.

View Story
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