Elementary, Mr. Watson: The Anatomy of Your PCB Component, Part 1

One of the classes I dreaded the most each year in school was biology. This was because I knew it was only a matter of time before I would face the rite of passage for most high school students: dissecting a frog. It wasn’t something I ever looked forward to. We had to go through the same educational exercise and maybe with the same apprehension for most of us. But my point in bringing up the painful experiences of our high school years is, although it was difficult, I did learn a powerful lesson: Every part has a purpose.

Figure 1: A mandatory high school experience: frog dissection.

Imagine doing the same thing to your PCB components. What would we find if we took a simple component, placed it on the table, sliced it open, and dug deep down? More importantly, like our amphibious friend, what is the purpose of each part? I get this question all the time: What should be in my components? Let’s take a look.

For the past several months, we looked at the five pillars of our library; we’re now ready to load that library up with some components. First, of course, we all know the importance of our library, but even more important is what exactly you store there and the quality of those components.

I sat down to enjoy an apple the other day. I spent some time cleaning and polishing it, and it looked great. I took a big bite, and do you know what’s worse than finding a worm in an apple? Finding half a worm. Although everything looked nice and shiny on the outside, on the inside it was rotten. That story is an excellent example of many of our libraries. They may be nice and shiny on the outside, but on the inside, we have worms because we have poor quality components.

Component Overview
With technology and innovations in our industry constantly changing and advancing, we can easily see this on display with the number of available components. Depending on the source, the variety of electronic components on the market is almost endless. Octopart has over 19 million, and IHS Markit exceeds 900 million. But with so many options, there is cohesion with every PCB component. We see that every component is made of the same C_Watson_Fig2.jpgessential parts and structure when examined.

In the early days of our industry, designs got done with components with just basic information of a schematic symbol, footprint, and some basic parameter information. Now components have massive details and information; everything needed for the entire design, fabrication, and assembly process is all capsulized in a small convenient package.

Every component is divided into two main categories. The first is information, and the second is the models. As we will see, it is essential to have all the various parts of the component since each part has its purpose and use in the design process.

We begin by looking at the information side of our component. Information drives our industry. Having the best information helps avoid duplicating components and knowing that you have the correct and best part for what you are designing.

Name and Description
What you intend to call a particular component is where everything begins. I highly recommend perusing my July 2020 column, PCB Components Naming Convention. In that piece, we discussed the specific naming standards for your schematic components and models and how to ensure that they are organized to find things easily and not create duplicates.

There are several common mistakes made here. First, many designers provide too much information in the name field. Instead of showing only the essential information, it becomes a pseudo description field. Keep in mind that when searching for a specific component, you have both the name and the description to find what you’re looking for, so it is unnecessary to duplicate the information. Instead, look at the name as a hook of essential information; the description holds the details.

A second mistake commonly made is using part numbers for the name. That works great if you have a complex component; for example, a specific component from a manufacturer. You can easily use the MFG part number as the name and what I usually do (because I am lazy) is copy the description of the component right off the datasheet. But it would help if you avoided that with general components, which are mainly your discrete. The discrete components have several manufacturers and suppliers, and distinguishing them by a single MFG will cause problems. Also, as your part choices will constantly change because of shifts in the supply chain or depreciation, you don’t want to tie them to a specific part number. For example, call a resistor by its basic information of value, tolerance, and size. More details can go in the description field.

The other reason is that it is difficult to decipher what a part number is saying. For example, knowing what CPF0603B1M0E1 represents is difficult, if not next to impossible. If you were wondering—it is a Resistor Thin Film 0603 1M Ohm 0.1% 1/16W ±25ppm/°C Molded SMD Paper T/R.

Parameter Information
The parameter information is the components’ details, which are very subjective according to the type of components. So, for example, you won’t have the same parameters for a chip resistor as a 4608 cells 402.58MHz FPGA. But as we remember, our library organization is broken down into categories of families and sub-families. So, a common rule would be to have the same parameter configuration for all the components in a family and sub-family. Then all the specific components in a family/subfamily are together and can quickly compare based on the same information.

Up to this point, most of the information attached to our components is static, meaning that they most likely won’t change. But with the sourcing information, we break into the dynamic side. Connecting the manufacture(s) and supplier(s) allows for the creation of your bill of material (BOM). As we are probably aware, that is like nailing Jell-o against the wall right now with supply chain shortages. That is even more reason to have excellent sourcing information for every component and should have both multiple part choices and alternate components.

A multiple-part choice is another component that exactly matches the form-fit-function (FFF), or another term often used is a drop-in replacement. The alternate components are ones that first meet the FFF criteria of your circuit, but may vary in some of the electrical parametric specifications. Use both to strengthen your component as much as possible. That broadens the options when going through the perils of part procurement.

Lastly, connect multiple datasheets to the component (with emphasis on multiple). When available, do not trust just a single datasheet. I know it may come as a shock to some, but datasheets have been known to be wrong. Many times the problem is not caught until it’s too late. So, attach all the information with all the datasheets available to reference. Comparing various parts from various manufacturers will flag any potential problems early. Your EE will thank you.

In my next column, I will take a deep look into your component models and the industry standards to use when creating them.

John Watson, CID, is a customer success manager at Altium. 

For more educational information from Altium, be sure to download The Printed Circuit Designer’s Guide to… Design for Manufacturing by David Marrakchi. You can also view other titles in our full I-007eBook library here



Elementary, Mr. Watson: The Anatomy of Your PCB Component, Part 1


One of the classes I dreaded the most in school each year was biology. This was because I knew it was only a matter of time before I would face the rite of passage for most high school students: dissecting a frog. It wasn’t something I ever looked forward to. We had to go through the same educational exercise and maybe with the same apprehension for most of us. But my point in bringing up the painful experiences of our high school years is, although it was difficult, I did learn a powerful lesson: Every part has a purpose.

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Elementary, Mr. Watson: The Five Pillars of Your Library, Part 5—Traceability


We have reached the end of this series regarding the five pillars of the component library. We now have a robust library that provides the required resources for the ever-changing industry. Above that is having a flexible library to grow with the company. The final pillar is traceability. Why is traceability so essential and considered a pillar of our library? Read on for details.

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Elementary, Mr. Watson: The Five Pillars of your Library, Part 4—Review


I trust that you have been enjoying this series on the five pillars of your library. Now that we have a single library managed using our revisioning, and we have lifecycle schemes organized so that we can easily find something in the component category, family, and subfamilies, we are now ready to look at one of our library's most vital principles and pillars: reviewable.

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Elementary, Mr. Watson: The Five Pillars of Your Library, Part 3—Architecture


Before I continue with the series of the five pillars of your library, I want to do a little review. Although every library is different, the five pillars are consistent with any sound library. You place these pillars to support a specific building section in building construction. To pull one out requires the remaining ones to hold the total weight above. So, each of these supports is needed for your library to succeed. You cannot choose which of them you intend to follow; to pull just one out results in the toppling of the others.

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Elementary, Mr. Watson: The Five Pillars of Your Library, Part 2—Managed


The 1972 classic movie “The Candidate” tells the story of Bill McKay (played by Robert Redford), who was running for the state senate. Although he was a long shot and an underdog, McKay ends up surprising everyone with an incredibly close win. After the concession speech of his opponent, a vast mob surrounds McKay. He fights through the crowd, trying to reach his campaign manager Marvin (played by Peter Boyle). Finally reaching him, McKay pulls Marvin aside into a hotel room, sits on the bed, and after several seconds of silence, finally asks a very intense question “So, what do we do now?” The campaign manager looks bewildered, so McKay asks the question again, “What do we do now?”

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Elementary, Mr. Watson: The Five Pillars of Your Library, Part 1


I have recently had some great conversations with many of you, and the same question keeps coming up: What does it takes to have an excellent component library? So, I have decided to kick off the new year by taking a deep dive into your PCB component libraries and looking in detail at the five pillars of your library. So along with taking the tree and the decorations down and making your New Year resolutions, let's resolve to take an honest look at our component libraries and get them in order.

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Elementary, Mr. Watson: PCB Data Management and Security


As a grandfather of six grandchildren, one of my great joys is spending time with them. There is nothing better than spending an afternoon at the park and especially playing on the teeter-totter. It's all fun and games until grandpa gets on one side, and they try to lift me. Then the harsh reality and a teachable moment in leverage, balance, and just how heavy grandpa really is hits pretty hard.

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Elementary, Mr. Watson: We’ve Never Done It That Way Before


The September edition of Design007 Magazine discussed the theme of collaborating and working with a team. In that issue, I wrote a feature article called “PCB Design Is a Team Sport.” After that edition was published, I had several follow-up questions and conversations with individuals; they agreed on the importance of teamwork but felt that it's easier said than done. It's challenging because of the inherent problem of team members accepting or handling change very well. Change it's a word that sends shivers down the spine of some. You know those sort of individuals. They're easy to identify. The ones that constantly remind everyone, "We never did it that way before." As if how we did things in the past was so much better.

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Elementary, Mr. Watson: First, Component Shortages, and Now Hot Dogs?


When I considered the title for this month’s article, I seriously considered calling it "From the Frying Pan Into the Fire" because I’m sure you’ve noticed recently that the component shortage problem has only worsened—we’re now seeing other supply lines breaking down.

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Elementary Mr. Watson: PCB Design—It's a Team Sport


One of the hard lessons of this past year was about the value of the team and collaboration. I have repeatedly heard how many of us have a newfound respect and appreciation for the teams we work with inside our companies. Out of necessity, we had to find new ways to collaborate.

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Elementary, Mr. Watson: The Danger of Rogue Libraries


For PCB designers, the most common part of the library is the collection of components used in the PCB design process. But, I have seen some libraries have other information, including a resource area, a group of documents, standards, and articles. So basically it can have anything you want.

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Elementary, Mr. Watson: Epic Fails with Design Rules


Various sciences, including physics, mathematics, chemistry, are significantly involved throughout the PCB design process, rules that can sometimes be bent but not broken. However, the rules that designers break and ignore altogether and very often are the design rules.

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Elementary, Mr. Watson: Managing Risk in PCB Design


PCB design is like bungee jumping. With the complexity of a PCB design, the intricate details, and various steps, it's rather easy to make mistakes. Those mistakes, many times, do not show up until it's too late and the board has gone off to fabrication and assembly. By the way, a good rule is not to use your assembly house as your quality control team for PCB designs.

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Elementary, Mr. Watson: Time to Market, from Ludicrous Speed to Plaid


Mel Brooks may have something to teach us about going "ludicrous speed" in getting our designs to the finish line. John Watson explains.

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Elementary, Mr. Watson: Trust but Verify


Over many years, I have seen some elaborate PCB library systems. However, the best ones were those not based on the size but rather the quality of the information. That old axiom is definitely “not quantity but rather quality.”

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Elementary, Mr. Watson: Paying the Price To Be a PCB Designer


Today, the electronics industry is flourishing with innovations and technologies. The result is that the “good” designers are left in the dust. Truthfully, our industry doesn't need more good designers; rather, we need great designers—those who can face any challenge and instead of cowering in the corner, looks at the task at hand and says, "Bring it on."

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Elementary, Mr. Watson: Demystifying Bypass Capacitors


As PCB designers, we work under the simple rule of cause and effect, and a PCB design can quickly become a petri dish for the butterfly effect to flourish. One of those areas that can quickly snowball into major problems is your PCB power distribution structure. When it goes wrong, it usually goes very wrong and has significant issues throughout your design.

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Elementary, Mr. Watson: Density Feasibility Putting 10 Lbs in a 5-Lb Bag


Whether on a customer, a system, or a PCB level, it’s essential to understand the final objective and how you intend to get there and meet the customer need at the forefront of any project. In this column, John Watson addresses density feasibility and more.

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Elementary, Mr. Watson: Location, Location, Location


When it comes to PCB design, one of the most overlooked principles is component placement. Similar to a home, the component location has a considerable impact on the quality and is the real value of a PCB design. John Watson examines five rules to follow when it comes to component placement.

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Elementary, Mr. Watson: Overcoming PCB Designs Pitfalls


When starting every PCB design, the hope is that we can navigate through any pitfalls that arrive. Unfortunately, many times, issues happen that you do not handle correctly; they fall through the cracks and end up in your PCB design. John Watson explains how that is when the real problems begin.

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Elementary, Mr. Watson: How to Ruin Your PCB Design in 4 Easy Steps


John Watson has seen firsthand how quickly PCB designs can “go off the rails” by not following a few simple principles. In this column, he looks at four practices that can easily ruin your PCB design.

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Elementary, Mr. Watson: PCB Components Naming Conventions


How you accurately analyze and identify certain information has a direct connection to the overall success of your PCB designs. In this column, John Watson focuses on the conventional naming scheme for the schematic symbol and footprint to prevent headaches and ulcers later.

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Elementary, Mr. Watson: Collaboration in the PCB Design Process


The past few months have been trying for everyone, with many of us working from home. However, there are still the underlining principles of collaboration to step into a role to finish the necessary tasks to keep a project moving forward. John Watson, CID, explains.

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Elementary, Mr. Watson: Reinventing Yourself


When COVID-19 first hit, many businesses were forced to close, and we immediately saw its impact on the service industry. Whatever challenge you’re facing, John Watson emphasizes that it’s time to hit the switch on reinventing.

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Elementary, Mr. Watson: The Positive Side of COVID-19


With the recent COVID-19 outbreak worldwide, most of us have been forced to reshuffle how we work, live, and play. Something like this has never happened before in our lifetimes, and it is scary and challenging, but difficult times develop resilient people. John Watson shares some of the positive things he has already noticed come out of this situation.

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Elementary, Mr. Watson: Are We There Yet?


Anyone who has taken a road trip with children knows the question, “Are we there yet?” very well. This question also applies to PCB design. If you are not careful, your PCB project could easily go off track and you could lose sight of what you are doing (objective), why (motivation), how (process), and when (schedule). John Watson emphasizes the importance of these fundamental questions.

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