PCB assembly drawing is one step in the PCB assembly procedure that you cannot skip. The process can be pretty tedious, especially when carrying it out manually. But before we move on to the complexity of the process, what does PCB Assembly Drawing entail? Why is this step crucial? And how can we make PCB Assembly Drawing easier to tackle? To get the answers to these questions, follow along to learn more.
What exactly is PCB Assembly Drawing?
Have you ever heard of PCB Assembly Drawing? Have you ever tried out PCB Assembly Drawing? If your answer to any of these questions is no, worry not because we are here to solve your mysteries. See, PCB Assembly Drawing is the presentation of a product or structure with its components connected to it. The components that connect to the main structure all undergo different fabrication processes. The assembly and installation of these components is such that all components fit and match with each other. They should all work harmoniously for the complete gadget to function right. Therefore messing up this drawing could make the PCB not function properly.
Most people confuse PCB Assembly Drawing with PCB Fabrication Assembly Drawing. Do you know the difference between the two? Well, if not, then here is the answer. See, Fabrication PCB Drawings contains data on how to build the PCB. On the other hand, the PCB assembly drawing shows how various components connect to the RAW print circuit board. These two drawings are crucial. However, they do not play the same role in PCB assembly.
What is present in a PCB Fabrication drawing?
To see the difference between these two drawings, let us look at some components found in a fabrication drawing:
- Dimensions – helps identify project material quantity. Dimensions include:
- The board’s length and width
- Thickness of the boards
- The board’s outline
- Hole charts – outlines parts that need special care
- Layer stack-up – influences project characteristics directly. For example impedance requirement handling varies according to material thickness stack up tolerance and thickness
PCB Assembly Drawing, Basics
Generic Items that are Crucial to PCB Assembly Drawing
Generating a PCB drawing follows some guidelines. These guidelines help standardize the process of generating PCB drawings. If you are looking to make a PCB Assembly Drawing, then here are some generic items that you should include:
Drawing Format – Some CAD PCB Drawing systems will prompt you to use drawing formats found in the system’s library. However, other systems will simply auto-generate the drawing format for you. In either case, you will combine the drawing format and your PCB’s layout to generate your drawing.
Board Outline – The board outline simply represents the PCB design outline from your layout database. In most cases, the board outline will include:
These two components appear on the fabrication drawing, whereby the dimensions are set. On the other hand, when the drawing reaches the PCB Assembly Drawing stage, referencing of these components occurs.
Identification Information – Your drawing format should have some areas on it that you should utilize to:
- Add in the drawing’s identification number
- It’s revision level
- The board’s name
- The corporates address
- Contact data
- The creation date
All this information helps uniquely identify your PCB, which is pretty crucial.
Key PCB Assembly Drawing Elements
While making a PCB assembly drawing, you will want to display:
- Every component’s shape
- Reference designators for the components in your drawing as per how soldering will occur in this particular board.
You should also include the mechanical parts which connect onto the board using mounting hardware. In some cases, you might need to add more effort to include these parts in your drawing. That is because the CAD footprint library sometimes does not have accurate representations of these parts. So you must go in manually.
Double-sided boards need a back view drawing and a front view drawing. These two sides can fit inside a single drawing sheet as long as the board is not large. However, if the board is large, you might need to use extra drawing sheets to cover the entire drawing.
You might also need to add an expanded view, which contains detail on the mechanical part’s connection for clarity.
If you include any manufacturing label, for example:
- An assembly tag
Then you must pinpoint it using a pointer. After identifying it, you then reference it in your notes. Anyone looking for it can easily identify it without straining a lot.
Is a list that features manufacturing instructions such as:
- Assembly details
- Industry standards
- Special feature locations
Assembly notes sometimes include a list of parts, but only when manufacturers request it.
All these elements can be modified to fit the specifications of a client. You can even omit some of these elements entirely if you feel like they do not apply in your client’s drawing.
When it comes to choosing the right elements to use in your drawing, you should consult your contract manufacturer. They will tell you what they require to generate your PCB. In doing so, you get to avoid repeating an entire PCB Assembly Drawing.
PCB Designing Tools, how can they help you?
Traditional PCB Assembly drawing tools were not superb in drafting capabilities. In fact, in most cases, people had to draft drawing by hand, which was a lot of work. However, those horrifying days are over. Now, modern-day PCB Assembly Drawing systems can generate impressive drawings automatically.
If you are using a traditional PCB Assembly Drawing system, we suggest updating it because you are missing out on a lot. Modern-day systems utilize special software which drafts out your drawing in a matter of minutes. Doing so saves you a lot of time and, ultimately, a lot of stress.
What’s more, this system is more accurate when comparing it to using freehand. This is because human errors are to the absolute minimum, which means that accuracy is almost always guaranteed.
To find modern-day PCB assembly drawing systems, simply search online and choose the one that favors you. Most of them have impressive user interfaces; hence using them is pretty easy.
PCB Assembly drawing is pretty crucial in the PCB assembly process. You should hence be extra careful when dealing with this step. Remember that your contractor generates your PCB according to your drawing. Therefore, omitting an element or a component can be catastrophic. However, if you follow the tips in this article, then the chances of messing up your PCB assembly drawing go down.