Oct 25 , 2021
PCB vs PCBA. The difference between a PCB and a PCBA is that a PCB is a bare circuit board, whereas a PCBA is a finished circuit board, by finished we mean a PCB with all of its components mounted.
A PCB (Printed Circuit Board) is a flat board made of non-conductive substrate materials with layers of copper circuitry placed internally or on the external surface.
A PCB’s purpose is to connect electronic components to create a PCBA.
Here’s a photo of a PCB.
Once all the necessary electronic components have been mounted onto the PCB, it becomes a PCBA.
Here’s a photo of a PCBA.
PCBA stands for Printed Circuit Board Assembly, the term can be used to refer to the PCB with mounted components or the assembly process itself.
Once a PCB becomes a PCBA, it can perform all the electronic functions it was designed for.
- What are The Different Types of PCB?
- How to Pick a PCBA Manufacturer? 5 Things to Know
- Beware of Fake Components on Your PCB
- PCBA Design
- How to Analyze the Cost of PCBA
- What Files are Needed to Manufacture a PCBA?
- What is a Box Build for PCBA?
- PCBA Manufacturing Conclusion
What are The Different Types of PCB?
1 . Single-Layer PCB
These PCBs are also called single-sided (one copper layer), they’re the most common and simple type of PCB used in most electronics.
The single-layer PCB has one coat of copper to serve as conducting material; a layer of solder mask to protect the PCB from oxidation; a silkscreen to mark the components on the PCB.
This PCB is used in low-cost and large-scale manufacturing.
2. Double Layer PCB
These PCBs are also called double-sided PCBs, the difference with the one-sided PCBs is that they have a layer of copper applied to both sides of the board.
The advantage of having both sides coated with copper as a conductive layer is that t allows for smaller PCBs.
These PCBs are used in devices such as phones and power converters.
3. Multi-Layer PCB
These PCBs have more than two conductive layers of copper.
They’re usually made by gluing together double-sided PCBs using heat-protective insulation glue. These PCBs are used in complex electronics.
Multi-layer PCBs allow higher component density and design complexity.
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Understanding the difference between PCB vs PCBA is simple.
The tricky part is knowing how to source both PCB and electronic components correctly.
You want to make sure you source your PCB and components from trusted vendors that will deliver quality and on time.
How to Pick a PCBA Manufacturer? 5 Things to Know
1. Not Everyone Provides Small PCBAs Runs
To avoid wasting everybody’s time, before you send a quotation email, find out if the manufacturer you’re reaching out to does small runs or large ones only.
Chances are that if you order your PCBs from China you can order any amount you want.
This is because Chinese manufacturers have been in the business for many years.
They have the capacity and have already covered their overhead costs, hence manufacturing a couple dozens for you will be okay, thousands too.
If you’re wondering if China is the best place to buy PCBs, don’t worry I’ll answer that later.
2. PCBA Circuit Design Must Be Thoroughly Tested
If you’re ordering a PCBA you already have a PCBA design, that’s a given, but has this PCBA design been tested thoroughly?
Did the engineers already build a working prototype of the electronic device to prove it works?
If the above hasn’t been done then there’s no point in ordering a batch of PCBAs, chances are, eventually, you’ll encounter design issues and money will be wasted.
It doesn’t matter if the PCB is of the utmost quality; if the circuit design is bad, everything is bad.
Electromagnetic issues are a big problem in PCBAs.
If by the time you get to testing for electromagnetic compatibility, the waves are still not within limits, then several months of product launch delay are ahead of you.
Before the project can move forward, the engineering team will have to find the place where the noise is and most likely do a redesign of the board, then test again.
3. PCBA Manufacturers and Testing Facilities
As we mentioned before, testing is vital.
Unfortunately, it’s also highly time-consuming, especially when you’re testing for certifications.
That’s why you need to make sure you partner up with a PCBA manufacturer that’ll make it as easy as possible to test your board.
4. The More Layers it Has The More You’ll Spend
There are 3 main types of PCB boards layout
- Single Side
Why are Multi-layered PCBs expensive?
- The manufacturing process is highly complex
- They take way more time to test
- They’re highly labor-intensive to produce
- Mistakes in assembly are close to impossible to rework
- The equipment to manufacture multilayer PCBs is expensive, not all manufacturers have it
- Multi Layers PCBA require more time to manufacture
After reading all of that, why would a design engineer decide to create a multilayer PCB?
Well, it’s because if done correctly, it outperforms single or double-layer PBCs in every aspect.
- Smaller size
- Lighter weight
- Better design functionality
Just to mention a few of the advantages.
Smartphones and smartwatches usually use multilayer PCBA.
I’m telling you all this not because you’re going to interfere in the decision of whether the PCB should be single or multilayer; because that’s an engineering decision.
But, because when the DFM team, which procurement has to be part of, starts discussing the PCB design, you should raise your hand and point out that multilayer PCBs are expensive.
Remember, hardware is a cash flow business, you want to be really careful with your money.
5- Finding a Team Player is Essential
Now, this might sound like a filler in this list, but it isn’t.
The secret to designing an easy to manufacture electronic that will meet its time to market is teamwork.
As early as possible in the product design stage, you want to invite your PCBA manufacturer to the discussion table to make sure they have the capacity and technology to manufacture your design.
That’s why a PCB manufacturer that’s willing to cooperate is important.
Beware of Fake Components on Your PCB
When you’re looking for an electronic components provider, you don’t only have to make sure that components:
- Are delivered on time
- The price is right
- Their End of Life stage won’t mess up your product life cycle
- They’re not fake
You read that right- fake.
In case you didn’t know there’s a black market for electronic components, it’s made of what’s known as Components Brokers.
They currently make up for 6 to 8% of the total electronic components market and makeup as much as $60 billion’ worth.
They’re not components manufacturers nor authorized distributors.
They’re small shops that “specialize” in sourcing components that are difficult to get or that are no longer manufactured.
Some of these brokers are legit, some are not, so be careful because if you choose the wrong ones you risk buying counterfeit components for your PCB.
If you’re wondering why you would need an electronic component that’s no longer being manufactured, well, that’s got to do with poor electronic design decisions.
Share this article with your engineering team
It also has some more information on component brokers and how to deal with them.
The design of a PCBA should be in line with DFMA guidelines to ensure mass manufacturing is done smoothly and on time.
PCBA Design – Technology
You’ll have to decide whether you want/need your PCBA manufactured with SMT technology or Through-hole technology.
The standard, nowadays, is to mainly use SMD components for your PCB as it is more cost-efficient; however, there’ll be occasions where you need THT components.
PCBA Design – Components
Now, this is highly important, especially right now ( 2021), when a shortage of components hits the whole industry.
While you’re designing your PCBA, make sure you keep active communication with your suppliers and check for the lead times.
You don’t want to get to the mass manufacturing stage and realize that half the components you chose have lead times of 52 weeks.
PCBA Design – Extra Space
Leave some extra space on your PCB for sensitive components that, in case lead times are more significant than expected when you reach mass manufacturing, can be swapped for others.
PCBA Design – Flex PCB
If you use flex PCBs, you better get acquainted with the particularities of flex soldering.
For example, make sure you solder the components away from the bending points, or else you risk breaking the solder pads.
How to Analyze the Cost of PCBA
- Labor Costs
- Tooling and Set up charges
- Turnaround Time
Let’s talk a little bit about each one
1. Labor Costs
This is the easiest one to understand. PCBA involves human labor and automated machinery.
The lower the wages in the country you choose to manufacture, the cheaper the labor costs, and the opposite holds too.
2. Tooling and Set Up Charges
If you’re looking for a custom PCB shape you’ll have to pay for tooling and set up charges for the production line the PCBA provider will have to set up.
If you’re looking for standard shape PCBs, then you’ll avoid tooling and set up charges.
3. Turnaround Time
You want your PCBA delivered in 5 days or in 3 weeks. The faster you want it the more expensive it will be.
Unless you get them done in China where turnaround time is crazy fast.
But for those doing it outside China, well, if you tell a PCBA manufacturer that you want your PCBs in 5 days, they’ll most likely have to
- Put some existing orders on hold
- Work extra time and pay for expedited shipping
They’ll charge you more for that.
Economies of scale apply here.
The more units you order the cheaper the price, especially in custom boards, as you’re able to pass tooling and set up costs onto many units.
Order a handful of customized boards and prepare to pay a lot.
SMT can provide you with cost savings as it is a highly automated process.
BGA takes considerably more time and effort to mount, and because it requires many electrical pins assembly costs are higher.
Are PCBAs always Cheaper in China?
The short answer is yes, PCBA is cheaper in China.
Allow me to give you some numbers for more clarity.
30 two-layer boards, 80x90mm in size will cost you US$ 339 from a PCBA manufacturer in Germany.
The same units with the same specifications will cost you US$20 in China.
Also, PCBA manufacturers in China have turnaround times of one week or less.
A USA PCBA will give you a turnaround time of a month and a unit price of US$3.48/unit for a 1k units’ order.
The same order made to a Chinese PCBA would cost you US$0.37/unit and have a turnaround time of 5 days.
Even after import tariffs are calculated, PCBA in China is cheaper and faster.
If you want to follow this topic and see what others have to say about it visit the evvblog, they have a discussion thread about it.
PCBA Manufacturers Alternatives in Asia
I gave you some examples of what PCBA manufacturers charge in Germany and the US, but you might be wondering, what about some other low-wage Asian country.
Look, it’s not all about low wages and cheaper costs, it’s also about expertise and technology.
Countries like Vietnam and India are good at lowering operational costs, but when it comes to complex electronics manufacturing, they lack expertise and technology.
One country that is becoming somewhat of an alternative – not cheaper than China though- for PCBA and electronics, in general, is Malaysia.
But here’s the thing about PCBA in Malaysia, as you know we manufacture B2B electronics, so we’re talking from experience here.
- SMT in Malaysia is more expensive
- SMT efficiency in Malaysia is a lot lower
- Shipping components reels from China to Malaysia is a hassle, especially for small runs
- Calculating labor costs is difficult as there’s a double-digit cost increase every year.
- Assembly workers in Malaysia tend to be slower than in Shenzhen.
In the end, PCBA manufacturing in Malaysia is more expensive and time-consuming than in China.
What Files are Needed to Manufacture a PCBA?
A PCBA manufacturer will need you to send them the following.
Gerber files are open ASCII vector format files that show information on each board layer of a PCB design.
Generating Gerber files will vary a bit depending on which PCB design software you use.
This is what a Gerber looks like, the different colors represent different layers.
Bill of Materials (BOM) for PCBA
The Bill of Materials will show all the components necessary to put together the PCBA. For your own benefit it should be clear and optimized for mass-manufacturing.
Here you can find all the details on how to optimize a BOM .
Pick and Place File
This is a file that shows all the components of the PCBA and their respective x-y coordinates and rotation. You can obtain this file from whichever PCB design software you’re using.
What is a Box Build for PCBA?
Before we wrap things up, allow me to introduce you to something related to PCBA and that you should consider when looking for a PCBA provider.
It can be as simple as fitting PCBAs into simple enclosures – plastic boxes.
Perhaps a plastic box with some interfaces and displays.
It can also involve more complex tasks such as the installation of extra components, routing of wire harnesses, and building custom made enclosures.
So, when you’re looking for a PCBA manufacturer, don’t forget to ask them about their box build services.
PCBA Manufacturing Conclusion
The difference between PCB and PCBA is that the first one is just the bare board, PCBA includes all the components mounted on the PCB.
When doing your search for a PCBA manufacturer remember
- Small or large PCBA runs make a difference
- A PCBA circuit design must be thoroughly tested before manufacturing
- Find a PCBA manufacturer with testing facilities
- The more layers a PCB has the more expensive will be
- A team player is key
Make sure you source electronic components from reliable providers.
The costs of a PCBA are calculated based on the following
- Labor Costs
- Tooling and Set up charges
- Turnaround time
For PCBA manufacturing, China is still the best option when it comes to price and turn around response.
To bring your PCBA to life you’ll need the following
- Gerber File
- Bill of Materials
- Pick and Place File
You also want to inquire about Box Build with your PCBA manufacturer.