PCB Assembly— Selecting a PCBA manufacturing firm for your project may end up being a challenging task. However, there are ways you can use to narrow down your options.
When you are in the market for a PCB firm to source your PCB, you need to be aware of several important issues.
Some of the things you need to factor in include their production capabilities, customer service record, flexibility and responsiveness, and quality standards, to mention but a few.
This article is all about PCB assembly and what you need to know about it.
1.What is PCB Assembly?
Referred to as PCBA in short, printed circuit board assembly or placement of components on the already fabricated PCB.
PCBA is slightly different from printed circuit board manufacturing, which deals with the circuit board’s fabrication.
Assembly is all about placing various components on an empty board to develop a fully functioning board.
Assemblers can achieve the placement of components either manually or mechanically. Mechanical assembly is the best choice based on its accuracy and precision.
2. PCB Assembly Type
Electronic designers in many parts of the globe tend to experience challenges in getting their prototype boards ready for testing and use.
For this reason, PCB assembly services and technologies are a necessity for them.
With the right assembly and technology, it’s possible to manufacture high-quality PCBs that will function as desired.
At this point, we will briefly highlight several PCB assembly services and technologies.
1. SMT Assembly (Surface Mount Technology)
A method whereby electrical components get mounted directly onto a PCB’s surface.
SMT components usually are PCBs’ surface face more than through-hole counterparts based on their short leads.
2. Mechanical Assembly
mechanical assembly of PCBs involves putting together PCB components in an assembly line.
Additionally, it also refers to assembled parts or products made in this manner. It’s putting products together to perform a specific function.
3. BGA Assembly (Ball Grid Array)
Ball Grid Array, also known as BGA in short, is another surface mount technology package.
IC, with many pins, mainly use this type of technology.
BGA is a low-cost packaging and high-density method that is ideal for bringing out some of the best circuit boards due to precision component placement.
4. Cable Assembly
a cable assembly is a group of wires or cables arranged into a single unit. Mostly, cable assembly can transmit power.
Also, cable assemblies are used for sending informational signals and provide power to several cables while organizing them in a package that’s easier to maintain and replace.
5. Axial Horizontal Assembly
axial leads protrude from every end of cylindrical or box-shaped components.
Axial-leaded components do resemble wire jumpers in terms of shape. They are mainly used to span short distances on a PCB.
Axial horizontal assembly comes in two configurations: right-angle through-hole and surface mount.
Here, leads do come from the opposite ends of the component.
6. Turnkey Assembly
A turnkey refers to a product or service ready for immediate use by the person purchasing it.
When applied to PCB assembly, the supplier gets to handle the printed circuit board project’s fundamental aspects.
It includes parts/components procurement and the manufacture of a PCB.
7. Radial Vertical Assembly
Radial vertical assembly involves placing components on a bare PCB hen the board area is limited.
Here, the order of components is done upright on the printed circuit board.
When talking of radial vertical assembly, leads do come from one end of the element.
8. Box-Build Assembly
Box-build assembly also goes by the name systems integration. Box build community is a complete assembly of the customer’s finished product.
The box refers to a PCB assembly in a cabinet that’s full of wires, a small enclosure, or a fully integrated electromechanical system with electronics and pneumatics.
9. Lead-free soldering
in commercial use, lead-free solders may contain tin, silver, copper, bismuth, zinc, indium, antimony, and other metal traces.
Lead-free soldering is the process of soldering by using lead.
However, it’s important to note that soldering with tips may produce fumes and dust that may be adequately hazardous.
10. Printing
PCB printing refers to transferring the layout and PCB schematics on glossy or photo paper for final production.
For the best results, the print output needs to be in the form of a shiny one side.
Printing is a critical step in the manufacture of a PCB. When done wrong, the results can be disastrous.
11. N2 System
N2 refers to a molecule of nitrogen gas. Nitrogen is a colorless and odorless gas that finds a lot of use in the manufacture of PCBs.
N2 system is the use of nitrogen gas with PCB manufacturing, including reflow soldering and selective soldering.
N2 unique method for preventing oxidation problems and convection reflow.
12. PCB Assembly: Varnishing
Varnish coating applied to the surface of the printed circuit board. The main aim is to protect the board and all its parts from corrosion and damage from the external environment.
Varnishes help PCBs to withstand harsh environmental conditions.
13. PCB Assembly: Testing
Printed circuit board testing is an essential step in the manufacture of PCBs. With tests, manufacturers can detect errors and rectify them early enough.
This way, they’ll be avoiding additional costs that come with the need to do reworks. With tests, there’s a detection of errors that may cause the board to malfunction.
14. Packaging
Printed circuit boards have to resist physical breakage and be out of moisture. Insufficient packaging is a matter that may affect the proper functionality of the board.
For better features of a commission, adequate packaging is essential. If you want to have PCBs that will function properly, make sure your manufacturer uses proper packaging.
PCB Assembly: SMT Assembly
Surface Mount Technology or SMT, in short, is a process of fabricating PCBs by the use of a through-hole approach.
SMT’s idea is to eliminate the need to make the leads of the components going through the PCB.
SMT is the first approach to PCB fabrication today. SMT is efficient, faster, and cost-effective.
1.Introduction to Surface Mount Technology
Surface Mount Technology was introduced way back in the 1960s, gaining popularity in the 80s.
Earlier, SMT technology went by the name planar mounting. SMT, unlike through-hole, doesn’t require the drilling of holes on a PCB.
SMT involves picking and placing components of a circuit on a bare board.
2.Advantages and Disadvantages of SMT PCB Assembly
There are several advantages and notable demerits that come with SMT PCB assembly. A more significant gift here includes placing more components in a smaller space without any difficulty as such.
Additionally, manufacturers can save on assembly costs. It is because the manufacturer does not need to use a lot of materials.
Furthermore, the SMT PCB assembly ensures the manufacture of boards with the ideal weight.
Soldering components directly on the PCB does save a lot of room.
While there are benefits that accompany SMT PCB assembly, there are few demerits of this process worth noting.
With SMT PCB assembly, it’s easy for components to break or drop during installation.
Additionally, as a manufacturer, you may have to invest heavily in SMT PCB assembly equipment.
Also, based on its technical complexity, high training and learning costs may be necessary.
3.SMT PCB Assembly Technology
Surface Mount Technology (SMT) is a type of printed circuit board assembly that involves getting parts of a PCB soldered directly on the surface of a PCB.
Surface mount technology is ideal compared to THT (Through-Hole Technology) that relies on drilled holes.
The following are what you may need to understand about SMT PCB Assembly Technology:
Development of SMT PCB Assembly Technology – as noted earlier, SMT PCB Assembly Technology is mounting electronic parts on a PCB board.
It’s different from conventional board assembly that involves the insertion of components through holes. The idea behind SMT development was to reduce manufacturing costs and make efficient use of PCB space.
With SMT technology development, it’s now possible to manufacture complex PCBs with excellent repeatability based on high automation levels.
Important Technology in the SMT Process – SMT is lately the most popular and widely preferred technology in PCBs’ assembly.
Since its advent, it has turned out to become the primary trend of electronics assembly.
One of the most critical technologies in the SMT process is the ability to set reflow soldering temperature so that the board’s components don’t suffer from the heat.
Advantages and Disadvantages Of Through Holes and SMT Assembly
As of now, you must be fully aware that modern PCBA design heavily relies on two methods:
Through-Hole Mounting and Surface Mounting. Both of them have their respective advantages and disadvantages worth noting. Let’s start with through-hole first.
Through-hole:
This method is ideal for THM’s advantages as it offers strong
mechanical bonds compared to SMT. THM is highly suitable for components that get subjected to mechanical stress. Also, THM is suitable for conducting tests and prototyping.
On the other hand, there are a few notable demerits with THM. For instance, this process is tasking to undertake as it demands precise drilling of holes on a bare PCB.
Additionally, THM tends to be slightly expensive when compared to SMT. THM may also be a less reliable method as some components may be fixed on the board manually. Man is prone to error.
SMT Assembly-Surface mount technology:
SMT is one of the best PCBA technologies out there. It comes with some advantages. For instance, with SMT, it’s possible to manufacture small-sized but highly effective PCBs.
SMT is also a low-cost procedure, not forgetting that it’s even faster. With SMT, there’s high accuracy based on the use of specialized equipment here.
Unfortunately, though, there are some disadvantages associated with SMT. For instance, it can be unreliable, primarily, if used as the only attachment.
Additionally, SMT isn’t ideal for circuits that may get exposed to rapid vibrations and stress.
4. How to Choose PCB Assembly Technology
Selecting PCBA technology depends on a lot of issues. If you are on a budget and need boards that will serve you properly, you can opt for those made under SMT technology.
If money isn’t a big problem, then through-hole assembly may suit you. That’s not all.
Do you want boards that will be able to withstand repeated vibration and stress?
If so, then through-hole technology is the right PCBA technology to use.
SMT assembly is easy to undertake compared to the through-hole crowd. Again, this is a factor that you need to consider.
5. PCB Assembly Process
ining a circuit board with other electronic components to embed in the final product. This process involves soldering various components on the circuit board to the circuit board according to the design requirements, and connecting them into a complete electronic product by means of surface mount technology (SMT) and perforation technology (THT).
PCB assembly is the process of comb:
Step 1: Solder Paste Stenciling
This is the first step of PCBA. It involves the application of solder paste to a bare board.
The solder paste is a thin and stainless-steel material. The parts where the paste is applied are where the pieces will sit on a complete PCB.
Step 2: Pick-and-Place
After assemblers are done with solder, picking and placing components follows. Mostly, this is a process achieved by the use of a unique robotic machine.
While such is achievable manually, machines are the best based on their accuracy.
Step 3: Reflow Soldering
The moment the solder paste and the components are rightfully in their place, they have to remain there.
For assemblers to achieve this, they must ensure that the solder paste solidifies to adhere to the board’s components.
Fortunately, this is achievable through reflow soldering.
Step 4: Inspection and Quality Control
After completing reflow soldering, the board needs inspection for quality control. Inspection checks for the functionality of the board. Here, the board is checked for matters to do with quality.
Step 5: Final Inspection & Functional Tests
After quality checks, final tests follow. These tests identify errors before a board can go into full manufacture.
The primary role of these tests is to avoid costly mistakes once the board hits the market.
test the assembly of the circuit board to ensure that all components work normally.
Check: Manually or automatically check the circuit board to ensure that there are no problems such as bad connectors, wrong components or misplaced components. Through these steps, the circuit board and other electronic components are effectively combined together to form a complete electronic product. PCB Assembly Design (DFA) emphasizes considering the assembly process at an early design stage to ensure optimal product design and production efficiency
Summary :
Are you in the market for the best-printed circuit board assembler? We are ready to assist you. Printed circuit board assembly is not a difficult task to undertake.
But if you are inexperienced or choose to partner with the wrong firm, you may end up with low-quality boards.
We are a group of experienced professionals ready to offer you state-of-the-art PCB Assembly and Manufacturing services.
We encompass the latest technology while assembling your boards. With us, rest assured of high-quality panels that go into quality control and functional tests before hitting the market.
I believe that after reading this article, you’ve gained a lot of knowledge of PCBA. You can contact us by email, and we can discuss more PCBA together and establish a friendly relationship.
We have one-stop solution for PCB manufacturing services with specialized support, reliable testing, and multi-functional features. In case if you have any questions, please feel free to contact us via email at sale@OEM-PCBA.com