We often hear the terms PCB assembly and manufacturing and assume they may be the same. Others claim that one is a prerequisite to the other in producing PCBs.
Well, PCB manufacturing and assembly are critical steps in producing electrical devices.
Without one, we wouldn’t have all the reliable, innovative electrical systems, and we often disregard them.
Today, we’re highlighting the main differences between PCB assembly and manufacturing.
Moreover, we’re looking at the vital steps in PCB assembly manufacturing.
Table of Contents
- What is PCB Assembly?
- What is PCB Manufacturing?
- General PCB Manufacturing Process
- Know the system’s electrical specifications.
- Design the schematic
- Create a PCB layout
- Set the design rules and requirements.
- Add in the components.
- Choose the materials
- Ready the copper-clad laminate.
- Lay the photoresist
- Etch the copper
- Drill the holes and plate the PCB.
- Apply the solder mask.
- Silkscreen and test the PCB
- How to Differentiate Between Assembly and Manufacturing
- The Types of PCB Assembly
- Final Remarks
What is PCB Assembly?
(Workers assembling PCBs by hand)
PCB assembly is the placing and soldering of electronic components on a printed circuit board. It entails assembling electronic components, including integrated circuits, onto the PCB.
In other words, it is populating a printed circuit board with components. Additionally, the placement of components on the board varies according to the board’s use.
What is PCB Manufacturing?
PCB manufacturing produces a printed circuit board from raw materials like copper-clad laminates. Other materials include insulators, substrates, and soldering materials.
In making a PCB, the first result is a thin board of insulating material like plastic or ceramic. Moreover, the PCB has conductive pathways etched onto it to connect crucial circuit components.
General PCB Manufacturing Process
(Manufacturing a PCB on a CNC machine)
Here are the general steps you should know to help you in manufacturing your PCB.
Know the system’s electrical specifications.
The first step during the manufacture of PCBs is to understand the electrical specifications of the system. For instance, you need to know the electrical load of the intended system.
Additionally, you need to understand the signal types and impedance characteristics, among others. Failure to do will lead to a malfunctioning printed circuit board.
Design the schematic
The next step is the design of the printed circuit board using specialized software.
The design process includes laying out the board and outlining the connection traces. At this stage, your design is still at the electrical level of the board’sboard’s design.
Create a PCB layout
Once the electrical design is complete, you’ll have to translate it into a set of manufacturing files known as Gerber files.
These files contain every detail necessary for the PCB’s fabrication, including the layout of the PCB. Other vital information includes the copper traces and the location of drill holes.
Moreover, some tools you can use to capture the schematic include Altium and Allegro. After designing, the tools give you an exact virtual representation of your board’s appearance.
Set the design rules and requirements.
Generally, it would be best to design your PCB according to the IPC rules and regulations. Moreover, there are local guidelines that each PCB manufacturer must adhere to avoid failure.
Therefore, it’s easier for you to consult a veteran PCB designer to help you with your project. Otherwise, you may find yourself going through lots of revisions.
Add in the components.
Consider the rules and regulations regarding placing components on the circuit board at this stage. Some standards prohibit specific layouts depending on the performance of a circuit.
Also, they may discourage the proximity of certain components if such a setup may introduce noise to the circuit.
Choose the materials
The next stage is selecting the PCB’s materials, like the substrate. Additionally, It involves choosing the solder mask and copper-clad laminate.
Ready the copper-clad laminate.
Here, cut the copper-clad laminate to size and clean it to remove all material that may ruin the manufacturing process. Further, coat it with a photosensitive layer at this stage.
Lay the photoresist
You’llYou’ll use the circuit design files to create a photomask. Next, use the photomask to expose the photoresist on the copper-clad laminate. The process develops a photoresist that leaves a circuit design pattern on the board.
Etch the copper
Etch away the excess copper material using an acid solution. Doing so leaves behind the circuit pattern that you desire.
Drill the holes and plate the PCB.
Here, you’ll drill the holes into the PCB, where you’ll mount your components. Moreover, you’ll create electrical connections through the layers by doing so. Afterward, plate the PCB with a copper layer for electrical conductivity.
Apply the solder mask.
Next, apply a solder mask to guard your circuit’scircuit’s copper traces and prevent stray soldering.
Silkscreen and test the PCB
In this step, you’ll print the component markings and other identification information onto the PCB. Finally, test the PCB to ensure it meets your earlier specifications.
How to Differentiate Between Assembly and Manufacturing
(Automatic machine for PCB welding or soldering)
The following are the primary differences between PCB assembly and PCB manufacturing:
First, PCB manufacturing is making the printed circuit board itself. On the other hand, PCB assembly entails filling the printed circuit board with electrical components.
Afterward, you’ll solder them to the board for a long-lasting connection.
Second, PCB manufacturing entails designing the PCB and selecting materials. Other steps in the manufacturing process include preparing the copper-clad laminate.
Next, place components onto the board using specialized machinery.
Third, PCB manufacturing requires specialized equipment and expertise to fabricate the physical PCB. In contrast, PCB assembly requires equipment that accurately places components onto the PCB.
Also, the equipment should solder the electrical components without causing short circuits.
Fourth, PCB assembly requires PCB manufacturing as a precursor. In other words, you need a pre-fabricated printed circuit board for assembly.
The Types of PCB Assembly
(An SMT PCB assembly line)
Common types of PCB assembly include:
Surface Mount Technology (SMT): SMT includes placing surface-mount components onto the surface of the PCB. Here, you’ll use specialized equipment like pick-and-place machines to make your work easier.
Through-Hole Technology (THT): THT involves inserting leaded components through holes in the PCB. Afterward, solder them to the other side of the PCB.
Mixed Technology: Involves both THT and SMT technologies in making PCBs. We use it when specific components are not available in surface-mount packages.
Microelectromechanical Systems (MEMS): This technique integrates mechanical and electrical parts on a single chip. Furthermore, wafer bonding is one of the specific assembly techniques needed for MEMS components.
The Package on Package (PoP) Technology: Here, you stack two or more SMT components on top of each other. The reason is that you want to increase your PCB’sPCB’s density.
Ball Grid Array (BGA): BGA is an SMT component containing solder balls on the package’spackage’s base in place of leads. Installing BGA components is challenging because of their high pin density.
Moreover, you’ll have to align the components during assembly, making the process more challenging.
Is assembly more profitable than manufacturing?
The profitability of an enterprise is a question that depends on many factors.
Some include the cost of materials and the market demand for a product. Also, the production scale will determine how much money you can make.
Due to the efficiency of large-scale production, high-volume PCB manufacturing may result in more profit.
On the other hand, smaller-scale PCB assembly may be more lucrative because of lower capital expenditure.
What is the relationship between assembly and manufacturing?
In most cases, PCB manufacturing is a prerequisite for assembly. You cannot assemble a PCB if you don’t have it. Therefore, you’ll need to make one and then assemble it later.
Can we consider assembly as a part of manufacturing?
Yes, we consider PCB assembly part of the overall PCB manufacturing process.
However, assembly is separate from the initial process of turning the raw materials into a circuit board. Usually, some people refer to this initial stage as the manufacturing phase.
Generally, the PCB manufacturing process is a complex procedure that requires expertise.
Additionally, it demands sophisticated equipment to ensure that you commit fewer errors.
On the other hand, assembly is quite manageable, especially if you know how to solder.
However, the assembly of miniature or specialized PCBs is challenging and costly.
Ultimately, ensure that you understand the electrical parameters of your circuit before manufacturing.