You need the best flexible PCB fabrication equipment to design reliable and efficient circuit boards.
Soldering components manually is practically impossible, especially when designing many circuit boards.
Generally, the PCB fabrication process involves four major steps, each using unique equipment: inspection, soldering, paste application, and automated component placement.
Surprisingly, flex PCB manufacturing equipment doesn’t come cheap and requires expert operating skills.
Nonetheless, you must understand the common PCB fabrication equipment and their operation.
We have prepared this article to help you if this is your desire. Keep reading to find out more.
Table of Contents
- Paste Application Equipment for FPC
- Automated Component Placement Equipment for FPC
- Flexible PCB Soldering Equipment
- Flexible PCB Inspection Equipment
- FAQ
- Conclusion
Paste Application Equipment for FPC
(A stencil frame for applying paste)
The flexible PCB assembly process starts with the solder paste application.
Think of solder paste as a glue that holds the PCB components together and involves mixing silver, lead, and tin metal alloys.
Therefore, you’ll need the following equipment during this critical step:
Solder Paste Printing Machine
Before you apply your solder paste, you must put a circuit board stencil on the board.
The stencil ensures that you apply solder paste on areas where components will sit.
Therefore, when applying solder paste, you must lock the circuit board and PCB stencil in an automated paste printer.
Next, a squeegee will then apply solder paste precisely on the pads.
Afterward, the printing machine applies a blade on the stencil to deposit and spread it evenly in the intended areas.
If you remove the stencil, you’re sure the solder paste is in the desired areas.
Solder Paste Inspection Machine
According to research, about 70% of issues related to SMD soldering arise from substandard or improper solder paste printing.
Therefore, there is a need to inspect the board after solder paste printing, and this is where solder paste inspection machines (SPI) come in.
Although efficient printing methods are enough for low-volume production, SPI is necessary during mass production to avoid rework costs.
Surprisingly, SPI machines use 3D cameras to capture and evaluate solder paste using factors like solder height, alignment, and volume.
Therefore, from the evaluation, you can easily identify areas that need rework from the evaluation.
Consequently, you’re guaranteed to produce efficient and high-quality circuit boards.
Automated Component Placement Equipment for FPC
Glue Dispensing Machine
Before placing components, a glue dispensing machine places glue dots in areas where the components will settle.
This holds everything in place until you solder contacts and leads.
We recommend this method for reflow and double-sided wave soldering to prevent components from dropping off.
Also, you can use it for wave soldering when the force from the solder wave might dislodge the large components.
Pick-and-Place Machine
(An automated pick-and-place machine)
The pick-and-place might be the most complex machine in the entire flex circuit board fabrication.
As the name suggests, it picks up the components and places them on the board.
Therefore, it has completely automated the traditional steps where humans could pick components manually using tweezers and put them on the board.
Surprisingly, the machine operates at lightning speeds working on about 30,000 components every hour.
Watching a pick-and-place machine in progress is amusing; you’ll be thankful for it.
Flexible PCB Soldering Equipment
(A soldering oven)
Reflow Soldering Machine
This is the most common technique and involves moving a populated board along a conveyor via an oven.
This oven is what we refer to as a reflow soldering machine.
Therefore, the board goes through different zones under controlled temperatures.
As a result, your solder paste will melt and harden to create a strong connection between the pads and components.
However, the reflow soldering machine uses external sources of heat. And the process presents the following benefits:
- The process is perfect for difficult assembly like SMT patch assembly. Also, Components like QFN and BGA can only be done using this process.
- It produces high welding quality. Surprisingly, reflow ovens use uniform temperature, convection conduction, and good soldering quality. Therefore, you can only expect an impressive soldering effect.
- Perfect for volume production.
Wave Soldering Machine
As the name suggests, these machines allow the circuit board to pass through a molten wave to solder components.
Before soldering begins, the machine applies a flux layer to clean component pads and contacts to guarantee solder adherence.
Moreover, the board goes through pre-heating after flux layer application to eliminate thermal shock.
However, this method is not commonly used compared to the reflow soldering above.
But wave soldering is popular for assembling through-hole components.
Surprisingly, wave soldering still presents the following advantages:
- Since the board has limited contact with high-temperature soldering time, there is less circuit board warpage.
- This method greatly improves solder joint quality.
Flexible PCB Inspection Equipment
(Visual measuring system)
After assembling the circuit board, you should inspect and test it for errors.
Without this process, you might end up with faulty products that won’t serve you for long.
Fortunately, the time for manual testing and inspection is gone, and we have reliable equipment.
Automated Optical Inspection (AOI)
For this process, you use optical methods to test and inspect for mistakes.
The AOI machine captures the circuit board surface and creates its image for serious analysis.
Consequently, it compares the captured image with a perfect reference board.
An AOI machine makes identifying shorts, scratches, and missing components easy.
Surprisingly, this method is very accurate and faster.
In-Circuit Testing
The in-circuit testing method uses a bed-of-nails fixture and presents an effective approach to testing the functionality of a populated PCB.
It has spring-loaded pogo pins, with each pin making contact with a node in the circuit board circuitry.
Therefore, you place and press a complete circuit board on the pin, which makes contact with many testing points on the board.
This way, the fixture will transmit test signals to detect the continuity breaks and evaluate performance.
To know whether a circuit board was tested using this method, check for small dimples on the soldered connection.
Surprisingly, some small dents on your circuit prove that thorough testing was done.
Functional Validation Test (FVT)
Finally, you do a functional validation test before shipping or using the circuit board.
Now, you’re testing for more than just the physical defects.
Therefore, you load the board with software to determine whether it will work effectively in the intended applications.
FTV testing simulates the final application environment by interfacing the circuit board through its test point or connector.
FAQ
Is flexible PCB manufacturing equipment expensive?
Apart from the complex flexible manufacturing process, the equipment is also very expensive.
This explains why few companies or individuals venture into circuit board manufacturing.
Also, it partly explains why flexible circuit boards are expensive.
Is it easy to operate flex PCB fabrication equipment?
As we highlighted, the flex PCB fabrication process is complex.
Therefore, this is something that you should leave to experts for the best results.
However, you can still learn and perfect over time.
What is flexible PCB fabrication?
This is the process of designing and manufacturing flexible circuit boards.
So that you understand, flexible PCBs are circuit boards that can bend or twist without defects.
The process yields highly reliable and effective circuit boards that fit into tighter spaces.
Also, the boards are lightweight, thus finding common application in wearables.
However, the complexity of the fabrication process makes the PCBs more costly.
Conclusion
Modern equipment has given rise to efficient and faster flexible PCB fabrications.
As we highlighted, the fabrication process involves four major steps: inspection, soldering, paste application, and automated component placement.
And each of these steps has unique equipment that makes everything possible.
However, we have to point out that flexible PCB fabrication equipment is somehow expensive.
Moreover, the equipment requires experts to operate and create reliable PCBs.
All in all, the machines are worth it, and you can use them in mass production.
