Through hole PCB assembly is a common technique used to build electronic circuits. This method involves inserting leads or terminals of components through holes drilled on the PCB and then soldering them to pads on the opposite side. The through hole components are usually larger and more robust than surface mount components, making them ideal for use in applications that require high levels of stress or operate at high speeds and extreme temperatures.

To perform through hole PCB assembly, you will need specialized equipment such as wave solder machines, solder fountains, lead formers, and component counters. These machines are designed to provide economical solutions for low to medium volume through hole assembly. Some of the top American, European, and Asian manufacturers of through hole equipment include Novastar, Dektec, and Torch.

DDM Novastar, for example, has been a leading manufacturer of economical OEM solutions for the low to medium volume, mixed assembly, and through-hole PCB assembly for over 30 years. Their OEM product suite covers the entire line of through-hole assembly and includes wave solder machines and selective solder systems. In this article, we will explore the different types of through hole PCB assembly equipment and their applications in the electronics manufacturing industry.

Overview of Through Hole PCB Assembly Equipment

Through hole PCB assembly equipment is used to assemble printed circuit boards that have components inserted through holes in the board. This type of assembly is commonly used for components that require high mechanical stability and high power handling.

The equipment used for through hole PCB assembly includes:

1. Wave Soldering Machines

Wave soldering machines are used to solder through hole components to the PCB. The PCB is passed over a wave of molten solder, which wets the leads of the through hole components and forms a mechanical and electrical bond between the leads and the PCB. This process is highly automated and can be used to solder a large number of PCBs in a short amount of time.

2. Selective Soldering Machines

Selective soldering machines are used to solder through hole components to the PCB in a selective manner. This means that only specific components are soldered, rather than the entire PCB. This process is useful when there are components on the PCB that cannot withstand the high temperatures of wave soldering.

3. Through Hole Component Insertion Machines

Through hole component insertion machines are used to insert through hole components into the PCB. These machines use a series of mechanical arms to pick up components and insert them into the holes on the PCB. This process is highly automated and can be used to insert a large number of components in a short amount of time.

4. Through Hole Component Lead Forming Machines

Through hole component lead forming machines are used to bend the leads of through hole components into the correct shape for insertion into the PCB. This process is highly automated and can be used to form a large number of leads in a short amount of time.

Overall, through hole PCB assembly equipment is essential for the production of high-quality PCBs that require high mechanical stability and high power handling. The equipment used for through hole PCB assembly is highly automated and can be used to produce a large number of PCBs in a short amount of time.

Drilling and Depaneling Machines

When it comes to through-hole PCB assembly equipment, drilling and depaneling machines are essential tools. These machines are used to create holes in the PCBs for components to be inserted, as well as to separate the individual PCBs from a larger panel.

Drilling Equipment

Drilling machines are used to create the holes in the PCBs. There are two main types of drilling machines: manual and automated. Manual drilling machines are typically used for small-scale production or prototyping, while automated drilling machines are used for larger-scale production.

Automated drilling machines are more precise and efficient than manual drilling machines. They use computer-controlled drills to create the holes in the PCBs, which ensures that the holes are placed exactly where they need to be. Some examples of automated drilling machines include the LPKF ProtoMat E44 circuit board plotter and the MicroLine 5000 depaneling and drilling system.

Depaneling Tools

Depaneling machines are used to separate individual PCBs from a larger panel. There are several different types of depaneling machines, including motorized, manual, and pneumatic machines. Motorized depaneling machines use a motor to separate the PCBs, while manual machines require the operator to physically separate the PCBs. Pneumatic machines use air pressure to separate the PCBs.

Some examples of depaneling machines include those offered by Manncorp Inc. Their motorized, manual, and pneumatic PCB depanelers provide fast, safe, and low-stress PCB separation. LPKF also offers depaneling machines, such as the MicroLine 5000 system, which can be used for both drilling and depaneling.

Overall, drilling and depaneling machines are essential tools for through-hole PCB assembly. Whether you are working on a small-scale project or a large-scale production run, these machines can help ensure that your PCBs are created and separated accurately and efficiently.

Component Insertion Systems

When it comes to through-hole PCB assembly, component insertion systems are a crucial part of the process. These systems are responsible for accurately placing components into the drilled holes on the PCB. There are two main types of component insertion systems: manual insertion stations and automated insertion machines.

Manual Insertion Stations

Manual insertion stations are the most basic type of component insertion system. These stations are operated by a person who manually places the components into the drilled holes on the PCB. While manual insertion stations are the most affordable option, they are also the slowest and least accurate. They are best suited for low-volume PCB assembly.

Automated Insertion Machines

Automated insertion machines are the most advanced type of component insertion system. These machines use robotic arms to pick up and place components onto the PCB. Automated insertion machines are much faster and more accurate than manual insertion stations, making them ideal for high-volume PCB assembly.

There are two main types of automated insertion machines: selective and wave. Selective insertion machines are used for placing components in specific locations on the PCB, while wave insertion machines are used for placing components on the entire PCB at once.

Automated insertion machines are more expensive than manual insertion stations, but they offer the benefits of increased speed and accuracy. These machines are also highly customizable, allowing for the creation of specialized insertion systems for specific PCB assembly needs.

In summary, component insertion systems are a critical part of through-hole PCB assembly. While manual insertion stations are the most affordable option, automated insertion machines offer increased speed and accuracy, making them the preferred choice for high-volume PCB assembly.

Soldering Equipment

Soldering is a crucial process in through-hole PCB assembly that involves the joining of electronic components to the PCB using molten metal. There are two primary types of soldering equipment used in through-hole PCB assembly: wave soldering machines and selective soldering systems.

Wave Soldering Machines

Wave soldering machines are commonly used in high-volume through-hole PCB assembly. These machines use a conveyor belt to move PCBs through a preheating zone, a fluxing zone, and a soldering zone. In the soldering zone, a wave of molten solder is created, and the PCB passes over the wave, which solders the components to the board.

Wave soldering machines are efficient and can solder a large number of components simultaneously. They are also cost-effective, making them a popular choice for high-volume production runs. However, they are not suitable for low-volume production runs, as they require a significant amount of setup time and are not easily reconfigurable.

Selective Soldering Systems

Selective soldering systems are used in low to medium-volume through-hole PCB assembly. These machines use a robotic arm to selectively apply solder to specific components on the PCB. This process is more precise and flexible than wave soldering, making it suitable for low-volume production runs or prototypes.

Selective soldering systems are also more environmentally friendly than wave soldering machines, as they use less solder and generate less waste. However, they are more expensive than wave soldering machines, making them less cost-effective for high-volume production runs.

In summary, both wave soldering machines and selective soldering systems are essential tools in through-hole PCB assembly. The choice between the two depends on the volume of production runs and the level of precision required.

Inspection and Quality Control

As with any manufacturing process, inspection and quality control are essential for ensuring the reliability and functionality of through hole PCB assembly equipment. In this section, we will discuss two common types of inspection equipment used in the through hole PCB assembly process: Optical Inspection Systems and X-Ray Inspection Equipment.

Optical Inspection Systems

Optical inspection systems are an essential tool in the through hole PCB assembly process. They allow for the detection of defects such as missing components, incorrect component orientation, and solder bridging. These systems use high-resolution cameras and advanced image processing algorithms to detect defects in real-time.

One of the advantages of optical inspection systems is their ability to inspect both sides of the PCB simultaneously, which can significantly reduce inspection time. Additionally, these systems can detect defects that may not be visible to the naked eye, such as hairline cracks or insufficient solder joints.

X-Ray Inspection Equipment

X-ray inspection equipment is another critical tool in the through hole PCB assembly process. It is used to detect defects that are not visible to the naked eye, such as solder voids, cold joints, and internal shorts. X-ray inspection equipment works by passing X-rays through the PCB, which are then detected by a sensor on the other side.

One of the advantages of X-ray inspection equipment is its ability to inspect internal components and connections. This is particularly useful for through hole PCBs, which have components that are inserted through pre-drilled holes. X-ray inspection equipment can detect any defects in the solder joints or connections that may be hidden from view.

In summary, inspection and quality control are essential for ensuring the reliability and functionality of through hole PCB assembly equipment. Optical inspection systems and X-ray inspection equipment are two critical tools used in the through hole PCB assembly process. They allow for the detection of defects that may not be visible to the naked eye, ensuring that the final product is of the highest quality.

Cleaning and Finishing Equipment

After the through-hole components are inserted into the PCB, the next step is to clean and finish the board. This is an essential step in ensuring the proper functionality and longevity of the PCB. There are various types of cleaning and finishing equipment available, each with its own benefits and drawbacks.

PCB Cleaning Systems

PCB cleaning systems are used to remove any flux residue, solder balls, or other contaminants from the PCB surface. This is important to ensure the proper functioning of the circuit and to prevent any corrosion or damage to the board. There are various types of PCB cleaning systems available, including:

• Ultrasonic cleaning systems: These systems use high-frequency sound waves to agitate the cleaning solution and remove any contaminants from the PCB surface.
• Spray cleaning systems: These systems use a spray nozzle to apply the cleaning solution to the PCB surface. The solution is then rinsed off with water.
• Batch cleaning systems: These systems use a tank to hold the cleaning solution and the PCBs are immersed in the solution. The solution is then agitated to remove any contaminants from the PCB surface.

PCB Finishing Equipment

PCB finishing equipment is used to apply a protective coating to the PCB surface. This coating helps to prevent any corrosion or damage to the board and also provides a smooth surface for any subsequent soldering or assembly processes. There are various types of PCB finishing equipment available, including:

• Hot air leveling machines: These machines use hot air to melt a layer of solder onto the PCB surface. The excess solder is then removed, leaving a smooth and even surface.
• Electroplating machines: These machines use an electrochemical process to deposit a layer of metal onto the PCB surface. This metal layer provides a protective coating and also helps to improve the conductivity of the board.
• Solder mask machines: These machines apply a layer of solder mask to the PCB surface. This mask helps to protect the board from any accidental soldering or short-circuiting and also provides a smooth surface for subsequent assembly processes.

It is important to choose the appropriate cleaning and finishing equipment for your specific PCB assembly needs. Consult with a professional or do thorough research to ensure that you select the right equipment for your application.

Frequently Asked Questions

What types of equipment are commonly used in through-hole PCB assembly?

There are several types of equipment used in through-hole PCB assembly, including insertion machines, wave soldering machines, selective soldering machines, and reflow ovens. Insertion machines are used to place components into the through-holes on the PCB. Wave soldering machines are used to solder the components to the board by passing the board over a wave of molten solder. Selective soldering machines are used to solder specific areas of the board that cannot be soldered using wave soldering. Reflow ovens are used in the assembly of surface mount components.

How do you determine the appropriate equipment for a specific through-hole PCB assembly project?

The appropriate equipment for a specific through-hole PCB assembly project depends on several factors, including the size and complexity of the board, the number of components to be assembled, and the desired throughput. It is important to consider the required accuracy, speed, and repeatability of the equipment when making a decision.

What are the cost considerations when investing in through-hole PCB assembly equipment?

The cost of through-hole PCB assembly equipment can vary greatly depending on the type and quality of the equipment. It is important to consider the initial cost of the equipment, as well as ongoing maintenance costs and the cost of replacement parts. Additionally, it is important to consider the expected lifespan of the equipment and the potential for future upgrades or modifications.

Can you describe the differences between wave soldering and selective soldering machines?

Wave soldering machines are used to solder the entire board by passing it over a wave of molten solder. Selective soldering machines, on the other hand, are used to solder specific areas of the board that cannot be soldered using wave soldering. This allows for greater precision and control over the soldering process, but can be slower and more expensive than wave soldering.

What factors should be considered when purchasing used through-hole PCB assembly equipment?

When purchasing used through-hole PCB assembly equipment, it is important to consider the condition of the equipment, the age of the equipment, and the availability of replacement parts. It is also important to consider the reputation of the seller and any warranties or guarantees that may be offered.

How has the evolution of through-hole technology impacted the design of assembly equipment?

The evolution of through-hole technology has led to the development of more advanced and precise assembly equipment. Modern equipment is often designed to be more versatile and adaptable, allowing for greater flexibility in the assembly process. Additionally, the development of surface mount technology has led to the integration of through-hole and surface mount components, requiring equipment that can handle both types of components.