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What you need to know about through-hole assembly process

Are you wondering how long the through-hole assembly will take from the beginning to the end? Do you know the steps to assemble a PCB? Have you sought PCB assembly services? Well, here you will get your issues about PCB sought. PCB assembly service is among the electronics manufacturing to install electronic parts. The installation is on any printed circuit board using the plated through-hole technology. 

The through-hole assembly is a means to produce electronic circuits. These circuits have components installed via the leads. It’s a mounting process that gets the leads inserted into drilled holes. The machine permits the solders on the circuit board component by manual or waves soldering. PCB design has changed from single-sided boards to double-sided and multilayer boards. The through-hole assembly is complex to attain the lasted electronics. 

SMT technology has replaced the construction of PCB manufacturing. In short, through-hole PCB assembly is the soldering through-hole components on a bare board by soldering the component leading via the holes of PBC boards.

Through-hole PCB components

The technology has two main components: axial and radial components.

Axial lead components 

Axial leads travel in a straight line via a component. The two ends of the component have a pair of lead wires. Both ends of the lead wires get mounted in two different holes on the circuit board. These components become flatter and closer to the board. They can help to shorten the distance on the circuit board.

Radial lead components 

Lead wires of these components protrude out from the body of a component to the surface on the same side. In most cases, they stand perpendicular to a circuit board. They need smaller space and cover short distances on a circuit board than their counterparts. The leads protrude parallel from the same mounting board. 

These two components are “twin” lead components. They have unique disadvantages and advantages. Axial leads get used because of their board snugness. On the other hand, radial leads use a small area. It makes radial them more advantageous for a high-density board. The axial configuration can come in different forms including: 

Through-hole PCB procedure

There are many ways you can approach the through-hole PCB assembly process. Your unique objectives will define the method that you will use. The two main procedures for through-hole assembly are manual and automated through-hole assembly. 

Manual through-hole assembly

Individuals take the initiative to solder circuit boards in small quantities. They aid in improving the PCB designs. It’s a method for many startups and smaller companies. These companies can’t afford to use an automated through-hole assembly process. One key characteristic of the manual process is that the circuit boards have varying qualities. Human beings aren’t machines. Thus, they can’t repeat the process accurately in the same format. The individuals can place the PCB incorrectly. 

It’s hard to use the manual process on smaller electronics with tiny circuit boards. You will face difficulties when you solder components. On the other hand, the manual assembling process is effective in large components. For example, through-hole led resistors and chip packages. Speed is another problem that affects the manual method. It’s hard to solder over 500 components in one sitting. It thus affects the production capacity at that particular sitting. You will need more time to solder wet using a hand solder iron, and its spread is also minimal. 

Operators get exposed to flux fumes and solder fumes that can develop cancer. Soldering irons can also burn them since they have to hold them intact until they cool and solidify. 

Automated through-hole PCB assembly

Machines do everything here. The machines are in a series of connections, each with special duties. A few repair technicians and operators are there to monitor the process. PCB stackers can aid in holding PCB in the entire process. Machines used here are:

All these components placed on a conveyor can solder over 500 components in an hour. You can fit the THM systems with minute vacuum-operated fans. It will limit exposure to compounds like copper, lead, and cadmium.

Through-hole PCB advantages

Through-hole PCB technology has existed for a long. The threat is that new technologies might replace it. Despite this, the following are the advantages you will get from this technology design. 


It has proved to be a real deal for effectiveness and durability when dealing with products that need secure connections. The technology withstands all the environmental stress that you can expose it to and remains in contact. You reinforce through-hole components when running them through the circuit board, unlike SMT components soldered on PCBs. Through-hole PCB fits well in aerospace and military electronics to endure extreme conditions. 

Strong mechanical bonds

The technology works well for components that have bulky or heavy compositions. These metals need stronger mechanical bonds in their PCBs that ordinary surface mount technology cannot offer. 

Easy prototyping

Designers get an easy time because of the easy manual adjustment and replacement capabilities. In addition, the through board circuit boards use breadboard sockets which aren’t crucial in prototyping. 

Through-hole PCB disadvantages

Expensive – Through-hole assembling process needs extra drilling, which makes it expensive.

It needs more space – The larger through-hole PCBs occupy huge spaces on the circuit board, limiting the circuit design. 

Rapid technological changes – More sophisticated electronics of smaller sizes are coming out daily. It makes the vast through-hole PCB components unsuitable for high-density and small-sized designs. 

Production speeds are low due to drilling involved in the assembling process. The assembling process is very demanding. 

Through-hole PCB applications

Many sectors use PCBs, from small devices to huge appliances. Here are the top sectors that use printed circuit boards. 

Medical devices 

PCBs are essential in monitoring, diagnostic and treatment devices. Implant PCB devices need to observe strict sanitation standards. The PCBs used in hospitals are in devices like:

  • Monitors
  • Infusion pumps
  • Internal devices like pacemakers
  • Medical imaging systems like ultrasonic scanners and CT scans


LEDs are famous for energy saving, compactness, and long life. You will get LED PCBs in residential, automotive, medical, storefront, and computer displays. 

Consumer electronics

A wide range of devices use the through-hole PCBs:

  • For example, communication devices like radios and smartphones use these through-hole PCBs.
  • Computers: Both for business and personal use.
  • Home appliances like microwaves and refrigerators. 

Other areas where through-hole PCBs are of use include:

  • Industrial equipment
  • Automotive components
  • Aerospace components
  • Marine time applications
  • Security and safety equipment’s
  • Telecommunication equipment
  • Defense and military applications


The rise in new technology has phased out some old manufacturing methods gradually. Though the through-hole PCB assembly may have some limitations, it has some value over the emerging technologies. Through-hole PCB strength and reliability offer a lasting effect to rely on for your needs. You can get fully automated, semi-automated, and manual insertion procedures through-hole assembly. Whether you are handling radial or axial lead components, the method you choose is vital. The assembling process that you will choose will depend on your preferences. 

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