Although SMT is very popular as an assembly technology, most applications still choose THT or a combination of SMT and THT processes. This is because the following advantages make it the preferred choice for certain applications.

THT PCB components provide strong connections between components. This enables the PCB to withstand environmental, thermal, and mechanical stresses during use.

Through hole assembly is beneficial for prototype design and rework, as components can be easily inserted, replaced, or reinserted during product development testing.

Through hole PCB assembly services are relatively cheaper than SMT technology for prototype design and mass production. THT is a mature manufacturing method.

In PTH assembly, there is no need to invest a large amount of money to purchase expensive surface mount machines, only wave soldering or soldering iron is needed.

Due to various challenges in through-hole PCB assembly, automatic component insertion machines are more favored than manual processes. The following are challenges that must be considered and addressed during through-hole assembly planning:

Strict assembly tolerances for THT and hybrid THT/SMD technologies.

The lead wire is prone to deformation and bending.

There are various types and variations of THT components.

Ergonomic issues for manual laborers.

Defects in THT PCB assembly, such as excessive solder, bridging, dehumidification, and porosity

Through hole components are widely used in industrial applications of robot systems, circuit control, and sensor technology.

Through hole PCB components allow for large-sized leads, which can adapt to high current applications, especially for equipment and devices used in the aerospace and military fields.

The components in through-hole assembly have excellent electrical performance and are suitable for high-frequency end-user applications such as RF circuits.

The engine system, sensing and control modules for automotive applications also use through-hole PCBs. Most electronic products also use through-hole technology integrated with SMT to achieve optimal design.

The assembly of through-hole PCBs follows quality standards to maintain and improve quality. The IPC standard specifies measures and guidelines for the electrical and assembly requirements of THT assembly. IPC also provides a set of standards for visual quality and manufacturing standards. SMT and THT assembly may produce different types of defects due to significant differences in materials, component types, processes, and parameter control between these two technologies.

The following is a list of potential defects that through-hole PCB assembly manufacturers must pay attention to and take appropriate control of:

Component lifting:During the wave soldering process, components may be disturbed, leading to component warping. Changes in lead length can also cause components to warp. The factors that affect the length and angle of the lead include lead material, diameter, and hardness.

Missing components:This defect refers to the component not being located in its expected position. This may be due to incorrect settings or improper picking and placement of components during assembly. Missing components can be easily corrected online.

Wrong direction:This situation occurs when the placement direction of components is opposite to the assumed direction in the PCB layout.

Adequate inspection is required:The detection of the above-mentioned defects can be done manually or automatically. The inspection process is crucial for ensuring the quality of the PCB. Image processing technology is used to compare the assembled circuit board with a reference known good unit image. If there is not sufficient testing, the circuit board may enter subsequent processes and cause testing failures, or worse, the circuit board may detach from the entire assembly process and be shipped to the customer.

Focus on detection and occurrence control:The quality control of through-hole PCB assembly should focus on detection and occurrence control. Like occurrence control, through-hole PCB assembly services should have monitoring control to understand common defects. This is usually analyzed through a Pareto chart to gain a clear understanding of the main defects. Then a root cause analysis must be conducted to investigate potential through-hole PCB assembly machine issues, process gaps, material quality issues, and inconsistencies in the PCB production process.

If pursuing cost-effective FPC manufacturing services, choosing a Chinese manufacturer is the best choice. As a manufacturing powerhouse, China has abundant resources, cheap labor, and a large number of technical personnel. We recommend Haibo, a Chinese FPC assembly service provider with over 10 years of experience, who has performed outstandingly in various aspects

Efficient and reasonable quotation:There is an efficient quotation process to assist you in making decisions, providing reasonable prices and highly competitive quotes in China.
High quality and reliable products:Produce high standard printed circuit boards, manufacture and test according to specifications, international standards, and internal controls, and conduct pre production inspections to ensure robust processes.
Quick and on-time delivery:The assembly equipment is in good condition, with high productivity, minimal downtime, short delivery time, and also provides urgent services.
Timely and effective response:Always respond to customer needs, provide accurate information, answer questions through multiple channels, and offer one-stop services.
Strong technical strength:China's FPC manufacturing technology is leading, and Haibo has a complete SMT solution that covers assembly, inspection, and other capabilities. It also provides prototype production and customization services.