What is Surface Mount Assembly?

What is Surface Mount Assembly?

Discover the power of Surface Mount Assembly with Profab Electronics. Compact size, speed, precision, and more. Your partner for top-quality PCB assembly

At a Glance: Essential Insights

Compact Component Size: Surface Mount Assembly allows for smaller components and higher component density, enabling the production of smaller devices with more functionalities.

Increased Speed and Efficiency: SMT assembly is faster and more efficient, as automated equipment can place and solder components, resulting in higher throughput and reduced labor costs.

Stencil Printing: A crucial step in the SMT process, stencil printing ensures that the precise amount of solder paste is applied to the PCB, which is critical for achieving reliable solder joints.

Component Placement: High-speed robotic pick-and-place machines accurately place SMT components onto the PCB, ensuring proper alignment and adherence to the solder paste.

Reflow Soldering: The PCB is passed through a reflow oven, where the solder paste melts and solidifies, creating a secure bond between the components and the PCB.

Inspection and Testing: Assembled PCBs undergo thorough inspection and testing, such as Automated Optical Inspection (AOI), X-ray inspection, or functional testing, to ensure the quality and functionality of solder joints and components.

Additional Processes: Depending on the complexity of the PCB, additional processes like selective soldering, conformal coating, or potting may be employed to ensure reliability and durability.

Selecting a Manufacturer: When choosing an SMT assembly manufacturer, consider their expertise in the field, experience in prototype and volume PCB assembly, and their ability to handle your specific requirements.


As the world of technology forges ahead, the methods we employ in electronic assembly manufacturing continually evolve. Surface Mount Assembly (SMT) has been a mainstay for several decades, with ongoing advancements in electronics components driving improvements in this assembly technique. But what exactly is SMT Assembly, and how has it revolutionized electronics manufacturing?

SMT assembly is a process in electronics manufacturing that leverages high-speed robotic machines to place surface mount components onto printed circuit boards (PCBs). Unlike Through Hole Assembly, where components are inserted through the board, SMT components are placed directly onto the surface of the PCB. This type of assembly is frequently used in the production of high-density electronic products, including RF communication devices, medical devices, and commercial/industrial products such as smartphones, computers, and home automation systems.

Advantages of Surface Mount Assembly

SMT assembly offers several benefits over traditional Through Hole Assembly, including:

Compact Component Size

SMT components are considerably smaller, allowing for higher component density. This capability enables products to be smaller in size or to feature an increased number of functionalities. As electronics continue to shrink, SMT remains a vital assembly method for accommodating new design trends and requirements. For instance, the compact nature of SMT components enables manufacturers to produce slim smartphones, tablets, and wearables without compromising on functionality or performance.

Increased Speed and Efficiency

SMT assembly is faster and more efficient, as components can be placed and soldered using automated equipment. This automation results in higher throughput, reduced labor costs, and improved consistency in the final product. With the ability to place thousands of components per hour, SMT assembly lines can quickly produce large volumes of electronic products, meeting the ever-growing demands of consumers.

The Surface Mount Assembly Process: Key Steps

The Surface Mount Assembly process involves several essential steps, including:

  1. Stencil Printing: A stencil printer applies solder paste to the PCB's surface, depositing it on the pads where components will be placed. The stencil ensures that the precise amount of solder paste is applied, which is critical for achieving reliable solder joints.

  2. Component Placement: High-speed robotic machines, known as pick-and-place machines, accurately place SMT components onto the PCB, adhering them to the solder paste. These machines utilize advanced vision systems to ensure the accurate placement of even the smallest and most intricate components, such as microchips and resistors.

  3. Reflow Soldering: The PCB is passed through a reflow oven, where the solder paste melts and solidifies, creating a secure bond between the components and the PCB. The reflow oven utilizes a carefully controlled temperature profile, gradually heating the PCB to prevent thermal stress while ensuring that the solder reaches the appropriate melting point for a strong bond.

  4. Inspection and Testing: The assembled PCB undergoes thorough inspection and testing to ensure the quality and functionality of the solder joints and components. Inspection methods may include automated optical inspection (AOI), X-ray inspection, or functional testing. AOI systems, for example, use cameras and image processing software to compare the assembled PCB to a reference image, identifying any discrepancies or defects in solder joints or component placement.

  5. Additional Processes (if required): Depending on the complexity of the PCB, additional processes such as selective soldering, conformal coating, or potting may be employed to ensure the reliability and durability of the final product.

Selecting a Surface Mount Assembly Manufacturer

When selecting an electronics manufacturing company for SMT assembly, it is crucial to consider their expertise in the field. SMT assembly requires specialized equipment and highly trained personnel to ensure accurate component placement and reliable soldering. Look for a manufacturer with experience in both prototype and volume PCB assembly and one that can handle your specific needs. Additionally, consider the manufacturer's track record of meeting deadlines, maintaining quality control, and their ability to adapt to evolving technologies.

Profab Electronics: Your Partner in Surface Mount Assembly Excellence

In the competitive landscape of electronics manufacturing in the USA, Profab Electronics stands out as a trusted, family-owned business offering a full range of contract manufacturing services, including Surface Mount Assembly. With a focus on high-tech and high-quality manufacturing solutions, Profab Electronics caters to a variety of industries, ensuring your products are assembled to the highest standards.

State-of-the-Art Facilities and Equipment

Our cutting-edge facilities and equipment enable us to deliver exceptional SMT assembly services, ensuring the highest levels of accuracy, efficiency, and quality. From advanced stencil printers to high-speed pick-and-place machines, we continually invest in our infrastructure to remain at the forefront of electronics manufacturing.

Skilled and Experienced Team

Our skilled and experienced team of technicians and engineers bring a wealth of expertise to every project. We understand the complexities and nuances of SMT assembly, and our commitment to ongoing training ensures that we stay abreast of the latest advancements and best practices in the field. This dedication to excellence guarantees that your products receive the highest quality of care and attention.

Customized Solutions and Superior Customer Support

At Profab Electronics, we pride ourselves on offering customized solutions tailored to your unique needs. We work closely with you to understand your product requirements and provide personalized guidance throughout the manufacturing process. Our superior customer support ensures that you are always informed and confident in our ability to bring your vision to life.

Consistent Quality and Continuous Improvement

Our commitment to consistent quality and continuous improvement is evident in our robust quality management system. We implement stringent quality control measures at every stage of the manufacturing process, ensuring that your products meet or exceed industry standards. Our dedication to improvement drives us to constantly refine our processes, adopt new technologies, and optimize our operations.

To learn more about Through Hole Assembly techniques and their applications, we encourage you to explore our in-depth guide by clicking the following link: What is Through Hole Assembly? A Comprehensive Guide of a Classic Technique in Electronics Manufacturing. This resource will provide valuable insights into the fascinating world of Through Hole Assembly and help you make informed decisions when selecting the best assembly method for your electronic products.

About Profab Electronics

Profoundly embedded in the electronics manufacturing sector, Profab Electronics has been steadfast in its commitment to deliver excellence for over three decades. Our unparalleled experience, fortified by our stringent quality standards, positions us as a trusted partner in the realm of Electronics Manufacturing Services (EMS).

We're an ISO 9001 and AS9100 certified company, and our adherence to these globally recognized standards attests to our unyielding quest for quality. Our team comprises experts who hold formative training on the latest IPC standards, ensuring that we consistently produce electronic products of the highest caliber.

Our proficiency lies in PCB assembly, offering a spectrum of services ranging from Surface Mount (SMT) to Through-Hole Assembly. From the initial stages of prototyping to high volume pcb assembly, we offer comprehensive solutions to meet client requirements.

At Profab Electronics, we synergize our expertise and experience to deliver high-quality electronic products. Our unwavering commitment to quality, innovation, and customer satisfaction has established Profab Electronics as a leader in the electronics manufacturing industry. Trust us to bring your technological visions to life.