Surface Mount Technology (SMT) is a manufacturing process that involves applying electronic components directly onto the surface of a printed circuit board (PCB). This method allows for automated production, enabling broader assembly to create fully functional circuit boards. Any electronic component mounted in this way is known as a surface mount device (SMD). In contrast to traditional manufacturing techniques, SMT eliminates the need for through-hole placement of components; instead, components are attached to the circuit board via a reflow soldering process.

　　Initially termed planar mounting by IBM, SMT was pioneered and implemented in the 1960s for building mini-computers. It subsequently replaced the earlier through-hole technology. However, it only gained substantial attention after surface mount components captured 10% of the market share in 1986. By 1990, the dominant technology used in advanced printed circuit assemblies (PCAs) included surface mount devices, commonly known as SMDs.

　　SMT components feature small leads, and solder is used to secure the SMDs to the PCB surface.

　　During the through-hole technology era, components were introduced via lead holes drilled into the PCB. The dimensions of these holes were precisely adjusted prior to the soldering process to accommodate each component. SMT streamlines the assembly process by bypassing the drilling step; SMDs are quickly sorted and attached to the PCB surface with minimal or no lead holes, significantly accelerating device assembly.

　　Considering the precision required to achieve top-tier surface mount assemblies (SMAs), manually performing the SMT assembly process can be quite tedious and time-consuming. Therefore, to enhance efficiency, automated assembly machines are primarily used in SMT manufacturing, especially for mass production.

　　Surface mount technology components are more compact than through-hole components, contributing to the manufacture of stylish and aesthetically pleasing electronic devices suitable for the contemporary era. Consequently, SMT is used in virtually all electronic devices today, including toys, kitchen appliances, laptops, and smartphones.

　　 What are the types of SMT equipment?

　　Surface mount components differ significantly from leaded components. SMT components are not designed to connect two points but rather to be placed on a circuit board and then soldered.

　　The leads of SMT components do not pass through holes on the circuit board, unlike the expected configuration of traditional leaded components. Different package designs are customized for different component types. Broadly speaking, these package styles can be categorized into three main groups: passive components, transistors and diodes, and integrated circuits. The following overview delves deeper into these three classifications of SMT components:

　　1. Passive Components:

　　2. Transistors and Diodes:

　　3. Integrated Circuits (ICs):

　　In summary, the diverse package styles of SMT components cater to the specific requirements of various electronic components, offering advantages in terms of space efficiency, automated assembly, and accommodating contemporary design prerequisites.

　 　What is the surface mount technology process?

　　1. SMC and PCB preparation;

　　2. Solder paste printing;

　　3. Component placement;

　　4. Reflow soldering;

　　5. Cleaning and inspection;

　　 What are the differences between SMT and through-hole technology?

　　 Component Mounting:

　　SMT: Components are directly attached to the PCB surface using small, flat leads or by soldering directly to pads on the PCB.

　　Through-hole: Components have leads that pass through openings in the PCB and are soldered on the opposite side.

　　 Structure and Size:

　　SMT: Components in SMT are generally smaller and lighter, allowing for higher component density and smaller PCBs.

　　Through-hole: Through-hole components are typically larger, and the holes required for their leads restrict the available PCB space.

　　 Assembly Process:

　　SMT: SMT assembly is highly automated, utilizing pick-and-place machines for precise component placement and reflow ovens for soldering.

　　Through-hole: Assembly can be manual or automated. Components are inserted into holes, and soldering is typically done via wave soldering or manual methods.

　　 Mechanical Strength:

　　SMT: SMT components are directly soldered to the PCB surface, resulting in good mechanical strength and resistance to shock.

　　Through-hole: Through-hole components gain mechanical strength from leads passing through the PCB, but their reliance on leads can make them more susceptible to mechanical stress.

　 　Cost:

　　SMT: Generally more cost-effective for high-volume production due to automation and smaller component size.

　　Through-hole: Can be more time-consuming and costly, especially for large and complex boards, often requiring manual labor.

　　 Design Flexibility:

　　SMT: Offers greater design flexibility, particularly suitable for compact, high-density designs.

　　Through-hole: Suitable for designs where robustness and repairability are prioritized, or for components not available in SMT packages.

　　 Repair and Rework:

　　SMT: Rework can be more challenging due to the smaller size of SMT components and dense circuitry.

　　Through-hole: Through-hole components are generally easier to rework and repair.

　　 Industry Trends:

　　SMT: Widely used in modern electronics manufacturing, especially for high-volume production and miniaturized devices.

　　Through-hole: Still used for specific applications, especially where reliability and repairability are critical, or for specialized components.

　　In contemporary electronics manufacturing, SMT and through-hole technologies are often used in combination (called mixed technology assembly) to optimize the advantages of each method for different components on a single PCB.