Introduction to SMT process: What are the Differences from SMD?

Introduction to SMT process: What are the Differences from SMD?

Table of Contents:

1, Introduction to SMT process: What are the Differences from SMD?
2, What is SMT?
3, What are the differences between SMT, SMD, SMA and SME?
4, SMT production process
5, Advantages of SMT Technology
6, Introduction to SMT Equipment

1, Introduction to SMT process: What are the Differences from SMD?
As electronic products become increasingly complex in function and thinner and lighter in appearance, the precision of electronic components is also getting higher and higher. Due to cost considerations, many factories are gradually entrusting the soldering of electronic components to professional technical factories. Among them, SMT is currently the most mainstream soldering technology.

2, What is SMT?
SMT (Surface Mount Technology), also known as surface mounting technology, refers to a technology that installs electronic components such as resistors, capacitors, transistors, and volume circuits onto the surface of a circuit board (PCB). Surface soldering is mainly done by printing Solder Paste on the circuit board to be soldered, placing electronic components, melting the paste at high temperature, allowing the paste to coat the electronic components, and when the temperature cools and solidifies, surface soldering is completed.

3, What are the differences between SMT, SMD, SMA and SME?
These three words are all closely related to SMT. In simple terms, SMT is a soldering technology, SMD and SMA are electronic components to be soldered, and SME is the soldering machine.

Abbreviation, full name, Chinese explanation
SMT Surface Mount Technology is the technology of installing electronic components on the surface of a circuit board
SMD Surface Mount Device (SMT) is a single electronic component installed on the surface of a circuit board, such as resistors, capacitors, and integrated circuits
SMA Surface Mount Assembly (SMT) is an electronic component installed on the surface of a circuit board, and this component contains one or more combinations of electronic components, such as Bluetooth modules and WIFI modules
SME Surface Mount Equipment is a machine that installs SMDS on the surface of circuit boards

4, SMT production process
To successfully install electronic components on a circuit board through SMT, mainly three processes need to be gone through:

Process description: Use the equipment
Solder paste printing
Print solder paste at the positions on the PCB where electronic components need to be installed with a solder paste printer
2. Make a patch
Place electronic components at the positions where solder paste is printed on the PCB with a component placement machine
3. Re-welding heating
Through the reflow oven heating, the solder paste on the PCB is melted to connect and fix the electronic components to the PCB in the reflow oven

5, Advantages of SMT Technology
The biggest difference between SMT and the previous through-hole mounting technology is that SMT does not require reserving through-holes for the pins of electronic components, thus allowing for the use of smaller electronic components. There are mainly the following three advantages for electronic products to adopt SMT technology:

1. Thinner and lighter in size:
By using smaller electronic components, the required circuit board area will also decrease, and the volume of electronic products can become lighter.

2. More high-end products:
When electronic components become smaller and thinner, electronic products can be applied to more diverse fields, such as micro-robots, cpus, portable electronic products, etc., and more precise and high-end products can be designed.

3. Easier mass production:
SMT uses machinery and equipment to complete surface soldering. Compared with the manual insertion operation in the past, it is more suitable for mass production, and the manufacturing process is also more stable than through-hole insertion.

6, Introduction to SMT Equipment

Dispensing machine

SMT equipment recommendation - The dispensing machine is used to precisely dot, inject, apply and drip liquid to the correct position of the product. It can be used for dotting, drawing lines, circular or arc-shaped shapes. This model is patented for the Automatic Process Calibration Injection Technology (CPJ), which can automatically compensate for the viscosity of the colloid to maintain a fixed amount of glue. It will also automatically measure the weight of each glue point and adjust the pressure to maintain the consistency of the glue amount for each component

Fully automatic solder paste printing machine
SMT Equipment Introduction - The fully automatic solder paste printer is a fully automatic model. After setting the relevant parameters, it can automatically feed in the board, align, print solder paste, and discharge the board. It can automatically optically correct the printing position. The printing accuracy is ±12.5. The two-stage waiting mode can reduce the machine's transportation time. It supports multiple printing demolding modes and can select the best printing conditions for different parts.

Nitrogen reflow soldering furnace
Professional SMT equipment - nitrogen reflow oven
Uniformly heated gas is provided to melt the solder paste, allowing electronic components to be connected to the circuit board. Compared with the common reflow oven, the nitrogen reflow oven can effectively reduce the bubbles at the solder joints and avoid thermal damage to power devices at a high-quality level.

Chip placement machine
SMT equipment application - A surface mount technology (SMT) placement machine is a device that accurately places electronic components on a PCB by moving the placement head. It can identify various types of component patterns and place components at high speed and high precision. It is divided into two sections, with each section consisting of two tables for CHIP processing. Each Table is equipped with 12 suction nozzles, capable of simultaneously processing 12 CHIP components.

Selective wave soldering
SMT product equipment - Selective wave soldering is used in through-hole mounting processes. By taking advantage of the easy movement of small nozzles, the PCB is fixed on the rack, and the nozzles are moved to bring the solder solution into contact with the solder pins of electronic components. The tin pot and tin pump system can move freely in the X/Y/Z axis directions, and the entire process can precisely control the tin eating position through the program.

Welding selection machine
High-quality SMT equipment - adjustable PCB positioning frame of the soldering machine, two tin POTS with independent Z-axis control, increase the flexibility of soldering, and two nozzles of different sizes can be used according to different solder joints.

Automatic soldering machine
The automated SMT equipment - the automatic soldering machine is an automated soldering device that can significantly save the time for replacing fixtures. During the soldering process, it can simultaneously position the products to be soldered. It is equipped with a soldering iron thermometer to measure the temperature and make corrections based on the actual temperature. It is also equipped with a built-in temperature check system. If the temperature is abnormal, it cannot act. Automatic pneumatic nozzles and roller brushes can also be used to clean the soldering iron tip.

Selective coating/dispensing system
Taiwan SMT equipment - Selective coating/dispensing system is used to precisely spray liquids and colloids onto the correct positions of products, providing a stable amount of adhesive for a wide range of PCBS, BGA, etc. The mechanical drive mechanism with XYZ repeatability accuracy of 25 microns can flexibly perform conformal coating and dispensing.