China PCB industry development under the changing situation
Printed circuit boards market developing in recent years
The recent status of Shenzhen PCBA SMT factory
Top 10 PCBA manufacturers in China
Taiwanese PCB output value creates the high record at first half year of 2021
China PCB industry reshuffle speeds up in 2021
What Is the Real Status of China PCB Industry?
Prototype and small volume PCB companies in China
Passive component prices increase under COVID-19 outbreaks in Malaysia and Philippines
Four major entry barriers in the PCB industry
History of PCB Development in China
China is still the SMT manufacturing center
New trend of the PCBA turnkey manufacturing market
Chinese CCL production capacity increase recent years
solution to the 32.768kHz crystal oscillator cannot oscillate
Challenge of energy conservation and environmental protection to the development of PCB
Limata's innovative LUVIR technology
Development prospect of LED plant lighting market
TPCA promotes PCB-ECI standardization
20H principle in PCB design
3W principle in PCB design
China's PCB output value will increase 2022
PCB equipment business prospects are promising
Automotive intelligence and electrification, PCB will obtain opportunity
Analysis of the reason why the pad is easy to fall off when the circuit board is soldered
Introduction to BGA Technology
What causes the print circuit board (PCB) trace open?
How to solve the problem of Rigid-Flex PCB expansion and shrinkage?
What will happen to the PCB industry in 2019?
2018 PCB Development Focus
PCBA circuit board Industry Recent Situation
2020 China SMT industry development situation
Evolution of THT plug-in process and SMT process
2015 PCB market grow slowly
Copper foil price rise 30% in few months
PCB factories facing upstream price rising
HDI and FPC growth fast in hot season
Japanese PCB industry consecutive 8months decline
AOI application in electronic manufacturing service
Parts placement precautions of double side reflow PCB
Analysis and improve of open defect in PCB
PCB panelization method
CCL and PCB price expected to increase
FPC new trend and application
Russia will Spurn AMD, Intel for Locally-Made Processors
Japan PCB industry 5months decline in 2016
Korean PCB industry in 2015&2016
Current challenges and opportunities of PCB chemicals
Taiwanese PCB industry grow slowly in 2016
HDI and FPC enable IoT
PCB factories are moving out from Shenzhen
Latest PCB industry China
High end PCB is popular in recent years
Nippon Mektron FPCB manufacturing supported Orbotech
Production capacity expanding raise PCB market concern
Choice for location of fiber glass factories
Fast development in East and South Asia PCB industry
Technical gap between Mainland China and Taiwan PCB industry
Deficiencies of small and medium China domestic PCB enterprises
Taiwan PCB enterprises into automotive PCB industry
Shenzhen to be the World’s PCB trading center
2015 Q3 Taiwan PCB production value released by TPCA
Moving in to inland regions, PCB industry pattern is changing in China
Challenge of PCB from Wearable electronics
Innovation in PCB manufacturing technology
Chinese PCB industry growth trend
2014 Global PCB output reach $60.2 Billion
Flexible PCB grow fast in Japan PCB industry
PCBA turnkey service is a New Trend in PCB manufacturers
Revolution SMT brings to Electronics
China Local PCB maker compete with Taiwan maker in HDI
Time to Build China PCB industrial Brand
Scanning the electromagnetic waves in printed circuit board
Develop trends in integrated circuit industry
PCB market growing in 2016
Impact of CNY Devaluation on China PCB industry
RF power Device market grow rapid in 2015
Advantage of SysPCB
HDI flexible pcb new trends in 2015
PCB Material Development
New material for flexible PCB
Express PCB Manufacturer
Taiwan PCB manufacturers expending, orders from China IT Company
Demands of mobile boards become weakness
PCB material supplier of high-frequency active layout of the front-end
ARLON high-frequency material
See through the design connotation of Aiptek’s pocket projector

Evolution of THT plug-in process and SMT process

Since the introduction of SMT production lines in 1985, China's SMT technology has been developed for more than 30 years. According to incomplete statistics, there are currently about 50,000 SMT production lines in China, and the total number of placement machines exceeds 100,000, accounting for 40% of the world. It is the world's largest and most important SMT market.


First. The characteristics of SMT process technology

The characteristics of SMT process technology can be compared with the traditional through-hole insertion technology (THT). From the perspective of assembly process technology, the fundamental difference between SMT and THT is "sticking" and "inserting." The difference between the two is also reflected in all aspects of the substrate, components, solder joint shape and assembly process method.


THT uses leaded components. The circuit connection wires and mounting holes are designed on the printed board. The component leads are inserted into the pre-drilled through holes on the PCB, and then temporarily fixed, wave soldering is used on the other side of PCB. The wave soldering technology performs welding to form reliable solder joints and establish long-term mechanical and electrical connections. The main components and solder joints of the components are respectively distributed on both sides of the PCB. With this method, since the components have leads, when the circuit is dense to a certain extent, the problem of reducing the volume cannot be solved. At the same time, the faults caused by the proximity of the leads and the interference caused by the lead length are also difficult to eliminate.


DIP package (DualIn-linePackage) is a part package in the THT plug-in process, also called dual in-line package technology, which is the simplest package method. Refers to integrated circuit chips packaged in dual in-line form. Most small and medium-sized integrated circuits use this form of packaging, and the number of pins generally does not exceed 100. The DIP packaged CPU chip has two rows of pins, which need to be inserted into the chip socket with the DIP structure.


On the traditional THT printed circuit board, the components and solder joints are located on each sides of the board; while on the SMT circuit board, the solder joints and components are on the same side of the board. Therefore, on the SMT printed circuit board, the through holes are only used to connect the wires PTH on both sides of the circuit board, the number of holes is much smaller, and the diameter of the holes is much smaller. In this way, the assembly density of the circuit board can be greatly improved.


Second, the evolution of THT plug-in technology and SMT technology

The surface mount technology (SMT) is developed from the traditional through hole insertion technology (THT), but it is different from the traditional THT. THT technology is the traditional electronic assembly process, wave soldering technology is generally used for the soldering of the through-hole plug-in component (THD) printed board assembly. However, wave soldering has many shortcomings: high-density, fine-pitch SMD components cannot be distributed on the soldering surface; bridging and missing soldering are easy to happen; flux spraying is required; printed boards are warped and deformed by greater thermal shock.


Due to the increasing density of current circuit assembly, high-density, fine-pitch SMD components will inevitably be distributed on the soldering surface. The traditional wave soldering process has been unable to do this. The soldering surface SMD components can only be reflowed firstly, And then manually solder the remaining plug-in solder joints, but there is a problem of poor solder joint quality consistency.


Third, the characteristics of SMT surface assembly technology

1. SMT finished PCBA, high assembly density, small size and light weight: The volume and weight of SMD components are only about 1/10 of that of traditional DIP through-hole insert components. After adopting SMT, the volume of electronic products is reduced by 40%~60%. 60%~80% weight reduction;

2. The PCBA quality performance of SMT welding is stable: the solder joints are firm and reliable, the anti-vibration ability is strong, and the solder joint defect rate is low;

PCBA soldered by SMT has stable electrical properties and low energy consumption: short parts and wiring, fast transmission and low energy consumption, reduced electromagnetic and radio frequency interference, with stable and reliable high-frequency characteristics;

3. SMT is easy to realize automation, improves production efficiency, saves materials, energy, equipment, manpower and time, and reduces costs by 30% to 50%.

Therefore, SMT will inevitably advance with the times, and it will continue to achieve rapid development for a long time in the future.