How to Judge the Acceptance of PCB Quality
Which Color Circuit Board Sells the Most Expensive
Method to Solve the Noise Interference of Power Supply on High-frequency PCB Board
Disassembly Skills of Chip Components on PCB
What Factors Should Be Considered in the Selection of High-frequency PCB CCL
How to Place Special Components during PCB Layout
What Are the Functions of Capacitors in Circuits?
Testing Techniques for Common Electronics Components
What to do if There is a Short Circuit on the PCB
Desoldering Principles and knowhow during PCBA Processing
Black Oxidation of the Inner Layer of the Multilayer PCB
How to Ensure the High-performance Design of PCB
What Is the Printing Process of SMT Solder Paste?
PCB without fiducial mark, Is There Any Way to do SMT for It
What Are the Benefits of Reserving Break-up Tab for PCB Production
How Does SMT Affect PCB Production Time and Speed It Up
Classification of PCBs from three aspects
Common Problems and Solutions for Dry Film pasting during PCB Manufacturing process
Several Elements to Inspect after PCB Design
What is a halogen-free circuit board?
What Do Capacitive Coupling and Decoupling Mean?
What Are the Differences Between PCB Paste Mask and Solder Mask?
How PCBA Is Packaged and Shipped
How long can PCBA finished products be stored?
What Are the Differences and Relations Between PCB, PCBA, and SMT?
PCB Baking Specifications
PCB "Solder Mask Tenting" and "Solder Mask Opening"
Five reasons for PCB deformation and six solutions
Importance of first article inspection of PCBA board
Temperature zone standard for SMT reflow soldering
Small and medium volume PCB manufacturers in China
The main reason for PCBA cleaning
For power filter, the more capacitors, the better?
What does PCBA programming mean?
Content of PCB incoming testing
What conditions must be met for PCB circuit board soldering?
What is Blind via and Buried via
PCBA Manufacturers Temperature and Humidity Sensitive Components Management
Why choose Shenzhen SMT processing factory?
How long does it take to calculate the quotation for PCBA manufacturing?
Introduction of PCB design clearance requirements
Explanation of BOM, DIP, SMT, SMD
Introduction of the process of PCBA prototype
How to prevent pseudo soldering or cold soldering defects in PCBA manufacturing?
Factors that affect the Price of FPCB
What information is required for SMT processing at PCBA factory?
Skills of using 0ohm resistor in PCB design
How to select a PCBA manufacturer
SMT processing solder joint quality inspection
Characteristics difference between immersion gold PCB and gold plating PCB
Common malfunctions of Circuit Board Caused by Moisture
A Few Rules about PCB Panelization
Compare of multi-layer PCB with single/double layer PCB
Why do we need to introduce so many subdivided GND
Difference between immersion gold boards and gold plating boards
Aluminum PCB structure
Classification of different GND in circuit
Why PCB baking is necessary during manufacturing process
The handle and precautions of OSP board in SMT process
How to choose capacitors for filter decoupling
How to choose filter capacitor for switching power supply
5 database need for SMT process
Function of three-terminal capacitor
Introduction of PCB OSP surface treatment
Method of inspecting the quality of SMT by step
How to find the short point between VCC and GND
Difference between 850nm and 940nm infrared LED
Component layout of PCB SMT DFM
Pad shape influence on the strength and reliability of the soldering joints
The difference between high temperature solder paste and low temperature solder paste
Introduction to manual welding processing
Manual visual inspection in PCBA processing
Characteristics of the conformal coating process
Difference between hardware engineers and software engineers
PCBA processing operation rules
China PCB upstream materials has continued to soar
Difference between serial buses and parallel buses
The key points of quality control in PCBA processing
Common causes of solder beading during SMT process
Analysis of the advantages and disadvantages of HASL PCB surface
Requirements for layout of components during SMT assembly
Selection of electronic components and CCL for PCBA
Performance and appearance quality inspection of components.
Quality and Reliability of SMT Chip Processing and Production
Coupling and decoupling function of capacitor
Two methods to connect digital ground and analog ground
Common sense in SMT process

The difference between high temperature solder paste and low temperature solder paste

Solder paste is one of the indispensable materials in the PCB soldering industry. Solder paste is divided into lead-free solder paste and leaded solder paste. There are high-temperature solder paste and low-temperature solder paste in lead-free solder paste. China SMT processing plant SYS Technology introduces the difference between high temperature solder paste and low temperature solder paste:

The melting point of common solder paste is 138° (low temperature) and 217° (high temperature). The low temperature is composed of tin and bismuth, and the high temperature is composed of tin, silver and copper. For LEDs products, we still recommended to use high-temperature lead-free solder paste, which has high reliability and is not easy to be cracked. There are also SMT chip manufacturers that use solder paste with a melting point of 183°, and the ratio of tin, silver, and copper is different from the melting point of 217°.

The melting point of pure tin is about 230°C. Generally speaking, the melting point of alloy (a mixture of two or more metals) is lower than that of elemental metal, and the melting point is different depending on the type and content of the alloy. The solder paste will be mixed with different additives according to different requirements to make different types of solder paste, so the melting point will also be different.

1. Composition: High temperature solder paste is generally composed of tin, silver, copper and other metal elements, while low temperature solder paste is composed of tin and bismuth.

2. Melting point: high temperature solder paste is composed of tin, silver and copper, low temperature is tin bismuth, low temperature melting point is 138, and high temperature melting point is 210-227.

3. The difference between reflow soldering: most of the low temperature solder paste is used in the second reflow of the double-sided reflow soldering process, because the if first reflow surface has larger components, and the same melting point is used for the second reflow, it is easy to cause the large devices on the first reflow surface (the second reflow is inverted) to be de-soldered or even fall off. Therefore, the low temperature solder paste is generally used for the second reflow, and when it reaches the melting point, the solder on the first reflow surface will not melt twice.

4. Application difference: after adding Bi to low temperature solder paste, its melting point temperature will be greatly reduced, and the composition of bismuth is also relatively brittle, generally only used for static products, normal application is for the LED field; high temperature solder paste has higher reliability and is not easy to de-solder and crack, the fields of application of will be more extensive.

5. Different formula maturity: The formula of high temperature solder paste is relatively more mature, with stable ingredients and moderate wettability, the formula of low temperature solder paste has lower maturity, unstable ingredients, easy to dry, and poor viscosity retention.