Technical
PCB related knowledge- The purpose of each layer of the PCB
How to do heat resistance testing for PCB board
Detailed explanation of rigid-flex board and IC carrier board
PCBA prototype procedure
Defects which can be detected by the SPI
What are the spacing requirements for designing PCB circuit boards?
What are the classification and advantages of PCB metal substrates?
Difference between the processing technology of 1Layer AL PCB and 2Layer AL PCB
Introduction of FPC Cable and its usage
advantages of Shenzhen SMT assembly factory
inspection items before PCB ordering
usages of ceramic substrates
main applications of PCB boards
Cost-effective PCB product services
How to check short circuit of a circuit board during manual soldering
Identify the polarity of electronic components during PCBA processing
Means Which Can Prevent Component Shifting in SMT Processing
Skills of PCB prototype manual soldering
Reasons for the shift of Components in the SMT Process
Seven Types of PCB Probes
What Should Be Paid Attention to in Layout of High-frequency PCB
Precautions for PCB CCL Selection
Advantages of LED Plant growth light
Advantages of using LED grow lights to grow industrial hemp
Detailed explanation of PCB manufacturing process and precautions
Detailed explanation of PCB manufacturing process and precautions
How to draw multilayer PCB on Altium Designer
Three basic elements of interference and how to suppression them.
Decrease interference between digital circuit and analog circuit
SMT Component Placement Process Of Parts : Manual Placement
SMT factory incoming PCB material inspection
Basic concepts commonly used in PCB design
Ideas and principles of High speed PCB layout
Component layout rules and safety distance considerations
SMT assembly process quality specification
5 points in PCB layout
Professional interpretation of SMT
Advantages and disadvantages of different PCB surface treatment
Special process in PCB prototype
Why the via hole become open after component assembly
Keep the cost of the PCB as low as possible
what are the causes of PCB board heating radiation problem
Pad size and via diameter dimensions consideration in PCB prototyping
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?

How to prevent pseudo soldering or cold soldering defects in PCBA manufacturing?

PCBA manufacturing processing mainly refers to the soldering the PCB circuit board and the components through the soldering process. Soldering defects such as pseudo soldering or cold soldering are prone to occur during the soldering process. And pseudo soldering or cold soldering will seriously affect the reliability of the product and greatly increase the maintenance cost of the product.

The problem of pseudo soldering and cold soldering defects in PCBA soldering processing is caused by many reasons, mainly because the solder can not fully wet the pads and components pins, and the components and circuit board pads cannot be fully soldered. In the PCBA production process, specific prevention can be done in the following ways.

1. Moisture-proof storage of components
If the components are exposed in the air for too long, which will cause the components to absorb moisture and oxidize the components, as a result, the oxide cannot be fully removed from the components during the soldering process, resulting in the defects of pseudo soldering. Therefore, during the soldering process, the components with moisture should be baked, and the oxidized components should be replaced. Generally, the PCBA processing plant will be equipped with an oven to bake the components absorbed moisture.

2. Choose solder paste from well-known brands
The pseudo soldering and cold soldering defects that appear in the PCBA soldering process have a great relationship with the quality of the solder paste. The unreasonable configuration of the tin alloy composition and flux composition can easily lead to weak flux activating during the soldering process, and the solder paste cannot fully wet the pad, resulting in pseudo soldering and cold soldering defects. Therefore, you can choose solder paste from well-known brands such as SMIC, Alpha, and Vital.

3. Adjust printing parameters
The problem of pseudo soldering and cold soldering is largely due to the lack of tin. In the printing process, adjust the pressure of squeegee, select the appropriate stencil can reduce such defects, and the stencil opening should not be too small to avoid too little tin.

4. Adjust the reflow soldering temperature curve
During the reflow soldering process, it is necessary to control the soldering time. If the time in the preheating zone is not enough to fully activate the flux and remove the surface oxides on the soldering area or the time in the soldering zone is too long or too short, it will cause pseudo soldering and cold soldering.

5. Try to use as many as reflow soldering and reduce manual soldering
Generally, when using an electric soldering iron for manual soldering, the technical requirements of the soldering personnel are relatively high. If the temperature of the soldering iron tip is too high or too low, or the soldered components become loose during soldering, which can easily cause pseudo soldering and cold soldering. Use reflow soldering can reduce external factors caused by human and improve the quality of soldering.

6. Avoid too high or low temperature of the electric soldering iron
In the manual soldering processing and repair soldering of PCBA, improper operation will lead to the temperature of the soldering iron tip to be too high or too low when using an electric soldering iron, which will easily result in pseudo soldering and cold soldering. Therefore, when soldering, keep the soldering iron tip clean, select different output power electric soldering irons according to the size of different parts and solder joints, and components shapes, and control the soldering temperature between 300°C and 360°C.

The pseudo soldering and cold soldering caused in the PCBA soldering process are caused by many factors. The above is just a list of some relatively common reasons. Through the above preventive measures, combined with the actual situation, the pseudo soldering and cold soldering defects can be effectively reduced.