Technical
What are the advantages and applications of flexible microcircuits?
FPC Reinforcement Types
Criteria for Classification of electronic Component Classes
Four softwares suitable for beginners to draw PCB circuit boards
What information is needed for SMT processing?
What are the advantages of small and medium batch SMT processing?
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

Disassembly Skills of Chip Components on PCB

The chip components on PCB are new micro-miniature components with no leads or short leads. It is directly mounted on PCB and is a special device for SMT. Chip components has the advantages of small size, light weight, high installation density, high reliability, strong vibration resistance, good high-frequency characteristics, and strong anti-interference ability. At present, it has been widely used in computer equipment, mobile communication equipment, video camera, color TV tuner, VCD and other products, with rapid development.

Commonly used chip components are: (1) chip resistors (2) chip capacitors (3) chip inductors (4) chip diodes (5) chip transistors (6) chip small integrated circuits.

These chip components are very small in size and are fragile to heat and conflict. Some IC lead pins are many and difficult to disassemble, which brings great difficulties to maintenance. Therefore, scientific disassembly methods are very important. Common disassembly methods are as follows.


PCB IC repair


1. Dedicated soldering iron tip disassembly method
Purchase a dedicated "∏-shaped" soldering iron tip. The width and length of the notch of the "∏-shaped" head can be determined according to the size of the part to be disassembled. The special soldering iron tip can melt the solder of the lead pins on both sides of the disassembled part at the same time, so the disassembled components can be easily removed. It can also use a self-made soldering iron tip to disassemble.

Self-made method:
Choose a section of red copper tube whose inner diameter matches the outer diameter of the soldering iron tip, clamp one end flat with a vise or hammer flat, and drill small holes, as shown in Figure (a). Then use two red copper boards or red copper tubes to be longitudinally dissected, and flattened for machining into the same size as the length of the disassembled part, and drill small holes, as shown in Figure (b). Flatten the end face, polish it clean, and finally assemble it into the shape shown in figure (c) with bolts, cover it on the tip of the soldering iron, heat it and dip it in tin, and then set it aside.

For rectangular chip components with two solder joints, as long as the soldering iron tip is tapped into a flat shape so that the width of the end face is equal to the length of the component, the two solder joints can be heated and melted at the same time to remove the chip component.

2. Tin-absorbing copper mesh method
The tin-absorbing copper mesh is a mesh belt woven with fine copper wires. The fine copper wires can also be replaced by metal shielded wires or multi-strand flexible wires. When in use, cover the wires on the multiple pins, apply rosin alcohol flux, heat it with a soldering iron, and pull the wires, the solder on each pin will be absorbed by the wires. Cut off the wires that have been soldered, repeat it several times, and the solder on the pins will gradually decrease until the pins are separated from PCB.

3. Tin-melting cleaning method
When the multi-pin components are melted by heating the solder with an anti-static soldering iron, clean the solder with a toothbrush, oil painting brush, paint brush, etc., and the components can also be quickly disassembled. After the components are disassembled, the printed board should be cleaned in time to prevent residual tin from causing short circuits in other parts.

4. Lead pull and disassembly method
This method applies to the disassembly of chip-mounted integrated circuits. Use an enameled wire of appropriate thickness and certain strength to pass through the gap inside the pin of the integrated circuit, fix one end of the enameled wire at a certain position, and hold the other end by hand. When the solder melts, pull the enameled wire to "cut" the solder joints, and the integrated circuit pins are separated from PCB.

5. Solder suction device disassembly method
There are two types of solder suckers: ordinary solder suckers and electric soldering irons. 

When the ordinary solder sucker is in use, press down the piston rod of the solder sucker. When the soldering joint of the disassembled part is melted by the electric soldering iron, put the suction nozzle of the solder sucker close to the melting point, press the release button of the solder sucker, and suck away the molten tin at the time of the piston rod of the device bounces back. Repeat the operation several times, and the disassembled parts will be made to separate from PCB.

Tin-absorbing soldering iron is a special suction tool that assembles an ordinary solder sucker and an electric soldering iron, and its usage is the same as that of an ordinary solder sucker.

It should be noted that, it requires preventing static electricity in the process of local heating, and the power of the soldering iron and the size of the soldering iron tip should be appropriate.