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
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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
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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

Component layout of PCB SMT DFM

I. Component layout of SMT/PCB
1. When the circuit board is placed on the conveyor belt of the reflow soldering furnace, the transmission direction of the equipment should be at a vertical angle to the long axis of the components, which can prevent the components from drifting or "tombstones" on the board during the reflow soldering process.

2. The components on the PCB should be evenly distributed, especially the high-power components should be dispersed, to avoid local overheating on the PCB when the circuit is working, which will affect the reliability of the solder joints.

3. For double-sided mounting components, the larger components on both sides should be installed in dispersed positions, otherwise the welding effect will be affected due to the increase of local heat capacity during the welding process.

4, PLCC/QFP and other components with pins on outsides cannot be placed on the wave soldering surface side.

5. The long axis of the large device mounted on the wave soldering surface should be parallel to the direction of solder wave flow, so as to reduce the solder bridging between the component leads.

6. The large and small SMT components on the wave soldering surface should not be lined up in a straight line and should be staggered to prevent pseudo soldering and missing soldering caused by the "shadow" effect of the solder wave during soldering.

II. The pads on the SMT/PCB
1. For SMT components on the wave soldering surface, the pads of larger components (such as transistors, sockets, etc.) should be appropriately enlarged. For example, the pads of SOT23 can be lengthened by 0.8-1mm, which can avoid the "shadow effect" due to component, which will result in empty welding.

2. The size of the pad should be determined according to the size of the component. The width of the pad is equal to or slightly larger than the width of the electrode of the component, the welding effect is the best.

3. Between two interconnected components, avoid using a single large pad, because the solder on the large pad will drag the two components to the middle. The correct way is to separate the pads of the two components, Use a wire to connect between the two pads. If the wire is required to pass a larger current, several wires can be connected in parallel, and the wires are covered with soldermask.

4. There should be no through holes on or near the pads of SMT components, otherwise during the reflow process, after melting the solder on the pads will flow along the through holes, resulting in pseudo soldering, insufficient tin, or flow to the other side of the board and cause a short circuit.