PCBA Tech - About PCB copper coating process and SMT chip material

Advantages of PCB Copper Cladding Process

Copper-clad has a very important position in the PCB production process. Sometimes the success or failure of copper-clad is related to the quality of the entire board. The so-called copper coating is to fill the empty space of the PCB substrate with solid copper.

There are two methods of copper coating: large area copper coating and grid copper coating. Large area copper coating increases current and shielding. However, if wave soldering is used, the board may lift up and even blisters. Grid copper can reduce the heating surface of copper, and play a role in electromagnetic shielding to a certain extent. However, the grid is composed of traces, and if the width of traces is not appropriate, interference signals will be generated.

Advantages of PCB Copper Cladding Process

Copper coating in SMT chip processing has many benefits for PCB, such as improving noise immunity, reducing potential difference, reducing ground impedance, improving anti-interference ability, reducing voltage drop, improving power efficiency, and connecting to ground to reduce Loop area, heat dissipation, and impedance reduction. There are many advantages of copper clad PCB board. When operating, you should pay attention to the following matters:

1. If the PCB has many grounds, such as SGND, AGND, GND, etc., the most important "ground" should be used as a reference for independent copper pour.

2. The crystal oscillator in the circuit is a high-frequency emission source. The copper-clad nearby surrounds the crystal oscillator, and then the shell of the crystal oscillator is grounded separately.

3. Don't have sharp corners, that is, an angle greater than 180°, otherwise it will form a transmitting antenna.

Patch materials in SMT patch processing

In the process of electronic product patch processing, there are many factors that affect product quality, such as patch processing equipment, technology, technology and PCB board design that we often know, and the selection of patch processing materials also has a great impact on product quality . Choosing the right substrate material can effectively improve product performance and ensure product quality. So what are the patch materials in patch processing? Let's learn about it with Jingbang Technology.

There are two main types of patch materials in patch processing. One is organic patch materials represented by metal-based patches; the other is inorganic patch materials represented by ceramic patches and porcelain shaft-coated copper patches. .

1. Metal patch: use 0.3mm-2.Omm thick metal plate, such as aluminum plate, steel plate, copper plate, epoxy prepreg and copper foil. The metal plate can realize large-area patch processing, and has the following performance characteristics:

(1) Good mechanical properties: The metal-based patch has high mechanical strength and toughness, which is better than rigid material patches, can be used for large-area patch processing, and can undertake the installation of overweight components. In addition, the metal-based patch The patch also has high dimensional stability and flatness.

(2) Good heat dissipation performance: Since the metal patch is in direct contact with the prepreg, it has excellent heat dissipation performance. The metal patch is used for patch processing. The metal patch can play a role in heat dissipation during processing. The heat dissipation capacity depends on the material and thickness of the metal patch and the thickness of the resin layer. Of course, while considering heat dissipation performance, electrical performance, such as electrical strength, etc., should also be considered.

(3) Capable of shielding electromagnetic waves: In high-frequency electronic circuits, preventing the radiation of electromagnetic waves has always been a matter of concern to designers. The use of metal-based patches can act as a shielding plate to shield electromagnetic waves.

2. Electronic functional ceramic materials: Electronic functional ceramics are one of the basic materials of microelectronic devices and have the following advantages:

(1) New packaging materials for large-scale integrated circuits and new high-performance insulating ceramics for high-frequency insulation;

(2) It can replace imported new microwave ceramics and dielectric ceramics and ferroelectric ceramics for ceramic capacitors;

(3) Special electronic ceramic materials and products for high-performance chip components for large-scale integrated circuits.

There are many types of patch materials in SMT patch processing, each with its own advantages. It is necessary to select the appropriate patch material according to the actual use and processing conditions to ensure the final product molding quality.