pcb blog

Basic knowledge of PCB board making-FS Technology

PCB concept

PCB can be said to be common or uncommon in our lives. It is an important electronic component and a support for electronic components. All electronic products in our lives contain PCB boards. The full name of PCB is Printed Circuit Board, which is called "printed" circuit board because it is made by electronic printing.

The role and function of PCB in various electronic devices

1. Pad: Provide mechanical support for fixing and assembling various electronic components such as integrated circuits.​​

2. Wires: wires used to connect various electronic components, which can help circuit boards achieve wiring and electrical connection (signal transmission) or electrical insulation between components. Provide the required electrical characteristics.

3. Green oil and silk screen: Provide solder mask graphics for automatic assembly, and provide identification characters and graphics for component insertion, inspection, and maintenance.

Development history of PCB technology

Since the advent of PCB, if we look at the development of PCB assembly technology,FS TECHhas divided it into three stages

THT-Through Hole Technology Stage

The role of metallized holes:

(1). Electrical interconnection---signal transmission

Literally, the electrical appliances are directly connected or indirectly connected through transformers and the like

(2). Supporting components---pin size limits the reduction of through hole size

a. Rigidity of the pins

Pin, also called pin. It is the wiring from the internal circuit of the integrated circuit (chip) to the peripheral circuit, and all the pins constitute the interface of this chip. A segment of the end of the lead, which is formed by soldering to form a solder joint with the pad on the printed board. Pin can be divided into bottom, toe, side and other parts.

b. Requirements for automated instrumentation

There are three ways to increase density

(1) Under the regulations (aperture ≥ 0.8mm) to reduce the size of the device hole, why is there a regulation? This is because of the rigidity of the component Pin pins and the limitation of the insertion precision.

(2) Control line width/spacing: 0.3mm—0.2mm—0.15mm—0.1mm

(3) Increase the number of layers of the circuit board: the better the technology, the more layers can be added, FS technology can achieve all the layers, 64 layers - 12 layers - 10 layers - 8 layers - 4 layers - double-sided - single noodle,

SMT-Surface Mount Technology Stage PCB

1. The role of the via hole: it only plays the role of electrical interconnection, the aperture can be as small as possible, and the hole can also be plugged.

2. The main way to increase the density

①. The size of the via hole decreases sharply: 0.8mm—0.5mm—0.4mm—0.3mm—0.25mm

②. The structure of the via has undergone essential changes:

a. Advantages of buried blind hole structure: increase wiring density by more than 1/3, reduce PCB size or reduce the number of layers, improve reliability, improve characteristic impedance control, reduce crosstalk, noise or distortion (due to short lines, small holes )

b. Hole in pad eliminates relay holes and connections

③ Thinning: Double-sided: 1.6mm—1.0mm—0.8mm—0.5mm

④PCB flatness: