PCB News - Understanding of core components in PCBA processing

Understanding of core components in PCBA processing
In PCBA processing, we need to have an understanding of PCB circuit boards and be familiar with the smt placement process; but there are many core components in addition. For example: chip, which is used as the core component of the circuit board. In the past few years, the topic of chips has been relatively hot. The following will mainly talk about the chips in the core devices in PCBA processing. Please see below.
1. Packaging materials

1. Metal packaging: As the name suggests, metal packaging is made of metal in the use of materials. Because metal has better ductility and is easy to stamp, the packaging has high precision, and the size is convenient for strict cutting, and it is more beneficial to the regularity of the size. It can be used in mass production, and the price is relatively low because of the convenience of production.

2. Ceramic packaging: ceramic materials have very high anti-corrosion, moisture-proof, and anti-oxidation characteristics, and excellent electrical properties. This kind of packaging is more suitable for harsh working conditions and high-density packaging materials.

3. Metal-ceramic package: Because the package has both the excellent characteristics of metal and the advantages of ceramic-based materials, it is top grade in terms of overall performance.

4. Plastic encapsulation: The plastic substrate itself is low in price and strong in plasticity, so the production process is simple, which can meet the special requirements of mass production.

2. How to load the chip

Bare chips, we often see in the process instructions in the smt chip processing plant, can be divided into formal mounting and flip mounting. So what is formal and flip? That is, when the chip is loaded, the one with the wiring side facing up is a positive chip, and vice versa is a flip chip.

Three, the type of substrate of the chip

The substrate is the basis of the chip and is used to carry and fix the bare chip. The substrate must have the functions of insulation, heat conduction, isolation and protection, and in its main function, it is a bridge between the internal and external circuits of the chip.

1. Materials: Divided into organic materials and inorganic materials;

2. Structure: single-layer, double-layer, multi-layer and composite 4 types.

Four, package ratio

To evaluate the pros and cons of integrated circuit packaging technology, an important indicator is the packaging ratio, namely

Package ratio = chip area ÷ package area

The closer this ratio is to 1, the better. The chip area is generally small, and the package area is limited by the lead pitch, which makes it difficult to further shrink.

The packaging technology of integrated circuits has undergone several generations of changes. From SOP, QFP, PGA and CSP to MCM, the packaging ratio of the chip is getting closer and closer to 1, the number of pins has increased, the pin spacing has been reduced, and the weight of the chip has decreased. Power consumption is reduced, technical indicators, operating frequency, temperature performance, reliability and practicability have all made great progress.

From the above analysis from the chip packaging materials, loading methods, substrate types, and packaging ratios, we must have a deeper understanding of the chips and learn a lot of chip knowledge. Nowadays, many chips in SMT processing are directly obtained from the supplier, and the main structure knowledge of the chip is not involved; however, many customers ask questions about the chip, so this article gives you the help of the understanding of the core components in PCBA processing. Everyone share some, thank you.