PCBA Tech - Understand SMT, PCB, PCBA, DIP

1. SMT is called surface mount technology (or surface mount technology), which is divided into no leads or short leads. It is a circuit assembly technology that is soldered and assembled by reflow soldering or dip soldering. It is also the most popular in the electronics assembly industry. A kind of technology and craftsmanship.

SMT features: IPCB's substrate can be used for power supply, signal transmission, heat dissipation, and structure.

SMT characteristics: able to withstand the temperature and time of curing and soldering. The flatness meets the requirements of the manufacturing process. Suitable for rework work. Suitable for the manufacturing process of the substrate. Low dielectric count and high resistance. The commonly used materials for our product substrates are healthy and environmentally friendly epoxy resins and phenolic resins, which have good flame resistance, temperature characteristics, mechanical and dielectric properties and low cost. The above is that the rigid substrate is solidified. Our products also have flexible substrates, which are used to save space, fold or turn, and move. They are made of very thin insulating sheets and have good high-frequency performance. The disadvantage is that the assembly process is difficult and it is not suitable for fine pitch applications. I think the characteristics of the substrate are small leads and spacing, large thickness and area, better thermal conductivity, harder mechanical properties, and better stability. I think the mounting technology on the substrate is electrical performance, reliability, and standard parts. We not only have fully automatic and integrated operation, but also have the dual guarantee of manual review, machine review and manual review. IPCB's product qualification rate is as high as 99.98%.

2. PCB is one of the most important of electronic components. Generally, the conductive pattern made of printed circuits, printed components or a combination of the two on the insulating material according to a predetermined design is called a printed circuit. The conductive pattern that provides electrical connections between components on an insulating substrate is called a printed circuit board (or printed circuit board), which is an important support for electronic components and a carrier that can carry components. I think we usually open the computer keyboard to see a piece of soft film (flexible insulating substrate), printed with silver-white (silver paste) conductive patterns and healthy bit patterns. Because the general screen printing method obtains this kind of pattern, we call this kind of printed circuit board a flexible silver paste printed circuit board. The printed circuit boards on the various computer motherboards, graphics cards, network cards, modems, sound cards and household appliances that we saw in the Computer City were different. The substrate used in it is made of paper base (usually used for single-sided) or glass cloth base (usually used for double-sided and multilayer), pre-impregnated phenolic or epoxy resin, one or both sides of the surface layer are glued with copper-clad sheets and then laminated to cure Become. This kind of circuit board copper clad sheet material, we call it rigid board. And then make a printed circuit board, we call it a rigid printed circuit board. We call single-sided printed circuit boards with printed circuit patterns on one side, and printed circuit boards on both sides with printed circuit patterns on both sides. The printed circuit boards formed by double-sided interconnection through hole metallization are called double-sided boards. If one double-sided as the inner layer, two single-sided as the outer layer, or two double-sided as the inner layer and two single-sided as the outer layer of the printed circuit board, the positioning system and the insulating bonding material alternate together and The printed circuit board with the conductive pattern interconnected according to the design requirements becomes a four-layer or six-layer printed circuit board, also called a multilayer printed circuit board.

3. The whole process of PCB which goes through surface mount technology (SMT) and the insertion of DIP plug-in is called PCBA process. In fact, it is a PCB with a patch. One is a finished board and the other is a bare board. PCBA can be understood as a finished circuit board, that is, after all the processes of the circuit board are completed, it can be counted as PCBA. Due to the continuous miniaturization and refinement of electronic products, most of the current circuit boards are attached with etching resists (laminated or coated). After exposure and development, the circuit boards are made by etching. In the past, the knowledge of cleaning was not enough because the assembly density of PCBA was not high, and some believed that the flux residue was non-conductive, benign, and would not affect the electrical performance. Today's electronic assemblies tend to be miniaturized, even smaller devices, or smaller pitches. Pins and pads are getting closer and closer. Nowadays, the gap is getting smaller and smaller, and contaminants may get stuck in the gap. This means that relatively small particles may remain between the two gaps. An undesirable phenomenon that causes a short circuit. In recent years, the electronics assembly industry has become increasingly aware of and calling for cleaning, not only for products, but also for environmental requirements and the protection of human health. Therefore, there are many cleaning equipment suppliers and solution suppliers, and cleaning has become one of the main contents of technical exchanges and discussions in the electronics assembly industry.

4. DIP is called dual in-line packaging technology, which refers to the integrated circuit chip that is packaged in dual in-line form. This packaging form is also used in most small and medium-sized integrated circuits, and the number of pins generally does not exceed 100 . A CPU chip with DIP packaging technology has two rows of pins, which need to be inserted into a chip socket with a DIP structure. Of course, it can also be directly inserted into a circuit board with the same number of solder holes and geometric arrangement for soldering. DIP packaging technology should be especially careful when plugging and unplugging from the chip socket to avoid damage to the pins. The characteristics of DIP are: multilayer ceramic double in-line DIP, single-layer ceramic double in-line DIP, lead frame DIP (including glass ceramic sealing type, plastic encapsulation structure type, ceramic low-melting glass packaging type), etc. Wait. DIP plug-in is a link in the electronic manufacturing process. There are manual plug-ins and AI machine plug-ins. Insert the specified material into the specified position. The manual plug-in has to go through wave soldering to solder the electronic components on the board. For the inserted components, check whether they are inserted incorrectly or missing. DIP plug-in post-welding is a very important process in the processing of PCBA patch. Its processing quality directly affects the function of PCBA board, and its importance is very important. Then post welding is because some components cannot be welded by wave soldering machine according to the limitation of process and materials, but can only be done by hand. This also reflects the importance of DIP plug-ins in electronic components. Only by paying attention to details can it be perfect.

IPCB company provides SMT, PCB, PCBA, DIP one-stop service.