PCB board basic materials and classification knowledge
There are a variety of PCB substrates, circuit printing service and there are two main categories: organic and inorganic. The organic substrate is made of reinforced materials such as glass fiber cloth, also known as copper clad plate, and the inorganic substrate is mainly ceramic plate and ceramic coated steel substrate. Let Shenzhen PCB manufacturer explain PCB substrate and classification knowledge for you:
According to the rigidity and flexibility of the medium materials used in the production of the substrate, PCB fabrication company the PCB board can be divided into rigid circuit boards, flexible printed circuit boards and rigid and flexible combined circuit boards. Rigid circuit board refers to a printed circuit board made of copper foil pressed on the surface of a non-flexible substrate; It is required to be smooth, have a certain mechanical strength, and can play a supporting role. Flexible printed circuit board refers to a printed circuit board made of laminated copper foil on the surface of a flexible substrate; Good heat dissipation, ultra-thin, flexible, folding and winding, free to move and expand in three-dimensional space. Rigid flexible circuit board is a combination of rigid plate and flexible plate, mainly used for the electrical connection of rigid plate and flexible plate.
PCB board is divided into single panel, double panel and multi-layer board according to the number of copper-clad foil layers. A single panel is a printed circuit board with only one surface covered with a conductive pattern. Dual panels are printed circuit boards with conductive patterns on both sides of the insulating substrate. A multilayer board is a printed circuit board made of alternating layers of copper foil and an insulating substrate. The electrical interconnection between the layers is achieved through gaskets, perforations, blind holes and buried holes. Most of the multi-layer boards are 4-8 layer structures, and the current international highest level can reach nearly 100 layers.
Modern technology advances rapidly, and PCBS are constantly changing, china PCB but the estimate that remains unchanged in principle is the production process of PCBS. What are the production steps? The following Xiaobian will analyze it for you:
1. Print the circuit board.
Use transfer paper to draw a good circuit board printing information technology to develop, here we must pay attention to is that the slippery side to their own. Usually, two circuit boards can be printed on a piece of paper. The selection problem is that China, as an enterprise, needs to print the best one for the research, design and production of circuit boards.
2. Cut the copper clad plate
What is copper clad plate? The sides of the circuit board are covered with copper film. The photosensitive laminate was used to cut the copper-clad plate, and the circuit board diagram was made. Cut the copper-clad plate to the size of the circuit board, taking care not to cut too much and waste materials.
3. Pretreat the copper-clad plate
The oxidation layer on the surface of the copper clad plate needs to be polished with fine sandpaper to ensure that the carbon powder on the heat transfer paper can be firmly printed on the copper clad plate when the circuit board is transferred. (The polished surface should be bright without obvious stains).
4. Transfer circuit board
Cut the printed circuit board to the appropriate size, attach one side of the printed circuit board to the copper clad plate, align the copper clad plate into the heat transfer machine. Generally transfer printing 2-3 times, the circuit board can be strongly transferred and printed on the copper-clad plate. Tips: The heat transfer machine needs to be preheated, the temperature is set at 160-200 degrees Celsius, because the temperature is very high, so pay attention to safety when operating!
5. Corrode circuit boards and reflow furnaces.
First of all, our country needs students to check the results of their own analysis to understand whether the circuit board design method is complete. If it is found that there is a Chinese minority enterprise development without good transfer printing, the local people's government can use some black oil pens to learn self-repair, and then conduct management research on corrosion. When the exposed copper film on the circuit board is completely corroded away, the circuit board is removed from the corrosive liquid to clean the data, and a circuit board is corroded in this way.
Composition of corrosion solution: concentrated hydrochloric acid: concentrated hydrogen peroxide: water = 1:2:3, when preparing corrosion solution, first use water, then add concentrated hydrochloric acid, concentrated hydrogen peroxide, concentrated hydrogen peroxide, concentrated hydrogen peroxide, if the operation of concentrated hydrochloric acid, concentrated hydrogen peroxide or corrosion solution splashed on the skin or clothes, clean in time with water, due to the use of strong corrosive solution, must pay attention to safety during operation!
6. Drill holes for the circuit board
Electronic components need to be inserted into the circuit board, so you need to drill holes in the circuit board. The choice of drill pin is determined by the thickness of the electronic component pin. When drilling the drill, be sure to hold the circuit board tightly, maintain the speed of the drill, and do not drive too slowly.
7. Circuit board pretreatment
The final step (drilling) requires the PCB to be pre-treated by wiping the ink off the printed board with fine sandpaper and then cleaning the PCB with water. After the water dries on the circuit board, apply the rosin water on one side of the circuit board, and the solidification of the rosin on the circuit board can be accelerated with hot air, which can be set in only 2-3 minutes. 8. Solder the electronics. This is the last step. All electronic components are welded to the circuit board and energized. So far, the production process of the PCB board has been completed.
Related Hot Topic
What are the two printing techniques?
Here are some examples of the most popular and often used kind:Off-set lithography; flexible lithography.Digital printing. Large-format printing. Printing on a screen.using 3D printing.LED UV.