Instructions for purchasing PCB blind buried vias

by:A-TECH      2021-03-17
With the current development of portable product design in the direction of miniaturization and high density, PCB design becomes more and more difficult, and higher requirements are placed on the PCB production process. In most of the current portable products, the BGA package with a pitch of less than 0.65mm uses the blind and buried via design process. So what is the blind and buried via? Answer for you! Blind holes are mostly small holes with a diameter of 0.05mm~0.15mm. The buried blind holes are formed by laser hole formation, plasma etching and photo-induced hole formation. Usually laser hole formation is used, and laser hole formation is divided into CO2 and YAG Ultraviolet laser machine (UV). Blind vias (Blind vias / Laser Vias): Blind vias are vias that connect the inner traces of the PCB to the traces on the surface of the PCB. This hole does not penetrate the entire board. Buried vias: Buried vias are the type of vias that only connect the traces between the inner layers, so they are invisible from the surface of the PCB. The figure is a schematic diagram of the cross-sectional structure of an 8-layer board: A: through hole (L1-L8) B: buried hole (L2-L7) C: blind hole (L7-L8) D: blind hole (L1-L3) Note: The following examples all take 8-layer boards as examples. Blind buried vias, also known as HDI boards, are often used in high-end products such as mobile phones, GPS navigation, etc. The structure of conventional multilayer circuit boards contains inner layers. The circuit and the outer layer circuit, and then use the process of drilling and metallization in the hole to realize the connection function between the inner layers of the circuit. Next, let's learn about its precautions and maintenance. Matters needing attention If you want to copy the board of the blind buried via circuit board, the difficulty is relatively high. Generally, when copying the board on the mobile phone board and HDI board, you will encounter blind buried vias, so pay attention to the following items: 1. Be careful, do it before copying the board Good preparation; 2. The equipment must be advanced; 3. During the process of copying the board, it must be constantly compared with the original board; 4. Pay attention to the inspection and repeat the inspection many times. Blind and buried vias maintenance In order to ensure that the blind and buried vias are in good working condition and reduce the failure rate of the circuit boards, the circuit boards should be maintained, including annual maintenance and semi-maintenance. The maintenance methods are as follows: 1. Annual maintenance of blind and buried vias (1 ) Regularly check the capacity of the electrolytic capacitor in the circuit board. When it is found that the capacity of the electrolytic capacitor is less than 20% of the nominal capacity, it should be replaced in time; in general, the working life of the electrolytic capacitor is about 10 years, so to ensure the circuit board For normal work, all electrolytic capacitors should be replaced in about 10 years; (2) For high-power devices coated with heat-dissipating grease, check whether the heat-dissipating grease is dry or not, and remove the dry heat-dissipating grease if it is dry. After that, apply new heat-dissipating silicone grease to prevent the high-power components in the circuit board from being burnt out due to poor heat dissipation; (3) Clean the dust on the circuit board in time to ensure that the circuit board is clean. 2. Semi-maintenance for blind buried holes (1) Clean the dust on the circuit board quarterly, and use a special cleaning fluid for the circuit board. After cleaning the dust on the circuit board, use a blower to dry the circuit board; (2) ) Observe whether the electronic components in the circuit board have passed through high temperature traces, and whether the electrolytic capacitors have bulged and leaked, and they should be replaced if any. With the development of electronic products to high density and high precision, the same requirements are put forward for the blind and buried circuit boards. Of course, some matters must be paid attention to, and at the same time, it must be maintained to ensure the usability of the blind and buried circuit boards. From here to jump to the pricing page https://www./
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