altium single layer pcb
2023-01-04 15:53:08 altium single layer pcb 318 Viewed
The general aluminum PCB is altium single layer PCB, which is a kind of PCB board. Altium single layer PCB has good thermal conductivity and is used in the LED industry. At present, the most commonly used LED altium single layer PCB has two sides, the white side is for soldering the LED pins, and the other side shows the natural color of aluminum, which is usually applied to the heat-conducting part after applying the heat-conducting paste.
Altium single layer PCB is a metal-based copper clad laminate with good heat dissipation function. Generally, an altium single layer PCB consists of three layers, which are the circuit layer (copper foil), the insulating layer and the metal base layer. For high-end use, it is also designed as a double-sided board, and the structure is a circuit layer, an insulating layer, an aluminum base, an insulating layer, and a circuit layer. Very few applications are multilayer boards, which can be made by laminating ordinary multilayer boards with insulating layers and aluminum substrates.
The PCB boards we talk about the most are generally copper-based PCBs, which are also divided into single-layer boards and multi-layer boards according to the number of layers. Compared with altium single layer PCBs, copper-based PCBs have relatively special materials and better heat dissipation. Relatively better, so it will be relatively more expensive in terms of PCB price. What needs to be explained here is that the altium single layer PCB cannot make holes. So you can easily see whether the board is an altium single layer PCB through the finished PCB!
Altium single layer PCB is a metal-based copper-clad laminate with good heat dissipation function, and there are currently ceramic PCBs and so on.
Function of Altium Single Layer PCB
(1) Heat dissipation
At present, many double-sided boards and multi-layer boards have high density and high power, and it is difficult to dissipate heat. Conventional PCB substrates such as FR4 and CEM3 are poor conductors of heat, and the interlayer insulation prevents heat from being dissipated. Local heating of electronic equipment cannot be ruled out, leading to high temperature failure of electronic components, and altium single layer PCB can solve this heat dissipation problem.
(2) Thermal expansion
Expansion with heat and contraction with cold is a common nature of matter, and the coefficients of thermal expansion of different materials are different. Altium single layer PCB can effectively solve the problem of heat dissipation, so that the problem of thermal expansion and cold contraction of different materials of components on the altium single layer PCB can be alleviated, and the durability and reliability of the whole machine and electronic equipment can be improved. Especially to solve the problem of thermal expansion and contraction of SMT (Surface Mount Technology).
(3) Dimensional stability
The size of Altium single layer PCB is much more stable than the printed board of insulating material. Altium single layer PCB, aluminum sandwich panel, heated from 30°C to 140~150°C, the size change is 2.5~3.0%.
(4) Other reasons
Altium single layer PCB has a shielding effect; replaces brittle ceramic substrates; uses surface mount technology; reduces the real effective area of printed boards; replaces components such as radiators, improves heat resistance and physical properties of altium single layer PCB products; reduces production cost and labor.
Structure of Altium Single Layer PCB
(1) Metal substrate
Altium single layer PCB base material, use LF, L4M, Ly12 aluminum, requires expansion strength of 30kgf/mm2, elongation 5%. Aluminum base thickness is 1.0~3.2mm.
(2) Insulation layer
Altium single layer PCB acts as insulation, usually 50~200um. If it is too thick, it can play an insulating role, and the effect of preventing short circuit with the metal base is good, but it will affect the heat dissipation; if it is too thin, it can dissipate heat better, and it is easy to cause a short circuit between the metal core and the component lead. The insulating layer (or prepreg) is placed on the altium single layer PCB that has been anodized and insulated, and the copper layer on the surface is firmly bonded together by lamination.
Altium Single Layer PCB Production
(1) Oxidation treatment of Altium single layer PCB: strong degreasing and cleaning (sodium hydroxide)-neutralization with dilute nitric acid-roughening (altium single layer PCB surface forms a honeycomb shape)-oxidation ( 3UM )-acid-base neutralization-sealing-baking. Every process must ensure the quality, otherwise it will affect the adhesion of altium single layer PCB.
(2) The entire production process of Altium single layer PCB is not allowed to scratch the aluminum base surface, touch the aluminum base with hands, get wet or any other pollution, otherwise the adhesion of the altium single layer PCB will be affected.
(3) The insulating layer of Altium single layer PCB must be kept clean and dry, as fine impurities affect its withstand voltage performance, and moisture can easily cause delamination.
(4) The protective film should be pasted flat without gaps or air bubbles, otherwise the altium single layer PCB will be corroded, discolored and blackened by the potion during altium single layer PCB processing.
Altium Single Layer PCB Circuit Production
1. Machining: Altium single layer PCB can be drilled, but no burrs are allowed on the edge of the hole after drilling, which will affect the withstand voltage test; milling the shape is very difficult; and punching the shape requires the use of advanced molds and molds. The production is very skillful, as one of the difficulties of altium single layer PCB; after the shape is punched, the edges are required to be very neat, without any burrs, and not to damage the solder mask on the edge of the board.
2. The entire altium single layer PCB production process is not allowed to scratch the aluminum base surface: the aluminum base surface will be discolored and blackened after being touched by hands, or exposed to certain chemicals. This is absolutely unacceptable, so the whole process is not acceptable. One of the difficulties in the production of altium single layer PCB is to bruise and not touch the aluminum substrate.
3. Over-voltage test: communication power altium single layer PCB requires 100% high-voltage test, some customers require direct current, some require alternating current. The voltage requirements are 1500V, 1600V, the time is 5 seconds, 10 seconds, 100% of the altium single layer PCB Test; dirt on the board surface of the altium single layer PCB, burrs on the edges of holes and aluminum substrates, sawtooth lines, bruises at any point, and the insulating layer of the altium single layer PCB will cause fire in the high voltage test.
Altium Single Layer PCB Technical Requirements
Dimensional requirements, including altium single layer PCB board size and deviation, thickness and deviation, verticality and warpage; appearance, including cracks, scratches, burrs and delamination, aluminum oxide film, etc.;
In terms of function, it includes the requirements for peel strength, surface resistivity, minimum breakdown voltage, dielectric constant, flammability and thermal resistance of altium single layer PCB.
Compared with the traditional FR4, the altium single layer PCB can minimize the thermal resistance, so that the altium single layer PCB has excellent thermal conductivity; compared with the thick film ceramic circuit, the mechanical properties of the altium single layer PCB are extremely excellent. In addition, altium single layer PCB has the following unique advantages: Compliant with RoHs requirements; more suitable for the SMT process;
In the circuit design scheme, heat dissipation is handled extremely effectively, thereby reducing the operating temperature of the module, prolonging the service life, improving power density and reliability; reducing the assembly of heat sinks and other hardware (including thermal interface materials), and shrinking the altium single layer PCB. The product volume of PCB reduces hardware and assembly costs; optimizes the combination of power circuits and control circuits; replaces fragile ceramic PCB boards to obtain better mechanical durability.