sales@ipcb.com
Common PCB board thickness include:According to the standards of the International Electronics Commission (IPC), common pcb board thickness include 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm (the most common pcb board thickness, suitable for most applications),2.0mm, 2.4mm, 3.0mm, 3.2mm, 3.5mm, 4.0mm, 6.4mm. Among them, the thickness of 1.6mm is regarded as a balance point in most cases, which can meet most application requirements and have good stability and reliability.
I. Setting PCB board thickness
Application scenarios:
For devices with small product size and low power consumption requirements, 0.4mm or 0.6mm thin boards can be selected.
For devices with high power consumption, 1.6mm or thicker boards should be selected to provide better mechanical support and heat dissipation performance.
2. Setting the thickness of each layer of PCB
Stacking structure design: The stacking structure design of PCB should follow the principle of symmetry, including the symmetry of dielectric layer, copper foil thickness and graphic distribution. This helps to ensure the overall performance and stability of the circuit board.
As the number of layers increases, the complexity of signal transmission increases, and the appropriate copper foil thickness helps to ensure signal quality.
In some high-power density electronic products, such as power amplifiers, inverters, etc., it may be necessary to take into account the heat dissipation requirements by reasonably selecting the copper foil thickness of the inner and outer layers.
Adjustment and setting:
In design software (such as Altium Designer), the pcb board thickness information of each layer can be viewed and adjusted through the "Layer Stack Manager".
When adjusting, it is necessary to note that the sum of the thickness of each layer will determine the final board thickness.
After determining the stacking structure of the PCB board, the process capability parameters such as copper foil thickness, prepreg specifications, etc. should be obtained from the PCB manufacturer. These parameters will affect the board thickness setting and the final PCB performance.
3. Dielectric layer thickness:
It is recommended that the dielectric layer thickness is not less than 0.1mm to prevent voltage breakdown.
The thickness of the inner layer board (such as 1~4 layers) can be selected as 0.1mm.
pcb board thickness
Copper foil thickness:
The copper foil thickness affects the line width and line spacing. The inner layer copper thickness is usually greater than or equal to 0.5oz (ounce). The finished copper thickness is generally equal to the thickness of the base copper, and the surface finished copper thickness is equal to the thickness of the base copper plus 0.5oz.
PCB board thickness of copper is generally divided into 1oz (35μm), 2oz (70μm) and 3oz (105μm). Of course, the pcb board thickness of the copper depends on the type of board you make. The copper thickness of the power supply with high current switching is 2oz. For signal transmission, usually, a thickness of 1oz is sufficient. Here are the details. Ordinary double-sided boards are 1 ounce.
• The inner layer of the multi-layer board is generally 1/2oz, 1/3oz, and the outer layer is 1oz, 1/2oz, and 1/3oz.
• The copper thickness of the power board is higher.
70% of the circuit boards use 35μm copper foil thickness, which mainly depends on the purpose of the PCB and the size of the signal voltage and current. In addition, for PCBs that require excessive current, some parts will use 70μm copper thickness and 105μm copper thickness. Pay attention to foils that improve yield; at the same time, avoid core boards with different thickness copper foils on both sides of the inner layer.
In addition, there is 12μm for ultra-high density patterns, such as build boards for thin boards, and 105μm for high current patterns for thick boards. Thicker copper foil is also used for circuit boards that carry large currents.
There are standards such as JIS, JPCA, IPC, UL, etc. for printed circuit boards, and the materials and pcb board thickness vary according to the standards. PCB thickness is not only the thickness of the board itself, but also the thickness of the copper foil part, the thickness of the plating part, etc. It varies depending on the material of the printed circuit board.
Other factors affecting PCB board thickness:
PCB core thickness:
The substrate, also known as the dielectric or core, is an insulating material that separates two conductor layers. The core is a copper-clad material that hardly changes its thickness during the manufacturing process of the circuit board.
Therefore, in a two-layer printed circuit, there will be a center substrate in the middle of the two copper layers, usually called TOP and BOTTOM.
The standard thickness of the substrate is 1.6 mm for two-layer circuits and 4/6-layer multilayer circuits. However, in general, the more layers there are, the thicker the printed circuit board is, due to the minimum thickness of the layer.
Note:
Because of mechanical reasons or characteristic impedance, thicker (e.g. 3.2 mm) or smaller (e.g. 0.2 mm) thickness may be required.
Prepreg thickness:In the layer structure of a printed circuit board, there are always 2 to 3 prepregs (resin-filled glass fiber fabrics) and their copper cladding between 2 cores, which are pressed together with the core material.
Unlike the core material, the prepreg changes its effective thickness during the pressing process. Therefore, the pcb board thickness depends on the pcb manufacturer, its process settings, and the ratio of copper coverage area to open space.
pcb board thickness
PP sheet and core board
Prepreg is a thin sheet insulation material for PCB. Prepreg is not a semi-cured sheet before being laminated, also known as prepreg material, which is mainly used as a bonding material and insulation material for the inner layer conductive pattern of a multilayer printed circuit board. After the Prepreg is laminated, the semi-cured epoxy resin is squeezed open, begins to flow and solidify, bonding the multi-layer circuit board together and forming a reliable insulator.
The core in the above figure is the basic material for making printed circuit boards. Core, also known as the core board, has a certain hardness and thickness, and is copper-clad on both sides. Therefore, the multi-layer board is actually made by laminating the Core and Prepreg.
Inner layer PCB board thickness:
In addition to the order of layers, the real customization of the stacking also includes the definition of the internal PCB thickness. In particular, the vertical distance between the floors where the copper tracks are placed. It is important to clarify right away that there is no complete freedom in the internal thickness value. Because in reality, these thicknesses are the result of a specific construction order of the printed circuit. In a sense, to get a certain thickness configuration, you have to build it in a certain structure.
After reading this introduction, you are right have a good understanding of pcb board thickness.