What is a mcpcb? Pros and Cons 0f Metal core board 20222022-02-04
What is a mcpcb? PCB has succeeded in meeting the need for electronics that can fit components in the smallest range. PCBs are an extremely versatile and essential part of everyday life. So what do you know about electronic circuit board PCB? Today we will share with you the most basic knowledge about this printed circuit board!
Among all metal core PCBs, metal core PCBs are the most common. Base materials include metal core core and standard FR4. It features a heatsink housing that effectively dissipates heat to cool components and increase overall product performance. Currently, metal core printed circuits are considered the solution for high capacity and tight tolerance applications.
If you need to process metal core PCB, please contact Future Electronics for advice and support:
Advantages of metal core PCB
Environmentally friendly: Metal core is non-toxic and recyclable. What is a mcpcb? Metal core production is also beneficial for energy savings due to ease of assembly. For printed circuit suppliers, the use of this metal helps protect the environment.
Heat dissipation: High temperatures can cause severe damage to electronic devices, so you should use materials that can help dissipate heat. Metal core can transfer heat away from critical components, thereby minimizing the damage it can cause to the board.
PCBs use guides, backing pads and other similar features etched onto copper plate and coated onto a non-conductive surface. Capacitors, resistors and other components are soldered on the PCB if appropriate
Mounting holes on mcpcb
What is a mcpcb? First of all, it is necessary to correctly lay the diameters of the mounting holes. It is necessary to pay attention to the tolerances that are provided for in accordance with gost for plated holes with reflow (POS, HAL, hot tinning).
As a rule, they are all “minus” and very significant. For non-reflow plating (immersion tin, immersion gold, tin-cobalt) these tolerances are slightly less.
Plated and non-plated holes
For plated holes, it is obligatory to have pads on top and bottom. In the inner layers of metal core pcb board, it is allowed to remove areas to which there is no connection. But we can do these ourselves when preparing the board for production.
- For non-plated holes
- Mounting holes
Separately, it is worth stopping at the mounting holes.
What is a mcpcb? Due to the fact that it is almost impossible for us to unambiguously distinguish mounting holes without plating (with a plus or minus tolerance) from mounting holes (with only a plus or minus tolerance). It is necessary either to specify these mounting holes, or to the PCB designer lay an enlarged hole. The manufacturer considers it a normal mounting hole without plating.
Blind vias on metal core pcb board
Blind vias (blind via) – metallized holes of a multilayer printed circuit board , having access to only one side of the printed circuit board , i.e. from the outer layer to any inner.
A feature of such holes is the restriction on the minimum diameter – it cannot be less than the drilling depth. This is due to the closed space of the “glass” and the corresponding difficulties in metallization of such holes.
What is a mcpcb? Don’t use Complex padstacks unless absolutely necessary? In PCAD-200x (possibly in other CAD systems) there is such a feature. For complex padstacks, it is possible to describe which layers the hole passes through. Accordingly, it will be output to the drilling file for the corresponding layers.
In order for the hole to appear in the drilling file, the hole between the layers must be present in the description of the complex site.
Finishing coating of printed circuit boards
To preserve the solderability of printed circuit boards, ensure the flatness of the coating and for reliable mounting of electronic components and solder joints, it is necessary to protect the copper surface of the printed circuit board pads, the so-called finish metal protective coating.
We offer you an optimal list of finishing coatings, which will allow you to choose one or two, in extreme cases, three options that meet all the requirements for cost, solderability, reliability, etc., for the manufacture of your mcpcb .
Hot tinning POS-63 (HASL)
The process of hot tinning the board comes by immersing in a bath of molten solder for a limited time and quickly removing it with a hot air jet. You can do it by removing excess solder and leveling the coating.
- The most well-known and traditionally used coating method, the technology of its application and further use of HASL-coated boardsis well developed;
- Similarly, good solder joint strength;
- Furthermore, withstands many soldering cycles.
- Significant flatness of contact pads;
- Moreover, contains lead, harmful to the environment and service personnel;
- It is difficult to use for boardswith a large ratio of the thickness of the board and the diameter of the plated hole;
- Similarly, significant thermal load on the board, which can cause it to warp;
- severe thermal shock experienced by the interlayer connections of a multilayer board when immersedin molten solder
- Small-pitch component pad closures are possible; it is not recommended to use this method for components with a pitch of less than 0.5 mm;
- Uneven coating thickness on contact pads of different sizes and orientations.
Immersion gold plating
What is a mcpcb? A chemically applied coating is a thin layer of gold deposited over a nickel sublayer. The function of gold is to provide good solderability and protect nickel from oxidation, and nickel itself serves as a barrier to prevent mutual diffusion of gold and copper.
- Flat surface, uniform coating thickness
- Suitable for installing fine pitch components
- Furthermore, does not affect the size of plated holes
- Withstands repeated thermal cycling
- Similarly, suitable for push and slide contacts
- Solderability is highly dependent on the correct choice of cleaners, flux and soldering modes.
- Printed circuit boards shouldbe stored vacuum-packed in dry storage cabinets
- Contains nickel, which is considered a carcinogen
- Not optimal for boardswith high speed signals
- Black spots may appear
- Restrictions on the gaps of the pattern open from the protective mask and on the FAF.