A Must - Read for PCB Peers! The Production Process of Aluminium - based PCBs Revealed!

An aluminium - based PCB is a kind of metal - based PCB and has excellent heat dissipation function. Generally speaking, a single - sided aluminium - based PCB consists of three layers: a circuit layer, a dielectric layer and an aluminium base layer.  The structure of a double - sided aluminium - based PCB is more complex and generally consists of a circuit layer, an insulating layer, an aluminium base layer, an insulating layer and a circuit layer.  There is wiring on both sides.  However, to use the wiring on both sides, appropriate wiring connections need to be made between the two layers.

Aluminium - based PCBs are widely used in fields such as LED lighting, hybrid integrated circuits, automobiles, office automation, high - power electrical equipment and power supply equipment due to their excellent heat dissipation, good machinability, dimensional stability and electrical performance.

I. Why is Aluminium Used in Circuit Boards?

The aluminium PCB stack consists of three layers: copper foil, an insulating layer and metallic aluminium.  

Since there is an insulating layer, can the metal layer use any other materials other than aluminium?  Such as copper PCBs, stainless - steel PCBs, iron - plate PCBs, etc. Considering cost and technical performance, aluminium plates are an ideal choice.  The available aluminium plates include 6061, 5052, 1060, etc. If higher thermal conductivity, mechanical, electrical and other special performances are required, metal PCBs can also be made of copper, stainless - steel, iron, etc.

I. What Are the Functions of Aluminium-based PCBs? 

1. The surface adopts SMT (Surface Mount Technology), which has good thermal performance in circuit design.

2. It can reduce the temperature and extend the service life of products.

3. It can reduce the volume, hardware and assembly costs.

4. It can replace ceramic substrates and obtain better mechanical durability.

II. Differences between Aluminium-based PCBs and FR4 PCBs

1. Aluminium-based PCBs on the market are generally single-sided and double-sided ones. PCB boards are a large category, and aluminium-based PCBs are just one type of PCB boards.

2. Generally speaking, the main material of aluminium-based PCBs is aluminium plates, while the main material of PCBs is FR-4.

3. Compared with PCB boards, metal-core circuit boards are superior to PCBs in terms of heat dissipation, and their thermal conductivities are also different. Due to its good heat dissipation, the price of aluminium-based PCBs is also higher.

III. How to Manufacture Aluminium PCBs?

Manufacturing Process:

Cutting - Drilling - Dry Film Optical Imaging - Plate Inspection - Etching - Corrosion Inspection - Green Oil - Legend - Green Inspection - Tin Spraying - Aluminium Base Surface Treatment - Plate Punching - Final Inspection - Packaging - Shipping.

Detailed Descriptions of Some Processes:

1. Cutting

(1) The aluminum substrate with a protective film on the surface must be used.

(2) There is no need to bake the board after cutting.

(3) Handle with care and pay attention to protecting the surface.

2. Drilling

(1) The drilling parameters are the same as those of FR - 4 PCB.

(2) Drill with the copper sheet facing up.

3. Dry Film

(1) Incoming Inspection: The protective film on the surface of the aluminum substrate must be inspected before grinding.

(2) Grinding the Board: Only the copper surface is treated.

(3) Coating: The copper surface and the aluminum base surface must be coated, and the interval between grinding the board and coating should be controlled within 1 minute.

(4) Clapping: Pay attention to the accuracy of clapping.

(5) Exposure: The exposure ruler and residual glue should be 7 - 9 grids.

(6) Development: Operate with care to avoid scratching the protective film and the surface of the aluminum base.

4. FQC (Final Quality Control) Inspection

(1) The circuit surface must be inspected according to MI (Manufacturing Instructions) requirements.

(2) The dry film on the aluminum base surface should have no film peeling or damage.

IV. Precautions for Aluminum Substrate Manufacturers

1. Pay attention to the operation standards during the production process to prevent losses caused by production operation mistakes.

2. The surface of the aluminum substrate has poor wear resistance and must be handled gently to avoid scratching the board surface.

3. When production is not continuous, maintenance should be strengthened to ensure the stability of later - stage operation.

As a well - known PCB manufacturer, PCB MASTER Company has rich experience and advanced technical level in the production and application of aluminum substrates and has won customers' praise for its high quality and reasonable price.

Double - Sided Aluminum Substrate

PCB Material: Aluminum PCB

Data Layers: 2 Layers

Color: White/Black

Finished Thickness: 1.2mm

Copper Thickness: 1oz

Surface Treatment: Lead - free HASL (Hot Air Solder Leveling)

Thermal Conductivity: 2.0w/m.k

Special Process: The 2 - layer aluminum PCB needs to be manufactured according to the 4 - layer PCB process.

Application: High - end LED Desk Lamps

PCB board ---- circuit board ---- circuit board factory ----PCB MASTER company (www.pcbmaster.com) provided