E-Tech

The thickness of copper plays a pivotal role in thick copper printed circuit boards. The cost is contingent on the copper's weight, measured in ounces, hence 20 oz thick copper is pricier than 16 oz.

Copper finds applications in fume hoods, countertops, stand-up roofs, trim roofs, downspouts, and gutters. It boasts pre-perforated hammered panels.

Copper measurements are denoted in ounces by weight. Upon exposure to air, copper develops a bronze hue, influenced by various factors. Its color spectrum ranges from black to green, brown, or intermediate shades. Although many misconstrue this color change as corrosion, it's merely a chemical reaction, unrelated to product lifespan. In fact, copper's durability is enhanced by this reaction.

Now, let's delve briefly into the definition of a 20 oz limit PCB.

A 20oz PCB can be succinctly defined as a thick printed circuit board housing a copper layer with a thickness of 20 ounces. This signifies that the PCB possesses substantial thermal capacity and can accommodate high levels of current flow.

To determine the thickness of a 20 oz PCB, one must first understand the dimensions of a 1 oz PCB and then multiply it by 20. A 1 oz PCB measures 1.37 mils or 0.00137 inches in thickness. Accordingly, the thickness of a 20 oz metal core PCB would be 20 times 1.37 mils, equating to 27.4 mils or 0.0274 inches.

The integration of heavy copper in circuit boards is a strategic response to the escalating demands for high current and power in various industries such as automotive, military, electric energy, solar energy, and computing.

The emergence of 20oz PCBs is poised to supplant archaic metal strips and conventional cable routing methods. This innovative transmission structure not only enhances production efficiency but also curtails system maintenance and wiring expenses.

Manufacturing a 20 oz PCB introduces several challenges compared to conventional methods used for Traditional PCB manufacturing. These complexities encompass processes such as drilling, lamination structures, solder mask application, precise etching, and more. Currently, the production of heavy copper PCBs involves three distinct approaches:

Due to the limited availability of thick copper foil in the market, factories often possess copper foil with a thickness of only 5 oz. Orders requiring copper foil thickness beyond this level typically involve initial processing with 5 oz copper foil, followed by electroplating to achieve the desired thickness.

This approach takes into consideration both the overall cost of processing, including the extended electroplating duration and the high production capacity of electroplating equipment. The challenge lies in maintaining uniformity during etching, which directly stems from the uniformity achieved during the electroplating process.

In this method, a layer of exceptionally heavy copper foil is applied through lamination. While this technique offers improved uniformity in copper thickness compared to electroplating thickening, it still necessitates multiple etching stages.

This technique entails etching both the front and back sides of the copper foil. Initially, one side of the copper foil undergoes etching to create the desired pattern at half-depth. This partially etched pattern is then pressed onto the board before proceeding with lamination. After lamination, the second side of the copper foil undergoes etching, resulting in the removal of remaining copper thickness and substrate. This leaves the initially etched pattern embedded in the substrate.