The aluminum substrate ink is the ink printed on the LED aluminum substrate, which is mainly used for solder protection and maintenance. Common aluminum substrate inks are white solder mask inks, and black silk screen text inks are printed on them.
What is an aluminum substrate?
The aluminum substrate is a metal copper clad laminate with better heat dissipation function than the traditional PCB circuit board. The ordinary single panel is composed of three layers of structure, which are the circuit layer, the insulating layer and the metal base layer. Commonly found in LED lighting products. There are two sides, the white side is welded, and the other side shows the nature of metal aluminum. Generally, it will be applied with thermal conductive paste and then contact with the thermal conductive part. Of course, there is also a special ceramic plate.
The aluminum substrate used for high-end applications is also designed as a double-sided board, which is structured as a circuit layer, an insulating layer, an aluminum base, an insulating layer, and a circuit layer. There are few aluminum substrates with multi-layer boards. Multi-layer aluminum substrates can be made by bonding ordinary single-layer boards with insulating layers and aluminum bases.
LED aluminum substrate is also a kind of PCB circuit board, but the material of the printed substrate is aluminum alloy. In the past, the material of our ordinary circuit board was glass fiber, but because the heat of the LED light source is larger than some components, it is used for LED lamps. The circuit boards are generally aluminum substrates.
What is the general request for aluminum substrate white oil?
Sulfur-free and environmental protection: It is inevitable that there will be some sulfur elements in white oil (mainly concentrated in sulfhydryl groups). LED lamps, backlights, especially COB packages, on the one hand, partially adopt silver plating process, on the other hand, because the fluorescent lamp itself contains silver, the sulfur reacts with silver over a long period of time to generate silver sulfide (black), resulting in light decay, The lights dim. Ag+S---Ag2S. Therefore, the requirements for the sulfur content of the aluminum substrate white oil will be higher than that of the ordinary circuit board solder mask white oil.
Aluminum substrate is also a kind of circuit board, but it requires faster heat conduction, so the reflectance must be better.
What is the reason for the white solder resist ink used on the aluminum substrate?
The aluminum substrate is commonly used as a backlight source board, LED circuit board, and light reflection is a major function. The higher the reflectivity of white oil, the brighter the lighting effect. At present, the market recognizes this, mainly for South Korea and Japan orders, in addition, TV backlights used to use high-reflective white oil in large quantities.
The basic reflectivity of the solder mask white oil on the market today is 68~75%, including the solar solder mask WT02, which has a reflectivity of 73.6%. The reflectance test must be measured by a special instrument. If the white oil reflectance reaches 80%, take a TV as an example, a common backlight board, 6 lamp beads, and the use of high-reflectivity solder mask white oil can reduce the use of one Lamp beads, or 0.5W can be used instead of 0.7W lamp beads without affecting the brightness.
Aluminum substrate white oil classification
At present, the solder mask white oil for aluminum substrates is divided into yellow white and blue white, that is, warm white and cool white. The manufacture of solder mask white oil is different from green oil and has considerable technical difficulties. Under normal conditions, resins and white pigments (titanium dioxide) will turn yellow at a high temperature of 210 degrees. Most factories use shade blue (blue pigment) to neutralize yellow to make it have better whiteness after high temperature. In essence, it greatly reduces aluminum. White oil reflectivity and brightness of the substrate.