Production method for aluminum nitride ceramic substrate for LED

Abstract

The invention discloses a production method for an aluminum nitride ceramic substrate for an LED. The production method is characterized by comprising the following steps that firstly, burdening is conducted, high-purity directly-nitrided aluminum nitride powder or self-propagating aluminum nitride powder and three-component compound sintering aids are mixed; secondly, ball grinding is conducted, ethyl alcohol / methylbenzene or ethyl alcohol / butanone and glycerin or castor oil are added for ball grinding for 24-25 hours at the rotating speed of 482 rad / s, and polyvinyl butyral and polyethylene glycol are added for ball grinding for 26-27.5 hours at the rotating speed of 505 rad / s; thirdly, vacuum defoaming is conducted, and defoaming is conducted in the negative-pressure environment of 9.5*104-9.4*105 Pa; fourthly, tap casting is conducted; the height of a scraper is controlled to be 2.4-2.7 mm, and the casting tape speed is 0.1-0.3 m / minute; fifthly; rubber removing is conducted, and rubber removing is conducted in a continuous type rubber removing furnace continuously for 2-3 h at the temperature of 450-580 DEG C; sixthly, sintering is conducted, and sintering is conducted in a muffle furnace under the protection of the mixed atmosphere of hydrogen and nitrogen at the temperature of 1550-1680 DEG C. The aluminum nitride ceramic substrate for the LED has good heat conductivity, the reliable electric insulating property, the low dielectric constant and the low dielectric loss.

Description

technical field [0001] The invention relates to a production method of an aluminum nitride ceramic substrate, in particular to a production method of an aluminum nitride ceramic substrate for an LED. Background technique [0002] Ceramic substrate materials are widely used in power electronics, LED packaging, multi-chip modules and other fields due to their excellent thermal conductivity and air tightness. The choice of LED heat dissipation substrate also has design differences depending on the circuit design, size, luminous efficiency and other conditions of the LED. At present, the most common ones on the market are: 1) system circuit board, which is mainly used as the final heat conduction of the LED to the The heat dissipation system in the atmosphere, heat dissipation fins or shells, and the types listed as system circuit boards include: aluminum substrate (MCPCB), printed circuit board (PCB) and flexible printed circuit board (FPC); ② LED chip substrate, which belongs ...

AI Technical Summary

Problems solved by technology

However, alumina ceramics are not easy to sinter and compact, and their thermal conductivity is low, and the thermal expansion coefficient does not match Si; beryllium oxide has a higher thermal conductivity than metal aluminum, and it is used in occasions that require high thermal conductivity, but it decreases rapidly after the temperature exceeds 300 °C. , the most important thing is that its own development is limited due to its toxicity; aluminum nitride has two very important performance values: one is high thermal conductivity, and the other is an expansion coefficient that matches Si

The disadvantage is that even a very thin oxide layer on the surface will affect the thermal conductivity, and only strict control of materials and processes can produce aluminum nitride substrates with better consistency

At present, the large-scale aluminum nitride production technology is still immature in China. Compared with alumina, the price of aluminum nitride is relatively high, which is also a bottleneck restricting its development.