Nine, micro-connection technology Uv Light Headlamp,Ultraviolet Headlamp,Uv Head Lamp,Uv Head Torch Ningbo Alite Lighting Technology Co.,Ltd , https://www.alite-tmwt.com
A wiring box with 256 to 400 connection points requires a connection technique using a thin copper wire. The main problem here is oxidation and a small process window. It is also ideal to use gold instead of copper because the conductivity and heat dissipation of gold are better. In addition, the connection on the steel sheet is not a suitable solution for large-scale series production due to the problem of rapid oxidation. A better solution is Kulicke & Soffa's patented "anti-oxidation process" that joins the gold wire to the copper surface.
In this process, the circuit board is cleaned on a circular plate to remove copper oxide, and a circuit board is covered with a protective film, and then a gold ball is soldered to the surface of the copper terminal, and ultrasonic waves can be used to penetrate the protective layer and copper. The terminals are soldered together, and the OP2-Gold60 can be used to connect the copper terminals of the 60μm network cable. The technology for testing thin copper wire on copper plates is being tested and was adopted in 2003.
Another new connection technology can be applied in the field of packaging technology and semiconductor substrate technology. The NCS (Nano-Terminal Connection System) technology is based on pyramidal particles coated with a layer of conductive material. The large side of the particles is placed on the substrate, and the pressure on the bottom surface of the particles is low, so that the pressure at the top of the particles increases in inverse proportion to the cross-sectional area thereof, and then the tip of the particles is pressed against the joint (eg, integrated circuit substrate). And inserted into the deformed material to achieve electrical connection. Diamond powder having a size of 4 to 25 μm and coated with nickel is generally used as such a particulate matter.
Regarding the connection of the integrated circuit to the silicon substrate, the surface is connected by argon ion bombardment to obtain a good quality, and the bombardment does not affect the electronic characteristics. Although the joint is somewhat imperfect, it can also be joined at low temperature and low pressure because of its thermal conductivity and matrix material.
In most cases, parts fabricated using microsystem technology can be assembled into a combined microsystem using a TLP connection. For this purpose, a multi-layer system in which high-melting-point elements such as steel or nickel and low-melting-point elements such as tin or indium are used is connected to each member. The TLP brazing system can use a "magnetron sputter ion plating PVD process" while adjusting the temperature of the substrate. The substrate temperature using a particular element can be guaranteed to be a grain structure and to utilize each TLP layer uniformly. In addition to tempering by electrical resistance heating, the substrate can be tempered by a series of intercooling and etching processes. However, the substrate temperature must never be the same as the melting point of a particular element to avoid the formation of a metallic intermediate phase in the process.
Today, various microfabrication processes for metal microsystems can be performed using laser radiation, and current manufacturing precision is 10 μm. In principle, their focusing ability is better. Basically, short-wave lasers (Nd: YD lasers and excimer lasers) are suitable for micromachining; Nd:YAD lasers transmit rays to processing locations through mirrors or optical fibers. . In order to obtain the smallest focus diameter, the quality of the beam is required to be high, which is determined by the design of the laser resonator. Using a dedicated multi-lens focusing system and telescope, the resulting focus diameter is closest to the theoretically available minimum focus diameter. The process of micromachining can be programmed using the CNC system.
The following are examples of applications for laser micromachining with Nd:YAG lasers:
(1) An electronic contact spring with a 10 μm slit.
(2) High-speed drilling of large-area special steel foil (100 μm aperture).
(3) Miniature engraving.
(4) Track welding of special steel foil (weld width is about 70 μm) and laser microbending.
In the wire connection of electronic components, the synchronous laser beam brazing process is a new development, the laser can simultaneously expose all the wire connection points. The system technical prerequisite for synchronous laser beam brazing is related to the beam forming element, which uniformly transmits the laser light to the various connection points. These requirements can be achieved, for example, by projecting light onto each side of the component. This solution uses a fixed length of accurate light and is being used in industrial applications.
An improved way of this method is to adapt the resulting beam to the geometry and mesh size of the part to be welded. Each spot should be completely coincident with the connection of one part, so that the entire absorbed laser energy is used to heat the connected object, and the substrate is not exposed to radiation when the light is used.
Latest developments in foreign welding technology (9)