Silicon transient voltage suppressor (TVS) is one of silicon diodes, and has extremely fast response speed (less than 1ns) and relatively high surge current absorption ability, and can be used to protect equipment or circuits, even integrated circuits, MOS devices, hybrid circuits, and other voltage sensitive semiconductor devices from transient overvoltage generated by static electricity, inductive load switching, and induced lightning strikes. PAM-XIAMEN can supply CZ grown silicon diode wafer with following parameters for TVS diode application. More specifications of CZ silicon wafer please refer to https://www.powerwaywafer.com/silicon-wafer/cz-mono-crystalline-silicon.html.
1. Diode Silicon Wafer for TVS Diode Fabrication
|Product||Lapped Si Wafer|
|Minority Carrier Lifetime||N/A|
|Primary Flat Orientation||N/A|
|Primary Flat Length||N/A|
|Secondary Flat Orientation||N/A|
|Surface Processing||as required|
2. How to Make TVS Silicon Diode Array on Silicon Substrate?
Here we take the N+ substrate for further explain the processing procedures that how TVS diode design prepared on N+ Si substrate. Firstly, grow N- epilayer on the substrate, followed by local p+ doping on N-type silicon epitaxial diode layer to form a PN junction.
Then, metal aluminum is deposited on the N-type epitaxial layer, and the aluminum layer is photolithographed to form a TVS anode. After the anode of silicon diode is produced, the surface of the silicon wafer is passivated and the back of the silicon wafer is thinned. Then, a metal gold layer is deposited on the back of the silicon wafer, and gold atoms diffuse to form a composite center. And finally, the negative electrode of TVS is formed on the back of the silicon wafer.
3. What Is TVS Silicon Diode?
TVS diode is an efficient transient voltage protection device commonly used internationally in the form of a diode. When both ends of a TVS are subjected to reverse transient high voltage surges, it can transform the high impedance at both ends into low impedance in a time of 10-12 seconds, absorbing up to several kilowatts of surge power, keeping the voltage clamp between the two poles at a predetermined value, effectively protecting precision components in electronic circuits from various surge pulses and static electricity damage. There are two types of TVS: one is a unidirectional TVS (Unidirectional) used to protect DC voltage, and its cathode should be connected to the positive end of the voltage; Another type is bi-directional TVS (Bi directional), which is equivalent to two unidirectional TVS connected in reverse series, and can be used without considering the positive and negative poles of the voltage.
The working principle of TVS silicon diode is that connect the silicon TVS diode in parallel with the IC, and when the circuit operates normally, the TVS diode is in the OFF state, consuming only a certain amount of leakage current. When an overvoltage such as surge is applied, the TVS diode will become ON, and the TVS side will consume pulse current to clamp the overvoltage and protect the IC in the rear section.
4. Application of TVS Silicon Diode
Due to its advantages such as fast response time, high transient power, low leakage current, breakdown voltage deviation, easy control of clamping voltage, no damage limit, and small volume, TVS diode is currently widely used in various fields such as computer systems, communication equipment, AC/DC power supplies, automotive electronics, electronic ballasts, household appliances, industrial instruments, I/O ports, CAN, USB, MP3, PDAS, GPS, CDMA, GSM, 3G, 4G, digital camera protection, etc.