Rectifier is a controllable rectifier device based on controllable silicon (thyristor) and centered on intelligent digital control circuits, which converts AC to DC. It is abbreviated as silicon rectifier, also known as thyristor rectifier, thyristor rectifier, etc. Silicon rectifier advantages include high efficiency, no mechanical noise and wear, fast response speed, small size, light weight and etc. PAM-XIAMEN can supply semiconductor substrates for controlled rectifier fabrication, like the silicon substrate specification listed as follows. For more substrates please refer to https://www.powerwaywafer.com/products.html.
1. Single Crystal Silicon Wafer for Rectifier Production
PAM220113 – SI
| No. | Item | Requirement | Defect Type | Control System | AQL | CPK |
| 1 | Method | FZ or MCZ | – | – | – | – |
| 2 | Diameter | 100±0.3mm | Minor | Gauge | 1 | – |
| 3 | Thickness | 260±15um | Minor | Micrometer | – | 1.33 |
| 4 | Conductivity Type | N | – | – | – | – |
| 5 | Dopant | Phosphorous | – | – | – | – |
| 6 | Orientation | (1,1,1) | – | – | – | – |
| 7 | Orientation Deviation | ±1° | – | – | – | – |
| 8 | Resistivity at Wafer Center | 72~88Ωcm | Critical | Four Point Probe | – | 1.66 |
| 9 | RRV | <15% | Critical | Four Point Probe | – | 1.66 |
| 10 | Carbon Content | <1ppm | – | – | – | – |
| 11 | Minority Carrier Life Time | >200us | – | – | – | – |
| 12 | TTV | <20um | – | – | – | – |
| 13 | Orientation Flat | _(1,1,0)±2° | Critical | – | 0.065 | – |
| 14 | Flat Length | 32.5±2.5mm | Minor | – | 1 | – |
| 15 | Secondary Flat | 45° clockwise/16-20mm (Note 1) | – | – | – | – |
| 16 | Warp | – | – | – | – | – |
| 17 | Roughness | <0.7um | – | – | – | – |
| 18 | Dirtness | Without | Critical | Optical | 0.065 | – |
| 19 | Cracks | Without | Minor | Optical | 1 | – |
| 20 | Scratches | Without | Minor | Optical | 1 | – |
| 21 | PIN Holes | Without | Minor | Optical | 1 | – |
| 22 | Edge Chips>0.8mm | Without | Minor | Optical | 1 | – |
| 23 | Edge Rounding | Yes | – | – | – | – |
| 24 | Surface Finished | Wire Cut | – | – | – | – |
| Note: 1: Angle defined with respect to flat, clockwise as viewed from the seed-end of the crystal; 2: Ingot – identity should be kept for Item No. 11. | ||||||
2. About Silicon-controlled Rectifier (SCR)
The current of a semiconductor PN junction is high during forward bias and low during reverse bias. Silicon rectifier diode is a type of PN junction diode that utilizes the unidirectional conductivity of PN junctions to convert AC current into DC. Devices with a current capacity of less than 1 ampere are usually referred to as rectifier diodes, while devices with a current capacity of more than 1 ampere are referred to as rectifiers. The commonly used semiconductor rectifiers include silicon rectifiers and selenium rectifiers, with many product specifications, ranging from tens of volts to thousands of volts, and currents from a few amperes to thousands of amperes.
Silicon materials have a large bandgap and good thermal conductivity, making them suitable for producing high-power rectifier devices. High voltage silicon stacks are often used in high-voltage rectifier devices, which are composed of multiple rectifier device cores connected in series. Their reverse withstand voltage is determined by the withstand voltage of the cores and the number of cores connected in series, with a maximum withstand voltage of several hundred kilovolts. If a high-frequency rectifier circuit is used at very high frequencies, when the cycle of the AC voltage is equivalent to the recovery time from the on state to the off state of the rectifier, the rectifier no longer has a rectification effect on the high-frequency voltage. To meet the needs of high-frequency operation, gold doping is usually used in silicon controlled rectifier to shorten the lifespan of injected minority carriers and achieve the goal of reducing recovery time.
In order to reduce the possibility of device damage caused by overvoltage breakdown and improve the reliability of rectifier devices, silicon avalanche rectifiers can be used. In this type of device, when the reverse voltage exceeds the allowable peak value, a uniform avalanche breakdown occurs across the entire PN junction, and the device can operate under high voltage and current, so it can withstand considerable reverse surge power. When making this type of device, it is required to have few wafer defects, uniform resistivity, flat junction surface, and appropriate protection should be provided for the exposed junction area to avoid surface breakdown.
3. Application of Silicon Rectifier
1) The main application of rectifiers is to convert AC power into DC power.
2) Silicon-controlled rectifiers are also used for detecting amplitude modulation (AM) radio signals. The signal may be amplified before detection (amplifying the amplitude of the signal), and if not amplified, a diode with a very low voltage drop must be used. When using a rectifier for demodulation, it is necessary to carefully match capacitors and load resistors. If the capacitance is too small, too much high-frequency component will be transmitted, while if it is too large, it will suppress the signal.
3) The rectifier of silicon is also used to provide the voltage with fixed polarity required for welding. The output current of this circuit sometimes needs to be controlled, and the diode in the bridge rectifier is replaced with a thyristor, and its voltage output is adjusted through phase control triggering.
For more information, please contact us email at victorchan@powerwaywafer.com and powerwaymaterial@gmail.com.