TW201816983A - Rectifying device of integrated series-connected Schottky diode increasing the reverse withstand voltage by serially connecting the Schottky diode - Google Patents

Abstract

This invention provides a rectifying device of an integrated series-connected Schottky diode. At least two lead frames are respectively connected to the cathodes on the reverse sides of Schottky diode chips, an anode on the front side of the first Schottky diode chip is connected to a first conductor, each of anodes of the other Schottky diode chips is connected to a second conductor respectively to be bridged to the lead frame located at the position of the former Schottky diode chip and sequentially and serially connected to at least two Schottky diode chips. Also, the first conductor, the lead frame located at the position of the last Schottky diode chip and the second conductor are respectively connected to an anode pin, a cathode pin, and an external pin of an electrode pin set. Then, the lead frames are provided with plastic bodies. The reverse withstand voltage can be increased by serially connecting the Schottky diode which is singlely arranged, low in cost, relatively low in the withstand voltage, and shorter in the reverse recovery time, and furthermore, the effects of simplicity and convenience in production, small volume, high yield rate, and lower cost due to the adoption of automatic production are achieved.

Description

   Integrated series Schottky diode rectifier   

The invention provides an integrated series Schottky diode rectification device, especially a Schottky diode connected in series using a single device and a lower cost withstand voltage and a faster reverse recovery time to increase the reverse direction. Withstand pressure, and then achieve the advantages of simple manufacturing, small size, high yield, and automated production to make the cost even lower.

According to the rapid growth of electronic technology and the development trend of light, thin, short, and small electronic products, many electronic products have been miniaturized. Almost many components in circuit boards are manufactured using integrated circuit processes. Production, and the integrated circuit type of electronic components in the application, you must consider more aspects, such as withstand voltage, anti-noise, the internal components of the problem of mutual interference, etc., especially applied to the power supply side components on the circuit board For the tolerance of voltage and current, it is more important to consider. When the voltage and current passed are too large, the insufficient voltage of the integrated circuit may be burned due to overheating. If the voltage is sufficient, the product must also be considered. The circuit characteristics between the components in the circuit to ensure the effect of the overall use.

Furthermore, among the electronic components at the power end of electronic products (such as power supplies, motor drivers, etc.), diodes are the most widely used. Diodes have the characteristics of one-way conduction and reverse circuit breaking. Circuits such as power supplies, inverters, and drivers are mostly used for high-frequency, low-voltage, and high-current rectification, so that the power supply can stably output DC power. Such diodes are generally called rectifier diodes and are widely used in consumer products. In the fields of electronics, communications, automotive, aerospace, medical and other fields, and because rectifier diodes have been developed toward integrated circuit, some manufacturers have packaged multiple diodes in the same integrated circuit and installed them Only one bipolar volume body circuit is needed when the circuit board is used, so the manufacturing cost can be reduced.

In addition, common non-linear loads in power supply circuits include circuits such as rectifiers and switching power supplies in power supplies. Since non-linear loads change the sine wave of the AC current input into the power transmission system into other waveforms, the input current is reduced in addition to the original In addition to the frequency (fundamental frequency) of the power supply, there will be many high-frequency harmonic currents, causing a large phase difference between the input current and the voltage, so that the power factor (ratio of effective power to apparent power, PF) decreases, and because the effective utilization of power in the power circuit is not high, it will increase the loss of electrical energy. Therefore, the common practice in the industry is to add a power factor correction (PFC) circuit to the power circuit, which can not only improve the stability of the power supply And its apparent power decreases after power factor correction, so it can increase the power factor of the power circuit, reduce high frequency harmonic pollution and improve power quality, so that the power utilization rate can also be improved.

As countries now pay more and more attention to the issues of global warming, energy conservation and carbon reduction, and in order to meet the demand for energy conservation and carbon reduction in products in terms of energy use, the requirements for the efficiency and quality of power supply from power supplies are also increasing, in order to save energy. And power costs, so in the front stage of the power supply, a boost power factor correction circuit is generally used, and the continuous current mode (CCM) input inductor current does not drop to zero, so the inductor voltage changes are small, and the power supply Each component on the circuit can have lower conduction loss, electromagnetic interference and smaller input filters, and can prevent the high-frequency transient impulse current of the power system from the power transmission system, in order to meet the product power factor requirements and international harmonics Current specifications; and because the power circuit has high reverse voltage (such as 600V) and high frequency (such as greater than 100KHz) operating characteristics, its power switch is not conducting when the zero inductor current, so you need to use high reverse voltage and faster reverse Recovery speed characteristics of rectifier diodes to reduce switching losses. Generally, switching power supply circuits use a single 600V or higher withstand voltage. Complex diode (FRD) or silicon carbide (SiC) Schottky diode (SBD) to rectify, but the reverse recovery time (Trr) of the fast recovery diode is not fast enough and the reverse recovery charge (Qrr) is not small enough. Causes rectification efficiency is not good enough (power factor is not high enough) and there are large loss and ripple, noise interference and other problems. In addition, the silicon carbide Schottky diode has a fast reverse recovery speed and good rectification efficiency, but the cost is very high. Is expensive, and the forward voltage loss is large, so the usage rate is not universal.

However, the structure of general rectifier diodes can be used to achieve reverse withstand voltage addition by series diode chips, and parallel diode chips can be used to add rated operating currents. However, practical applications of rectifier diodes in the past years In the parallel method, a symmetrical frame structure is used, and two diode chips are welded on the surface of the frame, and each diode chip is electrically connected to the pins by bonding wires or welding. Then, a plastic packaging material (such as epoxy resin) is formed on the frame to form a plastic package which can cover the diode chip, the bonding wire and the lead therein, and at the same time, make the top of the frame and the input of the lead and the input of the lead at the same time. The ends are exposed outside the plastic package. This kind of symmetrical frame structure used in parallel is simple and has the effect of facilitating processing and automated mass production.

However, the serial connection method is because in the conventional symmetrical frame structure, two diode chips must be soldered on the surface of the frame in one forward and one reverse direction, and then subsequent bonding leads, packaging, etc. are not only very Is difficult to process, lacks quantitative production and reliability, so the industry rarely uses serial diode chips for mass production; and because multiple diode chips are connected in series in practical applications, due to multiple diode chips The inconsistent electrical characteristics easily lead to static pressure imbalance, and the dynamic voltage changes caused by the end product design under different conditions, resulting in the failure of the series diode chip to withstand the voltage evenly, such as two 300V two in series. Polarity chip, in the power circuit and design application with a total reverse voltage of 400V, the front and back stage power supply will cause two diode chips to not be equally distributed to the same 200V voltage. When a polar wafer withstands a reverse working voltage of more than 300V, it will cause the diode wafer to be broken down and fail, so the traditional serial diode To increase the reverse breakdown voltage of the wafer is not reliable manner, so that it is difficult to make a series diode chip voltage multiplier manner used in various power supply circuit design, the key that is engaged in the research for improvement anxious to those in this industry.

Therefore, in view of the problems and shortcomings of the above-mentioned custom, the inventor collected relevant information and evaluated and considered it from various parties, and made continuous trials and modifications with years of R & D experience in this industry to design such a series of applications. The invention patent of rationality, convenience, universal applicability and long-term reliability, integrated design to reduce the use of space, and high-power density integrated series Schottky diode rectifiers were born.

The main purpose of the present invention is that the at least two lead frames are respectively connected to the cathode of the Schottky diode wafer back surface, and the first conductor is connected to the anode of the front surface of the first Schottky diode wafer. And other Schottky diode wafer anodes are respectively connected with a second conductor for bridging the lead frame of the previous Schottky diode wafer position, and at least two Schottky diodes are connected in series in this order. The first conductor, the lead frame of the last Schottky diode chip, and the second conductor are connected to the anode, cathode, and external pins of the electrode pin group, and then The lead frame is provided with a plastic package. This series connection uses Schottky diode chip integrated structure design with extremely high electrical characteristics consistency, which not only can stably increase the static pressure balance in series and the reverse withstand voltage. Average and use a single device and a low cost Schottky diode (especially silicon-based Schottky diode) connected in series to increase the reverse breakdown voltage compared to the same type Fast recovery diode or carbon Silicon Schottky diodes, lower voltage silicon Schottky diodes have shorter reverse recovery time, lower reverse recovery losses and lower costs, and the integrated design occupies less space, thereby achieving simple manufacturing, Small size, high yield, and automated production make the cost even lower.

The secondary purpose of the present invention is that the two adjacent Schottky diode chips connected in series are connected to the external pins of the electrode pin group to form a voltage equalizing or voltage regulating foot, and the anode pins, The cathode pin and the external pin test the reverse voltage that each Schottky diode chip is subjected to during operation. The electrode pin group can be further connected to the buffer circuit of the circuit board according to the actual needs, and passed through the anode. The pins, cathode pins, and external pins are connected in parallel with the corresponding Schottky diode chip, and the buffer circuit includes a resistor, a capacitor, or a series resistor and capacitor to reduce the Schottky diode where the voltage is too high. The working voltage of the chip can prevent the Schottky diode chip connected in series from failing to withstand the reverse voltage evenly, and it can also solve the problem of voltage average and stability in different circuit designs, so as to achieve the rationality of series operation, Convenience, universal applicability and long-term reliability.

Another object of the present invention is that when the integrated series Schottky diode rectifier device is applied to a switching power supply of a power supply, a correction circuit based on its power factor can be used to have two electrical devices in series with high consistency. The Schottky diode chip is stable and has a high average reverse voltage. The resistance and capacitance of a reasonable buffer circuit can be calculated based on the electrical characteristics of the first Schottky diode chip. Externally connected to the buffer circuit to improve the withstand voltage tolerance and avoid breakdown caused by excessive high voltage breakdown. The reverse voltage of each Schottky diode chip is compared with the use of a single booster During the operation of the polar body, the reverse voltage that it bears has been reduced by about half, and the Schottky diode chip with a lower withstand voltage has a shorter reverse recovery time and lower reverse recovery loss. By connecting the Schottky diode in series, The voltage division processing of the chip can speed up the power factor correction circuit exchange speed, lower power loss and better rectification efficiency, thereby improving the power factor of the switching power supply and reducing high frequency harmonic pollution to ensure the power supply. The quality of the power supply increases the utilization rate of the power supply and reduces the cost. It is widely applicable to various high-frequency, high-voltage, and high-current switching power supply applications, and can better meet the development and needs of energy saving and high efficiency.

1‧‧‧lead frame

11‧‧‧ substrate

12‧‧‧ heat sink

121‧‧‧through hole

2‧‧‧ Schottky diode chip

21‧‧‧First Conductor

22‧‧‧Second Conductor

23‧‧‧ third conductor

3‧‧‧ electrode pin set

31‧‧‧Anode pin

32‧‧‧ cathode pin

33‧‧‧External Pin

4‧‧‧Plastic body

5‧‧‧ buffer circuit

51‧‧‧resistance

52‧‧‧Capacitor

The first diagram is a schematic structural diagram of a preferred embodiment of the present invention.

The second diagram is a schematic diagram of two Schottky diodes connected in series according to the present invention.

The third figure is a schematic view of a Schottky diode connected to a lead frame according to the present invention.

The fourth diagram is a schematic diagram of two Schottky diodes connected in series according to the present invention.

The fifth diagram is a schematic diagram of three Schottky diodes connected in series according to the present invention.

The sixth diagram is a schematic diagram of a buffer circuit including a resistor according to the present invention.

The seventh diagram is another schematic diagram of the buffer circuit of the present invention including a resistor.

The eighth diagram is a schematic diagram of a buffer circuit including a capacitor according to the present invention.

The ninth figure is another schematic diagram of the buffer circuit of the present invention including a capacitor.

The tenth figure is a schematic diagram of the buffer circuit of the present invention including a capacitor and a resistor connected in series.

The eleventh figure is a waveform diagram of the reverse recovery time and the reverse recovery charge obtained during the normal temperature test of the present invention.

The twelfth figure is a waveform diagram of the reverse recovery time and the reverse recovery charge obtained during the high temperature test of the present invention.

The thirteenth figure is a waveform diagram of the reverse recovery time and the reverse recovery charge obtained when the conventional fast recovery diode is tested under normal temperature conditions of the present invention.

The fourteenth figure is a waveform diagram of the reverse recovery time and the reverse recovery charge obtained when the conventional fast recovery diode is tested under high temperature conditions according to the present invention.

The fifteenth figure is a waveform diagram of reverse recovery time and reverse recovery charge obtained by testing another conventional fast recovery diode under normal temperature conditions according to the present invention.

The sixteenth figure is a waveform diagram of reverse recovery time and reverse recovery charge obtained by testing another conventional fast recovery diode under high temperature conditions according to the present invention.

In order to achieve the above-mentioned object and effect, the technical means and structure adopted by the present invention, the drawings and detailed description of the structure and function of the preferred embodiment of the present invention are as follows.

Please refer to the first, second, third, fourth, and fifth figures, which are structural diagrams of the preferred embodiment of the present invention, a schematic diagram of two Schottky diodes connected in series, and Schottky diodes connected to the leads. The schematic diagram on the frame, the schematic diagram of two Schottky diodes in series, and the schematic diagram of three Schottky diodes in series. It can be clearly seen from the figure that the integrated cascade Schottky diode of the present invention The rectifying device includes at least two lead frames 1, a plurality of Schottky diode wafers 2, an electrode pin group 3, and a plastic package 4, wherein:

The lead frame 1 is a flat substrate 11 (such as a metal plate made of copper or copper alloy), and a width is set above the substrate 11 of at least one lead frame 1 compared to the substrate 11. The heat sink 12 is a large copper material, and a circular through hole 121 is provided on the surface of the heat sink 12.

The front and back sides of the Schottky diode wafer 2 have anodes and cathodes respectively, and each cathode is connected to the surface of the substrate 11 of the lead frame 1 by means of solder or conductive glue, and the first Xiao The anode of the tetrode diode wafer 2 is connected to the first conductor 21 by means of solder or conductive glue, and the anode of the other Schottky diode wafer 2 is connected to the first conductor by means of solder or conductive glue, respectively. Two conductors 22, and each of the second conductors 22 is connected in series with the lead frame 1 at the position of the previous Schottky diode wafer 2 by means of solder or conductive glue, and the last Schottky two A third conductor 23 may be further connected to the cathode of the electrode body wafer 2 by means of solder or conductive glue.

The electrode pin group 3 includes an anode pin 31, a cathode pin 32, and at least one external pin 33 located between the anode pin 31 and the cathode pin 32. The anode pin 31 is made of solder or conductive glue. It is connected to the first conductor 21 on the first Schottky diode wafer 2 by other methods, and the cathode pin 32 is connected to the cathode of the last Schottky diode wafer 2 to connect the cathode pin 32 is connected to the third conductor 23 on the last Schottky diode wafer 2 by means of solder or conductive glue, or the third conductor 23 can be omitted and the last Schottky diode The cathode lead 32 directly or indirectly extends outward from the lead frame 1 at the position of the chip 2 and the external lead 33 is connected with any two adjacent Schottky diode chips 2 in series by means of solder or conductive glue, respectively. The second conductor 22 is connected, and at least one lead frame 1 of any two adjacent Schottky diode chips 2 can also directly or indirectly extend an external pin 33 outward, or according to actual needs. Or apply design changes, so they are explained together in the following description Close to Chen.

The plastic package 4 is integrally formed on the lead frame 1 by using epoxy resin or other plastic sealing materials, and is covered with the Schottky diode wafer 2 and the electrode pin group 3 to form an insulating body. The connection ends of the anode pins 31, the cathode pins 32 and the external pins 33 are respectively exposed outside the plastic package 4.

In this embodiment, the Schottky diode chip 2 refers to an unpackaged silicon Schottky diode based on silicon (Si), and two or three (as shown in the fourth and fifth figures) The Schottky diode wafer 2 (such as D1, D2, D3, etc.) are connected to the lead frame 1, respectively, and the anode of the first Schottky diode wafer 2 uses a first conductor 21 (such as copper or aluminum). (Bonding leads, overlapping copper frames) are bridged to the anode pin 31 of the electrode pin group 3, and the cathode of the last Schottky diode wafer 2 is connected indirectly by a third conductor 23 or directly soldered On the cathode pin 32, any two adjacent Schottky diode wafers 2 connected in series are bridged by the anode of the latter Schottky diode wafer 2 respectively by the second conductor 22 in sequence to the previous one. The lead frame 1 is connected in series with the cathode of the Schottky diode wafer 2. The lead frame 1 is formed on the lead frame 1 with a plastic sealing material, and the Schottky diode wafer 2 and the electrode pin group 3 can be covered therein. The plastic package 4 and the heat sink 12, the anode pin 31, the cathode pin 32 and the external pin 33 of the lead frame 1 are respectively exposed outside the plastic package 4. There are at least two Schottky diode wafers 2 with an extremely high consistency in electrical characteristics. The integrated structure design not only can stably increase the static pressure balance of the Schottky diode wafers 2 in series, but also make Schottky two Polar body chip 2 withstands the reverse withstand voltage more evenly, and can use a single device and cheaper low-voltage silicon Schottky diodes in series to increase the reverse withstand voltage, compared to the fast recovery of the same type. Polar body or silicon carbide Schottky diode, etc., the lower withstand voltage silicon Schottky diode has a shorter reverse recovery time, lower reverse recovery loss and reduced costs, and the integrated design occupies less space. Multiple silicon Schottky diodes with high consistency in electrical characteristics can be selected for serial use, thereby achieving the advantages of simple manufacturing, small size, high yield, and automated production to make the cost even lower.

The above-mentioned integrated tandem Schottky diode rectifying device can connect at least two Schottky diode wafers 2 in series on at least two lead frames 1, and has an anode pin 31 and a cathode of an electrode pin group 3. Pin 32, and any two adjacent Schottky diode chips 2 connected in series are connected with external pins 33 to form a voltage equalizing or regulating pin, and anode pin 31, cathode pin 32, and external pins can be used. Pin 33 tests the reverse voltage that each Schottky diode chip 2 receives during operation, and configures resistors, capacitors, etc. on the circuit according to actual needs, so that external pin 33 can be used for external voltage sharing resistors, Adjust resistors, capacitors, etc. to reduce the voltage of the Schottky diode chip 2 at an excessively high voltage position to balance dynamic voltage changes, and to prevent multiple Schottky diode chips 2 in series from being able to withstand reverse voltages on average The failure can also solve the problems of voltage average and stability in different circuit designs. It has great flexibility and reliability, which makes the integrated series Schottky diode rectifier device realize the rationality and convenience of series operation. Sex, universal applicability, and Reliable and integrated design reduces the space required for use, and achieves high power density design and market requirements for products that are light, thin, short, and small. It can also be applied to all different application areas and is more capable of Meet the development and needs of energy saving and high efficiency.

The rectification device of the integrated series Schottky diode of the present invention is based on the principle of series voltage division (the series is the withstand voltage addition), and the power supply circuit and the front-end power supply cause the boost diode in the design application. Different composition characteristics of voltage, and the use of two Schottky diode chips 2 (silicon Schottky diode) connected in series with lower voltage resistance and faster reverse recovery time can be equivalent to voltage series (such as D1 + D2 = 300V + 300V or 350V + 350V), or you can use front high back low or front low back high series in accordance with the actual different voltage distribution (such as D1 + D2 = 350V + 250V) and use silicon Schottky diodes Reverse recovery time and lower reverse recovery charge characteristics make its power factor correction circuit have better rectification efficiency, lower ripple and noise interference, and based on lower withstand voltage silicon Schottky diode has lower Cost can better meet the demands of economic benefits and high efficiency.

Please refer to the sixth, seventh, eighth, ninth, and tenth diagrams, which are schematic diagrams of a buffer circuit including a resistor according to the present invention, another schematic diagram, a schematic diagram of a buffer circuit including a capacitor, and another schematic diagram of a buffer circuit including a capacitor in series. It can be clearly seen from the figure that the rectification device of the integrated series Schottky diode of the present invention can be assembled on a circuit board by using the electrode pin group 3 plug-in to make the circuit's buffer circuit ( (Snubber Circuit) 5 can be connected in parallel with the corresponding Schottky diode chip 2 on the lead frame 1 through at least two pins of the anode pin 31, the cathode pin 32, and the external pin 33, and is connected to the buffer circuit 5 The number and position of the component settings can be determined according to the reverse voltage that each Schottky diode chip 2 is subjected to during operation in order to adjust the Schottky diode at the corresponding position of the buffer circuit 5. The working voltage of the chip 2 is, for example, a Schottky diode chip 2 at a position where the voltage is too high, and the buffer circuit 5 includes at least one resistor 51, a capacitor 52, or a resistor 51 and a capacitor 52 connected in series to achieve voltage equalization adjustment. Purposes.

In this embodiment, the buffer circuit 5 includes a resistor 51, and the resistance value can be selected and matched according to the actual working voltage of each Schottky diode chip 2. As shown in the sixth figure, two Schottky devices are connected in series. The electrode pin group 3 connected to the base diode chip 2 has an external pin 33. The two ends of the first resistor 51 of the buffer circuit 5 are respectively connected to the anode pin 31 and the external pin 33. The second The two ends of the resistor 51 are respectively connected to the external pin 33 and the cathode pin 32. As shown in the seventh figure, the electrode pin group 3 connected to the three Schottky diode chips 2 in series has two external pins. 33. The two ends of the first resistor 51 of the buffer circuit 5 are respectively connected to the anode pin 31 and the first external pin 33, and the two ends of the second resistor 51 are respectively connected to the first and second external pin 33. The two ends of the third resistor 51 are connected to the second external pin 33 and the cathode pin 32, respectively.

In another embodiment, the buffer circuit 5 includes a capacitor 52, and its capacity value can be selected and matched according to the actual operating voltage of each Schottky diode chip 2. As shown in the eighth figure, two serial Xiao The electrode pin group 3 connected to the special diode chip 2 has an external pin 33. The two ends of the first capacitor 52 of the buffer circuit 5 are respectively connected to the anode pin 31 and the external pin 33. The second The two ends of each capacitor 52 are respectively connected to the external pin 33 and the cathode pin 32; as shown in the ninth figure, the electrode pin group 3 connected to the three Schottky diode chips 2 in series has two external pins. Pin 33, two ends of the first capacitor 52 of the buffer circuit 5 are respectively connected to the anode pin 31 and the first external pin 33, and two ends of the second capacitor 52 are respectively connected to the first and second external pin 33 The 33 terminals are connected, and the two ends of the third capacitor 52 are connected to the second external pin 33 and the cathode pin 32, respectively.

In another embodiment, the buffer circuit 5 includes a resistor 51 and a capacitor 52 in series. As shown in the tenth figure, the electrode pin group 3 connected to the two Schottky diode chips 2 in series is provided with an external The two ends of the resistance 51 of the pin 33 and the buffer circuit 5 are respectively connected to the anode pin 31 and one end of the capacitor 52, and the other end of the capacitor 52 is connected to the cathode pin 32, so that the integrated series Schottky II of the present invention can be connected. The rectifying device of the polar body is applied to the switching power supply circuit of the switching power supply, wherein the switching power supply circuit includes a bridge rectifier and a step-up power factor correction circuit, and the bridge rectifier input terminal is connected to an AC power source (such as 115VAC ~ 277VAC), and 600V is generally selected as the reverse voltage that the boost diode can withstand in the boost power factor correction circuit, which can meet the AC power supply's boost power factor within the above voltage range. Need for correction.

As mentioned above, the step-up power factor correction circuit uses a series of two Schottky diode chips 2 (such as D1 and D2) with extremely high consistency in electrical characteristics to stabilize and average higher reverse voltage. According to the electrical characteristics of D1, a reasonable resistance value and a capacitance value of the buffer circuit 5 are calculated, and the electrode pin group 3 is externally connected to the buffer circuit 5 to improve the voltage tolerance that D1 can withstand, thereby avoiding the first one The Schottky diode chip 2 fails due to excessively high voltage breakdown. In actual application, the reverse voltage that each Schottky diode chip 2 withstands is compared with the use of a single booster diode 2. During the operation of the polar body, the reverse voltage it has reduced is about half, and the Schottky diode chip 2 is a silicon Schottky diode with a lower withstand voltage. Its reverse recovery time is shorter and the loss of reverse recovery is shorter. Lower, through this voltage division processing of multiple Schottky diode chips 2 in series, the voltage exchange speed of the power factor correction circuit can be accelerated, the power loss becomes lower, and the efficiency of rectification is better, thereby improving the switching power supply. Power factor of circuit, reduce high frequency harmonic pollution Ensure the quality of power supply, and power efficiency improvement and reduce costs.

Please refer to the eleventh, twelfth, thirteenth, fourteenth, fifteenth, and sixteenth figures, which are the reverse recovery time and reverse recovery charge waveform diagrams obtained during the normal temperature test of the present invention, and the high temperature test The obtained reverse recovery time and reverse recovery charge waveform diagram, the reverse recovery time and reverse recovery charge waveform diagram obtained when the conventional fast recovery diode is tested under normal temperature conditions, and the reverse recovery obtained when tested under high temperature conditions Time and reverse recovery charge waveform diagram, reverse recovery time and reverse recovery charge waveform diagram obtained when another conventional fast recovery diode is tested under normal temperature conditions, and reverse recovery time and reverse direction obtained when tested under high temperature conditions The waveform diagram of the recovered charge can be clearly seen from the figure. When the integrated series Schottky diode rectifier device of the present invention is applied to a switching power supply of a power supply, various types of booster power factor correction circuits can be used to correct the circuit. Different modes, including continuous conduction mode (CCM), discontinuous conduction mode (DCM), and boundary conduction mode (CRM). The high reverse voltage is the same or different Schottky diode chip 2 (such as D1, D2) in series to increase the reverse withstand voltage, and the actual test results under normal temperature and high temperature conditions can tell the integration of the invention Compared with the fast recovery diode, the rectifier of the Schottky diode in series has the shortest reverse recovery time (Trr) and the smallest reverse recovery charge (Qrr).

In this embodiment, a switching power supply with an output power of 90W is taken as an example. The maximum reverse voltage actually endured by the power factor correction circuit is 400V. However, in order to maintain a certain margin, a withstand voltage value (acceptable The maximum reverse voltage) is a boosted diode of 600V. The rectification device of the integrated series Schottky diode of the present invention uses two Schottky diode chips 2 (such as D1 and D2) in series to divide the voltage. It is a silicon Schottky diode based on silicon. Its withstand voltage is between 300V and 350V. In actual work, the test results illustrated in Table 1 below can be obtained, compared with the use of a single Fast recovery diode with a withstand voltage of 600V (such as the fast recovery diode MUR460 produced by Vishay GS manufacturer), the first Schottky diode with the model number PFCD860 (KTH) in this embodiment The highest reverse voltage actually experienced by chip 2 is 244V, the highest reverse voltage actually experienced by the second Schottky diode chip 2 is 56V, and the withstand voltage value can be reselected according to the actual test results between 200V ~ 250V The silicon Schottky diode as the second Schottky diode chip 2; however As shown in the test results illustrated in Table 1, it can be clearly known that the reverse recovery time of two Schottky diodes connected in series in this embodiment is 13.8ns, which has a low reverse recovery loss and can reduce high-frequency switching power loss. The cost is lower than that of SiC Schottky diodes. In order to control the cost of the power factor correction circuit, a single fast recovery diode with a withstand voltage of 600V has a reverse recovery time of 39.2ns. After the power factor is corrected by the power factor, the effective power of the power supply tends to increase gradually with the power of the load. Therefore, the power loss becomes lower and the efficiency of the rectification is better. Therefore, the power factor of the switching power supply is improved, and the utilization rate of the power supply is improved. Reduced costs.

Please refer to the eleventh to sixteenth figures, where the eleventh and twelfth figures are waveform diagrams of the present embodiment when tested at working temperatures of 25 ° C and 125 ° C, respectively, and the thirteenth and fourteenth figures are Waveforms of conventional fast-recovery diodes (such as MUR460 from Vishay GS) when tested at 25 ° C and 125 ° C, respectively. The fifteenth and sixteenth figures are another conventional fast-recovery diodes (such as Yenyo manufacturers). The produced model is MUR460 fast-recovery diode.) The waveform diagrams when tested at the working temperature of 25 ℃ and 125 ℃, respectively, can be clearly known from the figure disclosed above. The Schottky diode of this embodiment The reverse recovery time of the actual test of wafer 2 is 14.2ns at 25 ° C and 19.0ns at 125 ° C. Compared with the fast recovery diode with a single withstand voltage of 600V, the reverse recovery time is at 25 ° C. Between 33.0 ~ 39.0ns, and between 79.4 ~ 89.4ns at 125 ℃, through this series of two Schottky diode chips with lower withstand voltage and faster reverse recovery time , Can significantly improve the electrical characteristics, so the power loss of the power factor correction circuit is reduced and the rectification efficiency is greatly improved. And increase the power factor of the switching power supply, so that the switching loss, conduction loss and leakage loss of the power supply can be minimized. It is widely applicable to various high-frequency, high-voltage and high-current switching power supply applications. Meet the development and needs of energy saving and high efficiency.

The above detailed description is only a description of a preferred feasible embodiment of the present invention, but this embodiment is not intended to limit the scope of the patent application of the present invention, and other equivalent changes and modifications made without departing from the spirit of the technology disclosed by the present invention Changes should be included in the scope of patents covered by the present invention.

To sum up, the above-mentioned integrated series Schottky diode rectifier device of the present invention can really achieve its efficacy and purpose when in use. Therefore, the present invention is an invention with excellent practicality, and it is in line with the invention patent. To apply for the requirements, I will submit an application in accordance with the law, and I hope that the trial committee will grant this case as soon as possible to protect the inventor's hard invention.

Claims (12)

    An integrated series Schottky diode rectifier includes: at least two lead frames; each cathode on the back of a plurality of Schottky diode chips is respectively connected to the lead frame, and the first Schottky diode is connected to the lead frame; A first conductor is connected to the anode on the front of the polar body wafer, and a second conductor is connected to the anode of the other Schottky diode wafer, and each second conductor is bridged to the previous Schottky diode. At least two Schottky diode wafers are connected in series on the lead frame at the chip position; the electrode pin group includes an anode pin, a cathode pin, and at least one external pin, wherein the anode pin and the first The first conductor on a Schottky diode chip is connected, the cathode pin is connected to the cathode of the last Schottky diode chip, and the external pins are respectively connected to two adjacent Schottky diodes in series. The second conductor of the body chip is connected; and the plastic package is arranged on the lead frame and covers the Schottky diode chip and the electrode pin group, and the anode pin, the cathode pin and the external pin are exposed on the Plastic body.         The rectification device of an integrated series Schottky diode according to item 1 of the scope of the patent application, wherein the lead frame is a flat substrate having a copper or copper alloy material, and is disposed above the substrate of at least one lead frame There are heat sinks that are wider than the substrate.         The rectification device of an integrated series Schottky diode as described in item 1 of the scope of patent application, wherein the Schottky diode chip is a silicon Schottky diode based on silicon.         The integrated series Schottky diode rectifier device according to item 1 of the scope of the patent application, wherein the plurality of Schottky diode chips have the same electrical characteristics and are equivalent to a series voltage, and can withstand the highest reverse voltage the same.         The integrated series Schottky diode rectifier device according to item 1 of the scope of the patent application, wherein the plurality of Schottky diode chips have the same electrical characteristics and are equivalent to a series voltage, and can withstand the highest reverse voltage different.         According to the integrated rectifier device of the Schottky diode in series as described in the first item of the patent application scope, a third conductor is connected to the cathode of the last Schottky diode chip, and the third Schottky diode chip is connected by the third conductor. The conductor is connected to the cathode pin of the electrode pin group.         The rectification device of an integrated series Schottky diode as described in item 1 of the scope of the patent application, wherein the cathode pin of the electrode pin group is directly on the lead frame of the last Schottky diode chip position. Or indirectly outward.         The rectification device of an integrated series Schottky diode according to item 1 of the scope of the patent application, wherein the external pin of the electrode pin group is at least one of the positions of any two adjacent Schottky diode chips. The lead frame extends directly or indirectly outward.         The rectification device of an integrated series Schottky diode as described in item 1 of the scope of the patent application, wherein the electrode pin group is further connected with a buffer circuit, and the buffer circuit passes the anode pin, the cathode pin and an external connection. At least two of the pins are connected in parallel with the corresponding Schottky diode chip on the lead frame.         The rectifying device of the integrated series Schottky diode as described in item 9 of the scope of the patent application, wherein the buffer circuit includes at least one resistor.         According to the integrated rectifier device of the series Schottky diode described in item 9 of the scope of the patent application, the buffer circuit includes at least one capacitor.         The integrated series Schottky diode rectifier device according to item 9 of the scope of patent application, wherein the buffer circuit includes a resistor and a capacitor in series.