CN103219695B - A kind of over-current protection method and overcurrent protection ic chip package thereof - Google Patents

Abstract

The invention relates to an overcurrent protection method and an integrated circuit chip package for overcurrent protection. The method includes, using two magneto-sensitive elements; the two magneto-sensitive elements are respectively placed on one side of the conductor passing through different currents in the protected electronic device; the two magneto-sensitive elements respectively input the electric signals with a difference value induced into a differential amplification The input terminal of the circuit; the signal output by the differential amplifier circuit is used as the input signal of the overload protection driving circuit. The chip unit includes a packaging substrate, a bonding wire, a protected electronic device, and first and second magnetic sensitive elements. The protected electronic device is placed on the packaging substrate, and its pins are led to corresponding The first magnetic sensitive element is fixed on the side of the pad connected to the pin of the protected electronic device or the side of the pin; the second magnetic sensitive element is placed on the package substrate and the induction signal is smaller than that of the first magnetic sensitive element. any position. The advantage is that the induction signal does not affect the system, and noise can be suppressed, and the detected signal is more accurate.

Description

A kind of overcurrent protection method and overcurrent protection integrated circuit chip packaging

technical field

The invention relates to overcurrent protection technology, in particular to an overcurrent protection method and an overcurrent protection integrated circuit chip package.

Background technique

When a power electronic device is in an abnormal working state or a short circuit occurs, an overcurrent situation will occur, which will cause the circuit to fail to work normally and even damage the device. Therefore, the overcurrent protection circuit of power electronic devices is an indispensable part of the circuit system.

Resistive current sensing or Hall sensing is often used in traditional overcurrent protection methods. Resistive current sensing is to connect a corresponding resistor in the circuit, and realize overcurrent protection by detecting the current passing through the resistor. This overcurrent protection method increases the total power by increasing the corresponding resistance, which has a greater impact on the system. However, the overcurrent protection of the Hall sensor is greatly affected by the external environment. In order to ensure the accuracy of detection, a compensation circuit needs to be added, which increases the complexity of the overcurrent protection circuit.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art, and provide an overcurrent protection method and its corresponding overcurrent protection integrated circuit chip package that has no influence on the performance of the protected system and has a simple circuit structure. Its specific technical scheme is as follows:

The overcurrent protection method includes using two magnetic sensitive elements; the two magnetic sensitive elements are respectively placed on the side of the conductor passing different currents in the protected electronic device; the two magnetic sensitive elements respectively input the induced electrical signals with difference values into one The input end of the differential amplifier circuit; the signal output by the differential amplifier circuit is used as the input signal of the overload protection drive circuit.

The over-current protection method is further designed in that the differential-mode voltage gain of the differential amplifier circuit is 50-120 dB, and the common-mode rejection ratio is 80-140 dB.

The overcurrent protection integrated circuit chip package includes a package substrate provided with pads and bonding wires, and is characterized in that it also includes protected electronic devices and first and second magnetic sensitive elements, and the protected electronic devices are placed On the packaging substrate, the pins in the protected electronic device are led to the corresponding pads by bonding wires, and the first magnetic sensitive element is fixed on the side of the pad connected to the pins of the protected electronic device, Or one side of the pin; the second magnetic sensitive element is placed on any other position on the packaging substrate where the induced current is smaller than that of the first magnetic sensitive element.

The package of the overcurrent protection integrated circuit chip is further designed in that the second magnetic sensitive element is placed on a side of the packaging substrate where the induced current is smaller than that of other pads or pins of the first magnetic sensitive element.

The package of the overcurrent protection integrated circuit chip is further designed in that the magnetic sensitive element is formed by bonding a layer of high magnetostrictive material between two layers of high voltage electric material, and leads out from between an adjacent layer by a wire, Form the signal output terminal.

The invention uses a magnetic sensitive material for sensing, and converts the magnetic field signal generated by the current conductor into an electrical signal. The generation of the electrical signal does not consume power, and is without power, so it does not affect the total power of the system and the circuit impedance, and has no effect on the performance of the original circuit. Influence; the two passive signals are amplified by differential, which can greatly suppress various noises, so that the detected overcurrent signal is more accurate and reliable.

Description of drawings

Fig. 1 Closed-loop control block diagram formed by overcurrent protection integrated circuit chip package, protected electronic devices and overcurrent protection drive circuit.

Fig. 2 is a schematic structural diagram of an overcurrent protection integrated circuit chip package.

In the figure, 4—protected electronic device, 5—substrate, 6, 6′—pad, 8, first magnetic sensitive element, 8′ second magnetic sensitive element, 7—bonding wire.

detailed description

The overcurrent protection method of the present invention adopts two magnetic sensitive elements, the two magnetic sensitive elements are respectively placed on one side of the conductor passing through different currents in the protected electronic device, and the two magnetic sensitive elements respectively input the induced AC current signal into a differential The input terminal of the amplifier circuit, the signal output by the differential amplifier circuit is used as the input signal of the drive circuit corresponding to the overload protection, forming a closed-loop control, see Figure 1.

The two magnetic sensitive elements in the above method are formed by bonding a layer of high magnetostrictive material (such as Terfenol-D) with epoxy resin between two layers of high-voltage electric materials (such as PMN-PT piezoelectric single crystal material), and The wires are led out from between an adjacent layer to form a signal output terminal to lead out the induction signal. The signal drawn from the output terminal of the magnetic sensor is input into a differential amplifier circuit. The differential amplifier circuit has a good differential mode voltage gain, generally 50~120dB, and a high common mode rejection ratio, generally 80~140dB.

The protected electronic device and the magnetic sensitive element in the above method can be integrated in a circuit chip unit, as shown in FIG. Sensitive element 8, second magnetic sensitive element 8' and bonding wire 7. The protected electronic device is a chip or circuit with a large current in the system or circuit, such as: insulated gate transistor IGBT, intelligent power module IPM, switching power supply IC, high current voltage regulator IC, high current step-down IC and high current Boost IC, etc. The protected electronic device 4 is placed on the packaging substrate 5 , and several pins in the protected electronic device have corresponding bonding wires 7 leading to corresponding pads 6 . Generally, the two magnetic sensitive sensors are placed in different positions, the first magnetic sensitive element 8 is placed on the side of the conductor pad with a large current passing through, which can generate a large induced current, and the second magnetic sensitive element 8' is placed At any position of the package 5, the second magnetic sensitive element 8' can only sense a small induced current or even no induced current. In this embodiment, the second magnetic sensitive element 8' is placed on the side of the conductor pad 6' through which a weak current flows.

When the above-mentioned chip unit works, the current on the relevant pins of the protected electronic device 4 is transmitted to the conductor pads 6, 6' respectively through the bonding wire 7, and the current generates a magnetic field around the pads, and the first and second magnetic fields The sensitive elements respectively detect the magnetic fields around the corresponding pads, and then output voltage signals of different values, and then input the two detected voltage signals with differences to the input terminals of the differential amplifier circuit. Since the interference environment of the two magnetic sensors in the system is the same, the input to the differential amplifier circuit has the same noise signal, and the same noise signal, that is, the common mode signal, is suppressed after passing through the differential amplifier circuit, and the output is the amplified signal of the magnetic field signal to be detected. The amplified magnetic field voltage signal is fed back to the corresponding drive circuit for overload protection, and the relevant opening action is performed to achieve the function of overcurrent protection.

Claims (4)

1. an over-current protection method, is characterized in that comprising two magneto sensors adopting and formed by one deck high-magnetostriction material that bonds between two-layer high-tension electricity material, and is drawn between an adjacent layer by wire, form signal output part; This two magneto sensor is placed in the conductor side of protected electronic device by different electric current respectively; The signal of telecommunication with difference sensed is inputted the input of a differential amplifier circuit by two magneto sensors respectively; The signal that this differential amplifier circuit exports is as the input signal of overload protection drive circuit.

2. a kind of over-current protection method according to claim 1, is characterized in that the differential mode voltage gain of described differential amplifier circuit is 50 ~ 120dB, common-mode rejection ratio 80 ~ 140dB.

3. an overcurrent protection ic chip package, comprise the base plate for packaging and nation's alignment that are provided with pad, characterized by further comprising protected electronic device and first, second two magneto sensor, form signal output part, described protected electronic device is placed on base plate for packaging, pin in this protected electronic device causes corresponding pad by nation's alignment, and described first magneto sensor is fixed on the pad side be connected with described protected pin of electronic device, or described pin side; Second magneto sensor is placed in induced current on base plate for packaging and is less than on other optional position of the first magneto sensor; Described magneto sensor is formed by one deck high-magnetostriction material that bonds between two-layer high-tension electricity material, and is drawn between an adjacent layer by wire.

4. a kind of overcurrent protection ic chip package according to claim 3, is characterized in that described second magneto sensor is placed in induced current on base plate for packaging and is less than other pad of the first magneto sensor or the side of pin.