Inductive coupling island chip architecture with high-voltage isolation function and packaging method

Abstract

The invention relates to an inductive coupling island chip architecture with a high-voltage isolation function and a packaging method, the inductive coupling island chip architecture comprises an inductive module consisting of a plurality of inductive couplers, namely an inductive coupling island, each inductive coupler comprises a primary inductive coupling coil, a secondary inductive coupling coil, two primary wires, two secondary wires, a metal through hole, a metal routing pad, an N-type diffusion layer and a P-type substrate, two ports of the primary inductive coupling coil are connected with the top layer metal wire bonding pad through two primary connecting wires, and two ports of the secondary inductive coupling coil are connected to the top layer metal wire bonding pad through two secondary connecting wires and metal through holes respectively; when the three-substrate chip packaging structure is adopted, the inductance module, the signal transmitting module and the signal receiving module are respectively arranged on three different packaging substrates, and when the two-substrate chip packaging structure is adopted, the signal transmitting module and the signal receiving module are respectively arranged on two different packaging substrates. And the inductance module and the signal transmitting module or the signal receiving module are arranged on the same packaging substrate.

Description

Technical Field

[0001] The present invention belongs to the field of high-voltage-resistant and anti-interference electronic isolation chips, and particularly relates to an inductively coupled island chip architecture with a high-voltage isolation function and a packaging method therefor. Background Art

[0002] Inductive isolation utilizes the electromagnetic induction principle of an inductive coupler to achieve electronic isolation between two circuits. This technology is commonly used in electronic systems, especially in situations where it is necessary to prevent high voltages or noise from propagating from one circuit to another. The basic idea of inductive isolation is to use an inductive coupler or transformer as a medium to allow the transmission of signals or energy, while preventing a direct conduction current loop between the two isolated circuits. In an inductive isolator, a change in the current in the primary coil generates a changing magnetic field in the coupler, and this magnetic field in turn generates an induced electromotive force in the secondary coil of the coupler, thereby transferring the signal or energy from the primary circuit to the secondary circuit.

[0003] In applications where electronic isolation is used, such as signal transmission between a high-voltage circuit and a low-voltage circuit, or preventing noise interference in a sensitive measurement system, the isolation between the primary coil and the secondary coil of the inductive coupler can provide the required high-voltage or noise isolation. Since there is no direct conduction current loop connection between the primary coil and the secondary coil of the inductive coupler, the circuits at both ends of the isolator can operate at different voltages, thereby achieving high-voltage isolation, while reducing signal noise and crosstalk. With the continuous strengthening of the trend towards miniaturization and portability of electronic devices, the traditional transformer core and winding forms have greatly restricted the overall volume and cost of electronic devices.

[0004] In recent years, integrating magnetic components such as capacitors and inductors into chips has become the mainstream development trend. To achieve the goal of chip system integration, an inductive isolation transformer is usually made by winding metal into a planar spiral structure, and the isolated inductive coupler and the circuit of the signal transmitting module or the circuit of the signal receiving module are fabricated on the same chip using integrated circuit technology. Therefore, the entire chip has to be fabricated using a high-voltage process, which increases the area and cost of the chip. Due to the limitations of the chip area and semiconductor process on the on-chip integrated inductive isolation transformer, it is impossible to optimize the effective coupling coefficient and coil quality factor under a given area, which will reduce the transmission efficiency of signals or energy.

[0005] Moreover, since the inductive coupler and the chip where the signal transmitting module is located or the chip where the signal receiving module is located share the P-type substrate of the chip, it will cause mutual interference between the internal circuit and the isolated inductor, resulting in a large loss of the transmitted signal on the isolated inductor, causing signal attenuation, and reducing the anti-interference ability of the system, affecting the accuracy and reliability of signal transmission. Summary of the Invention

[0006] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide an inductive coupling island chip architecture with a high-voltage isolation function and a packaging method, which can improve the overall efficiency of inductive coil coupling, make it easy to integrate, reduce the chip area, improve the chip integration degree, and only the inductive isolation island chip requires a high-voltage process, while the chips constituting the signal transmission module and the signal reception module can be fabricated by a low-voltage chip process. The design of the inductive coupler can be independently optimized, the chip area can be reduced, the chip manufacturing cost can be lowered, and it has strong high-voltage resistance and anti-interference ability.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] In a first aspect, an inductive coupling island chip architecture with a high-voltage isolation function includes an inductive module composed of a plurality of inductive couplers, that is, an inductive coupling island. An inductive coupler includes a primary inductive coupling coil and a secondary inductive coupling coil. The primary inductive coupling coil and the secondary inductive coupling coil form an inductive coupling channel. The primary inductive coupling coil is a planar coil, including two primary wirings, metal vias, and two primary metal bonding pads. The two ports of the primary inductive coupling coil are connected to the two primary metal bonding pads through the primary wirings and the metal vias. The secondary inductive coupling coil is also a planar coil, including two secondary wirings, metal vias, and two secondary metal bonding pads. The two ports of the secondary inductive coupling coil are connected to the two secondary metal bonding pads through the secondary wirings and the metal vias; the primary inductive coupling coil and the secondary inductive coupling coil are in different metal layers. Each inductive coupler is placed on an independent PN junction, and all the PN junctions are constructed on the same P-type substrate. When a three-substrate chip packaging structure is adopted, the inductive module, the signal transmission module, and the signal reception module are respectively placed on three different packaging substrates. When a two-substrate chip packaging structure is adopted, the signal transmission module and the signal reception module are respectively placed on two different packaging substrates, and the inductive module and the signal transmission module or the signal reception module are placed on the same packaging substrate.

[0009] Further, when a two-substrate chip packaging structure is adopted, the inductive module and the signal transmission module are placed on the same packaging substrate, and the signal reception module is separately arranged on another packaging substrate.

[0010] Further, when a two-substrate chip packaging structure is adopted, the inductive module and the signal reception module are placed on the same packaging substrate, and the signal transmission module is separately arranged on another packaging substrate.

[0011] Further, the primary inductive coupling coil and the secondary inductive coupling coil of the same inductive coupler, the two primary wirings, the two secondary wirings, the metal vias, and the four metal bonding pads are all constructed on an independent N-type diffusion layer, and the N-type diffusion layer of the same inductive coupler constructs an independent PN junction on the P-type substrate.

[0012] Further, the PN junctions of several inductive couplers are all constructed on the same P substrate.

[0013] Further, the primary coupling coil and the secondary coupling coil of the inductance module are respectively connected to the circuits of the signal transmitting module and the signal receiving module through wire bonding.

[0014] Further, the metal through-hole is a connection hole between different metal layers; the two primary metal wire bonding pads and the two secondary metal wire bonding pads are both placed on the top metal layer of the inductive coupler.

[0015] Further, the two primary metal wire bonding pads form the primary port of the inductive coupler. The output port of the signal transmitting module is connected to the primary port of the inductive coupler. The output signal of the signal transmitting module is transmitted to the primary inductive coupling coil through the primary port. The two secondary metal wire bonding pads form the secondary port of the inductive coupler. The secondary port of the inductive coupler is connected to the input port of the signal receiving module. The signal transmitted by the signal transmitting module is transmitted to the primary inductive coupling coil through the primary port of the inductive coupler. The signal transmitted in the primary inductive coupling coil is induced to the secondary inductive coupling coil and is transmitted to the signal receiving module through the secondary port of the inductive coupler.

[0016] In a second aspect, a method for packaging an inductive coupling island chip with a high-voltage isolation function uses an inductive coupling island chip architecture with a high-voltage isolation function as described in the first aspect and any optional implementation manner thereof of the present invention. The inductance module, the signal transmitting module, and the signal receiving module are all packaged on three different packaging substrates, or the inductance module and the signal transmitting module or the signal receiving module are packaged on the same packaging substrate, and the signal receiving module and the signal transmitting module are packaged on two different packaging substrates.

[0017] The beneficial technical effects of the present invention are as follows: By integrating the inductive coupling coil alone on a chip and separating it from the signal transmitting module and / or the signal receiving module on other chips, an inductive coupling island is formed. The inductive coupling island does not need to be integrated with the signal transmitting module or the signal receiving module at the same time, making the inductive coupling island have the independence of design and optimization and good integration. At the same time, the signal transmitting module and the signal receiving module can be fabricated using ordinary processes instead of high-voltage processes, thereby reducing the overall cost, shortening the production time, improving the product yield, and enhancing the design flexibility. The inductance coil group on the inductive coupling island is constructed on the PN junction of an independent P-type substrate, thereby reducing the interference between inductive coupler groups and making the inductive coupling island have good anti-interference performance. Description of the Drawings

[0018] Figure 1Top view of an inductively coupled island chip architecture with high - voltage isolation function shown in Embodiment 1 of the present invention;

[0019] Figure 2 Schematic diagram of an architecture with triple - substrate packaging in an inductively coupled island chip architecture with high - voltage isolation function shown in Embodiment 1 of the present invention;

[0020] Figure 3 Schematic diagram of an architecture with dual - substrate packaging in an inductively coupled island chip architecture with high - voltage isolation function shown in Embodiment 1 of the present invention;

[0021] Figure 4 Schematic diagram of the process of detecting and transmitting the rising edge and falling edge of an electrical pulse signal through two channels of an inductively coupled island in an inductively coupled island chip architecture with high - voltage isolation function shown in Embodiment 1 of the present invention, thereby completing the isolation transmission process of a digital signal;

[0022] Figure 5 Schematic diagram of the process of OOK - type modulation and isolation transmission of a digital signal using one channel of an inductively coupled island and a method of adding a pulse carrier in an inductively coupled island chip architecture with high - voltage isolation function shown in Embodiment 1 of the present invention. Using this method, an inductively coupled island with M channels can transmit M digital signals;

[0023] Figure 6 Schematic diagram of the process of realizing a regulated isolation power supply with feedback function using two channels of an inductively coupled island in an inductively coupled island chip architecture with high - voltage isolation function shown in Embodiment 1 of the present invention. One inductively coupled channel serves as an energy - transfer channel, and the other inductively coupled channel serves as a feedback - signal channel;

[0024] Figure 1 Where: 1 - primary inductive coupling coil, 11 - first primary connection, 12 - second primary connection, 2 - secondary inductive coupling coil, 21 - first secondary connection, 22 - second secondary connection, 3 - third metal bonding pad, 4 - fourth metal bonding pad, 5 - first metal bonding pad, 6 - second metal bonding pad, 7 - metal via, 8 - N - type diffusion layer, 9 - P - type substrate. Detailed implementation manners

[0025] The present invention will be further described below in conjunction with the accompanying drawings and detailed implementation manners.

[0026] Embodiment 1

[0027] As Figure 1As shown in the figure, an inductively coupled island chip architecture with a high-voltage isolation function provided by an embodiment of the present invention includes an inductance module composed of a plurality of inductive couplers. The inductance module composed of a plurality of inductive couplers is also called an inductively coupled island. The primary inductive coupling coil and the secondary inductive coupling coil of a group of inductive couplers form an inductive coupling channel.

[0028] Each inductive coupler includes a primary inductive coupling coil 1, a secondary inductive coupling coil 2, a first primary connection 11, a second primary connection 12, a first secondary connection 21, a second secondary connection 22, metal bonding pads 3 - 6, a metal via 7, an N-type diffusion layer 8, and a P-type substrate 9.

[0029] Among them, the first primary connection 11 of the primary inductive coupling coil 1 is connected to the first metal bonding pad 5, and the second primary connection 12 of the primary inductive coupling coil 1 is connected to the second metal bonding pad 6; the first primary connection 11 and the second primary connection 12 constitute the two primary connections of the inductive coupler, and the first metal bonding pad 5 and the second metal bonding pad 6 constitute the two primary metal bonding pads of the inductive coupler.

[0030] The first secondary connection 21 of the secondary inductive coupling coil 2 is connected to the third metal bonding pad 3; the second secondary connection 22 of the secondary inductive coupling coil 2 is connected to the fourth metal bonding pad 4. The first secondary connection 21 and the second secondary connection 22 constitute the two secondary connections of the inductive coupler, and the third metal bonding pad 3 and the fourth metal bonding pad 4 constitute the two secondary metal bonding pads of the inductive coupler.

[0031] The primary inductive coupling coil 1 and the secondary inductive coupling coil 2 are in two different metal layers (the second metal layer and the third metal layer respectively). The first primary connection 11 and the second primary connection 12 of the primary inductive coupling coil 1 are in another same metal layer (the first metal layer). The two primary metal bonding pads 5 and 6 connected to the two primary connections 11 and 12 constitute the primary port of the inductive coupler. The output port of the signal transmitting module is connected to the primary port of the inductive coupler. The output signal of the signal transmitting module is transmitted to the primary inductive coupling coil 1 through the primary port of the inductive coupler. The first secondary connection 21 and the second secondary connection 22 of the secondary inductive coupling coil 2 are in another same metal layer (the fourth metal layer). The two secondary metal bonding pads 3 and 4 connected to the two secondary connections 21 and 22 constitute the secondary port of the inductive coupler. The secondary port of the inductive coupler is connected to the input port of the signal receiving module. The signal transmitted in the primary inductive coupling coil 1 is induced to the secondary inductive coupling coil 2 and transmitted to the signal receiving module through the secondary port of the inductive coupler.

[0032] The metal vias 7 are connection holes between different metal layers; the metal bonding pads 3 - 6 are ports for connecting the internal signals of the chip to the package pins. The metal vias connect the wiring of different metal layers to the corresponding metal bonding pads. The N - type diffusion layer 8 and the P - type substrate 9 provide an independent PN - junction for each inductor coil group, reducing the crosstalk between inductor coil groups caused by the P - type substrate 9.

[0033] The primary inductive coupling coils 1, secondary inductive coupling coils 2, first primary wiring 11 and second primary wiring 12, first secondary wiring 21 and second secondary wiring 22, all metal vias 7, and metal bonding pads 3 - 6 of the same group of inductive couplers are all constructed on an independent N - type diffusion layer 8. Multiple N - type diffusion layers 8 are all disposed on the same P - type substrate 9 to form several independent PN - junctions on the P - type substrate 9.

[0034] As Figure 2 shown, in the embodiment of the present invention, a three - substrate package is adopted, and the inductive isolation island chip is separated from both the signal - transmitting module chip and the signal - receiving module chip, and are respectively disposed on three different package substrates.

[0035] As Figure 3 shown, in the embodiment of the present invention, a two - substrate package is adopted. Chip 1 is the chip where the signal - transmitting module is located, and chip 2 is the chip where the signal - receiving module is located. The inductive coupling island and the signal - transmitting module or the signal - receiving module can share a package substrate, but the signal - transmitting module and the signal - receiving module cannot share the same package substrate. The connection between the inductive coupling island and the signal - transmitting module and the signal - receiving module is completed through metal wire bonding. In this way, the isolation of high and low potentials between the signal - transmitting module and the signal - receiving module is realized and the mutual interference is reduced. Obviously, the advantage of the two - substrate package is that the package volume is small and the cost is low, but the isolation withstand voltage is not as high as that of the three - substrate package.

[0036] The inductor coil groups on the inductive coupling island adopt independent N - type diffusion layers and form independent PN - junctions with the P - type substrate, thereby reducing the interference between inductive couplers. Also, because the inductive coupling island is relatively independent on the chip, it provides a design space for improving the efficiency of the inductor coils and also increases its applicability in different isolation systems. At the same time, three signal and energy transmission circuit architectures are proposed using the flexible architecture of the inductive coupling island.

[0037] Figure 4The following is a circuit diagram for transmitting the rising edge and falling edge of a signal in a digital signal isolation circuit using the inductively coupled island chip disclosed in the embodiments of the present invention. The signal transmitting module includes a pulse edge discriminator, a rising edge driver, and a falling edge driver. The signal receiving module includes two pulse flip-flops, a logic integration circuit, etc. After the input signal square wave passes through the pulse edge discriminator, it is divided into two parts, the rising edge and the falling edge, which respectively enter the rising edge driver and the falling edge driver to drive two primary coils of the inductive coupler in the inductively coupled island chip. The two primary coils of the inductive coupler couple the rising edge and the falling edge of the signal of the signal transmitting module to two corresponding secondary coils respectively. The coupled voltage of the secondary coil is output to the corresponding pulse flip-flop of the signal receiving module, and after being integrated by the logic integration circuit, a square wave consistent with the input signal is obtained, thus realizing the digital signal transmission function under high-voltage isolation.

[0038] Figure 5 The following is a system circuit block diagram for completing OOK modulation in a digital signal coupling circuit using the inductively coupled island chip disclosed in the embodiments of the present invention. The signal transmitting module includes a pulse amplifier, and the signal receiving module includes a pulse envelope detector. After the input signal with a carrier passes through the pulse amplifier, it drives the primary coil of the inductor in the inductively coupled island chip. The primary coil of the inductive coupler couples the signal of the signal transmitting module to the secondary coil and transmits it to the pulse envelope detector of the signal receiving module. Finally, a square wave signal related to the envelope of the carrier signal is output, thus realizing the function of digital signal transmission under high-voltage isolation.

[0039] Figure 6 The following is a system block diagram for completing an isolated regulated power supply circuit using the inductively coupled island chip disclosed in the embodiments of the present invention. The signal transmitting module includes a power supply driving circuit and a logic control circuit, and the signal receiving module includes a full-wave rectifier and a voltage regulation detection circuit. After the external power supply powers on the power supply driving circuit, the power supply driving circuit generates high-frequency pulses to drive the primary coil of the transformer in the inductively coupled island chip. After the primary coil of the transformer couples the energy of the signal transmitting module to the secondary coil, a DC voltage is obtained through the full-wave rectifier. After the DC voltage passes through the voltage regulation detection circuit, a signal with a voltage comparison result is output and transmitted to the logic control circuit of the signal transmitting module through the inductor coil group in the inductively coupled island chip. After the logic control circuit processes the signal with the voltage comparison result, a control signal is obtained to control the pulse start and stop of the power supply driving circuit, thus realizing the functions of high-voltage isolation, energy transmission, and stable output voltage.

[0040] Embodiment 2

[0041] As Figure 2As shown in the figure, an embodiment of the present invention provides an inductively coupled island chip packaging method with a high-voltage isolation function. The method adopts an inductively coupled island chip architecture with a high-voltage isolation function described in Embodiment 1 of the present invention and any of its optional embodiments. In the embodiment of the present invention, the packaging substrate has three independent chip packaging substrates. The inductively coupled island chip, the chip where the signal transmitting module with different voltage domains is located, and the chip where the signal receiving module is located are respectively packaged on different packaging substrates, forming a three-substrate architecture.

[0042] As Figure 3 shown in the figure, an embodiment of the present invention provides another inductively coupled island chip packaging method with a high-voltage isolation function. The method adopts an inductively coupled island chip architecture with a high-voltage isolation function described in Embodiment 1 of the present invention and any of its optional embodiments. In the embodiment of the present invention, there are two independent chip packaging substrates. The inductively coupled island chip and the chip where at least one of the signal transmitting module and the signal receiving module with different voltage domains is located are packaged on the same packaging substrate, and are respectively packaged on different packaging substrates with the chip where the other signal transmitting module or signal receiving module with different voltage domains is located, forming a two-substrate packaging architecture. That is, the inductively coupled island chip and the chip where the signal transmitting module is located are packaged on the same packaging substrate, and the chip where the signal receiving module is located is separately packaged on another packaging substrate. Or the inductively coupled island chip and the chip where the signal receiving module is located are packaged on the same packaging substrate, and the signal transmitting module is separately packaged on another packaging substrate. It can be seen from the above embodiments that an inductively coupled island chip architecture and a packaging method with a high-voltage isolation function disclosed by the present invention are easy to integrate by forming an inductance module with several inductive coupler channels, can reduce the chip area, and improve the chip integration degree. By adopting a two-substrate or three-substrate chip packaging structure, the chips at both ends of the inductive isolator can be fabricated using a low-voltage chip manufacturing process, thereby reducing the manufacturing cost of the chip. By adopting an inductively coupled island, direct integration of the inductive coupling coil with other chips can be avoided, and the high-voltage isolation of the system can be achieved only by fabricating the inductive isolation island chip using a high-voltage process, while the chips of the transmitting module and the receiving module only need to be fabricated using an ordinary semiconductor process. Moreover, the inductive couplers on the inductively coupled island are constructed on independent formed PN junctions, which can reduce the interference between inductive coupler channels. Also, since the inductively coupled island is on an independent chip, it provides a design space for improving the coil efficiency and increases its applicability in different electronic isolation systems.

[0043] The device and method described in the present invention are not limited to the embodiments described in the specific embodiments. Those skilled in the art can obtain other embodiments according to the technical solutions of the present invention, which also belong to the scope of the technical innovation of the present invention.

Claims

1. An inductively coupled island chip architecture with high-voltage isolation function, characterized in that: It includes an inductance module composed of a number of inductive couplers, namely inductive coupling islands. An inductive coupler includes a primary inductive coupling coil and a secondary inductive coupling coil. The primary inductive coupling coil and the secondary inductive coupling coil form an inductive coupling channel. The primary inductive coupling coil is a planar coil, including two primary wirings, metal vias, and two primary metal bonding pads. The two ports of the primary inductive coupling coil are connected to the two primary metal bonding pads through the primary wirings and the metal vias. The secondary inductive coupling coil is also a planar coil, including two secondary wirings, metal vias, and two secondary metal bonding pads. The two ports of the secondary inductive coupling coil are connected to the two secondary metal bonding pads through the secondary wirings and the metal vias; the primary inductive coupling coil and the secondary inductive coupling coil are in different metal layers. Each inductive coupler is placed on an independent PN junction, and each PN junction is built on the same P-type substrate. When using a three-substrate chip packaging structure, the inductance module, the signal transmitting module, and the signal receiving module are respectively placed on different three packaging substrates. When using a two-substrate chip packaging structure, the signal transmitting module and the signal receiving module are respectively placed on different two packaging substrates, and the inductance module and the signal transmitting module or the signal receiving module are placed on the same packaging substrate.

2. The inductively coupled island chip architecture with a high-voltage isolation function as described in claim 1, characterized in that: When using a two-substrate chip packaging structure, the inductance module and the signal transmitting module are placed on the same packaging substrate, and the signal receiving module is separately set on another packaging substrate.

3. The inductively coupled island chip architecture with high-voltage isolation function according to claim 1, characterized in that: When using a two-substrate chip packaging structure, the inductance module and the signal receiving module are placed on the same packaging substrate, and the signal transmitting module is separately set on another packaging substrate.

4. The inductively coupled island chip architecture with a high-voltage isolation function as described in claim 1, wherein: The primary inductive coupling coil and the secondary inductive coupling coil of the same inductive coupler, the two primary wirings, the two secondary wirings, the metal vias, and the four metal bonding pads are all built on an independent N-type diffusion layer. The N-type diffusion layer of the same inductive coupler builds an independent PN junction on the P-type substrate.

5. The inductively coupled island chip architecture with a high-voltage isolation function according to claim 4, characterized in that: The PN junctions of a number of inductive couplers are all built on the same P substrate.

6. The inductively coupled island chip architecture with high-voltage isolation function according to claim 1, characterized in that: The primary coupling coil and the secondary coupling coil of the inductance module are respectively connected to the circuits of the signal transmitting module and the signal receiving module through metal bonding.

7. The inductively coupled island chip architecture with a high-voltage isolation function according to claim 1, characterized in that: The metal via is a connection hole between different metal layers; the two primary metal bonding pads and the two secondary metal bonding pads are all placed on the top metal layer of the inductive coupler.

8. The inductively coupled island chip architecture with high-voltage isolation function according to claim 6, characterized in that: The two primary metal bonding pads form the primary port of the inductive coupler. The output port of the signal transmitting module is connected to the primary port of the inductive coupler. The output signal of the signal transmitting module is transmitted to the primary inductive coupling coil through the primary port. The two secondary metal bonding pads form the secondary port of the inductive coupler. The secondary port of the inductive coupler is connected to the input port of the signal receiving module. The signal transmitted by the signal transmitting module passes through the primary port of the inductive coupler to the primary inductive coupling coil. The signal transmitted in the primary inductive coupling coil is induced to the secondary inductive coupling coil and is transmitted to the signal receiving module through the secondary port of the inductive coupler.

9. An inductively coupled island chip packaging method with high-voltage isolation function, which adopts an inductively coupled island chip architecture as described in any one of claims 1-8. The inductance module, the signal transmitting module and the signal receiving module are all packaged on three different packaging substrates, or the inductance module and the signal transmitting module or the signal receiving module are packaged on the same packaging substrate, and the signal receiving module and the signal transmitting module are packaged on two different packaging substrates.

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