A half-bridge power module

Abstract

The present invention provides a half-bridge power module, comprising: a positive copper layer, an output copper layer and a negative copper layer attached to the upper surface of the insulating substrate from top to bottom; an upper switch tube and an upper diode of an upper bridge arm are staggered and attached to the positive copper layer, a cathode of the upper diode is welded to the positive copper layer, and an anode of the upper diode is connected to the output copper layer through a bonding wire; a first end of the upper switch tube is welded to the positive copper layer, and a second end is connected to the output copper layer; a lower switch tube and a lower diode of a lower bridge arm are staggered and arranged on the output copper layer; a cathode of the lower diode is welded to the output copper layer, and an anode of the lower diode is connected to the negative copper layer through a bonding wire; a first end of the lower switch tube is welded to the output copper layer, and a second end is connected to the negative copper layer through a bonding wire; the specifications and quantity of the connecting bonding wires on the diode chip are the same, and the specifications and quantity of the connecting bonding wires on the switch tube chip are the same. The present invention can achieve better static current sharing characteristics.

Description

Technical Field

[0001] The present invention belongs to the field of power modules, and more specifically, relates to a half-bridge power module. Background Art

[0002] Power modules can withstand high voltage and high current and have high reliability. They are widely used in many occasions such as transportation, aerospace, and industrial fields.

[0003] In order to achieve a larger on-current value, multiple chips are generally connected in parallel, using multiple switch tube chips and multiple diode chips in parallel to form a bridge arm. If the static current flowing through the parallel chips is unbalanced, the temperature of some chips will be higher than other chips, making them more susceptible to damage, affecting the long-term reliability of the module. The chip layout needs to be reasonably designed. Most traditional multi-chip parallel power modules have poor static current balancing performance due to the inconsistent current path lengths between the parallel chips. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a half-bridge power module with multiple chips in parallel, aiming to solve the problem that most traditional multi-chip power modules have poor static current balancing performance due to inconsistent current path lengths between parallel chips.

[0005] To achieve the above object, the present invention provides a half-bridge power module, comprising: an insulating substrate, an upper bridge arm, a lower bridge arm, a positive electrode copper layer, a negative electrode copper layer and an output electrode copper layer;

[0006] The positive electrode copper layer, the output electrode copper layer and the negative electrode copper layer are attached to the upper surface of the insulating substrate from top to bottom; the width of the positive electrode copper layer is the same as the width of the output electrode copper layer;

[0007] The upper bridge arm is composed of N upper switch tubes and N upper diodes; the N upper switch tubes and N upper diodes are arranged alternately, arranged in a first row with equal spacing, and attached to the positive electrode copper layer; each upper switch tube is reversely connected in parallel with its adjacent upper diode, the cathode of the upper diode is welded on the positive electrode copper layer, and the anode of the upper diode is connected to the output electrode copper layer through a bonding wire; the first end of the upper switch tube is welded on the positive electrode copper layer, the second end is connected to the output electrode copper layer through a bonding wire, and the third end is connected to a drive signal;

[0008] The lower bridge arm is composed of N lower switch tubes and N lower diodes; the N lower switch tubes and N lower diodes are arranged in a staggered manner, arranged in a second row with equal spacing, and attached to the output electrode copper layer; the central axes of the first row and the second row remain parallel; N is an integer greater than or equal to 2; each lower switch tube is reversely connected in parallel with its adjacent lower diode, the cathode of the lower diode is welded on the output electrode copper layer, and the anode of the lower diode is connected to the negative electrode copper layer through a bonding wire; the first end of the lower switch tube is welded on the output electrode copper layer, the second end is connected to the negative electrode copper layer through a bonding wire, and the third end is connected to the drive signal; the specifications and quantity of the bonding wires connecting each upper diode to the output copper layer are the same, the specifications and quantity of the bonding wires connecting each lower diode to the negative electrode copper layer are the same, the specifications and quantity of the bonding wires connecting each upper switch tube to the output electrode copper layer are the same, and the specifications and quantity of the bonding wires connecting each lower switch tube to the negative electrode copper layer are the same;

[0009] When the upper switch tube and the lower switch tube are MOSFET, the first end is the drain, the second end is the source, and the third end is the gate; when the upper switch tube and the lower switch tube are IGBT, the first end is the collector, the second end is the emitter, and the third end is the gate.

[0010] In an optional embodiment, the insulating substrate is divided into two symmetrical parts: a left insulating substrate and a right insulating substrate;

[0011] The upper bridge arm, the lower bridge arm, the positive electrode copper layer, the negative electrode copper layer and the output electrode copper layer are symmetrically distributed on the upper surfaces of the left insulating substrate and the right insulating substrate;

[0012] The positive copper layers on the left insulating substrate and the right insulating substrate are connected by positive copper layer bonding wires, the negative copper layers on the left insulating substrate and the right insulating substrate are connected by negative copper layer bonding wires, and the output copper layers on the left insulating substrate and the right insulating substrate are connected by output copper layer bonding wires, so as to realize electrical connection between the left insulating substrate and the right insulating substrate; the number of the positive copper layer bonding wires is the same as the number of the output copper layer bonding wires;

[0013] The specifications of the bonding wires connecting the left insulating substrate and the right insulating substrate are the same.

[0014] In an optional embodiment, the bonding wires connecting the upper switch tube and the upper diode to the output electrode copper layer are located on the same straight line parallel to the central axis at the output electrode copper layer;

[0015] The bonding wires connecting the lower switch tube and the lower diode to the negative electrode copper layer are located at the same straight line parallel to the central axis at the landing point of the negative electrode copper layer.

[0016] In an optional embodiment, the width of the negative electrode copper layer is smaller than the width of the positive electrode copper layer and the width of the output electrode copper layer, so that the third end of the lower switch tube is connected to the lower driving copper layer through a driving bonding wire, so that the third end of the lower switch tube receives a driving signal; the lower driving copper layer is located at the lower end of the negative electrode copper layer;

[0017] The number of bonding wires of the negative electrode copper layer is greater than the number of bonding wires of the positive electrode copper layer, so as to compensate for the inconsistent resistance of the output electrode copper layer and the negative electrode copper layer per unit length on the current path when the lower switch tube or the lower diode is turned on due to the narrowing of the width of the negative electrode copper layer, so that the resistance on the current path of the lower switch tube or the lower diode connected in parallel on the left insulating substrate and the right insulating substrate can be kept consistent.

[0018] In an optional embodiment, the third end of the upper switch tube is connected to the upper drive copper layer through a drive bonding wire so that the third end of the upper switch tube receives a drive signal; the upper drive copper layer is located at the upper end of the positive copper layer.

[0019] In an optional embodiment, a driving resistor is connected in series in the driving circuit of each upper switch tube and each lower switch tube, so that the driving signals of each switch tube are consistent.

[0020] In an optional embodiment, the half-bridge power module further includes: a heat dissipation substrate; and the insulating substrate is placed on the heat dissipation substrate.

[0021] In general, the above technical solution conceived by the present invention has the following beneficial effects compared with the prior art:

[0022] The present invention provides a half-bridge power module. Compared with the prior art, through layout design and control of the number of bonding wires, the parasitic resistance values ​​on the current paths of the parallel switch tubes or diodes can be consistent during the static current flow period, thereby achieving static current sharing; avoiding the problem that the temperature of individual chips is higher than that of other chips due to the unbalanced static current flowing through the parallel chips, thereby affecting the reliability of the long-term operation of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a half-bridge power module of multiple chips connected in parallel provided by an embodiment of the present invention;

[0024] Figure 2 It is a schematic diagram of a multi-chip parallel half-bridge power module provided by an embodiment of the present invention with the housing and terminals removed;

[0025] Figure 3 1 is a schematic diagram of a circuit topology corresponding to a half-bridge power module of multiple chips connected in parallel provided by an embodiment of the present invention;

[0026] In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein: 1 is a positive terminal, 2 is a negative terminal, 3 is an output terminal, 4 is an upper bridge arm drive terminal, 5 is a lower bridge arm drive terminal, 6 is a thermistor terminal, 7 is an overcurrent protection terminal, 8 is an upper bridge arm switch tube, 9 is an upper bridge arm diode, 10 is a lower bridge arm switch tube, 11 is a lower bridge arm diode, 12a and 12b are positive copper layers, 13a and 13b are output copper layers, 14a and 14b are negative copper layers, 15 is a driving resistor, 16 is a thermistor, 17 is a first copper layer bonding wire cluster, 18 is a second copper layer bonding wire cluster, 19 is a third copper layer bonding wire cluster, 20 is an upper bridge arm bonding wire cluster, 21 is a lower bridge arm bonding wire cluster, 22 is a driving bonding wire, 23a and 23b are DBC substrates, 24 is a heat dissipation substrate, and 25 is a housing; wherein in the above-mentioned figure marks 12a, 12b, 13a, 13b, 14a, 14b, 23a and 23b, a represents the right half, and b represents the left half. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] In view of the above improvement requirements of the existing multi-chip parallel power module, the present invention provides a multi-chip parallel half-bridge power module, which aims to achieve better static current sharing characteristics.

[0029] To achieve the above objectives, the present invention adopts the following technical solution: a multi-chip parallel half-bridge power module, including an upper bridge arm, a lower bridge arm, a DBC substrate, and a positive copper layer, a negative copper layer, and an output copper layer located on the upper surface of the DBC substrate.

[0030] The upper bridge arm is composed of N switch tube chips and N diode chips (N is greater than or equal to 2); the N switch tube chips and N diode chips of the upper bridge arm are staggered and arranged in a row with equal intervals, and attached to the positive copper layer; the source of the upper bridge arm switch tube chip and the anode of the diode chip are vertically connected to the output copper layer through the upper bridge arm bonding wire cluster, and the landing points of each upper bridge arm bonding wire cluster are on the same straight line.

[0031] The lower bridge arm is composed of N switch tube chips and N diode chips (N is greater than or equal to 2); the N switch tube chips and N diode chips of the lower bridge arm are staggered and arranged in a row with equal intervals, placed parallel to the switch tube chip and diode chip of the upper bridge arm, and attached to the output electrode copper layer; the source of the lower bridge arm switch tube chip and the anode of the diode chip are vertically connected to the negative electrode copper layer through the lower bridge arm bonding wire cluster, and the landing points of each lower bridge arm bonding wire cluster are on the same straight line.

[0032] Furthermore, in order to facilitate the connection of the driving bonding wire of the lower bridge arm switch tube chip, the negative electrode copper layer is narrower than the positive electrode copper layer and the output electrode copper layer.

[0033] Furthermore, the DBC substrate and the corresponding copper layer are divided into two pieces, which are connected by a copper layer bonding wire cluster; since the negative copper layer is narrower than the positive copper layer and the output copper layer, in order to obtain better static current sharing characteristics of the lower bridge arm, the number of bonding wires used in the third copper layer bonding wire cluster connecting the negative copper layer is greater than the first copper layer bonding wire cluster and the second copper layer bonding wire cluster connecting the positive copper layer and the output copper.

[0034] Furthermore, the positive electrode copper layer is connected to the positive terminal at the edge, the negative electrode copper layer is connected to the negative terminal on the same side, and the output electrode copper layer is connected to the output terminal on the other side.

[0035] Through this connection method, the length of the current paths between the parallel switch tubes can be consistent, and the length of the current paths between the parallel diode tubes can be consistent, thereby achieving better static current sharing.

[0036] Furthermore, the upper and lower bridge arm switch tube chips are connected to the drive terminals through drive bonding wires and drive copper layers; preferably, a drive resistor is connected in series in the drive circuit of each switch tube so that the drive signals of the parallel switch tube chip switches are consistent; in order to make the resistance value of the external drive resistor more optional, the resistance value of the drive resistor should be as small as possible, preferably 1Ω~3Ω.

[0037] Furthermore, the switch tube can be a silicon chip, a silicon carbide chip or a gallium nitride chip, preferably a silicon carbide chip; the diode is preferably a silicon carbide Schottky diode.

[0038] The present invention provides a multi-chip parallel-connected half-bridge power module, which aims to achieve better static current sharing characteristics.

[0039] Figure 1 FIG. 1 is a schematic diagram of the structure of a half-bridge power module with multiple chips connected in parallel according to an embodiment of the present invention; Figure 2 The figure shows a schematic diagram of a multi-chip parallel half-bridge power module provided by an embodiment of the present invention with the housing and terminals removed;

[0040] The upper bridge arm is composed of an upper bridge arm switch tube 8 and an upper bridge arm diode 9; as a specific embodiment of the present invention, the upper bridge arm switch tube 8 is composed of 4 switch tube chips, and the upper bridge arm diode 9 is composed of 4 diode chips; the upper bridge arm switch tube 8 and the upper bridge arm diode 9 are staggered and arranged in a row with equal spacing; the upper bridge arm switch tube 8 and the upper bridge arm diode 9 are welded on the positive copper layers 12a and 12b; the source of the switch tube 8 and the anode of the diode 9 are vertically connected to the output copper layers 13a and 13b through eight groups of upper bridge arm bonding wire clusters 20, and the landing points of each upper bridge arm bonding wire cluster 20 are located on the same straight line;

[0041] The lower bridge arm is composed of a lower bridge arm switch tube 10 and a lower bridge arm diode 11;

[0042] As a specific embodiment of the present invention, the lower bridge arm switch tube 10 is composed of 4 switch tube chips, and the lower bridge arm diode 11 is composed of 4 diode chips; the lower bridge arm switch tube 10 and the lower bridge arm diode 11 are staggered and arranged in a row with equal spacing; the lower bridge arm switch tube 10 and the lower bridge arm diode 11 are welded on the output electrode copper layers 13a and 13b; the source of the switch tube 10 and the anode of the diode 11 are vertically connected to the negative electrode copper layers 14a and 14b through eight groups of lower bridge arm bonding wire clusters 21, and the landing points of each lower bridge arm bonding wire cluster 21 are located on the same straight line;

[0043] In order to facilitate the connection of the driving bonding wire 22 of the lower bridge arm switch tube chip 10, the negative electrode copper layer is narrower than the positive electrode copper layer and the output electrode copper layer;

[0044] The DBC substrate 23a and 23b and the corresponding copper layer are divided into two pieces, and the two pieces are connected by a copper layer bonding wire cluster; since the negative copper layer is narrower than the positive copper layer and the output copper layer, in order to obtain a better static current sharing characteristic of the lower bridge arm, the number of bonding wires used in the third copper layer bonding wire cluster 19 connecting the negative copper layers 14a and 14b is greater than the first copper layer bonding wire cluster 17 and the second copper layer bonding wire cluster 18 connecting the positive copper layer and the output copper layer;

[0045] The positive copper layers 12a and 12b are connected to the positive terminal 1 at the edge, the negative copper layer 14 is connected to the negative terminal 2 on the same side, and the output copper layers 13a and 13b are connected to the output terminal 3 on the other side;

[0046] Through this connection method, the length of the current paths between the parallel-connected switch tubes can be made consistent, and the length of the current paths between the parallel-connected diodes can be made consistent, thereby achieving better static current sharing.

[0047] Furthermore, the upper and lower bridge arm switch tube chips 8 and 10 are connected to the drive terminals 4 and 5 through the drive bonding wires 22 and the drive copper layer; as a specific embodiment of the present invention, a drive resistor 15 is connected in series in the drive circuit of each switch tube chip 8 and 10, so that the drive signals of the parallel switch tube chips are consistent; the resistance value of the drive resistor 15 is 1Ω to 3Ω;

[0048] As an embodiment of the present invention, the switch tube chips 8 and 10 are selected as silicon carbide switch tube chips, and the diode chips 9 and 11 are selected as silicon carbide Schottky diodes.

[0049] The multi-chip parallel half-bridge power module provided in an embodiment of the present invention also includes: a heat dissipation substrate 24, a housing 25, a thermistor 16, a thermistor terminal 6 and an overcurrent protection terminal 7; wherein the thermistor 16 and the thermistor terminal 6 are used to detect the internal temperature of the module, and the overcurrent protection terminal 7 detects the drain potential of the upper bridge arm switch tube chip 8 for overcurrent protection.

[0050] Figure 3 As shown, it is a schematic diagram of the circuit topology corresponding to the half-bridge power module of multi-chip parallel connection provided by an embodiment of the present invention; each part thereof is similar to Figure 1 and Figure 2 The marked parts correspond to the

[0051] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above examples. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

[0052] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A half-bridge power module, characterized in that: include: Insulating substrate, upper bridge arm, lower bridge arm, positive electrode copper layer, negative electrode copper layer and output electrode copper layer; The positive electrode copper layer, the output electrode copper layer and the negative electrode copper layer are attached to the upper surface of the insulating substrate from top to bottom; the width of the positive electrode copper layer is the same as the width of the output electrode copper layer; The upper bridge arm is composed of N upper switch tubes and N upper diodes; the N upper switch tubes and N upper diodes are arranged alternately, arranged in a first row with equal spacing, and attached to the positive electrode copper layer; each upper switch tube is reversely connected in parallel with its adjacent upper diode, the cathode of the upper diode is welded on the positive electrode copper layer, and the anode of the upper diode is connected to the output electrode copper layer through a bonding wire; the first end of the upper switch tube is welded on the positive electrode copper layer, the second end is connected to the output electrode copper layer through a bonding wire, and the third end is connected to a drive signal; The lower bridge arm is composed of N lower switch tubes and N lower diodes; the N lower switch tubes and N lower diodes are arranged in a staggered manner, arranged in a second row with equal spacing, and attached to the output electrode copper layer; the central axes of the first row and the second row remain parallel; N is an integer greater than or equal to 2; each lower switch tube is reversely connected in parallel with its adjacent lower diode, the cathode of the lower diode is welded on the output electrode copper layer, and the anode of the lower diode is connected to the negative electrode copper layer through a bonding wire; the first end of the lower switch tube is welded on the output electrode copper layer, the second end is connected to the negative electrode copper layer through a bonding wire, and the third end is connected to the drive signal; the specifications and quantity of the bonding wires connecting each upper diode to the output copper layer are the same, the specifications and quantity of the bonding wires connecting each lower diode to the negative electrode copper layer are the same, the specifications and quantity of the bonding wires connecting each upper switch tube to the output electrode copper layer are the same, and the specifications and quantity of the bonding wires connecting each lower switch tube to the negative electrode copper layer are the same; When the upper switch tube and the lower switch tube are MOSFET, the first end is the drain, the second end is the source, and the third end is the gate; when the upper switch tube and the lower switch tube are IGBT, the first end is the collector, the second end is the emitter, and the third end is the gate.

2. The half-bridge power module according to claim 1, characterized in that: The insulating substrate is divided into two symmetrical parts: a left insulating substrate and a right insulating substrate; The upper bridge arm, the lower bridge arm, the positive electrode copper layer, the negative electrode copper layer and the output electrode copper layer are symmetrically distributed on the upper surfaces of the left insulating substrate and the right insulating substrate; The positive copper layers on the left insulating substrate and the right insulating substrate are connected by positive copper layer bonding wires, the negative copper layers on the left insulating substrate and the right insulating substrate are connected by negative copper layer bonding wires, and the output copper layers on the left insulating substrate and the right insulating substrate are connected by output copper layer bonding wires, so as to realize electrical connection between the left insulating substrate and the right insulating substrate; the number of the positive copper layer bonding wires is the same as the number of the output copper layer bonding wires; The specifications of the bonding wires connecting the left insulating substrate and the right insulating substrate are the same.

3. The half-bridge power module according to claim 1, characterized in that: The bonding wires connecting the upper switch tube and the upper diode to the output electrode copper layer are located on the same straight line parallel to the central axis at the output electrode copper layer; The bonding wires connecting the lower switch tube and the lower diode to the negative electrode copper layer are located at the same straight line parallel to the central axis at the landing point of the negative electrode copper layer.

4. The half-bridge power module according to claim 2, characterized in that: The width of the negative electrode copper layer is smaller than the width of the positive electrode copper layer and the width of the output electrode copper layer, so that the third end of the lower switch tube is connected to the lower driving copper layer through the driving bonding wire, so that the third end of the lower switch tube receives the driving signal; the lower driving copper layer is located at the lower end of the negative electrode copper layer; The number of bonding wires of the negative electrode copper layer is greater than the number of bonding wires of the positive electrode copper layer, so as to compensate for the inconsistent resistance of the output electrode copper layer and the negative electrode copper layer per unit length on the current path when the lower switch tube or the lower diode is turned on due to the narrowing of the width of the negative electrode copper layer, so that the resistance on the current path of the lower switch tube or the lower diode connected in parallel on the left insulating substrate and the right insulating substrate can be kept consistent.

5. The half-bridge power module according to claim 2, characterized in that: The third end of the upper switch tube is connected to the upper drive copper layer through a drive bonding wire, so that the third end of the upper switch tube receives a drive signal; the upper drive copper layer is located at the upper end of the positive electrode copper layer.

6. The half-bridge power module according to any one of claims 1 to 5, characterized in that: A driving resistor is connected in series in the driving loop of each upper switch tube and the lower switch tube, so that the driving signals of each switch tube are consistent.

7. The half-bridge power module according to any one of claims 1 to 5, characterized in that: Also includes: Heat dissipation substrate; the insulating substrate is placed on the heat dissipation substrate.

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