WO2021230617A1

WO2021230617A1 - Power module

Info

Publication number: WO2021230617A1
Application number: PCT/KR2021/005876
Authority: WO
Inventors: 김종욱
Original assignee: 주식회사 아모센스
Priority date: 2020-05-15
Filing date: 2021-05-11
Publication date: 2021-11-18
Also published as: KR20210141371A

Abstract

The present invention relates to a power module comprising: a ceramic board (300) which includes a ceramic base material and electrode patterns formed on the top surface and the bottom surface of the ceramic base material; a housing (100) to which the ceramic board (300) is mounted and which has terminals disposed at both ends; and bus bars (700) for connecting the electrode patterns of the ceramic board (300) and the terminals through surface-to-surface bonding. The present invention has the advantage of minimizing resistance and heat generation by using the bus bars having a structure that passes high current or low resistance of voltage.

Description

power module

The present invention relates to a power module, and more particularly, to a power module having improved performance by applying a high output power semiconductor chip.

The power module is used to supply high voltage current to drive motors such as hybrid vehicles and electric vehicles.

Among the power modules, the double-sided cooling power module has a substrate on top and a bottom of a semiconductor chip, respectively, and a heat sink on an outer surface of the substrate, respectively. The double-sided cooling power module has an excellent cooling performance compared to a single-sided cooling power module having a heat sink on one side, and thus its use is gradually increasing.

The double-sided cooling power module used in electric vehicles, etc., has a power semiconductor chip such as silicon carbide (SiC) and gallium nitride (GaN) mounted between the two substrates. It is important to satisfy both high strength and high heat dissipation characteristics at the same time.

An object of the present invention is to provide a power module that has high strength and high heat dissipation characteristics, has excellent bonding characteristics, can reduce a volume by minimizing a current path, and can improve efficiency and performance.

Another object of the present invention is to provide a power module in which resistance is as low as possible and heat generation is minimized by applying a bus bar having a structure that passes a low resistance of a large current or voltage.

Another object of the present invention is to provide a power module maximizing the flexibility of a bus bar.

Another object of the present invention is to connect both sides of a bus bar to a terminal and an electrode pattern (metal layer) of a ceramic substrate to improve bonding performance and apply a laser welding method to implement a structure for passing large current and voltage. to provide a module.

According to a feature of the present invention for achieving the above object, the power module of the present invention includes a ceramic substrate including a ceramic substrate and electrode patterns formed on upper and lower surfaces of the ceramic substrate, and the ceramic substrate is installed at both ends. It includes a housing in which the terminals are disposed, and a bus bar connecting the electrode pattern of the ceramic substrate and the terminal face-to-face.

The bus bar may be a copper ribbon having a predetermined area.

The bus bar may include a laser welding region bonded to the terminal and a laser on one side and a laser welding region bonded to the electrode pattern and a laser on the other side of the bus bar.

In the bus bar, an area of a laser welding region bonded to the terminal and a laser may be relatively larger than an area of a laser welding region bonded to the electrode pattern and a laser.

The busbar may have a curved structure.

The busbar may have a thickness ranging from 0.1 mm to 0.5 mm.

The electrode pattern includes a first electrode pattern, a second electrode pattern, and a third electrode pattern, the terminal includes a first terminal and a second terminal, the bus bar connects the first terminal and the first electrode pattern, The first terminal and the third electrode pattern may be connected, and three for connecting the second terminal and the second electrode pattern may be included.

The bus bar may have a through slot formed therein.

The bus bar includes a first laser welding region bonded to the terminal and a laser on one side and a second laser welding region bonded to the electrode pattern and a laser on the opposite side on the other side, and the through slot includes the first laser welding region and the first laser welding region. It may be formed between two laser welding regions.

A plurality of through slots may be formed at regular intervals in the horizontal or vertical direction.

The bus bar may be formed to have a relatively high height on the other side compared to one side and to be curved.

The bus bar may be formed so that an intermediate portion connecting one side and the other side is curved.

The bus bar may be respectively bonded to the terminal and the electrode pattern of the ceramic substrate by laser welding.

Laser welding may be formed in a zigzag pattern shape.

The present invention has high strength and high heat dissipation characteristics, has excellent bonding characteristics, can reduce a volume by minimizing a current path, and is optimized for high-speed switching to improve efficiency and performance.

In addition, the present invention has an effect of lowering the resistance as much as possible and minimizing heat generation by applying a bus bar having a structure that passes a low resistance of a large current or voltage.

In addition, the present invention has the effect of maximizing the bondability of the bus bar by using the laser welding method, and simplifying the process of connecting the bus bar to the terminal and the electrode pattern.

In addition, the present invention has the effect of maximizing the flexibility of the bus bar even when a relatively thick copper ribbon is applied, thereby preventing deterioration and damage of the copper ribbon due to torsion or vibration between connection parts, and external impact.

In addition, the present invention has the effect of maximizing the bonding performance by applying a large-area laser welding method to connect both sides of the bus bar to the terminal and the electrode pattern (metal layer) of the ceramic substrate.

In addition, since the present invention performs laser welding in a zigzag pattern shape, a large junction area is secured and a structure that passes a low resistance of a large current or voltage is implemented, while the resistance can be lowered to the maximum and heat generation can be minimized. .

1 is a perspective view of a power module according to an embodiment of the present invention.

2 is an exploded perspective view of a power module according to an embodiment of the present invention.

3 is a side cross-sectional view of a power module according to an embodiment of the present invention.

4 is a perspective view showing a housing according to an embodiment of the present invention.

5 is a perspective view showing a lower ceramic substrate according to an embodiment of the present invention.

6 is a view showing an upper surface and a lower surface of a lower ceramic substrate according to an embodiment of the present invention.

7 is a perspective view showing an upper ceramic substrate according to an embodiment of the present invention.

8 is a view showing an upper surface and a lower surface of an upper ceramic substrate according to an embodiment of the present invention.

9 is a plan view of a PCB substrate according to an embodiment of the present invention.

10 is a perspective view illustrating a state in which a connection pin and a bus bar are installed on an upper ceramic substrate according to an embodiment of the present invention.

11 is a perspective view showing a bus bar according to an embodiment of the present invention.

12 is a photograph showing a laser welding area of a bus bar according to an embodiment of the present invention.

13 is a side cross-sectional view illustrating a state in which a bus bar connects a terminal and an electrode pattern according to an embodiment of the present invention.

14 is a perspective view showing a bus bar according to another embodiment of the present invention.

15 is a cross-sectional view showing a bus bar connecting a terminal and a metal layer of a ceramic substrate according to an embodiment of the present invention.

16 is a perspective view illustrating a shape of a bus bar according to an embodiment of the present invention.

17 is a diagram of a bus bar for explaining a laser welding shape according to an embodiment of the present invention.

*Description of symbols*

10: power module 100: housing

101: guide rib 102: locking jaw

103: fastening hole 104: support hole

200: lower ceramic substrate 201: ceramic substrate

202,203: metal layer 210: NTC temperature sensor

220: insulation spacer 230: interconnection spacer

300: upper ceramic substrate 301: ceramic substrate

302,302: metal layer 310: cutting part

320: through hole 330: via hole

400: PCB board 401: guide groove

410: capacitor 500: heat sink

501: through hole 610: first terminal

620: second terminal 630: support bolt

700: bus bar 900: connecting pin

710, 720: laser welding area 730: through slot

G: semiconductor chip (GaN chip)

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a power module according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a power module according to an embodiment of the present invention.

1 and 2 , the power module 10 according to the embodiment of the present invention is an electronic component in the form of a package formed by accommodating various components constituting the power module in a housing 100 . The power module 10 is formed in a form to protect by arranging a substrate and elements in the housing 100 .

The power module 10 may include a plurality of substrates and a plurality of semiconductor chips. The power module 10 according to the embodiment includes a housing 100 , a lower ceramic substrate 200 , an upper ceramic substrate 300 , a PCB substrate 400 , and a heat sink 500 .

The housing 100 has an empty space that is opened vertically in the center, and the first terminal 610 and the second terminal 620 are positioned on both sides. In the housing 100, a heat sink 500, a lower ceramic substrate 200, an upper ceramic substrate 300, and a PCB substrate 400 are sequentially stacked at regular intervals up and down in the empty space in the center, and the first terminals on both sides A support bolt 630 for connecting the external terminal to the 610 and the second terminal 620 is fastened. The first terminal 610 and the second terminal 620 are used as input/output terminals of power.

As shown in FIG. 2 , in the power module 10 , the lower ceramic substrate 200 , the upper ceramic substrate 300 , and the PCB substrate 400 are sequentially accommodated in an empty space in the center of the housing 100 . Specifically, the heat sink 500 is disposed on the lower surface of the housing 100, the lower ceramic substrate 200 is attached to the upper surface of the heat sink 500, and the upper ceramic substrate 300 is on the upper side of the lower ceramic substrate 200. These are arranged at a predetermined interval, and the PCB substrate 400 is arranged at a predetermined interval on the upper ceramic substrate 300 .

The state in which the PCB substrate 400 is disposed in the housing 100 is the

guide grooves

401 and 402 formed to be recessed into the edge of the PCB substrate 400 and the guide ribs 101 formed in the housing 100 to correspond to the

guide grooves

401 and 402 . ) and the locking jaw 102 may be fixed. A plurality of

guide grooves

401 and 402 are formed around the edge of the PCB substrate 400 according to the embodiment, and some of the guide grooves 401 are guided by the guide rib 101 formed on the inner surface of the housing 100 . and the guide groove 402 of the remaining part of them is hung through the locking protrusion 102 formed on the inner surface of the housing 100 .

Alternatively, the heat sink 500, the lower ceramic substrate 200, and the upper ceramic substrate 300 are accommodated in the empty space in the center of the housing 100, and the state in which the PCB substrate 400 is disposed on the upper surface is a fastening bolt ( (not shown) may be fixed. However, fixing the PCB substrate 400 to the housing 100 with a guide groove and a clasp structure reduces the assembly time and simplifies the assembly process compared to the case of fixing with a fastening bolt.

The housing 100 has fastening holes 103 formed at four corners. The fastening hole 103 communicates with the communication hole 501 formed in the heat sink 500 . The fixing bolt 150 is fastened through the fastening hole 103 and the communication hole 501 , and the end of the fixing bolt 150 passing through the fastening hole 103 and the communication hole 501 is the heat sink 500 . It may be fastened to a fixing hole of a fixing jig to be disposed on the lower surface.

The bus bar 700 is connected to the first terminal 610 and the second terminal 620 . The bus bar 700 connects the first terminal 610 and the second terminal 620 to the upper ceramic substrate 300 . Three bus bars 700 are provided. One of the bus bars 700 connects the + terminal of the first terminals 610 to the first electrode pattern a of the upper ceramic substrate 300 , and the other connects the - terminal among the first terminals 610 . It is connected to the three electrode pattern (c), and the other one connects the second terminal 620 to the second electrode pattern (b). The first electrode pattern (a), the second electrode pattern (b), and the third electrode pattern (c) will be described later with reference to FIGS. 7 and 10 .

As shown in FIG. 3 , the power module 10 has a multilayer structure of a lower ceramic substrate 200 and an upper ceramic substrate 300 , and a semiconductor chip between the lower ceramic substrate 200 and the upper ceramic substrate 300 . (G) is located. The semiconductor chip (G) is any one of GaN (Gallium Nitride) chip, MOSFET (Metal Oxide Semiconductor Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), JFET (Junction Field Effect Transistor), HEMT (High Electric Mobility Transistor) However, preferably, the semiconductor chip (G) uses a GaN chip. The GaN (Gallium Nitride) chip (G) is a semiconductor chip that functions as a high-power (300A) switch and a high-speed (~1MHz) switch. The GaN chip has the advantage of being stronger in heat than the existing silicon-based semiconductor chip and reducing the size of the chip.

The lower ceramic substrate 200 and the upper ceramic substrate 300 are formed of a ceramic substrate including a metal layer brazed to at least one surface of the ceramic substrate and the ceramic substrate to increase the heat dissipation efficiency of the heat generated from the semiconductor chip (G). do.

The ceramic substrate may be, for example, any one of _{alumina (Al 2} O ₃ ), AlN, SiN, and Si ₃ N _{4 .} The metal layer is formed of an electrode pattern for mounting a semiconductor chip (G) and an electrode pattern for mounting a driving element, respectively, with a metal foil brazed on a ceramic substrate. For example, the metal layer is formed as an electrode pattern in a region where a semiconductor chip or peripheral components are to be mounted. The metal foil may be an aluminum foil or a copper foil as an example. For example, the metal foil is fired at 780° C. to 1100° C. on a ceramic substrate and brazed to the ceramic substrate. Such a ceramic substrate is called an AMB substrate. Although the embodiment is described by taking an AMB substrate as an example, a DBC substrate, a TPC substrate, and a DBA substrate may be applied. However, in terms of durability and heat dissipation efficiency, AMB substrates are most suitable. For the above reasons, the lower ceramic substrate 200 and the upper ceramic substrate 300 are AMB substrates as an example.

The PCB substrate 400 is disposed on the upper ceramic substrate 300 . That is, the power module 10 has a three-layer structure of a lower ceramic substrate 200 , an upper ceramic substrate 300 , and a PCB substrate 400 . The semiconductor chip (G) for high power control is disposed between the upper ceramic substrate 200 and the lower ceramic substrate 300 to increase heat dissipation efficiency, and the PCB substrate 400 for low power control is disposed on the uppermost portion of the semiconductor Prevents damage to the PCB substrate 400 due to the heat generated in the chip (G). The lower ceramic substrate 200 , the upper ceramic substrate 300 , and the PCB substrate 400 may be connected or fixed with pins.

The heat sink 500 is disposed under the lower ceramic substrate 200 . The heat sink 500 is for dissipating heat generated from the semiconductor chip (G). The heat sink 500 is formed in a rectangular plate shape having a predetermined thickness. The heat sink 500 is formed in an area corresponding to the housing 100 and may be formed of copper or aluminum to increase heat dissipation efficiency.

Hereinafter, the characteristics of each configuration of the power module of the present invention will be described in more detail. In the drawings for explaining the characteristics of each configuration of the power module, there are parts that are enlarged or exaggerated in order to emphasize the characteristics of each configuration, so there may be parts that do not match the basic drawings shown in FIG. 1 .

As shown in FIG. 4 , an empty space is formed in the center of the housing 100 , and a first terminal 610 and a second terminal 620 are positioned at both ends. The housing 100 may be formed by an insert injection method such that the first terminal 610 and the second terminal 620 are integrally fixed at both ends.

Existing power modules are applied by inserting and injecting connecting pins into the housing to connect spaced circuits, but this embodiment has a shape manufactured by excluding the connecting pins when the housing 100 is manufactured. This simplifies the shape because the connecting pin is not located inside the housing 100 to improve flexibility in the torsional moment of the power module.

The housing 100 has fastening holes 103 formed at four corners. The fastening hole 103 communicates with the communication hole 501 formed in the heat sink 500 . A support hole 104 is formed in the first terminal 610 and the second terminal 620 . A support bolt 630 for connecting the first terminal 610 and the second terminal 620 to an external terminal such as a motor is fastened to the support hole 104 (see FIG. 10 ).

The housing 100 is formed of a heat insulating material. The housing 100 may be formed of a heat insulating material so that heat generated from the semiconductor chip G is not transferred to the PCB substrate 400 above through the housing 100 .

Alternatively, the housing 100 may be made of a heat-dissipating plastic material. The housing 100 may be formed of a heat-dissipating plastic material so that heat generated from the semiconductor chip G can be radiated to the outside through the housing 100 . For example, the housing 100 may be formed of engineering plastic. Engineering plastics have high heat resistance, excellent strength, chemical resistance and abrasion resistance, and can be used for a long time at 150℃ or higher. The engineering plastic may be made of one of polyamide, polycarbonate, polyester, and modified polyphenylene oxide.

The semiconductor chip (G) operates repeatedly as a switch, which causes the housing 100 to be stressed by high temperature and temperature changes. It also has excellent heat dissipation properties.

In the embodiment, the housing 100 may be manufactured by insert-injecting a terminal made of aluminum or copper to an engineering plastic material. The housing 100 made of an engineering plastic material radiates heat to the outside by propagating heat. The housing 100 may be made of a high heat dissipation engineering plastic that may have higher thermal conductivity than a general engineering plastic material and is lightweight compared to aluminum by filling the resin with a high thermal conductivity filler.

Alternatively, the housing 100 may have heat dissipation properties by applying a graphene heat dissipation coating material to the inside and outside of an engineering plastic or high-strength plastic material.

3 and 5 , the lower ceramic substrate 200 is attached to the upper surface of the heat sink 500 . Specifically, the lower ceramic substrate 200 is disposed between the semiconductor chip G and the heat sink 500 . The lower ceramic substrate 200 transfers heat generated from the semiconductor chip G to the heat sink 500 and insulates between the semiconductor chip G and the heat sink 500 to prevent a short circuit.

The lower ceramic substrate 200 may be soldered to the upper surface of the heat sink 500 . The heat sink 500 is formed in an area corresponding to the housing 100 and may be formed of a copper material to increase heat dissipation efficiency. As a solder for soldering joint, SnAg, SnAgCu, etc. may be used.

5 and 6 , the lower ceramic substrate 200 includes a ceramic substrate 201 and metal layers 202 and 203 brazed to upper and lower surfaces of the ceramic substrate 201 . In the lower ceramic substrate 200 , the thickness of the ceramic substrate 201 may be 0.68 t, and the thickness of the metal layers 202 and 203 formed on the upper and lower surfaces of the ceramic substrate 201 may be 0.8 t.

The metal layer 202 of the upper surface 200a of the lower ceramic substrate 200 may be an electrode pattern on which a driving element is mounted. The driving device mounted on the lower ceramic substrate 200 may be the NTC temperature sensor 210 . The NTC temperature sensor 210 is mounted on the upper surface of the lower ceramic substrate 200 . The NTC temperature sensor 210 is for providing temperature information in the power module due to heat generation of the semiconductor chip G. The metal layer 203 of the lower surface 200b of the lower ceramic substrate 200 may be formed on the entire lower surface of the lower ceramic substrate 200 to facilitate heat transfer to the heat sink 500 .

An insulating spacer 220 is bonded to the lower ceramic substrate 200 . The insulating spacer 220 is bonded to the upper surface of the lower ceramic substrate 200 and defines a separation distance between the lower ceramic substrate 200 and the upper ceramic substrate 300 .

The insulating spacer 220 defines the separation distance between the lower ceramic substrate 200 and the upper ceramic substrate 300 to increase the heat dissipation efficiency of the heat generated by the semiconductor chip G mounted on the lower surface of the upper ceramic substrate 300, Interference between the semiconductor chips G is prevented to prevent an electric shock such as a short circuit.

A plurality of insulating spacers 220 are bonded to each other at predetermined intervals around the upper surface edge of the lower ceramic substrate 200 . A gap between the insulating spacers 220 is used as a space to increase heat dissipation efficiency. In the drawing, the insulating spacers 220 are arranged around the edge of the lower ceramic substrate 200 as a reference, and for example, eight insulating spacers 220 are arranged at regular intervals.

The insulating spacer 220 is integrally bonded to the lower ceramic substrate 200 . The insulating spacer 220 may be applied to check alignment when the upper ceramic substrate 300 is disposed on the lower ceramic substrate 200 . When the upper ceramic substrate 300 on which the semiconductor chip G is mounted is disposed in a state where the insulating spacer 220 is bonded to the lower ceramic substrate 200 , the insulating spacer 220 is formed on the upper ceramic substrate 300 . ) can be applied to check the alignment of In addition, the insulating spacer 220 supports the lower ceramic substrate 200 and the upper ceramic substrate 300 , thereby contributing to preventing bending of the lower ceramic substrate 200 and the upper ceramic substrate 300 .

The insulating spacer 220 may be formed of a ceramic material for insulation between the chip mounted on the lower ceramic substrate 200 and the chip and the component mounted on the upper ceramic substrate 300 . For example, the insulating spacer _{may be formed of one selected from Al 2} O ₃ , ZTA, Si ₃ N ₄ , and AlN, or an alloy in which two or more thereof are mixed. Al ₂ O ₃ , ZTA, Si ₃ N ₄ , and AlN are insulating materials having excellent mechanical strength and heat resistance.

The insulating spacer 220 is brazed to the lower ceramic substrate 200 . When the insulating spacer 220 is soldered to the lower ceramic substrate 200, the substrate may be damaged due to thermal and mechanical shock during soldering or pressure firing, so that it is bonded by brazing. For the brazing bonding, a brazing bonding layer including an AgCu layer and a Ti layer may be used. Heat treatment for brazing can be performed at 780°C to 900°C. After brazing, the insulating spacer 220 is integrally formed with the metal layer 202 of the lower ceramic substrate 200 . The thickness of the brazing bonding layer is 0.005 mm to 0.08 mm, which is thin enough not to affect the height of the insulating spacer, and the bonding strength is high.

An interconnection spacer 230 is installed between the lower ceramic substrate 200 and the upper ceramic substrate 300 . The interconnection spacer 230 may perform electrical connection between electrode patterns in place of a connection pin in a substrate having an upper and lower multilayer structure. The interconnection spacer 230 may directly connect between substrates while preventing electrical loss and short circuit, increase bonding strength, and improve electrical characteristics. One end of the interconnection spacer 230 may be bonded to the electrode pattern of the lower ceramic substrate 200 by a brazing bonding method. In addition, the other end of the interconnection spacer 230 may be bonded to the electrode pattern of the upper ceramic substrate 300 by a brazing bonding method or a soldering bonding method. The interconnection spacer 230 may be Cu or a Cu+CuMo alloy.

7 is a perspective view showing an upper ceramic substrate according to an embodiment of the present invention, and FIG. 8 is a view showing an upper surface and a lower surface of the upper ceramic substrate according to an embodiment of the present invention.

7 and 8 , the upper ceramic substrate 300 is disposed on the lower ceramic substrate 200 .

The upper ceramic substrate 300 is an intermediate substrate having a stacked structure. The upper ceramic substrate 300 has a semiconductor chip (G) mounted on its lower surface, and constitutes a high-side circuit and a low-side circuit for high-speed switching.

The upper ceramic substrate 300 includes a ceramic substrate 301 and

metal layers

302 and 303 brazed to upper and lower surfaces of the ceramic substrate 301 . For the upper ceramic substrate 300, the thickness of the ceramic substrate is 0.38t and the thickness of the electrode pattern on the upper surface 300a and the lower surface 300b of the ceramic substrate is 0.3t as an example. The ceramic substrate must have the same pattern thickness on the upper and lower surfaces to prevent distortion during brazing.

The electrode pattern formed by the metal layer 302 on the upper surface of the upper ceramic substrate 300 is divided into a first electrode pattern (a), a second electrode pattern (b), and a third electrode pattern (c). The electrode pattern formed by the metal layer 303 on the lower surface of the upper ceramic substrate 300 corresponds to the electrode pattern formed by the metal layer 302 on the upper surface of the upper ceramic substrate 300 . The division of the electrode pattern on the upper surface of the upper ceramic substrate 300 into a first electrode pattern (a), a second electrode pattern (b), and a third electrode pattern (c) is a high-side circuit for high-speed switching. and to separate the low-side circuit.

The semiconductor chip G is provided in the form of a flip chip by an adhesive layer such as solder or silver paste on the lower surface 300b of the upper ceramic substrate 300 . As the semiconductor chip G is provided in the form of a flip chip on the lower surface of the upper ceramic substrate 300 , wire bonding is omitted so that the inductance value can be reduced as much as possible, thereby improving the heat dissipation performance.

As shown in FIG. 8 , two semiconductor chips G may be connected in parallel for high-speed switching. Two semiconductor chips (G) are disposed at positions connecting the first electrode pattern (a) and the second electrode pattern (b) among the electrode patterns of the upper ceramic substrate 300, and the other two are the second electrode patterns (b). ) and the third electrode pattern (c) are arranged in parallel at a position connecting it. For example, the capacity of one semiconductor chip G is 150A. Therefore, two semiconductor chips (G) are connected in parallel so that the capacity becomes 300A. The semiconductor chip G is a GaN chip.

The purpose of the power module using the semiconductor chip G is high-speed switching. For high-speed switching, it is important that the gate drive IC terminal be connected by a very short distance between the gate terminal of the semiconductor chip (G). Therefore, the connection distance between the gate drive IC and the gate terminal is minimized by connecting the semiconductor chips G in parallel. In addition, in order for the semiconductor chip G to switch at high speed, it is important that the gate terminal and the source terminal of the semiconductor chip G maintain the same distance. To this end, the gate terminal and the source terminal may be disposed such that the connection pin is connected to the center between the semiconductor chip G and the semiconductor chip G. If the gate terminal and the source terminal do not keep the same distance or the length of the pattern is different, a problem occurs.

The gate terminal is a terminal for turning on/off the semiconductor chip G by using a low voltage. The gate terminal may be connected to the PCB substrate 400 through a connection pin. Source terminal is a terminal for high current to enter and exit. The semiconductor chip G includes a drain terminal, and the source terminal and the drain terminal are divided into N-type and P-type so that the direction of the current can be changed. The source terminal and the drain terminal are responsible for input and output of current through the first electrode pattern (a), the second electrode pattern (b), and the third electrode pattern (c), which are electrode patterns for mounting the semiconductor chip (G). The source terminal and the drain terminal are connected to the first terminal 610 and the second terminal 620 of FIG. 1 in charge of input and output of power.

1 and 8 , the first terminal 610 shown in FIG. 1 includes a + terminal and a - terminal, and power introduced from the first terminal 610 to the + terminal is the upper portion shown in FIG. 8 . Through the first electrode pattern (a) of the ceramic substrate 300, the semiconductor chip (G) and the second electrode pattern (b) disposed between the first electrode pattern (a) and the second electrode pattern (b) 2 is output to the terminal 620 . And the power supplied to the second terminal 620 shown in FIG. 1 is disposed between the second electrode pattern (b), the second electrode pattern (b) and the third electrode pattern (c) shown in FIG. 8 . It is output to the - terminal of the first terminal 610 through the semiconductor chip G and the third electrode pattern c. For example, power flowing in from the first terminal 610 and passing through the semiconductor chip G and output to the second terminal 620 is supplied from the high side and the second terminal 620 and the semiconductor chip G ) through the power output to the first terminal 610 becomes a low side (Low Side).

As shown in FIG. 7 , the upper ceramic substrate 300 may have a cutting part 310 formed in a portion corresponding to the NTC temperature sensor 210 . An NTC temperature sensor 210 is mounted on the upper surface of the lower ceramic substrate 200 . The NTC temperature sensor 210 is for providing temperature information in the power module due to heat generation of the semiconductor chip G. However, since the thickness of the NTC temperature sensor 210 is thicker than the gap between the lower ceramic substrate 200 and the upper ceramic substrate 300 , interference between the NTC temperature sensor 210 and the upper ceramic substrate 300 occurs. In order to solve this problem, the upper ceramic substrate 300 of the portion that interferes with the NTC temperature sensor 210 is cut to form a cutting portion 310 .

A silicone liquid or epoxy for molding may be injected into the space between the upper ceramic substrate 300 and the lower ceramic substrate 200 through the cutting part 310 . In order to insulate between the upper ceramic substrate 300 and the lower ceramic substrate 200, silicone liquid or epoxy must be injected. In order to inject silicon liquid or epoxy into the upper ceramic substrate 300 and the lower ceramic substrate 200, one side of the upper ceramic substrate 300 may be cut to form a cutting part 310, and the cutting part 310 may be formed. is formed at a position corresponding to the NTC temperature sensor 210 to prevent interference between the upper ceramic substrate 300 and the NTC temperature sensor 210 . Silicon liquid or epoxy is used in the space between the lower ceramic substrate 200 and the upper ceramic substrate 300 and the upper ceramic substrate 300 and the PCB substrate 400 for the purpose of protecting the semiconductor chip (G), alleviating vibration, and insulating. You can fill in the space between them.

A through hole 320 is formed in the upper ceramic substrate 300 . The through hole 320 connects the semiconductor chip G mounted on the upper ceramic substrate 300 to the driving device mounted on the PCB substrate 400 in the shortest distance in the substrate structure of the upper and lower multilayers, and the lower ceramic substrate 200 It is for connecting the NTC temperature sensor 210 mounted to the PCB substrate 400 with the driving device mounted on the shortest distance.

Eight through-holes 320 are formed at a position where the semiconductor chip is installed, and two through-holes are installed at a position where the NTC temperature sensor is installed, so that a total of 10 can be formed. In addition, a plurality of through-holes 320 may be formed in the portion where the first electrode pattern a and the third electrode pattern c are formed in the upper ceramic substrate 300 .

The plurality of through-holes 320 formed in the first electrode pattern (a) allow the current flowing into the first electrode pattern (a) of the upper surface of the upper ceramic substrate 300 to be formed on the lower surface of the upper ceramic substrate 300 . It moves to the electrode pattern (a) and flows into the semiconductor chip (G). The plurality of through-holes 320 formed in the third electrode pattern (c) allow the current flowing into the semiconductor chip (G) to pass through the third electrode pattern (c) of the lower surface of the upper ceramic substrate (300) to the upper ceramic substrate (300). ) to move to the third electrode pattern (c) on the upper surface.

The through hole 320 may have a diameter of 0.5 mm to 5.0 mm. A connection pin is installed in the through hole 320 to be connected to the electrode pattern of the PCB substrate, and may be connected to the driving device mounted on the PCB substrate 400 through this. The connection between the electrode patterns through the through-holes 320 and the connection pins installed in the through-holes 320 in the upper and lower multi-layered substrate structure eliminates various output losses through the shortest distance connection, thereby improving the constraints according to the size of the power module. can contribute

A plurality of via holes 330 may be formed in the electrode pattern of the upper ceramic substrate 300 . The via hole 330 may be processed by at least 50% of the substrate area. The area of the via hole 330 described above has been described as an example in which at least 50% or more of the substrate area is applied, but is not limited thereto, and may be processed to 50% or less.

For example, 152 via holes may be formed in the first electrode pattern (a), 207 via holes may be formed in the second electrode pattern (b), and 154 via holes may be formed in the third electrode pattern (c). The plurality of via holes 330 formed in each electrode pattern are for conducting a large current and distributing a large current. When the electrode pattern on the upper surface and the electrode pattern on the lower surface of the upper ceramic substrate 300 are conducted in the form of a single slot, a high current flows only to one side, and problems such as short circuit and overheating may occur.

The via hole 330 is filled with a conductive material. The conductive material may be Ag or an Ag alloy. The Ag alloy may be an Ag-Pd paste. The conductive material filled in the via hole 330 electrically connects the electrode pattern on the upper surface and the electrode pattern on the lower surface of the upper ceramic substrate 300 . The via hole 330 may be formed by laser processing. The via hole 330 can be seen in the enlarged view of FIG. 8 .

As shown in FIG. 9 , the PCB substrate 400 is for switching the semiconductor chip G or for switching the semiconductor chip (GaN chip) using information sensed by the NTC temperature sensor (reference numeral 210 in FIG. 7 ). The driving element is mounted. The driving device includes a Gate Drive IC.

A capacitor 410 is mounted on the PCB substrate 400 . The capacitor 410 includes a semiconductor chip G disposed to connect the first electrode pattern a and the second electrode pattern b of the upper ceramic substrate 300 and the second electrode pattern (G) of the upper ceramic substrate 300 . It is mounted on the upper surface of the PCB substrate 400 at a position corresponding to a position between the semiconductor chip G disposed to connect b) and the third electrode pattern c.

When the capacitor 410 is mounted on the upper surface of the PCB substrate 400, which is a position between the semiconductor chips G, the semiconductor chip G and the Drive IC circuit using a connection pin (reference numeral 900 in FIG. 10). can be connected in the shortest distance, which is more advantageous for high-speed switching. As an example, ten capacitors 410 may be connected in parallel to match their capacity. In order to secure more than 2.5㎌ for decoupling at the input terminal, 10 high-voltage capacitors must be connected to secure the capacity. The related formula is confirmed at 56㎌/630V×5ea = 2.8㎌. The gate drive IC circuit includes a high side gate drive IC and a low side gate drive IC.

As shown in FIG. 10 , the power module 10 includes a connection pin 910 for performing electrical connection between electrode patterns.

The connection pin 910 is inserted into the through hole formed in the upper ceramic substrate 300 and the PCB substrate 400 to connect the gate terminal for mounting the semiconductor chip G and the electrode pattern for mounting the driving device. . Alternatively, the connection pin 910 is inserted into a through hole formed in the lower ceramic substrate 200, the upper ceramic substrate 300, and the PCB substrate 400 to mount the terminal and the driving element of the NTC temperature sensor. can be connected Alternatively, the connection pin 910 is inserted into the through hole formed in the upper ceramic substrate 300 and the PCB substrate 400 to connect the electrode pattern on which the semiconductor chip G is mounted and the electrode pattern on which the capacitor is mounted. have.

The connection pin 910 connects the GaN chip mounted on the upper ceramic substrate 300 to the driving device mounted on the PCB substrate with the shortest distance, thereby eliminating various output losses and enabling high-speed switching.

The connection pin 910 is installed on the upper ceramic substrate 300 . The connection pin 910 may be manufactured as a bundle type connection pin 900 by connecting a plurality of connection pins 910 to each other in order to maintain the verticality of the pins. The connection pin 910 may be manufactured in the form of a 2×2 pin, a 2×1 pin, or a 4×1 pin. Each of the connecting pins 910 may have a cylindrical shape, and a circular wing portion 911 may be formed on the outer periphery. The cylindrical connecting pin 910 may be inserted into a through hole (reference numeral 320 in FIG. 7 ) and soldered.

The bundle type connecting pin 900 may be formed by insert-injecting the plastic structure 920 into the plurality of connecting pins 910 . In the spaced electrode structure of the power module, there are a plurality of connection pins 910 connecting the spaced apart electrodes. Therefore, when the connecting pin 910 is manufactured as a bundle type connecting pin 900 in a structure for connecting a plurality of connecting pins 910 to each other, the positional accuracy of the connecting pin 910 and the convenience of assembly are increased to enhance the assembly of the power module 10 . Operation reliability can be improved.

As shown in FIGS. 10 and 11 , a bus bar 700 connecting the upper ceramic substrate 300 to

terminals

610 and 620 installed at both ends of the housing 100 is included.

There are three bus bars 700 , one connecting the + terminal of the first terminals 610 to the first electrode pattern a of the upper ceramic substrate 300 , and the other one connecting the first terminal 610 . The middle - terminal is connected to the third electrode pattern (c), and the other terminal is connected to the second terminal (620) and the second electrode pattern (b).

As shown in FIG. 11 , the bus bar 700 is formed in a copper ribbon shape having a predetermined area and includes a laser welding area 710 bonded to a terminal and a laser on one side and an electrode on the other side. and a laser welding region 720 bonded to the pattern. The bus bar 700 in the shape of a large-area copper ribbon connects the

terminals

610 and 620 and the electrode pattern of the upper ceramic substrate 300 by a laser welding method. This maximizes bonding performance, simplifies the process, and reduces resistance as much as possible to facilitate large current movement compared to wire connection or edge bonding.

The bus bar 700 has a larger area than the laser welding region 720 in which the laser welding region 710 bonded to the

terminals

610 and 620 is bonded to the electrode patterns a, b, and c of the upper ceramic substrate 300 . . The large-area laser welding region 710 reduces the resistance of the large power as much as possible. Furthermore, laser welding over a large area moves the current across the entire width, which lowers the resistance, which is advantageous for high-speed movement of current.

12 , the laser welding regions 951 and 953 may be joined in a zigzag shape, and the bonding area is wide. The copper ribbon shape having a predetermined bonding area forms a structure that passes a low resistance of a large current or voltage, and thus has an effect of lowering the resistance as much as possible. A thickness of the copper ribbon forming the bus bar 700 may be 0.1 mm to 0.5 mm. When the bus bar 700 connects the

terminals

610 and 620 and the electrode patterns a, b, and c with a large bonding area, the resistance can be lowered even when a copper ribbon of a relatively thin thickness is applied, and thus heat generation can be minimized. have.

The bus bar 700 may provide flexibility by adopting a curved structure. The flexibility allows the bus bar 700 to act as a buffer when the positions of the terminals and electrode patterns are twisted due to high temperature.

As shown in FIG. 13 , the bus bar 700 may be formed in a curved shape such that the portion bonded to the terminal 620 is at a relatively lower position than the portion bonded to the electrode pattern of the upper ceramic substrate 300 . can

14 shows a bus bar according to another embodiment of the present invention.

As shown in FIG. 14 , a through slot 730 may be formed in the bus bar 700a of another embodiment.

A plurality of through slots 730 are formed in the bus bar 700a connecting the large area laser welding area 710 and the small area laser welding area 720 . The through slot 730 is for maximizing the fluidity of the bus bar 700a. When a Cu ribbon with a thickness of 0.5 mm or more is applied to the bus bar 700a on which a large current or high voltage of the power module moves, to prevent deterioration and damage of the bus bar 700a due to torsion or vibration between connection parts, or external impact A plurality of through slots 730 are formed in the bus bar 700a. A plurality of through-slots 730 are formed in the horizontal or vertical direction to provide maximum flexibility to the bus bar 700 .

In the embodiment, a plurality of through slots 730 are formed with a predetermined interval between the large area laser welding area 710 and the small area laser welding area 720 .

In the present invention described above, since the bus bar connects the terminal and the electrode pattern with a large junction area, the current can move over the entire width, which is advantageous for high-speed movement of the current. can be minimized.

In addition, since the present invention provides flexibility by employing a bus bar having a curved structure, the bus bar can serve as a buffer when the positions of the terminals and electrode patterns are twisted due to high temperature, thereby improving the efficiency and performance of the power module. can

In addition, the present invention provides maximum flexibility by forming a through slot 730 in the bus bar, so that even if a copper ribbon having a thickness of 0.5 mm or more is applied, deterioration and damage of the copper ribbon due to torsion or vibration between connecting parts and external impact are prevented. can be prevented

As shown in FIG. 15 , both sides of the bus bar 700 are bonded to the

terminals

610 and 620 and the metal layer 302 forming the electrode pattern of the upper ceramic substrate 300 by laser welding. That is, one side of the bus bar 700 is bonded to the

terminals

610 and 620 by laser welding, and the other side of the bus bar 700 is bonded to the metal layer 302 of the upper ceramic substrate 300 by laser welding.

Laser welding can maximize the bonding performance, simplify the bonding process, and realize a bonding structure that can reduce resistance as much as possible. Laser welding is a welding method performed using a high-density energy beam.

The bus bar 700 has a shape in which one side is low and the opposite side is relatively high. The bus bar 700 is formed so that the portion bonded to the

terminals

610 and 620 is relatively low compared to the portion bonded to the metal layer 302 of the upper ceramic substrate 300, that is, the electrode patterns a, b, and c. Even if a height difference occurs at the position where the terminal is located, the

terminals

610 and 620 and the metal layer 302 can be stably connected.

As shown in FIG. 16 , the bus bar 700 is formed of a copper ribbon having a predetermined area. The bus bar 700 provides flexibility by adopting a curved structure. The flexibility allows the bus bar 700 to act as a buffer when the positions of the

terminals

610 and 620 and the metal layer 302 are twisted due to high temperature.

The bus bar 700 includes a first laser welding region 710 bonded to the

terminals

610 and 620 with a laser on one side and a second laser welding region 720 bonded to the metal layer 302 and a laser on the opposite side. include

The bus bar 700 in the form of a large-area copper ribbon connects the

terminals

610 and 620 and the metal layer 302 of the upper ceramic substrate 300 face-to-face by a laser welding method. This maximizes bonding performance, simplifies the process, and reduces resistance as much as possible to facilitate large current movement compared to wire connection or edge bonding. Specifically, since the bus bar 700 connects the

terminals

610 and 620 and the electrode patterns a, b, and c with a large junction area, the current can move over the entire width of the junction area, which is advantageous for high-speed movement of current, relatively Since the resistance can be lowered by applying a thin copper ribbon, heat generation can also be minimized.

The first laser welding region 710 has a larger area than the second laser welding region 720 . Specifically, in the bus bar 700 , the first laser welding region 710 bonded to the

terminals

610 and 620 is bonded to the metal layer 302 of the upper ceramic substrate 300 , that is, the electrode patterns a, b, and c. It has a larger area than the second laser welding region 720 . The large-area first laser welding area 710 reduces the resistance of the large power to the maximum to advantageously move the current at high speed. Furthermore, laser welding over a large area moves the current across the entire width, which lowers the resistance, which is advantageous for high-speed movement of current.

As shown in FIG. 17 , laser welding is formed in a zigzag pattern to secure a bonding area. The zigzag pattern has the effect of increasing the junction area to pass a large current and lowering the resistance as much as possible. A power module pursues a low resistance because a large current or voltage continuously moves due to its characteristics. The laser welding shape for bonding the bus bar 700 to the

terminals

610 and 620 or the metal layer 302 may employ a form in which a circular pattern is continuously repeated in addition to the above-described zigzag pattern in order to secure a large bonding area.

Referring to FIG. 12 , in laser welding, it can be confirmed that a zigzag pattern in which a U-shape is repeated up and down is formed in a shape, and a large bonding area is secured.

In the present invention described above, since the bus bar connects the terminal and the electrode pattern with a large junction area, the current can move over the entire width, which is advantageous for high-speed movement of current. can be minimized.

In addition, since laser welding is formed in a zigzag pattern, the present invention secures a bonding area, which is advantageous for high-speed movement of a large current.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is disclosed in the drawings and in the specification with preferred embodiments. Here, although specific terms have been used, they are only used for the purpose of describing the present invention and are not used to limit the meaning or scope of the present invention described in the claims. Therefore, it will be understood by those skilled in the art that various modifications and equivalent other embodiments of the present invention are possible therefrom. Accordingly, the true technical scope of the present invention should be defined by the technical spirit of the appended claims.

Claims

a ceramic substrate including a ceramic substrate and electrode patterns formed on upper and lower surfaces of the ceramic substrate;

a housing in which the ceramic substrate is installed and terminals are disposed at both ends; and

a bus bar connecting the electrode pattern of the ceramic substrate and the terminal face to face;

A power module comprising a.
According to claim 1,

The bus bar is a copper ribbon having a predetermined area.
According to claim 1,

The bus bar includes a laser welding region bonded to the terminal and a laser on one side and a laser welding region bonded to the electrode pattern and a laser on the opposite side on the other side.
According to claim 1,

In the bus bar, the area of the laser welding area joined to the terminal with a laser is relatively larger than that of the laser welding area where the electrode pattern is joined with the laser.
According to claim 1,

The bus bar is a power module having a curved structure.
According to claim 1,

The bus bar is a power module having a thickness in the range of 0.1mm to 0.5mm.
According to claim 1,

The electrode pattern includes a first electrode pattern, a second electrode pattern, and a third electrode pattern,

The terminal includes a first terminal and a second terminal,

The bus bar includes three for connecting the first terminal and the first electrode pattern, connecting the first terminal and the third electrode pattern, and connecting the second terminal and the second electrode pattern power module.
According to claim 1,

The bus bar is a power module in which a through slot is formed.
9. The method of claim 8,

The bus bar includes a first laser welding region bonded to the terminal and a laser on one side and a second laser welding region bonded to the electrode pattern and a laser on the opposite side on the other side,

The through slot is formed between the first laser welding region and the second laser welding region.
9. The method of claim 8,

The power module in which a plurality of the through slots are formed at regular intervals in a horizontal or vertical direction.
According to claim 1,

The bus bar is a power module in which the height of the other side is relatively high and curved compared to one side.
12. The method of claim 11,

The bus bar is a power module in which a middle part connecting one side and the other side is formed to be curved.
According to claim 1,

The bus bar is each connected to the terminal and the electrode pattern of the ceramic substrate by laser welding.
14. The method of claim 13,

The laser welding is a power module formed in a zigzag pattern shape.