Package carrier and power module

Abstract

The utility model discloses a packaging carrier plate and a power module. Wherein the packaging carrier plate comprises a heat conducting bottom plate and a circuit board which are connected with each other, the circuit board comprises an insulating substrate, an outer layer conducting circuit arranged on the outer side surface of the insulating substrate and a copper bar arranged in the insulating substrate, and the copper bar comprises a conducting strip and a mounting boss protruding from the conducting strip; the outer-layer conductive circuit is provided with a boss bonding pad connected with the mounting boss; the heat conduction bottom plate comprises an inner-layer copper foil, a ceramic core plate and an outer-layer copper foil, the ceramic core plate is arranged between the inner-layer copper foil and the outer-layer copper foil, and the inner-layer copper foil is connected with the circuit board. According to the utility model, the copper bar with the mounting boss is arranged in the insulating substrate of the circuit board, so that large-current transmission is realized, and meanwhile, a sufficient outer layer conductive circuit wiring area can be provided to promote miniaturization of the packaging substrate; the heat conduction bottom plate comprises the ceramic core plate, so that the voltage resistance of the packaging carrier plate can be improved.

Description

Technical Field

[0001] The utility model relates to the field of power chip packaging; more specifically, to a packaging carrier board for a power chip and a power module using the packaging carrier board. Background Art

[0002] Power modules, which incorporate power chips such as IGBTs (insulated-gate bipolar transistors) and / or MOSFETs (metal-oxide semiconductor field-effect transistors), are widely used in various electronic and power equipment. These power modules typically require high operating currents, requiring their packaging substrates to have both high current-carrying capacity and high voltage resistance to improve safety.

[0003] Chinese patent document CN110473836A discloses a heat dissipation substrate (package carrier) including a metal heat dissipation plate and a circuit board arranged on the metal heat dissipation plate. The circuit board and the metal heat dissipation plate are connected by a thermally conductive insulating adhesive layer. The circuit board includes an insulating substrate and a circuit structure loaded on the insulating substrate. The circuit structure includes a first conductive pattern that penetrates the insulating substrate in the thickness direction of the insulating substrate and a second conductive pattern arranged on the surface of the insulating substrate away from the metal heat dissipation plate.

[0004] In the above-mentioned prior art, on the one hand, the metal heat sink and the first conductive pattern within the insulating substrate are electrically isolated only by a thermally conductive insulating adhesive layer, resulting in insufficient voltage resistance. On the other hand, the entire surface of the first conductive pattern, which is used to transmit high current, is exposed from the outer surface of the insulating substrate, significantly reducing the wiring area on the outer surface of the insulating substrate and hindering the miniaturization of the package carrier. Therefore, there is a need to improve the structure of the existing package carrier. Utility Model Content

[0005] The main purpose of the utility model is to provide a packaging carrier board, which can not only realize large current transmission on the basis of miniaturization, but also has excellent voltage resistance performance.

[0006] Another object of the present invention is to provide a power module using the above-mentioned packaging carrier.

[0007] In order to achieve the above-mentioned main purpose, the utility model discloses a packaging carrier, comprising a heat-conducting base plate and a circuit board connected to each other; wherein, the circuit board comprises an insulating substrate, an outer conductive circuit arranged on the outer surface of the insulating substrate, and a copper bar arranged in the insulating substrate, the copper bar comprises a conductive sheet and a mounting boss protruding from the conductive sheet, and the outer conductive circuit is provided with a boss pad connected to the mounting boss; the heat-conducting base plate comprises an inner copper foil, a ceramic core board and an outer copper foil, the ceramic core board is arranged between the inner copper foil and the outer copper foil, and the inner copper foil is connected to the circuit board.

[0008] According to a specific embodiment of the present invention, the copper bar is arranged to penetrate the insulating substrate in the thickness direction of the insulating substrate to form a heat-conducting channel penetrating the insulating substrate, thereby realizing a direct heat-conducting connection between the copper bar and the inner copper foil; at the same time, the inner copper foil can also transmit large current together with the copper bar, thereby improving the current-carrying capacity of the packaging carrier.

[0009] According to a specific embodiment of the present invention, the copper bar is provided with a pin for connecting to an external power supply, the pin protrudes from the conductive sheet, and the outer conductive circuit is provided with a pin pad connected to the pin.

[0010] According to a specific embodiment of the present invention, the copper bar includes a first copper bar and a second copper bar that are separately arranged; wherein, the first copper bar and the second copper bar are both provided with one or more mounting bosses.

[0011] Furthermore, one or more switching bosses are provided on the second copper bar, and the outer conductive circuit includes a conductive part, one end of which is connected to the switching boss, and the other end of which extends to the side of the mounting boss of the first copper bar.

[0012] Furthermore, the inner copper foil includes a first connecting portion and a second connecting portion that are separately arranged, and the first connecting portion and the second connecting portion are connected to the first copper bar and the second copper bar respectively.

[0013] Furthermore, the gap between the circuit board and the ceramic core board is filled with an insulating material, and the first connecting portion and the second connecting portion are embedded in the insulating material.

[0014] According to a specific embodiment of the present invention, the circuit board further includes an inner conductive circuit arranged inside and / or on the inner surface of the insulating substrate.

[0015] According to a specific embodiment of the present invention, the package carrier further includes a heat sink connected to the outer copper foil.

[0016] To achieve the above-mentioned other object, the second aspect of the present invention discloses a power module, comprising the above-mentioned package carrier and a power chip mounted on the package carrier, wherein the drain of the power chip is connected to the mounting boss pad.

[0017] The technical solution of the utility model has the following beneficial effects:

[0018] The utility model arranges a conductive copper bar inside the insulating substrate of the circuit board, which can realize the transmission of large current; the copper bar includes a conductive sheet and a mounting boss protruding from the conductive sheet, and the mounting boss is exposed from the outer surface of the insulating substrate. The conductive sheet does not occupy the wiring space on the outer surface of the circuit board, which can increase the wiring area of ​​the outer conductive circuit of the circuit board and promote the miniaturization of the package carrier and the power module.

[0019] Furthermore, the present invention incorporates a ceramic core with excellent electrical insulation properties within the thermally conductive baseplate, which helps improve the package carrier's voltage resistance. Furthermore, the inner copper foil connections, along with the copper bars, can transmit high currents, enhancing the package carrier's current-carrying capacity.

[0020] In order to more clearly illustrate the purpose, technical solutions and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the package carrier in Example 1;

[0022] Figure 2 Schematic diagram of the top view of the copper bus in Example 1;

[0023] Figure 3 is a schematic structural diagram of the encapsulation module in Example 1;

[0024] Figure 4 It is a structural diagram of the packaging carrier in Example 2. DETAILED DESCRIPTION

[0025] The following description sets forth many specific details to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways other than those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0026] Example 1

[0027] like Figure 1As shown, the package carrier of Example 1 includes a circuit board 10 and a heat-conducting base plate 20 that are interconnected. Among them, the circuit board 10 includes an insulating substrate 11, a copper bar 12 and an outer conductive circuit 13, the copper bar 12 is arranged in the insulating substrate 11, and the outer conductive circuit 13 is arranged on the outer surface of the insulating substrate 11. It should be pointed out that the circuit board 10 in the present invention may also include an inner conductive circuit (not shown in the figure) arranged inside and / or on the inner surface of the insulating substrate 11. The insulating substrate 11 can form a composite laminate structure including an insulating core board (such as a FR-4 core board) and an insulating adhesive sheet, or it can be a single-layer structure with only an insulating core board.

[0028] Specific, combined Figure 1 and Figure 2 As shown, the copper bar 12 includes a conductive sheet 121 and a mounting boss 122. The conductive sheet 121 is embedded in the insulating substrate 11, and the mounting boss 122 protrudes from the conductive sheet 121 to the outer surface of the insulating substrate 11. The outer conductive line 13 is provided with a boss pad 131 connected to the mounting boss 122. Exemplarily, the boss pad 131 is a drain pad for connecting to the drain of the power chip.

[0029] Preferably, the copper bar 12 is arranged to penetrate the insulating substrate 11 in the thickness direction of the insulating substrate 11 to be directly connected to the thermal conductive base plate 20, so that the heat generated by the power chip mounted on the boss pad 131 can be quickly conducted to the thermal conductive base plate 20 through the copper bar 12.

[0030] Exemplarily, the copper bar 12 includes a first copper bar 12a and a second copper bar 12b, which are arranged separately. The first copper bar 12a and the second copper bar 12b are arranged in pairs to form a copper bar assembly. The insulating substrate 11 may be provided with one or more copper bar assemblies, that is, one or more groups of first copper bars 12a and second copper bars 12b. The first copper bar 12a is provided with one or more first mounting bosses 122a, and the second copper bar 12b is provided with one or more second mounting bosses 122b. Correspondingly, the outer conductive trace 13 is provided with a first boss pad 131a connected to the first mounting boss 122a and a second boss pad 131b connected to the second mounting boss 122b.

[0031] Furthermore, the first copper bar 12a is further provided with a first pin 123a for connecting to an external power source. The first pin 123a protrudes from the conductive sheet 121 of the first copper bar 12a to the outer surface of the insulating substrate 11. The second copper bar 12b is further provided with a second pin 123b for connecting to an external power source. The second pin 123b protrudes from the conductive sheet 121 of the second copper bar 12b to the outer surface of the insulating substrate 11. Correspondingly, the outer conductive circuit 13 is further provided with a first pin pad connected to the first pin 123a and a second pin pad connected to the second pin 123b (not shown in the figure).

[0032] In this embodiment, the second copper bar 12b is further provided with one or more switching bosses 124b protruding from its conductive sheet 121 to the outer surface of the insulating substrate 11. The first mounting bosses 122a, the second mounting bosses 122b, and the switching bosses 124b are provided in a one-to-one correspondence, and the switching bosses 124b are located between the corresponding first mounting bosses 122a and the second mounting bosses 122b. Accordingly, the outer conductive trace 13 also includes a conductive portion 132, one end of which is connected to the switching boss 124b, and the other end of which extends to the side of the first mounting boss 122a to form a first source pad 133.

[0033] The thermally conductive base plate 20 includes a ceramic core plate 21, an inner copper foil 22, and an outer copper foil 23. The ceramic core plate 21 is disposed between the inner copper foil 22 and the outer copper foil 23, and the inner copper foil 22 is connected to the circuit board 10. The thickness of the ceramic core plate 21, the inner copper foil 22, and the outer copper foil 23 can be set as needed and is not limited in this invention. For example, the thickness of the ceramic core plate 21 can be 0.1mm to 0.5mm; the thickness of the inner copper foil 22 and the outer copper foil 23 can be 0.2mm to 1.0mm, and the thickness of the inner copper foil 22 and the outer copper foil 23 can be the same or different.

[0034] Exemplarily, the inner copper foil 22 includes a first connecting portion 22a and a second connecting portion 22b, which are separately disposed and welded to the first copper bar 12a and the second copper bar 12b, respectively. Preferably, the first connecting portion 22a and the second connecting portion 22b have outer contours corresponding to the first copper bar 12a and the second copper bar 12b. The gap between the circuit board 10 and the ceramic core board 21 is filled with an insulating material 30, such as resin, and the first connecting portion 22a and the second connecting portion 22b are embedded within the insulating material 30. The first connecting portion 22a and the second connecting portion 22b can be one or more groups, with each group of first connecting portions 22a and second connecting portions 22b corresponding to a group of first copper bar 12a and second copper bar 12b.

[0035] The power module of the embodiment includes the above-mentioned package carrier and a plurality of power chips mounted on the package carrier. The power chips may be IGBT chips or MOSFET chips. The drain of each power chip is connected to a corresponding boss pad 131 .

[0036] The power module may include one or more power chip units, that is, each group of first copper bars 12a and second copper bars 12b is provided with a corresponding power chip unit. Figure 3 As shown, each power chip unit includes at least one first power chip 100 a and at least one second power chip 100 b .

[0037] Specific, combined Figure 1 and Figure 3 As shown, the drain 101 of the first power chip 100a is connected to the corresponding first boss pad 131a / first copper bar 12a, the source 102 of the first power chip 100a is connected to the corresponding first source pad 133 and electrically connected to the second copper bar 12b through the conductive part 132; the drain 101 of the second power chip 100b is connected to the corresponding second boss pad 132b / second copper bar 12b, and the source 102 of the second power chip 100b is connected to the second source pad 134 in the outer conductive circuit 13.

[0038] The gates of the first power chip 100 a and the second power chip 100 b are respectively connected to corresponding gate pads (not shown in the figure) in the outer conductive circuit 13 , which will not be further described here.

[0039] Example 2

[0040] like Figure 4 As shown, the difference between Example 2 and Example 1 is that the outer copper foil 23 of the heat-conducting base plate 20 in Example 2 is connected to a heat sink 40. The heat sink 40 can be a fin heat sink, a staggered heat sink, a water-cooled heat sink, or a temperature-equalizing heat sink with an evaporation-condensation chamber, and the present invention does not limit this.

[0041] Although the present invention has been described above through embodiments, it should be understood that the above embodiments are only used to exemplarily describe the feasible implementation plans of the present invention and should not be interpreted as limiting the scope of protection of the present invention. Any equivalent changes made by those skilled in the art in accordance with the present invention should also be covered by the scope of protection of the claims of the present invention.

Claims

1. A package carrier, comprising a heat-conducting base plate and a circuit board connected to each other; characterized in that: The circuit board includes an insulating substrate, an outer conductive circuit provided on the outer surface of the insulating substrate, and a copper bar provided in the insulating substrate, the copper bar including a conductive sheet and a mounting boss protruding from the conductive sheet, and the outer conductive circuit is provided with a boss pad connected to the mounting boss; The heat-conducting base plate includes an inner copper foil, a ceramic core plate and an outer copper foil. The ceramic core plate is arranged between the inner copper foil and the outer copper foil. The inner copper foil is connected to the circuit board.

2. The package carrier according to claim 1, wherein: The copper bar is arranged to penetrate the insulating substrate in a thickness direction of the insulating substrate.

3. The package carrier according to claim 1, wherein: The copper bar is provided with a pin for connecting to an external power supply, the pin protrudes from the conductive sheet, and the outer conductive circuit is provided with a pin pad connected to the pin.

4. The package carrier according to claim 1, wherein: The copper bar includes a first copper bar and a second copper bar that are separately arranged, and each of the first copper bar and the second copper bar is provided with one or more mounting bosses.

5. The package carrier according to claim 4, wherein: One or more switching bosses are further provided on the second copper bar. The outer conductive circuit includes a conductive part, one end of which is connected to the switching boss, and the other end of which extends to the side of the mounting boss of the first copper bar.

6. The package carrier according to claim 4, wherein: The inner copper foil includes a first connecting portion and a second connecting portion that are separately arranged, and the first connecting portion and the second connecting portion are connected to the first copper bar and the second copper bar respectively.

7. The package carrier according to claim 6, wherein: The gap between the circuit board and the ceramic core board is filled with insulating material, and the first connecting portion and the second connecting portion are embedded in the insulating material.

8. The package carrier according to claim 1, wherein: The circuit board further includes an inner conductive circuit arranged inside and / or on an inner surface of the insulating substrate.

9. The package carrier according to claim 1, wherein: The package carrier also includes a heat sink connected to the outer copper foil.

10. A power module, characterized in that: The power module comprises the package carrier according to any one of claims 1 to 9 and a power chip mounted on the package carrier, wherein the drain of the power chip is connected to the boss pad.

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