Power module and motor controller
By setting a boss at the bottom of the conductive layer under the insulating substrate of the power module, the problem of insufficient heat dissipation efficiency of the power module in the prior art is solved, and more efficient heat conduction and higher reliability are achieved.
Patent Information
- Application Number
- CN202421562402.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-03
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-07-03
AI Technical Summary
The heat dissipation efficiency of existing power modules is insufficient, and it is impossible to improve heat dissipation efficiency through layout optimization and increasing the density of heat dissipation teeth.
A boss is provided at the bottom of the lower conductive layer of the insulating substrate, and the projection of the boss is at least partially coincides with the projection of the chip. In this way, the heat conduction efficiency of the chip part is improved and the thickness of the connection layer is reduced to improve the thermal conductivity.
It improves heat dissipation efficiency, reduces the thermal resistance of the power module, and thus improves the reliability of the module.
Smart Images
Figure CN222826404U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of semiconductor equipment, in particular to a power module and a motor controller. Background Art
[0002] The power module is a package that combines power chips into a whole according to certain functional combinations. It has the advantages of small size and high power density, so it is widely used in various fields. The power module is usually composed of a substrate, a chip and a heat dissipation structure.
[0003] In order to achieve electrical functions, the conductive layer on one side of the substrate is usually etched, and the other side is used as a welding surface without etching and is directly connected to the heat dissipation structure. The chip is connected on the etched side through a sintering or welding process. The heat generated during the operation of the chip is mainly transferred downward through the substrate and dissipated through the heat dissipation structure. As power modules continue to develop towards higher power density, efficient heat dissipation is particularly important to ensure the output capacity of the module. However, in the prior art, due to the gradual reduction in module size, heat dissipation through layout optimization has reached a bottleneck, and the heat dissipation tooth density of the heat dissipation structure has also reached the processing limit. Therefore, it is impossible to improve the heat dissipation efficiency by optimizing the layout and increasing the heat dissipation tooth density. Utility Model Content
[0004] The main purpose of the utility model is to provide a power module, aiming to solve the problem that the heat dissipation efficiency of the existing power module is insufficient and the heat dissipation efficiency cannot be improved by optimizing the layout and increasing the density of the heat dissipation teeth.
[0005] To achieve the above object, the utility model provides a power module, comprising:
[0006] An insulating substrate, the insulating substrate comprising an upper conductive layer, an insulating layer and a lower conductive layer stacked in sequence from top to bottom, a surface of the upper conductive layer being connected to the chip, and the lower conductive layer being provided with a boss;
[0007] a heat sink connected to the lower conductive layer via a connecting layer;
[0008] The projection of the boss on the heat sink at least partially overlaps with the projection of the chip on the heat sink.
[0009] Preferably, the boss is integrally provided with the lower conductive layer.
[0010] Preferably, the distance between the connecting layer and the heat sink is the smallest.
[0011] Preferably, each chip has only one boss in the projection area of the heat sink.
[0012] Preferably, each chip has more than two bosses in the projection area of the heat sink, and there is a connecting platform between adjacent bosses, and the distance between the connecting platform and the heat sink is greater than the distance between the boss and the heat sink, and less than the distance between the lower conductive layer and the heat sink.
[0013] Preferably, the surface of the boss is parallel to the surface of the heat sink.
[0014] Preferably, the power module comprises a plastic shell, and the plastic shell limits the relative position of the chip and the insulating substrate.
[0015] Preferably, the heat sink comprises a contact layer and a plurality of heat dissipation teeth, the contact layer is in contact with the connection layer, and the plurality of heat dissipation teeth are arranged at intervals on a side of the contact layer away from the connection layer.
[0016] The utility model also provides a motor controller, and the motor controller is applied with the above-mentioned power module.
[0017] In the technical solution of the utility model, a boss is arranged at the bottom of the lower conductive layer to serve as a heat dissipation component. The projection of the boss at least partially overlaps with the projection of the chip, that is, the boss is arranged corresponding to the position of the chip. It can be understood that the chip is the main heat source, and the heat conduction efficiency of the chip part is improved by the boss arranged corresponding to the chip. At the same time, due to the setting of the boss, the thickness of the connecting layer can be reduced, thereby improving the thermal conductivity of the connecting layer, reducing the thermal resistance of the power module, thereby improving the heat dissipation efficiency and improving the reliability of the power module. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0019] Figure 1 It is a schematic structural diagram of a power module according to an embodiment of the utility model.
[0020] Description of Figure Numbers:
[0021]
[0022]
[0023] The purpose, features and advantages of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] It should be noted that all directional indications in this embodiment (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0026] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0027] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0028] In addition, the technical solutions of the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.
[0029] The utility model provides a power module 1.
[0030] See also Figure 1The power module 1 of this embodiment includes an insulating substrate 10 and a heat sink 20. The insulating substrate 10 includes an upper conductive layer 11, an insulating layer 12 and a lower conductive layer 13 stacked in sequence from top to bottom. The surface of the upper conductive layer 11 is connected to the chip 40, and the lower conductive layer 13 is provided with a boss 132. The heat sink 20 is connected to the lower conductive layer 13 through a connecting layer 131. The projection of the boss 132 on the heat sink 20 at least partially overlaps with the projection of the chip 40 on the heat sink 20.
[0031] It should be noted that the heat sink 20 and the lower conductive layer 13 can be connected by bonding or welding, and the connecting layer 131 is an adhesive or a welding layer. It can be understood that due to the limitations of the processing technology of the insulating substrate 10 itself, after the upper conductive layer 11 is etched, the coverage area is reduced, the stress is released, and the insulating substrate 10 naturally forms a warping deformation with a central bulge. In the subsequent sintering, welding, injection molding and other process processes, the warping amplitude may be further increased, which will eventually lead to an increase in the welding defect rate of the welding layer, or the bonding effect of the adhesive will deteriorate, the thermal resistance will increase, and then the reliability of the power module 1 will be reduced.
[0032] In the technical solution of the utility model, a boss 132 is provided at the bottom of the lower conductive layer 13 for use as a heat dissipation component. The boss 132 corresponds to the position of the chip 40. It can be understood that the chip 40 is the main heat source. The boss 132 provided corresponding to the chip 40 is used to improve the heat conduction efficiency of the chip 40. At the same time, due to the provision of the boss 132, the thickness of the connecting layer 131 can be reduced, thereby improving the thermal conductivity of the connecting layer 131, reducing the thermal resistance of the power module 1, thereby improving the heat dissipation efficiency, and improving the reliability of the power module 1.
[0033] In one embodiment, the boss 132 is integrally provided with the lower conductive layer 13. The boss 132 and the lower conductive layer 13 are integrally formed, that is, a thicker conductive material layer is etched to form the lower conductive layer 13 and the boss 132. Compared with the conventional method of etching only the upper conductive layer 11, the upper conductive layer 11 and the lower conductive layer 13 of the utility model are etched at the same time, which can reduce the warpage amplitude of the upper conductive layer 11 and the lower conductive layer 13 after processing, which helps to improve the welding yield of the welding layer, further reduce the thermal resistance, and improve the reliability of the power module 1.
[0034] Furthermore, the distance between the connection layer 131 and the convex platform 132 and the heat sink 20 is the smallest. The thickness of the connection layer 131 corresponding to the convex platform 132 is the smallest, so that the heat conductivity of the connection layer 131 at this location is the smallest, which makes it easier for the convex platform 132 to absorb heat from the chip 40 and transfer it to the heat sink 20 in time, thereby improving the heat dissipation efficiency and heat dissipation effect of the chip 40.
[0035] In one embodiment, each chip 40 has only one boss 132 in the projection area of the heat sink 20. Each chip 40 forms a heat dissipation function part through only one boss 132, which has a simple structure and is easy to process, meeting the heat dissipation requirements while improving production efficiency.
[0036] In another embodiment, each chip 40 has more than two bosses 132 in the projection area of the heat sink 20, and there is a connecting platform between adjacent bosses 132. The distance between the connecting platform and the heat sink 20 is greater than the distance between the boss 132 and the heat sink 20, and less than the distance between the lower conductive layer 13 and the heat sink 20.
[0037] Specifically, the surface of the boss 132 is parallel to the surface of the heat sink 20. When the surface of the boss 132 is parallel to the surface of the heat sink 20, the contact area between the two and the connection layer 131 is the largest, and the corresponding distances at each point of the two are the same, so that the heat dissipation speed at each part of the boss surface is the same, and the heat dissipation effect is optimal.
[0038] In one embodiment, the power module 1 includes a plastic shell 30, which limits the relative position of the chip 40 and the insulating substrate 10. The plastic shell 30 limits the chip 40 and the insulating substrate 10, ensuring that the chip 40 is always in close contact with the insulating substrate 10, ensuring the normal power supply function of the chip 40, and ensuring that the chip 40 is always arranged corresponding to the boss 132 to ensure the heat dissipation effect of the chip 40. At the same time, the plastic shell 30 can provide an additional protective layer to protect the electronic components inside the power module 1 from the influence of the external environment, such as moisture, dust, chemicals, etc., as well as mechanical shock and vibration; at the same time, the plastic encapsulation material usually has an insulating property, which can prevent short circuits or electrical contacts between different circuit components, thereby improving the safety of the power module 1.
[0039] In one embodiment, the heat sink 20 includes a contact layer 21 and a plurality of heat dissipation teeth 22. The contact layer 21 contacts the connection layer 131. The plurality of heat dissipation teeth 22 are spaced apart on a side of the contact layer 21 away from the connection layer 131. By providing a plurality of heat dissipation teeth 22, the contact area between the heat sink 20 and the air is increased, thereby improving the heat dissipation efficiency.
[0040] In one embodiment, the number of chips 40, bosses 132 and chip 40 mounting portions are all multiple, and multiple chips 40 are arranged at intervals, and each chip 40 is correspondingly provided with a chip 40 mounting portion and a boss 132. The chips 40 are arranged at intervals to prevent crosstalk between the chips 40 and improve heat dissipation efficiency.
[0041] Specifically, the thickness of the heat dissipation portion is 0.05 mm to 3 mm, and the thickness of the heat dissipation portion is 20% to 50% of the total thickness of the lower conductive layer 13. When the thickness of the heat dissipation portion is 20% to 50% of the total thickness of the lower conductive layer 13, better heat dissipation efficiency can be obtained, the warping amplitude of the substrate can be improved to the maximum extent, and the overall volume of the power module 1 can be reduced.
[0042] In one embodiment, the thickness of the connection layer 131 is H1, the thickness of the upper conductive layer 11 is H2, and H1≤H2. The upper and lower conductive layers 13 of the substrate are both etched, and stress release is performed simultaneously. Under the condition of ensuring that the thickness of the upper and lower conductive layers 13 is equal or the lower conductive layer 13 is thinner, the graphic design and warping of the upper conductive layer 11 are both in the optimal state, the warping amplitude of the substrate is reduced, the welding yield of the subsequent welding layer is improved, the thermal resistance uniformity is better, and the reliability of the module is improved.
[0043] Specifically, the thickness of the heat dissipation part is 25% to 75% of the thickness of the welding layer. The thickness of the heat dissipation part determines the reduction of the thickness of the corresponding welding layer. The thicker the heat dissipation part is, the thinner the welding layer below the heat dissipation part is. The reduction of the thickness of the welding layer helps to improve the thermal conductivity of the place, but too small a welding layer will lead to a decrease in welding quality. Therefore, when the thickness of the heat dissipation part is 25% to 75% of the thickness of the welding layer, the thermal conductivity of the place can be improved while ensuring the welding quality.
[0044] In one embodiment, the chip 40 is connected to the upper conductive layer 11 through a soldering layer, and the lower conductive layer 13 is connected to the heat sink 20 through a soldering layer. The material of the soldering layer is lead-free solder. The upper conductive layer 11 is an upper copper layer, the lower conductive layer 13 is a lower copper layer, and the insulating layer 12 is a ceramic layer. The structure in which the upper and lower conductive layers 13 and the insulating layer 12 are ceramic layers is a copper-clad substrate in the prior art. The copper-clad substrate has high dielectric strength, high mechanical strength, and high thermal conductivity, and has become the preferred substrate material for the power module 1. Lead-free solder, such as silver sintering, copper sintering, or copper-tin diffusion soldering material, has excellent thermal conductivity and is suitable for soldering between the lower conductive layer 13 and the heat sink 20.
[0045] The present invention also provides a motor controller, which is applied with the above-mentioned power module 1. The specific structure of the motor controller refers to the above-mentioned embodiment. Since the motor controller adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.
[0046] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A power module, characterized in that: include: An insulating substrate, the insulating substrate comprising an upper conductive layer, an insulating layer and a lower conductive layer stacked in sequence from top to bottom, a surface of the upper conductive layer being connected to the chip, and the lower conductive layer being provided with a boss; a heat sink connected to the lower conductive layer via a connecting layer; The projection of the boss on the heat sink at least partially overlaps with the projection of the chip on the heat sink.
2. The power module according to claim 1, characterized in that: The boss is integrally arranged with the lower conductive layer.
3. The power module according to claim 1 or 2, characterized in that: The connection layer has a minimum distance between the boss and the heat sink.
4. The power module according to claim 3, characterized in that: Each of the chips has only one boss in the projection area of the heat sink.
5. The power module according to claim 3, characterized in that: Each chip has more than two bosses in the projection area of the heat sink, and there is a connecting platform between adjacent bosses. The distance between the connecting platform and the heat sink is greater than the distance between the boss and the heat sink, and less than the distance between the lower conductive layer and the heat sink.
6. The power module according to claim 1, characterized in that: The surface of the boss is parallel to the surface of the heat sink.
7. The power module according to claim 1, characterized in that: The power module comprises a plastic shell, and the plastic shell limits the relative position of the chip and the insulating substrate.
8. The power module according to claim 1, characterized in that: The heat sink comprises a contact layer and a plurality of heat dissipation teeth, wherein the contact layer contacts the connection layer, and the plurality of heat dissipation teeth are arranged at intervals on a side of the contact layer away from the connection layer.
9. A motor controller, characterized in that: The motor controller is applied with a power module as claimed in any one of claims 1 to 8.