CN220526896U

CN220526896U - Power device assembly and electronic equipment

Info

Publication number: CN220526896U
Application number: CN202221674477.4U
Authority: CN
Inventors: 赵国源
Original assignee: Shenzhen Inovance Technology Co Ltd
Current assignee: Shenzhen Inovance Technology Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2024-02-23
Anticipated expiration: 2032-06-30

Abstract

The utility model discloses a power device assembly and electronic equipment, and belongs to the technical field of power components. The power device assembly includes: a heat sink; a power element, wherein the bottom of the power element is provided with a metal sheet; the heat conduction bonding glue layer is internally doped with insulating supporting filler, one surface of the heat conduction bonding glue layer is bonded with the metal sheet, and the other surface of the heat conduction bonding glue layer is bonded with the radiator. The utility model can reduce the heat radiation resistance of the power device component.

Description

Power device assembly and electronic equipment

Technical Field

The present utility model relates to the field of power devices, and in particular, to a power device assembly and an electronic device.

Background

In the related art, heat is generated when an electronic component works, and the electronic component needs to be timely radiated to ensure the normal operation of the electronic component. For the MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) field effect transistor taking an electronic component as a heat radiator, the existing MOS transistor is connected with the heat radiator through an adhesion process, but the scheme needs to place a layer of insulating material between a heating device and the heat radiator, then the insulating material is adhered to the heating device and the heat radiator respectively by using heat conduction adhesion materials on two sides of the insulating material, so that 3 requirements of fixing, heat conduction and insulation are simultaneously met.

However, the bonding process scheme uses insulating materials such as ceramic plates and PI films, so that the heat dissipation resistance of power device components such as MOS tube components is large.

Disclosure of Invention

The utility model mainly aims to provide a power device assembly and electronic equipment, and aims to solve the technical problem that in the prior art, the heat dissipation resistance of the power device assembly is large.

In order to achieve the above object, the present utility model provides a power device assembly, including:

a heat sink;

a power element, wherein the bottom of the power element is provided with a metal sheet;

the heat conduction bonding glue layer is internally doped with insulating supporting filler, one surface of the heat conduction bonding glue layer is bonded with the metal sheet, and the other surface of the heat conduction bonding glue layer is bonded with the radiator.

In an embodiment, the insulating support filler is provided as a particle piece, and a plurality of insulating support fillers with the same size are doped in the heat-conducting adhesive glue layer.

In an embodiment, the insulating support filler is a spherical particle member, and the diameter of the spherical particle member is the same as the thickness of the thermal conductive adhesive layer.

In one embodiment, the insulating support filler is glass beads.

In one embodiment, the thickness of the thermally conductive adhesive layer is greater than 0.2mm.

In one embodiment, the thermal conductivity coefficient of the thermal conductive adhesive layer is lambda, wherein lambda is more than or equal to 1.9W/Mk;

in one embodiment, the unit bonding strength of the heat-conducting bonding adhesive layer is F, and the unit area bonding strength is ps, wherein F is more than or equal to 1000N, and ps is more than or equal to 3Mpa.

In one embodiment, the viscosity of the heat-conducting adhesive layer is μ, wherein 60000CPS is less than or equal to μ is less than or equal to 100000CPS.

In a second aspect, the present application also provides an electronic device comprising a power device assembly as described above.

In an embodiment, the electronic device is any one of a frequency converter, an on-board charger, a voltage converter, or a photovoltaic inverter.

In the technical scheme of the utility model, the power element of the power device component is connected with the radiator through the heat-conducting adhesive layer, the heat-conducting adhesive layer is internally doped with the insulating supporting filler, one surface of the heat-conducting adhesive layer is adhered with the metal sheet, and the other surface of the heat-conducting adhesive layer is adhered with the radiator.

Compared with the existing power element and radiator which need to use insulating materials to meet the insulation safety rule requirement, the insulating support filler is doped in the heat conduction adhesive layer, so that the thickness of the heat conduction adhesive layer is larger than or equal to the insulation pressure-resistant thickness required by the insulation safety rule, the insulating materials between the power element and the radiator are omitted, the types and the thicknesses of medium layers between the power element and the radiator are reduced, and the heat dissipation thermal resistance of the power element is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a power device assembly according to an embodiment of the present utility model;

fig. 2 is a schematic structural diagram of another embodiment of the power device assembly of the present utility model.

Reference numerals illustrate:

reference numerals	Name of the name	Reference numerals	Name of the name
				10	Radiator	20	Power element
30	Heat-conducting adhesive layer	40	Insulating support filler

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present utility model are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

In the present utility model, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present utility model, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

In the related art, a power device, namely a power semiconductor device, is mainly used for a high-power electronic device in the aspect of electric energy conversion and control circuits of power equipment. However, the power device has self-loss during application and generates larger heat productivity, so that the heat dissipation problem of the power device needs to be prioritized during design. For the MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) field effect transistor, the first generation single-tube MOS uses the locking and fixing schemes such as the traditional screw direct locking, pressing buckle, pressing strip, spring clamp and the like to be fixed on a heat dissipation piece for heat dissipation, but the mode has the defects of large occupied structural space, large safety standard forbidden cloth space and the like. With the development of electronic products to high-density miniaturization, universal power products such as frequency converters, communication power supplies, automobile power supplies and the like do not use the traditional technology any more, and are gradually switched to a second-generation bonding and fixing technological scheme. If a ceramic plate is placed between the MOS tube and the heat dissipation piece, heat conduction adhesive glue is brushed on two sides of the ceramic plate to connect the MOS tube and the heat dissipation piece together. Or the MOS tube and the heat dissipation piece are insulated by an insulating heat-conducting adhesive film, and two side walls of the insulating heat-conducting adhesive film are respectively connected with the MOS tube and the heat dissipation piece. Or the MOS tube and the heat dissipation piece are insulated by an aluminum substrate, and the MOS tube is welded on the aluminum substrate by soldering tin.

Obviously, in the second generation bonding and fixing process scheme of the MOS tube, at least one insulating layer (such as a ceramic plate, an insulating film or an aluminum substrate) is needed between the MOS tube and the heat dissipation piece, so that the variety of the medium layer between the MOS tube and the heat dissipation piece is more, and further, the heat dissipation thermal resistance between the MOS tube and the heat dissipation piece is larger.

Therefore, the application provides a power heating component, through doping the higher insulating support filler of hardness in the heat conduction bonding glue film for the thickness of heat conduction bonding glue film is greater than or equal to the insulating withstand voltage thickness that satisfies insulating safety rule demand, thereby has cancelled the insulating material between power component and the radiator, reduces dielectric layer kind and thickness between the two, reduces power component's thermal resistance that dispels heat.

The concepts of the present application are further described below in conjunction with some specific embodiments.

Referring to fig. 1 and 2, the present embodiment provides a power device assembly, including: a power element 20, a heat sink 10, and a thermally conductive adhesive layer 30.

Wherein the bottom of the power element 20 has a metal sheet (not shown); the heat conductive adhesive layer 30 is doped with an insulating support filler 40. One surface of the heat conductive adhesive layer 30 is adhered to the metal sheet, and the other surface of the heat conductive adhesive layer 30 is adhered to the heat sink 10.

Specifically, the power element 20 may be a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) field effect transistor. The power device 20 has a voltage. Wherein the bottom of the power element 20, i.e. the side wall facing the heat sink 10, is provided with a metal sheet (not shown). It can be understood that, in normal operation, the circuit structure of the electronic device mounted with the power element 20 requires that the voltage of the power element 20 be within an allowable range, and the upper limit value of the range is the bearing voltage.

The heat sink 10 includes a first heat-conducting surface and a second heat-conducting surface, and exchanges heat with the casing of the electronic device directly or indirectly through the first heat-conducting surface, and exchanges heat with the power element 20 through the second heat-conducting surface. And it will be appreciated that a plurality of power elements 20 may be provided on the second thermally conductive surface of the heat sink 10.

The metal sheets of the power element 20 and the heat sink 10 are connected together by a heat conductive adhesive layer 30, and it is noted that the front projection of the heat conductive adhesive layer 30 on the heat sink 10 covers the front projection of the power element 20 on the heat sink 10. That is, in the process of applying the heat-conducting adhesive to form the heat-conducting adhesive layer 30, the applied amount of the heat-conducting adhesive should be enough to fully fill all the spaces between the power element 20 and the radiator 10, so as to avoid the situation that the heat conduction and safety insulation functions between the radiator 10 and the MOS tube cannot be satisfied due to the fact that the heat-conducting adhesive is not filled between the radiator 10 and the MOS tube.

In this embodiment, the heat conductive adhesive layer 30 is doped with an insulating support filler 40. Generally, the insulating support filler 40 is made of a material having a higher hardness than that of the thermal conductive adhesive layer 30, so that after the thermal conductive adhesive layer 30 is formed, the insulating support filler 40 inside the thermal conductive adhesive layer 30 will ensure that the thermal conductive adhesive layer 30 has a thickness that is greater than or equal to the dielectric thickness. That is, when the thickness of the thermal conductive adhesive layer 30 is greater than or equal to the insulation pressure-resistant thickness, the safety insulation requirement between the heat sink 10 and the power element 20 is satisfied. The insulation withstand voltage thickness is obtained according to the withstand voltage and the insulation withstand voltage characteristic parameter of the heat conductive adhesive. The material of the heat-conducting adhesive has corresponding insulating voltage-resistant characteristic parameters, such as compressive strength. It can be understood that the higher the voltage applied across the colloid, the greater the electric field force to which the charge in the material is subjected, the more likely the ionization collision occurs, resulting in colloid breakdown. The lowest voltage at which the gel breaks down is called the breakdown voltage of the gel. When a material with the thickness of 1 millimeter breaks down, the kilovolts of voltage required to be added is called the insulation compressive strength of the material, which is called withstand voltage for short, and the unit is: kv/mm. Therefore, when the withstand voltage of the current power heating device is known, the insulation withstand voltage thickness can be obtained according to the withstand voltage and the withstand voltage.

In other words, in the present embodiment, the insulating layer in the prior art is removed, and the power element 20 and the heat sink 10 are directly bonded together by using the heat-conducting adhesive, so as to realize the two functions of fixing and heat conduction. And the distance between the power element 20 and the radiator 10 is ensured to meet the requirement of the insulation voltage withstand characteristic parameter according to the heat conduction bonding material by the insulation supporting filler, so as to realize the third function, namely safety insulation.

In addition, in the present embodiment, since the dielectric material between the power element 20 and the heat sink 10 is reduced, the manufacturing and assembling process of the power device assembly is simplified, and thus the production efficiency is improved.

Wherein, at least two insulating support fillers 40 can be uniformly embedded in the heat-conducting adhesive layer 30, so that the thickness of each part of the heat-conducting adhesive layer 30 can be ensured to reach the insulating pressure-resistant thickness, and the situation that the partial area of the heat-conducting adhesive layer 30 does not reach the insulating pressure-resistant thickness is prevented.

In one embodiment, in order to facilitate the distribution of the insulating support filler 40 within the thermally conductive adhesive layer 30, the insulating support filler 40 is provided as spherical particles. And the diameter of the spherical particle piece is the same as the thickness of the heat conduction adhesive layer. The spherical particle pieces are fixed in size and regular in shape, so that the spherical particle pieces are easy to dope in the heat-conducting adhesive glue and are uniformly distributed.

In one embodiment, the insulating support filler 40 is glass beads. Specifically, referring to fig. 1, the insulating support filler 40 may be a structural filler having a regular shape and being dimensionally stable. I.e., after the formation of the thermally conductive adhesive layer 30, the structural filler is incorporated into the thermally conductive adhesive layer.

In one embodiment, the thickness of the thermally conductive adhesive layer 30 is greater than 0.2mm. That is, in this embodiment, the dielectric breakdown thickness is less than or equal to 0.2mm for the power device assembly.

In one embodiment, the thermal conductivity of the thermal conductive adhesive layer 30 is λ, where λ is greater than or equal to 1.9W/Mk;

the unit bonding strength of the heat conduction bonding adhesive layer 30 is F, and the unit area bonding strength is ps, wherein F is more than or equal to 1000N, and ps is more than or equal to 3Mpa. The viscosity of the heat-conducting adhesive layer 30 is mu, wherein mu is more than or equal to 60000CPS and less than or equal to 100000CPS.

Specifically, since the insulating support filler 40 is embedded in the heat-conducting adhesive layer 30, at this time, the insulating support filler 40 and the heat-conducting adhesive layer 30 together form an adhesive layer, and at this time, the adhesive layer should be verified by environmental reliability such as temperature impact, temperature circulation, high temperature and high humidity of the electronic product, and no colloid cracking defect such as colloid cracks and cracks between colloid and structural filler occurs. In order to meet the above requirements, in this embodiment, the thermal conductivity of the adhesive layer cannot be significantly deteriorated, and in this embodiment, the properties of the adhesive layer, that is, the conductive adhesive layer, should meet the following requirements:

(1) The heat conductivity coefficient lambda is more than or equal to 1.9W/Mk;

(2) The unit bonding strength thrust F is more than or equal to 1000N, and the unit area bonding strength is more than or equal to 3Mpa;

(2) Dielectric strength is more than or equal to 10000V/mm;

(3) The viscosity mu is 60000-100000 CPS.

For ease of understanding, a specific method of bonding the MOS transistors is shown below.

In this embodiment, the thickness of the insulation and voltage between the MOS tube and the radiator 10 is between 0.15 mm and 0.2mm.

At this time, the bonding method of the MOS tube comprises the following steps:

step S101, mixing the insulating support filler 40 with the heat-conducting adhesive to form the adhesive.

In this embodiment, the insulating support filler 40 is mixed with the heat conductive adhesive, so that the insulating support filler 40 is uniformly doped into the heat conductive adhesive.

It will be appreciated that in order to facilitate the mixing of the insulating support filler 40 with the thermally conductive adhesive, the insulating support filler 40 is made of a regularly shaped and dimensionally stable material, optionally glass beads.

The adhesive is required to be verified by environmental reliability such as temperature impact, temperature circulation, high temperature and high humidity of electronic products, and the like, and colloid cracking defects such as colloid cracks and cracks between colloid and structural filler are avoided. And the heat conduction property of the mixed adhesive can not be obviously deteriorated. Optionally, the properties of the adhesive layer should meet the following requirements:

(1) The heat conductivity coefficient lambda is more than or equal to 1.9W/Mk;

(2) Dielectric strength is more than or equal to 10000V/mm;

(3) The viscosity mu is 60000-100000 CPS.

Step S102, applying adhesive in the adhesive area corresponding to the MOS tube of the radiator 10 to form an adhesive layer.

Specifically, the adhesive can be applied by dispensing, steel screen printing, silk screen printing and the like, and the thickness of the adhesive is more than or equal to 0.2mm. The thickness may be such that the thickness of the thermally conductive adhesive layer 30 formed after the adhesive of the present embodiment is cured is greater than or equal to the insulation and pressure-resistant thickness.

In addition, the amount of the adhesive applied needs to ensure that after the MOS tube is bonded, all the space between the MOS tube and the heat spreader 10 can be fully filled, so that the orthographic projection of the thermally conductive adhesive layer 30 on the heat spreader 10 covers the orthographic projection of the power element 20 on the heat spreader 10.

Step S103, mounting the MOS tube on the adhesive layer to obtain the radiator 10 and power device assembly.

Specifically, the heat spreader 10 with the adhesive layer is placed in a regular arrangement on a chip tray with the adhesive facing up. After the chip mounter is positioned optically, the suction MOS tube is moved to the upper part of the radiator 10, and when the suction nozzle descends to a distance H from the surface of the adhesive layer, the vacuum suction function is closed, so that the MOS tube falls to the surface of the adhesive layer in a free falling mode. The H value is required to be determined according to specific project application requirements and different equipment mounting precision after the effect is actually measured.

Step S104, baking and curing the radiator 10 and the power device assembly to obtain the power device assembly.

Specifically, according to the technological parameters of the heat-conducting bonding glue, the radiator 10 and the MOS tube assembly are integrally put into a curing device, and the bonding glue layer is baked and cured, so that the heat-conducting bonding glue layer 30 embedded with the insulating support filler 40 is formed, and the required power device assembly is obtained. Wherein the curing device includes, but is not limited to, a reflow oven or a stereo oven.

After the power device component is obtained, whether the voltage resistance between the back pins of the MOS tube and the radiator 10 meets the requirement or not can be measured according to the voltage resistance requirement of the product. And then, the power device assembly can be put into a PCBA plug-in unit and a wave soldering process for use.

Based on the same inventive concept, the application also provides electronic equipment comprising the power device assembly. The specific structure of the power device assembly refers to the above embodiments, and because the electronic device adopts all the technical solutions of all the embodiments, the power device assembly at least has all the beneficial effects brought by the technical solutions of the embodiments, and is not described in detail herein.

The foregoing description is only of the optional embodiments of the present utility model, and is not intended to limit the scope of the utility model, and all the equivalent structural changes made by the description of the present utility model and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the utility model.

Claims

1. A power device assembly, comprising:

a heat sink;

the heat conduction bonding adhesive layer is bonded with the metal sheet on one surface, and the radiator is bonded on the other surface; and

the insulation support filler is embedded in the heat conduction adhesive layer, the insulation support filler is arranged as spherical particle pieces, and the diameter of the spherical particle pieces is the same as the thickness of the heat conduction adhesive layer, so that the thickness of the heat conduction adhesive layer reaches the insulation pressure-resistant thickness between the radiator and the power element.

2. The power device assembly of claim 1, wherein the insulating support filler is glass beads.

3. The power device assembly of claim 1, wherein the thermally conductive adhesive layer has a thickness greater than 0.2mm.

4. A power device assembly according to any one of claims 1 to 3, wherein the thermally conductive adhesive layer has a thermal conductivity of λ, wherein λ is greater than or equal to 1.9W/Mk.

5. A power device assembly according to any one of claims 1 to 3, wherein the thermal conductive adhesive layer has a bond strength per unit area of F and a bond strength per unit area of ps, wherein F is equal to or greater than 1000n and ps is equal to or greater than 3Mpa.

6. A power device assembly according to any one of claims 1 to 3, wherein the thermally conductive adhesive layer has a viscosity μ, wherein 60000CPS +.μ +.100000 CPS.

7. An electronic device comprising a power device assembly according to any of claims 1 to 6.

8. The electronic device of claim 7, wherein the electronic device is any one of a frequency converter, an on-board charger, a voltage converter, or a photovoltaic inverter.