Power module substrate and production system capable for high power applications

Abstract

The application relates to the technical field of micro power supply modules, and particularly discloses a power supply module substrate capable of being used in a high-power application scenario and a production system; wherein the power supply module substrate capable of being used in the high-power application scenario comprises: a plurality of substrates; the plurality of substrates are stacked in sequence; a plurality of the substrates are provided with a plurality of conductive holes along a normal direction; the conductive holes comprise conductive blind holes and / or conductive through holes; the conductive blind holes at least penetrate through two of the substrates; the conductive through holes penetrate through each of the substrates; the conductive holes are filled with paste-like conductive materials, and the paste-like conductive materials form columnar conductive structures after solidification. In the power supply module substrate, the columnar conductive structures improve the conductive performance, structural strength and heat conduction performance of the substrate. This makes it unnecessary to reduce the size of the module due to the structural strength and unnecessary to reduce the working current or power for heat dissipation, and fully releases the potential of high-power density packaging of the multilayer ceramic substrate.

Description

Technical Field

[0001] This application relates to the field of micro power module technology, and in particular to a power module substrate and manufacturing system that can be used in high-power application scenarios. Background Technology

[0002] Existing electronic products demand miniaturization, lightweighting, and high performance. System-in-Package (SiP) technology, due to its ability to heterogeneously integrate multiple functional chips and passive components, has become one of the ways to achieve miniaturization of micro power modules, allowing modules to perform complex functions in a smaller volume. In SiP micro power modules, the multilayer ceramic substrate is the core carrier. It is prepared using high-temperature co-fired ceramic (HTCC) or low-temperature co-fired ceramic (LTCC) technology, possessing good thermal stability, mechanical strength, and insulation properties, and its coefficient of thermal expansion matches that of silicon chips. Through printing, stacking, and co-firing processes, it can form a complex internal multilayer interconnect network and cavity structure to support various electronic components. Surface electrodes and pads are also set on the substrate surface for external electrical connections and internal component interconnection; while power management integrated circuits (PMICs, active devices requiring external power), capacitors, inductors (passive devices requiring no external power), etc., are mounted on the substrate surface or embedded in the cavity through sintering or soldering processes.

[0003] To achieve the conduction of circuits between different layers inside a multilayer ceramic substrate, existing multilayer ceramic SiP micro power modules drill holes in the ceramic green body and fill them with metal pastes such as silver paste or tungsten paste. After co-firing, vertical interconnecting vias are formed to achieve electrical connection between layers.

[0004] In practical applications, SiP micro power modules face limitations in high-reliability, high-power application scenarios.

[0005] First, ceramic substrates have inherent characteristics of high hardness and high brittleness, which makes them poor in terms of resistance to mechanical impact and bending. This characteristic is more pronounced on large-area substrates.

[0006] Meanwhile, ceramics have different coefficients of thermal expansion than internal metal wiring layers, surface-welded chips and components. During temperature cycling (changes in ambient temperature) or power cycling (fluctuations in module power), huge thermal stresses are generated. These stresses are concentrated at the edges and weak areas of the substrate, which poses a high risk of microcracks. Once microcracks are generated, they will gradually expand, eventually leading to substrate breakage and module failure. This results in a long-term decrease in the reliability and lifespan of the product in harsh environments with frequent vibrations, shocks, and high and low temperature changes.

[0007] Secondly, there are problems with high current transmission path impedance and limited conversion efficiency between substrates: Traditional multilayer ceramic substrates rely on vertical interconnect vias to achieve interlayer interconnection, but these vias have problems such as high hole wall roughness, insufficient filling density, and defects at the interface with the ceramic, resulting in high via resistivity. When the module is working under high current, the current passing through the interconnect structure will generate significant ohmic losses (electrical energy is converted into heat due to resistance), which directly reduces the power conversion efficiency and aggravates the internal temperature rise of the module, forming a vicious cycle of decreased efficiency and increased temperature rise, which limits the output power of the module.

[0008] Furthermore, although the thermal conductivity of ceramic substrates is better than that of ordinary PCB boards after cracks are generated, the microcracks on the substrate will hinder the heat flow. In addition, the extra heat generated by the low current transmission efficiency needs to be dissipated in time, which leads to the accumulation of heat in local areas and the formation of local hot spots. In order to avoid overheating, it is necessary to reduce the module's operating current or power, so that the high power density packaging potential that multilayer ceramic substrates should have cannot be fully utilized. Utility Model Content

[0009] In view of this, the purpose of this application is to provide a power module substrate and production system that can be used in high-power application scenarios to solve some or all of the above-mentioned problems.

[0010] To achieve the above-mentioned technical objectives, the first aspect of this application provides a power module substrate that can be used in high-power application scenarios, comprising: multiple substrates;

[0011] Multiple substrates are stacked sequentially;

[0012] The substrates are provided with a number of conductive holes along the normal direction;

[0013] The conductive via includes conductive blind vias and / or conductive through vias;

[0014] The conductive blind via penetrates at least two of the substrates;

[0015] The conductive vias penetrate each of the substrates;

[0016] The conductive hole is filled with a slurry-like conductive material, and the slurry-like conductive material solidifies to form a columnar conductive structure.

[0017] Furthermore, the slurry conductive material is a metal conductive slurry, a metal-ceramic composite conductive slurry, or a metal-carbon composite slurry.

[0018] Furthermore, among the plurality of substrates, the pads of the substrate located on the surface are provided with gold-plated structures.

[0019] Furthermore, the conductive hole occupies less than or equal to 20% of the area of ​​the substrate.

[0020] Furthermore, the conductive hole occupies 5-20% of the area of ​​the substrate.

[0021] Furthermore, the diameter of the conductive hole ranges from 0.075mm to 0.5mm.

[0022] Furthermore, the spacing between adjacent conductive holes is ≥0.15mm.

[0023] The second aspect of this application provides a power module substrate manufacturing system for producing power module substrates as described in any of the above claims that can be used in high-power application scenarios.

[0024] Furthermore, this includes: drilling machines, stacking machines, and grouting machines;

[0025] The drilling machine is used to drill holes in the substrate to form ungrouted conductive holes;

[0026] The stacking machine is used to stack multiple substrates at preset positions;

[0027] The grouting machine is used to inject a slurry-like conductive material into the ungrouted conductive holes before the multiple substrates are stacked.

[0028] Furthermore, it also includes: a mixer;

[0029] The mixer is used to stir the slurry conductive material to degas the slurry conductive material.

[0030] As can be seen from the above technical solutions, this application provides a power module substrate and production system that can be used in high-power application scenarios; wherein, the power module substrate that can be used in high-power application scenarios includes: multiple substrates; the multiple substrates are stacked sequentially; the multiple substrates are provided with a plurality of conductive holes along the normal direction; the conductive holes include conductive blind holes and / or conductive through holes; the conductive blind holes penetrate at least two of the substrates; the conductive through holes penetrate each of the substrates; the conductive holes are filled with a slurry conductive material, and the slurry conductive material solidifies to form a columnar conductive structure.

[0031] In the power module substrate provided by this solution, columnar conductive structures are embedded within conductive vias, serving as an internal support framework for multiple substrates. This compensates for the high hardness and brittleness of ceramic substrates, thereby improving the structural strength of the module and reducing the risk of stress concentration at substrate edges and weak areas, which could lead to cracking. Simultaneously, the columnar conductive structures electrically connect the substrates, reducing their resistivity. When the module is under high current, the low-resistivity columnar conductive structures reduce ohmic losses as current flows through interlayer interconnects, preventing excessive energy conversion into heat, improving power conversion efficiency, and avoiding a vicious cycle of decreased efficiency and increased temperature rise within the module. Furthermore, the columnar conductive material acts as a heat conduction channel between substrates. On one hand, it ensures the thermal conductivity of the substrate itself by reducing the risk of cracking; on the other hand, it quickly conducts locally accumulated heat to all areas of the substrate, achieving uniform heat dissipation and preventing hotspot formation. This allows the module to operate without being limited in size due to structural strength constraints or requiring a reduction in operating current or power for heat protection, fully realizing the potential of high-power-density packaging on multilayer ceramic substrates. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This application provides a schematic diagram of a power module substrate capable of being used in high-power applications, showing a structure with multiple substrates in a layered state.

[0034] In the figure: 10, substrate; 11, conductive hole; 111, conductive blind hole; 112, conductive through hole. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.

[0036] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a replaceable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0038] Please see Figure 1 The first aspect provided in this application embodiment offers a power module substrate suitable for high-power applications, comprising: a plurality of substrates 10, wherein the substrates 10 may be ceramic substrates. In this embodiment, the number and area of ​​the substrates 10 are not limited. The plurality of substrates 10 are stacked sequentially, wherein each substrate 10 may be configured with a structure of uniform size and neatly stacked in a facing manner.

[0039] Multiple substrates 10 have a number of conductive holes 11 disposed along the normal direction, where the normal direction of the substrate 10 refers to the direction perpendicular to the end face of the substrate 10. Taking the substrate 10 as a horizontally placed example, the normal direction is the vertical direction.

[0040] The conductive hole 11 includes a conductive blind hole 111 and / or a conductive through hole 112; the conductive blind hole 111 penetrates at least two substrates 10; the conductive through hole 112 penetrates each substrate 10; the conductive hole 11 is filled with a slurry conductive material, and the slurry conductive material solidifies to form a columnar conductive structure.

[0041] In this embodiment, the conductive blind via 111 penetrates only a portion of the substrate 10, but not the entire substrate 10. The conductive through-hole 112 penetrates the entire substrate 10.

[0042] In one embodiment, the conductive holes 11 in the power module substrate provided in this embodiment can all be conductive blind holes 111.

[0043] In one embodiment, the conductive holes 11 in the power module substrate provided in this embodiment can all be conductive through holes 112.

[0044] In one embodiment, the conductive hole 11 in the power module substrate provided in this embodiment can also be a conductive blind hole 111 and a conductive through hole 112.

[0045] In practical applications, the location of the conductive hole 11, whether the conductive hole 11 is a blind hole or a through hole, can be determined according to the circuit layout and other factors.

[0046] In this embodiment, the filling of the conductive blind via 111 with a paste-like conductive material can be performed when the substrate 10 is stacked to the corresponding number of layers. For example, if the substrate 10 includes 5 sheets, so that the final substrate has a 5-layer structure, and the conductive blind via 111 is configured to connect the 2nd, 3rd and 4th layers, then when the substrate 10 is stacked to 4 layers, the paste-like conductive material can be injected into the conductive blind via 111 of the 2nd layer first, and then the topmost substrate 10 can be stacked.

[0047] After the slurry-like conductive material is injected into the conductive hole 11, it gradually solidifies and eventually forms a columnar conductive structure. In practical applications, the slurry-like conductive material can be a metal conductive paste, a metal-ceramic composite conductive paste, or a metal-carbon composite paste. Among these, the metal conductive paste can be, for example, silver paste or copper paste. The metal-ceramic composite conductive paste can be, for example, silver-alumina, copper-aluminum nitride, or silver-boron nitride composite pastes, which have good high-temperature resistance. The metal-carbon composite paste can be, for example, silver-graphene, copper-carbon black, or silver-carbon nanotube composite pastes, which have good conductivity.

[0048] In this design, the columnar conductive structure abuts against the substrate 10 after solidification, thus serving as a supporting framework within multiple substrates 10. This improves the substrate 10's resistance to mechanical impact and bending, thereby reducing the risk of large-sized substrates 10 breaking due to vibration and impact. Simultaneously, the force transmission through the columnar conductive structure disperses and transmits mechanical and thermal stresses originally concentrated on a single substrate 10 to other substrates 10, reducing stress concentration and buffering the thermal expansion differences between different materials. This reduces the risk of cracks at the edges and weak areas of the substrate 10, enhances the long-term reliability of the substrate, extends the module's lifespan, allows for larger substrate configurations, and improves the substrate's applicability.

[0049] Regarding conductivity, the columnar conductive structure reduces the voids within the conductive vias 11 and lowers resistivity through its high conductivity. Simultaneously, the combined design of the conductive blind vias 111 and conductive through-holes 112 optimizes the current path according to interlayer interconnection requirements, avoiding unnecessary path losses. This significantly reduces ohmic losses on the module substrate under high-current operating conditions, directly improving power conversion efficiency and reducing additional heat generation, breaking the vicious cycle of traditional solutions and providing a foundation for increased module output power.

[0050] In terms of thermal conductivity, the columnar conductive structure improves structural strength, thereby reducing the probability of crack formation. At the same time, heat can be conducted with the current, thus ensuring the thermal conductivity of the substrate itself. Meanwhile, the low-loss design reduces additional heat sources. Combined with the thermal conductivity of the columnar conductive structure, it can promote the uniform diffusion of heat within the substrate and avoid the accumulation of local hot spots.

[0051] In one embodiment, the columnar conductive structures in different conductive holes 11 can be electrically connected through conductive lines 13, thereby forming a complete circuit on the substrate. In practical applications, the conductive lines 13 can be formed by brushing or injection of slurry.

[0052] In one embodiment, among the plurality of substrates 10, the pads of the substrate 10 located on the surface are provided with gold-plated structures.

[0053] The gold plating structure includes, but is not limited to, gold. Gold plating isolates the solder pads from air and moisture, preventing oxidation and increased contact resistance over time. Furthermore, the low resistivity of the gold plating further reduces the connection impedance between external components (such as PMICs and capacitors) and the substrate, minimizing power loss at the interface.

[0054] In one embodiment, the conductive hole 11 occupies less than or equal to 20% of the area of ​​the substrate 10.

[0055] The inventors have discovered that if the area ratio of the conductive hole 11 is too high, it will weaken the structural integrity of the substrate and occupy the arrangement space of other components. Therefore, in this embodiment, the area ratio of the conductive hole 11 to the substrate 10 is configured to be less than or equal to 20%, which can balance the two requirements. Preferably, the area ratio of the conductive hole 11 to the substrate 10 is 5-20%.

[0056] In one embodiment, the diameter of the conductive hole 11 is in the range of 0.075mm-0.5mm to accommodate the injection and filling requirements of the slurry conductive material, avoiding the difficulty of injecting the conductive material due to excessively narrow channels, and avoiding the difficulty of filling the conductive material tightly due to excessively large channel diameters.

[0057] In one embodiment, the hole spacing between adjacent conductive holes 11 is ≥0.15mm to ensure the structural strength of the substrate 10 between adjacent holes and avoid local cracking.

[0058] The second aspect of this application provides a power module substrate manufacturing system for producing power module substrates that can be used in high-power application scenarios, as described above.

[0059] In a more specific embodiment, the production system may include: a drilling machine, a stacking machine, and a grouting machine; the drilling machine is used to drill holes in the substrate 10 to form ungrouted conductive holes 11; the stacking machine is used to stack multiple substrates 10 at a preset position; and the grouting machine is used to inject a slurry-like conductive material into the ungrouted conductive holes 11 before the multiple substrates 10 are stacked.

[0060] Furthermore, it also includes: a mixer; the mixer is used to agitate the slurry conductive material to degas the slurry conductive material. Specifically, the agitator of the mixer can extend into the slurry storage component of the grouting machine to agitate the slurry conductive material.

[0061] It should be noted that the method of stacking multiple substrates 10 in an orderly manner is existing technology. For example, positioning circles can be set on the substrates 10 so that the stacking machine can position the substrates according to the positions of the positioning circles.

[0062] The above are merely preferred embodiments of this application and are not intended to limit the present invention. Although the present application has been described in detail with reference to examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A power module substrate suitable for high-power applications, characterized in that, include: Multiple substrates (10); Multiple substrates (10) are stacked sequentially; The multiple substrates (10) are provided with a number of conductive holes (11) along the normal direction; The conductive hole (11) includes a conductive blind hole (111) and / or a conductive through hole (112). The conductive blind via (111) penetrates at least two of the substrates (10). The conductive via (112) penetrates each of the substrates (10); The conductive hole (11) is filled with a slurry-like conductive material, and the slurry-like conductive material solidifies to form a columnar conductive structure.

2. The power module substrate for high-power applications according to claim 1, characterized in that, The slurry-like conductive material is a metal conductive slurry, a metal-ceramic composite conductive slurry, or a metal-carbon composite slurry.

3. The power module substrate for high-power applications according to claim 1, characterized in that, Among the plurality of substrates (10), the pads of the substrates (10) located on the surface are provided with gold-plated structures.

4. The power module substrate for high-power applications according to claim 1, characterized in that, The conductive hole (11) occupies less than or equal to 20% of the area of ​​the substrate (10).

5. The power module substrate for high-power applications according to claim 4, characterized in that, The conductive hole (11) occupies 5-20% of the area of ​​the substrate (10).

6. The power module substrate for high-power applications according to any one of claims 1 to 5, characterized in that, The diameter of the conductive hole (11) ranges from 0.075 mm to 0.5 mm.

7. The power module substrate for high-power applications according to claim 6, characterized in that, The hole spacing between adjacent conductive holes (11) is ≥0.15mm.

8. A power module substrate production system, characterized in that, Used for producing the power module substrate as described in any one of claims 1 to 7, which can be used in high-power applications.

9. The power module substrate production system according to claim 8, characterized in that, include: Drilling machines, stacking machines, and grouting machines; The drilling machine is used to drill holes in the substrate (10) to form ungrouted conductive holes (11). The stacking machine is used to stack multiple substrates (10) at a preset position; The grouting machine is used to inject a slurry-like conductive material into the ungrouted conductive holes (11) before the plurality of substrates (10) are stacked.

10. The power module substrate production system according to claim 9, characterized in that, Also includes: Blender; The mixer is used to stir the slurry conductive material to degas the slurry conductive material.

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