阅读说明：本技术 一种部件承载件和制造该部件承载件的方法 (Component carrier and method for producing the component carrier ) 是由 克里斯蒂安·维肯博格 于 2019-06-19 设计创作，主要内容包括：本发明涉及一种部件承载件,该部件承载件具有叠置件和暴露的高导热冷却结构的阵列件,所述叠置件包括至少一个电绝缘层结构和/或至少一个导电层结构,所述冷却结构与所述叠置件一体地形成并在所述冷却结构之间限定冷却通道。本发明还涉及一种制造该部件承载件的方法。(The present invention relates to a component carrier having an array of exposed highly thermally conductive cooling structures and a stack comprising at least one electrically insulating layer structure and/or at least one electrically conductive layer structure, the cooling structures being formed integrally with the stack and defining cooling channels between the cooling structures. The invention also relates to a method for producing the component carrier.)

1. A component carrier, comprising:

a stack comprising at least one electrically insulating layer structure and/or at least one electrically conductive layer structure;

an array of exposed high thermal conductivity cooling structures integrally formed with the stack and defining cooling channels between the cooling structures.

2. The component carrier of claim 1,

the cooling structure is integrally provided in the component carrier in one piece.

3. The component carrier of claim 1,

the cooling structure is formed on and/or in the stack by additive manufacturing, in particular by three-dimensional printing.

4. The component carrier of claim 1,

the cooling structure is located in a cavity of the stack such that the cooling structure does not protrude beyond the cavity.

5. The component carrier of claim 1,

the cooling structure is formed inside the stack with at least one layer structure above the cooling structure and at least one layer structure below the cooling structure.

6. The component carrier of claim 1,

the cooling structure is integrally provided in the material of the stack, there being no connecting medium between the cooling structure and the stack.

7. The component carrier of claim 1,

the cooling structure is a pillar, in particular a copper pillar.

8. The component carrier of claim 1,

the cooling channel is configured to at least partially surround the cooling structure with a cooling medium, in particular air.

9. The component carrier of claim 1, further comprising:

components mounted on and/or embedded in the stack, in particular electronic components mounted on and/or embedded in the stack,

wherein the component is in particular a component thermally coupled to the cooling structure.

10. The component carrier of claim 9, wherein,

the component is selected from the group consisting of an electronic component, a non-conductive and/or conductive inlay, a heat transfer unit, a light guiding element, an energy harvesting unit, an active electronic component, a passive electronic component, an electronic chip, a memory device, a filter, an integrated circuit, a signal processing component, a power management component, an optoelectronic interface element, a voltage converter, a cryptographic component, a transmitter and/or receiver, an electromechanical transducer, an actuator, a microelectromechanical system, a microprocessor, a capacitor, a resistor, an inductance, a battery, a switch, a camera, an antenna, a magnetic element, a further component carrier, and a logic chip.

11. The component carrier of claim 1,

the at least one electrically conductive layer structure comprises at least one of the group consisting of copper, aluminum, nickel, silver, gold, palladium and tungsten, any of the mentioned materials optionally being coated with a superconducting material, such as graphene.

12. The component carrier of claim 1,

the at least one electrically insulating layer structure comprises a layer of a resin, in particular a reinforced or non-reinforced resin, such as an epoxy resin or a bismaleimide-triazine resin; FR-4; FR-5; a cyanate ester; a polyphenylene derivative; glass; prepreg preparation; a polyimide; a polyamide; a liquid crystalline polymer; an epoxy-based reinforcing film; polytetrafluoroethylene; at least one of the group consisting of ceramics and metal oxides.

13. The component carrier of claim 1,

the component carrier is shaped as a plate.

14. The component carrier of claim 1,

the component carrier is configured as one of the group consisting of a printed circuit board and a substrate.

15. The component carrier according to claim 1,

the component carrier is configured as a laminate-type component carrier.

16. The component carrier of claim 1,

the cooling structure is manufactured by: applying a sacrificial structure on the stack, forming an opening in the sacrificial structure, filling the opening with a highly thermally conductive material, and removing the sacrificial structure.

17. A method of manufacturing a component carrier, wherein the method comprises:

forming a stack comprising at least one electrically insulating layer structure and/or at least one electrically conductive layer structure;

an array of exposed highly thermally conductive cooling structures is formed integrally with the stack, thereby forming cooling channels between the cooling structures.

18. The method of claim 17, wherein,

the array member forming the exposed high thermal conductivity cooling structure includes:

applying a sacrificial structure on the stack, in particular the sacrificial structure is a dry film structure;

forming an opening in the sacrificial structure;

filling the opening with a high thermal conductivity material; and

and removing the sacrificial structure.

19. The method of claim 17, further comprising:

forming an upper stack of at least one electrically insulating layer structure and/or at least one electrically conductive layer structure;

forming a lower stack of at least one electrically insulating layer structure and/or at least one electrically conductive layer structure;

sandwiching the stack between the lower stack and the upper stack;

-fixing together the stack, the lower stack and the upper stack, in particular by a lamination procedure.

20. The method of claim 17, further comprising:

the cooling structure is formed on and/or in the stack by additive manufacturing, in particular by three-dimensional printing.

Technical Field

The present invention relates to a component carrier comprising a thermally conductive cooling structure. Furthermore, the invention relates to a method of manufacturing a component carrier comprising a cooling structure.

Background

A component carrier, such as a Printed Circuit Board (PCB) or substrate, mechanically supports and electrically connects the electronic components. Electronic components are mounted on the component carrier and connected to each other to form a working circuit or an electronic assembly.

The component carrier may be a single-sided component carrier or a double-sided component carrier, or may have a multi-layer design. Advantageously, the multilayer component carrier allows a high component density, which is becoming increasingly important in the continued miniaturization of electronic components. Conventional component carriers known in the prior art comprise a laminated stack with a plurality of electrically insulating layer structures and a plurality of electrically conductive layer structures. The conductive layers are usually connected to each other by so-called micro vias or plated through holes. The conductive copper layer on the laminated stack surface forms an exposed structured copper surface. The exposed structured copper surfaces of the laminated stack are typically covered with a finish surface that completely covers the exposed structured copper surfaces.

However, thermal management becomes more important due to the high density of components in component carriers, especially in high power components. Efficient and integrated cooling is increasingly important. Especially for embedded power components or power components, heat has to be transported away. Thus, the large heat sink element is manufactured separately and attached to the component carrier, for example by means of a thermally conductive adhesive or welding, in order to transport heat away from the component carrier.

Accordingly, there may be a need for an improved component carrier comprising an efficient and compact heat sink.

Disclosure of Invention

According to a first aspect of the invention, a component carrier is presented. The component carrier comprises a stack with at least one electrically insulating layer structure and/or at least one electrically conductive layer structure. Further, the component carrier comprises an array of exposed high thermal conductivity cooling structures integrally formed with the stack and defining cooling channels between the exposed high thermal conductivity cooling structures.

According to another aspect of the invention, a method of manufacturing a component carrier is presented. According to the method, a stack comprising at least one electrically insulating layer structure and/or at least one electrically conductive layer structure is formed. Furthermore, an array of exposed high thermal conductivity cooling structures is integrally formed with the stack such that cooling channels are formed between the cooling structures.

In the context of the present application, the term "component carrier" may particularly denote any support structure capable of accommodating one or more components thereon and/or therein to provide mechanical support and/or electrical connection. In other words, the component carrier can be configured as a mechanical carrier and/or as an electronic carrier for the component. In particular, the component carrier may be one of a printed circuit board, an organic interposer and an IC (integrated circuit) substrate. The component carrier may also be a hybrid board combining different types of component carriers of the above-mentioned types of component carriers.

The component carrier comprises a stack of at least one electrically insulating layer structure and at least one electrically conductive layer structure. For example, the component carrier may be a laminate or a laminate of the one or more electrically insulating layer structures and the one or more electrically conductive layer structures, in particular a laminate or a laminate formed by applying mechanical pressure, if necessary supported by thermal energy. The mentioned stack may provide a plate-shaped component carrier which is capable of providing a large mounting surface for other components and which is still very thin and compact. The term "layer structure" may particularly denote a continuous layer, a patterned layer or a plurality of non-continuous islands in a common plane. In the context of the present invention, the term "layer structure" may be a single layer component or a multilayer component.

The high thermal conductivity cooling structure may include a material selected from at least one of copper, aluminum, and steel. The cooling structure may further include a material selected from at least one of silver, nickel, bronze, gold, titanium, tantalum, tungsten, molybdenum, and steel.

The thermally conductive cooling structure forms protrusions, wherein cooling channels are formed between the protrusions. The cooling structure may be formed by the design of the cooling edge and the cooling fin, respectively. Furthermore, as described below, the cooling structure may be formed as a cooling pin or cooling column, for example, having a circular, elliptical, oval or rectangular cross-section. Thus, the cooling structure forms a large dissipation surface, so that good cooling efficiency can be provided. In other words, by means of the cooling structure, a matrix of copper-filled openings (e.g. micro-holes) may be formed, and the material of the layer structure (dielectric material) around the openings may be removed to allow for e.g. air flow. Cooling structures may be placed in the cavity to reduce the thickness (z-dimension) and avoid handling damage.

With the present invention, the stack (with or without components inside) and the array are integrally formed. This means that the stack and the array are not formed separately in a separate manufacturing process, wherein the array is on the finished component, i.e. the stack and the array are mounted together in a final manufacturing step. By the present invention the term "integrally formed" is meant that the stack and the array are manufactured in one common manufacturing process. As described in further detail below, the stack is integrally formed together with the respective vias, signal lines and thermal paths of the stack and the array of cooling structures, rather than being formed separately in different manufacturing steps.

Thus, by the present invention, separate and additional heat sinks are not required, and thus material and space consumption can be reduced. Further, due to the integral formation of the heat sink, for example, a thermally conductive adhesive may be eliminated, so that thermal resistance caused by the adhesive may be reduced. Therefore, the length of the thermal path can also be reduced. Furthermore, the manufacturing process is simplified and the required material is reduced.

According to a further exemplary embodiment, the cooling structure is integrally provided in the component carrier in one piece (monolithically). The term "integrally provided in one piece" means that the cooling structure is formed in one piece within the stack and thermally coupled to a thermally conductive structure of the component carrier, such as a copper filled via or a thermally conductive component layer arranged on a component (e.g. an embedded component). In other words, there is no space between the material of the heat conducting cooling structure and the material of the heat conducting structure within the component carrier between the source of heat radiation and the heat sink side of the component carrier.

According to an exemplary embodiment of the invention, the cooling structure is formed on and/or in the stack by additive manufacturing, in particular by three-dimensional printing. Thus, according to an exemplary embodiment of the method, the cooling structure is formed on and/or in the stack by additive manufacturing, in particular by three-dimensional printing.

In the context of the present application, the term "additive manufacturing" may particularly denote a manufacturing process of an array of thermally conductive cooling structures, according to which the cooling structures are manufactured by sequentially adding material of parts that, when taken together, constitute the array of cooling structures. By this additional manufacturing, a stable and specific heat conductive formation of the cooling structure is possible, and there is no need to glue the cooling structure to the surface of the layer structure of the stack, thus no further intermediate adhesive layers or the like are needed. Exemplary manufacturing processes for additive manufacturing are described in the following exemplary embodiments. For example, 3D printing techniques, Selective Laser Sintering (SLS) procedures, Selective Laser Melting (SLM) procedures, and/or additional procedures may be used to perform additive manufacturing.

Thus, different materials can be placed directly into the stack of the respective stack. Undesirable cavity formation during manufacturing can be avoided.

The manufacture of the component carrier and/or the cooling structure may be formed by a 3D print head which is activated or controlled to form the cooling structure in an integrated and simultaneous manner with the stack of layer structures. Such three-dimensional printing may be done on the basis of a printing material, such as a powder-based technical material, which is sintered or melted through the metal surface, for example by a spatially limited thermal treatment, for example by a laser. Furthermore, the cooling structure may also be formed by spraying droplets of molten printing material through a nozzle or the like (such as an extrusion device or a plasma spraying device) to form a layer of the cooling structure, which is solidified after application to the layer structure or solidified layer of the stack.

In particular, three-dimensional printing as an additive manufacturing process includes, for example, 3D printing using powder, 3D printing using molten material, or 3D printing using fluid material. 3D printing using powder may particularly denote the use of powder as a printing material for 3D printing. Another process that uses a marking material (e.g., in powder form) is a selective laser sintering/melting (SLS/SLM) process, depending on whether the delivered local energy is to sinter or melt the layers together. Another process that uses printing material in powder form is the electron beam melting process (EBM, or also known as electron beam additive manufacturing EBAM). 3D printing using molten material may particularly denote fuse fabrication (FFF) or Fused Deposition Modeling (FDM). The molten material to be used in the process may be, inter alia, a plastic, such as ABS or PLA. 3D printing using fluid materials may particularly denote a manufacturing process working on the basis of a photosensitive fluid, such as a fluid UV-sensitive plastic (photopolymer). In particular, 3D printing using fluid materials may represent so-called Stereolithography (SLA). In this process, the cooling structure is also formed layer by layer.

By applying additive manufacturing, the cooling structure is directly and integrally formed on the layer structure of the stack. Thus, by using additive manufacturing, the cooling structure is arranged directly on the layer structure of the stack without any intermediate layer between the surface of the layer structure of the stack already manufactured and the cooling structure.

The additive manufacturing for forming the cooling structure is highly automated and does not require assembly of the heat dissipating structure after completion of the manufacturing steps of the component carrier, since the cooling structure is manufactured directly on the electronic component layer structure of the stack. Additive manufacturing allows the production of heat dissipating cooling structures with enhanced thermal conductivity controlled at the microstructure level.

According to another exemplary embodiment, the cooling structure is located in the cavity of the stack such that the cooling structure does not protrude beyond the cavity. In other words, the stack comprises an outer structure comprising a surface directed towards the environment of the component carrier. The outer structure is defined in a plane. Thus, the cavity is formed through the outer layer structure. Thus, the cooling structure, such as a plurality of spaced apart posts or needles, protrudes through the cavity to the outer structure without protruding above the outer surface of the outer structure in the environment.

Additionally or alternatively, at least a portion of the cooling structure is formed (e.g. by additive manufacturing) on the "top" of the stack, in particular on the outer surface of the stack.

According to another exemplary embodiment, a cooling structure is formed inside the stack, wherein there is at least one layer structure above the cooling structure and at least one layer structure below the cooling structure. The cooling structures are thus embedded within the stack, wherein the cooling channels between the cooling structures comprise an inlet and an outlet to the environment of the component carrier, so that, for example, a cooling fluid may flow through the cooling channels to transfer heat out of the component carrier.

For example, the component carrier is formed by three stacks, wherein an intermediate stack comprising the thermally conductive cooling structure is sandwiched between two other stacks. Thus, the intermediate stack may be integrally formed with the thermally conductive cooling structure, and the cover stack surrounds the array of thermally conductive cooling structures.

According to another exemplary embodiment, the cooling structure is integrally provided in the material of the stack without a connection medium therebetween, i.e. between the cooling structure and the stack. The cooling structure is integrated into the stack and thus formed together with the stack, for example by additive manufacturing as described above or by a common plating process.

Thus, the use of any heat resistant layer that can reduce, for example, heat dissipation from the component is avoided. For example, if the surfaces of the cooling structure and the heat generating component are made of a thermally conductive material (e.g., metal), a metal-to-metal bond is provided between the cooling structure acting as a heat sink and the metal surface on the component, avoiding the use of any glue, tape, or Thermal Interface Material (TIM), so that the thermal conductivity of currently available heat dissipating mounting techniques may be enhanced.

According to another exemplary embodiment, the cooling structure is a pillar, in particular a copper pillar. The cooling pins or posts may form, for example, a circular, oval or rectangular cross-section. Thus, the cooling structure forms a large dissipation surface, so that good cooling efficiency can be provided. The cooling structure may also be formed as a cooling edge and a cooling fin, respectively, for example.

The posts (and also the cooling fins) form protrusions to increase the overall surface area of the cooling structure. The entire surface area thus provides a larger surface, so that thermal conductivity with the environment of the component carrier can be provided. In particular, small and complex three-dimensional fin shapes can be manufactured by additive manufacturing.

According to a further exemplary embodiment, the cooling channel is configured to at least partially surround the cooling structure with a cooling medium, in particular air or a liquid, for example water.

According to an exemplary embodiment of the method for manufacturing a component carrier, the step of forming an array of exposed high thermally conductive cooling structures comprises: applying a sacrificial structure on the stack, forming an opening in the sacrificial structure, filling the opening with a highly thermally conductive material, and removing the sacrificial structure.

Thus, for example, as a first step, a sacrificial structure is applied on the stack, in particular in the cavity of the stack. The sacrificial structure may be a laser-drillable material and/or a material that can be plated with copper. Furthermore, the sacrificial structure may be a photoresist material, which may be removed by e.g. (ultraviolet) radiation or etching. Thus, the pattern of openings is formed in the sacrificial structure by irradiation or etching at the locations where the respective cooling structures should be formed. Next, the opening is filled with a highly thermally conductive material such as copper. Thereby, the opening is plated with a thermally conductive material. For example, a portion of the thermally conductive material may be removed (stripped) after plating the opening. Next, the sacrificial structure is removed. Thus, after removal of the sacrificial structures, cooling channels are defined between the thermally conductive cooling structures.

The sacrificial structure may be a dry film, in particular a photo-dry film. A dry film may be placed on the stack or in a cavity of the stack and a corresponding opening may be formed in the dry film by radiation.

For example, the stack may be formed of an epoxy material (an epoxy material with or without fibers such as fiberglass) or a photoresist material.

Furthermore, the openings may be formed directly in the stack, wherein the openings are formed with a desired pattern indicative of the pattern of the cooling structure. For example, if the stack is formed of a photoresist material, the sacrificial structures may be resistant to etchant or defined radiation. Thus, the material of the stack not covered by the sacrificial layer is removed by etching or by irradiation to form a defined opening within the stack. Next, the opening is subsequently filled with copper. In a further step, the sacrificial layer is removed such that the material of the stack is no longer covered by said sacrificial layer. Next, in a further step, material between the copper (i.e. thermally conductive) filled openings is removed, for example by drilling, etching or radiation, thereby removing stack material between the copper filled openings and thereby forming cooling channels between the cooling structures.

According to a further exemplary embodiment of the manufacturing method, an upper stack made of at least one electrically insulating layer structure and/or at least one electrically conductive layer structure is formed. Furthermore, a lower stack made of at least one electrically insulating layer structure and/or at least one electrically conductive layer structure is formed. The stack is sandwiched between the lower stack and the upper stack. Next, the stack, the lower stack and the upper stack are secured together, in particular by a lamination procedure (i.e. by applying heat and pressure to the respective stacks).

Thus, a cooling structure is formed in the inner closed cavity of the stack, with an upper stack above the cooling structure and at least one layer structure, for example a lower stack below the cooling structure. Thus, cooling structures are embedded, wherein cooling channels between the cooling structures comprise an inlet and an outlet to the environment of the component carrier, so that for example cooling fluid can flow through the cooling channels to transfer heat out of the component carrier.

The manufactured component carrier is thus formed by separate stacks, wherein an intermediate stack comprising the heat-conducting cooling structure is sandwiched between two further stacks. Thus, the intermediate stack may be integrally formed with the thermally conductive cooling structure, and the cover stack surrounds the array of thermally conductive cooling structures.

The stack may be formed of a low flow material. Thus, first, thermally conductive structures such as vias and cooling structures may be formed within the respective stacks. In the next step, three stacks are formed together. By using "low flow materials" for the respective stacks, the stacks can be laminated together by applying heat and pressure without the risk of, for example, the liquid material of the upper or lower stack flowing in the cavity due to heat treatment within the lamination procedure.

In the context of the present application, the term "low-flow material" (sometimes also referred to as "no-flow material") may particularly denote a material which has no or only a very limited tendency to flow during processing under external pressure and elevated temperature, particularly during lamination. In particular, the low flow material may have a sufficiently high viscosity at the lamination temperature (e.g. 150 ℃), for example at least 5000 poise, preferably at least 10000 poise. For example, when a common prepreg is heated under pressure, its resin melts (liquefies) and flows freely in any voids in the environment. The resin of a conventional prepreg remains fluid enough to flow freely for a period of time. In contrast, low-flow materials implemented according to exemplary embodiments of the present invention are specifically configured to inhibit or even eliminate flow during lamination such that the low-flow material substantially stays in place during lamination. However, when a "low flow material" or a "no flow material" is provided prior to lamination, the "low flow material" or "no flow material" may still be at least partially uncured. When a no-flow prepreg or a low-flow prepreg is joined to other layer structures during lamination, such a no-flow prepreg or a low-flow prepreg has a tendency not to substantially flow into step regions. In the presence of thermal energy and/or pressure, during lamination, ordinary prepregs may re-melt and the corresponding resin may flow into the tiny gaps. After the corresponding cross-linking process of the resin is completed, the resin is re-cured and then held spatially fixed. If a general prepreg is used for the component carrier according to the exemplary embodiment of the present invention, care should be taken to prevent excessive inflow of resin into a region that should remain free of resin to form a step (e.g., a recessed portion described below). However, when using low-flow prepregs or no-flow prepregs, these potential problems are overcome by preventing resin flow into the gap which should be kept material-free to correctly define the step.

According to a further exemplary embodiment, the component carrier further comprises a component, in particular an electronic component, mounted on and/or embedded in the stack, wherein the component is in particular thermally coupled to the cooling structure.

The at least one component may be selected from the group consisting of: a non-conductive inlay; a conductive inlay (e.g., a metal inlay, preferably a conductive inlay comprising copper or aluminum); a heat transfer unit (e.g., a heat pipe); photoconductive elements, such as optical waveguides or optical conductor connections; an electronic component, or a combination thereof. For example, the component may be an active electronic component, a passive electronic component, an electronic chip, a storage device (e.g. a DRAM or other data storage), a filter, an integrated circuit, a signal processing component, a power management component, an optoelectronic interface element, a voltage converter (e.g. a DC/DC converter or an AC/DC converter), a cryptographic component, a transmitter and/or receiver, an electromechanical transducer, a sensor, an actuator, a micro-electromechanical system (MEMS), a microprocessor, a capacitor, a resistor, an inductance, a battery, a switch, a camera, an antenna, a logic chip and an energy harvesting unit and discrete power devices such as simple switches, transistors, MOSFETs, IGBTs. However, other components may be embedded in the component carrier. For example, a magnetic element may be used as the component. Such a magnetic element may be a permanent magnetic element (e.g. a ferromagnetic element, an antiferromagnetic element or a ferrimagnetic element, such as a ferrite core) or may be a paramagnetic element. However, the component may also be a substrate, an interposer or another component carrier, for example in a plate-in-plate configuration. The component may be surface mounted on the component carrier and/or may be embedded inside the component carrier. In addition, other components, in particular those generating and emitting electromagnetic radiation and/or being sensitive to electromagnetic radiation propagating from the environment, may also be used as the component.

In one embodiment, the component carrier is a laminate type component carrier. In such embodiments, the component carrier is a composite of multiple layers that are stacked and joined together by the application of pressure (with heat, if necessary).

However, other components may be embedded in the component carrier. For example, a magnetic element may be used as the component. Such a magnetic element may be a permanent magnetic element (such as a ferromagnetic element, an antiferromagnetic element or a ferrimagnetic element, for example a ferrite core) or may be a paramagnetic element. However, the component may also be a further component carrier, for example in a plate-in-plate configuration. The component may be surface mounted on the component carrier and/or may be embedded inside the component carrier. In addition, other components, in particular those generating and emitting electromagnetic radiation and/or being sensitive to electromagnetic radiation propagating from the environment, may also be used as the component.

According to a further exemplary embodiment, the at least one electrically conductive layer structure comprises at least one of the group consisting of copper, aluminum, nickel, silver, gold, palladium and tungsten. Although copper is generally preferred, other materials or coated forms of other materials are possible, particularly coated with superconducting materials such as graphene.

According to another exemplary embodiment, the at least one electrically insulating layer structure comprises at least one of the group consisting of a resin (such as a reinforced or non-reinforced resin, for example an epoxy resin or a bismaleimide-triazine resin, more particularly FR-4 or FR-5), a cyanate ester, a polyphenylene derivative, glass (in particular glass fibers, multiple layers of glass, glass-like materials), a prepreg, a polyimide, a polyamide, a Liquid Crystal Polymer (LCP), an epoxy-based reinforced film, polytetrafluoroethylene (teflon), a ceramic and a metal oxide. Reinforcing materials, for example made of glass (multiple layer glass) such as mesh, fibers or spheres, may also be used. Although prepreg or FR4 is generally preferred, other materials may be used. For high frequency applications, high frequency materials, such as polytetrafluoroethylene, liquid crystal polymers, and/or cyanate ester resins, may be applied in the component carrier as an electrically insulating layer structure.

The layer structure of the component carrier may be formed by electroless nickel plating (EN), in particular a first surface-finished layer structure and/or a second surface-finished layer structure, more particularly a first surface-finished layer structure and/or a first surface-finished second layer structure.

This contributes to a compact design, wherein the component carrier still provides a large basis for mounting components thereon. Further, particularly a bare chip, which is an example of an embedded electronic component, can be easily embedded in a thin board such as a printed circuit board due to its small thickness.

According to an exemplary embodiment, the component carrier is configured as one of the group consisting of a printed circuit board and a substrate. In the context of the present application, the term "printed circuit board" (PCB) may particularly denote a plate-like component carrier which is formed by laminating several electrically conductive layer structures with several electrically insulating layer structures, for example by applying pressure, if necessary by supplying thermal energy. As a preferred material for PCB technology, the electrically conductive layer structure is made of copper, while the electrically insulating layer structure may comprise resin and/or glass fibers, so-called prepreg or prepreg material or FR4 material. The individual conductive layer structures can be connected to one another in a desired manner by forming through-holes through the laminate, for example by laser drilling or mechanical drilling, and by filling the through-holes with a conductive material, in particular copper, so as to form via holes as through-hole connections. In addition to one or more components that may be embedded in a printed circuit board, printed circuit boards are typically configured to receive one or more components on one or both opposing surfaces of a plate-like printed circuit board. They may be attached to the respective major surfaces by welding. The dielectric portion of the PCB may include a resin with reinforcing fibers, such as glass fibers.

In the context of the present application, the term "substrate" may particularly denote a widget carrier having substantially the same dimensions as the components (particularly electronic components) to be mounted thereon. More specifically, a baseplate may be understood as a carrier for electrical connections or electrical networks and a component carrier comparable to a Printed Circuit Board (PCB), however with a relatively high density of laterally and/or vertically arranged connections. The transverse connections are, for example, electrically conductive paths, while the vertical connections may be, for example, drilled holes. These lateral and/or vertical connections are arranged within the substrate and may be used to provide electrical and/or mechanical connections of accommodated or non-accommodated components (e.g. bare die), in particular of IC chips with printed circuit boards or intermediate printed circuit boards. Thus, the term "substrate" also includes "IC substrates". The dielectric portion of the substrate may include a resin with reinforcing balls (e.g., glass balls).

In an embodiment, the component carrier is a laminate type component carrier. In such embodiments, the component carrier is a composite of multiple layers that are stacked and joined together by the application of pressure (with heat, if necessary).

The above-described and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.

Drawings

Fig. 1 shows a schematic view of a component carrier comprising components coupled to an array of exposed high thermal conductivity cooling structures according to an exemplary embodiment of the present invention.

Fig. 2 shows a schematic view of a component carrier comprising an array of exposed high thermally conductive cooling structures according to an exemplary embodiment of the present invention.

Fig. 3 shows a schematic view of a component carrier comprising an array of exposed high thermally conductive cooling structures surrounded by a stack according to an exemplary embodiment of the present invention.

Detailed Description

The illustration in the drawings is schematically. It should be noted that in different figures, similar or identical elements or features are provided with the same reference signs or with reference signs which differ from the corresponding reference signs only in the first digit. In order to avoid unnecessary repetition, elements or features that have been elucidated with respect to the previously described embodiments are not again elucidated at a later position in the description.

Furthermore, spatially relative terms, such as "front" and "rear," "upper" and "lower," "left" and "right," and the like, may be used to describe an element's relationship to another element or elements as illustrated in the figures. Spatially relative terms may thus be applied to orientations that differ in use from the orientation depicted in the figures. It will be apparent that all of these spatially relative terms are merely for convenience of description and are not necessarily to be limiting, as it is contemplated that a device according to embodiments of the present invention may, in use, be oriented differently than those shown in the figures.

Fig. 1 shows a component carrier 100 comprising components 120 coupled to an array of exposed high thermal conductivity cooling structures 111 according to an exemplary embodiment of the invention.

The component carrier 100 comprises a stack 101, the stack 101 having at least one electrically insulating layer structure and/or at least one electrically conductive layer structure. Furthermore, the component carrier 100 comprises an array 110 of exposed highly thermally conductive cooling structures 111, which exposed highly thermally conductive cooling structures 111 are formed together in an integrated manner with the stack 101 and define cooling channels 112 between them.

The component carrier 110 is a support structure capable of receiving one or more components 120 thereon and/or therein to provide mechanical support and/or electrical or thermal connection, such as provided by the pads 121 and vias 104 shown. The component carrier 100 comprises a stack 101 of at least one electrically insulating layer structure and at least one electrically conductive layer structure. The layer structure of the component carrier 100 represents a continuous layer, a patterned layer or a plurality of non-continuous islands in a common plane.

The highly thermally conductive cooling structure 111 may comprise a thermally conductive material, such as copper. The thermally conductive cooling structure 111 forms protrusions, with cooling channels 112 formed between the protrusions. The cooling structure 111 is formed in an exemplary embodiment as a pin or post, such as a pin or post having a circular, elliptical, oval, or rectangular cross-section. Therefore, the cooling structure 111 forms a large dissipation surface, so that good cooling efficiency can be provided.

The pillars (and may also be referred to as cooling fins) form protrusions to increase the overall surface area of the cooling structure. The entire surface area thus provides a larger surface, so that thermal conductivity with the environment of the component carrier can be provided. In particular, small and complex three-dimensional fin shapes can be manufactured by additive manufacturing.

The stack 101 and the array member 111 are integrally formed. Thus, stack 101 and array 111 are formed in a common manufacturing common process. The stack 101 together with the respective vias 104, signal lines (pads 121) and the array 110 of cooling structures 111 of the stack are formed together in an integrated manner, rather than separately in different manufacturing steps.

As can be seen from fig. 1, the cooling structure 111 is integrally provided in the component carrier 100 in one piece. The cooling structure 111 is formed in a single piece within the stack 101 and is thermally coupled to thermally conductive structures of the component carrier, such as copper-filled vias 104 or thermally conductive component layers 122 arranged onto the components 120 (e.g. embedded components). The cooling structure 111 is formed on and/or in the stack 101, for example by additive manufacturing, in particular by three-dimensional printing, on and/or in the stack 101.

The cooling structure 111 is located in the cavity 102 of the stack 101 such that the cooling structure 111 does not protrude from the cavity, as shown in figure 1. In other words, the stack 101 comprises an outer structure comprising a surface 106 directed to the environment of the component carrier 100. The outer structure and the surface 106 of the outer structure are defined in a plane. Thus, the cavity 102 is formed and accessible by the outer structure. Thus, the cooling structure 111 (such as a plurality of spaced apart pillars) protrudes through the cavity 102 to the outer structure, and does not protrude above the outer surface 106 of the outer structure in the environment.

The cooling structure 111 is integrally provided in the material of the stack 101 without a connection medium therebetween, i.e. between the cooling structure 111 and the stack 101. As shown in fig. 1, no connecting layer, such as an adhesive layer, is required between the component 120 and the outer end of the cooling structure 111. During the manufacturing process, the heat conducting member layer 122, the vias 104, the heat conducting layer 105 and the cooling structure 111 may be formed in one material filling step (such as a copper filling step).

For example, the component 120 may first be embedded in the stack 101. Next, a layer structure of the stack 101, e.g. a prepreg layer, may be arranged on top of the component 120 provided with gaps, which are later filled with a layer 122 of a thermally conductive component. Next, a hole for the via 104 is drilled, for example by mechanical drilling or by laser drilling. In a next step, for example, the drilled holes and gaps are filled with copper. As another example, a plating procedure may be applied to provide a thermally conductive material in the opening.

Furthermore, the sacrificial structure may be applied on the stack 101, in particular in the cavity 102 of the stack 101. A pattern of openings is formed in the sacrificial structure (which may be a dry film). The openings are arranged with a predetermined pattern indicating the pattern of the heat conducting structure 111 to be formed. Next, a corresponding opening is formed in the stack 101 by etching (or by radiation if the stack 101 comprises a photoresist material). Next, the opening is filled with a high thermal conductive material such as copper to form a thermal conductive structure 111. In this step, the thermally conductive material may also fill not only the openings, but also the gaps and vias 104, such as described above. This results in a common one-piece filling of heat-conducting material being provided between the component 120 and the outer end of the cooling structure 111. Thus, the use of any heat resistant layer that can reduce, for example, heat dissipation from the component is avoided.

In a next step, the sacrificial structures may be removed, for example by drilling, etching or radiation, such that cooling channels between the cooling structures are formed.

The cooling channel 112 is configured to at least partially enclose the cooling structure 111, in which cooling medium, in particular air or liquid, for example water, is present.

Thus, the component carrier 100 of fig. 1 comprises embedded components 120 that generate heat. The component 120 may be, for example, a power module or a power module. Along the upper surface of the member 120, a heat conductive member layer 122 composed of, for example, copper is arranged to provide a large heat dissipation area. A further layer structure of the stack 101 is arranged on top of the layer 122 of heat conducting members. A plurality of vias 104 filled with copper are formed between the heat conductive member layer 122 and the heat conductive layer 105 to conduct heat from the heat conductive member layer 122 to the heat conductive layer 105. Between the environment and the heat conducting layer 105, an array 110 of spaced apart cooling structures 111 is formed, which are shaped like columns. The cooling structure 111 is arranged within the open cavity 102 of the stack 101 such that the cooling structure 111 may be embedded within said cavity 102 and does not protrude beyond the outer surface 106 of the stack 101. A plurality of cooling channels 112 are formed between the cooling structures 111 such that a cooling medium (e.g., air or water) can flow through the cooling channels 112 to guide heat out.

A pad 121 is formed on the side of the component 120 opposite the thermally conductive component layer 122 for providing a signal coupled to the component 120. Pads 121 may be electrically coupled to external conductive lines for functionally coupling with component 120. Further, an additional pad 121 may be formed on the side of the member 120 on which the heat conductive member layer 122 is disposed. Further, additional electrically and/or thermally conductive structures 103 may be embedded within the stack 101.

Fig. 2 shows a schematic view of a component carrier 100 according to an exemplary embodiment of the invention, the component carrier 100 comprising an array 110 of exposed high thermally conductive cooling structures 111. The component carrier 100 comprises a stack 101, which stack 101 has at least one electrically insulating layer structure and/or at least one electrically conductive layer structure. Furthermore, the component carrier 100 comprises an array 110 of exposed highly thermally conductive cooling structures 111, which are formed in an integrated manner with the stack 101 and between which cooling channels 112 are defined.

The component carrier 100 may be a Printed Circuit Board (PCB) comprising several further heat conducting structures 103. A cavity 102 is formed in the stack 101 of the component carrier 100. The cavity 102 is closed on one side by a heat conductive layer 105. The cooling structure 111 protrudes from the heat conductive layer 105 through the cavity 102. Therefore, the heat generated in the vicinity of the heat conductive layer 105 is efficiently guided to the opposite side of the stack 101 through the stack 101.

Fig. 3 shows a schematic view of a component carrier 100 according to an exemplary embodiment of the present invention, the component carrier 100 comprising an array 110 of exposed high thermally conductive cooling structures 111 surrounded by a stack 101. The cooling structure 111 is formed in the internal closed cavity 102 of the stack 101, with an upper stack 300 above the cooling structure and at least one layer structure, such as a lower stack 310 below the cooling structure 111. Thus, cooling structures 111 are embedded, wherein cooling channels 112 between the cooling structures 111 comprise inlets and outlets to the environment of the component carrier 100, so that for example a cooling fluid may flow through the cooling channels 102 for transferring heat out of the component carrier 100.

For example, the component carrier 100 is formed by separate stacks 101, 300, 310, wherein the intermediate stack 101 comprising the thermally conductive cooling structure 111 is sandwiched between the other two stacks 300, 310. Thus, the intermediate stack 101 may be integrally formed with the thermally conductive cooling structure 111 and cover the array member 110 surrounding the thermally conductive cooling structure 111 with the stacks 300, 310.

The cooling structure 111 is formed between two opposite heat conducting layers 105, thereby extending through the cavity 102. On top of one of the thermally conductive layers 105 there is connected a via 104 formed in the upper stack 300. On top of the other of the thermally conductive layers 105 there is connected a via 104 formed in the lower stack 310. Thus, for example, the full copper layer (heat conductive layer 105) is arranged on both sides of the cooling structure.

The stack 100, 300, 310 may be formed of a low flow material. Thus, first, thermally conductive structures such as vias 104 and cooling structures 111 may be formed within the respective stacks 100, 300, 310. In the next step, the three stacks 100, 300, 310 are formed together. In particular, when using "low flow materials" for the respective stacks 100, 300, 310, the stacks 100, 300, 310 may be laminated together without the risk of, for example, the liquid material of the upper stack 300 or the lower stack 310 flowing in the cavity 102 due to the heat treatment during lamination.

It should be noted that the term "comprising" or "comprises" does not exclude other elements or steps, and the use of the article "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims.

List of reference numerals

100 parts carrier

101 stack

102 cavity

103 additional heat conducting structure

104 via hole

105 heat conducting layer

106 surface of the substrate

110 array element

111 cooling structure

112 cooling channel

120 parts

121 pad

122 layers of thermally conductive members

300 Stack

310 lower stack.