Component carrier and method of manufacturing the same

Abstract

A component carrier includes a stack having at least one electrically conductive layer structure and/or at least one electrically insulating layer structure, a component including a terminal made of a first electrically conductive material and being embedded in the stack, a recess in the stack exposing at least a part of the terminal, an interface structure on the at least partially exposed terminal and an electrically conductive structure on the interface structure made of a second electrically conductive material.

Claims

1. A component carrier, comprising: a stack comprising at least one electrically conductive layer structure and/or at least one electrically insulating layer structure, the stack being defined by a stack top surface and a stack bottom surface; a component comprising a component body having a component body top surface and a component body bottom surface, and a terminal, the terminal being made of a first electrically conductive material and having a terminal uppermost surface being arranged in the stack and a terminal lowermost surface directly arranged on top of the component body top surface, the component and the terminal being embedded in the at least one electrically insulating layer structure of the stack; a recess in the stack exposing at least a part of the terminal; an interface structure on the at least partially exposed terminal, the interface structure having an interface structure top surface, wherein the interface structure contacts a surface which defines the recess in the stack; and an electrically conductive structure at least partly arranged on top of the interface structure top surface and at least partly above the stack top surface, the electrically conductive structure being made of a second electrically conductive material; wherein the second electrically conductive material is different from the first electrically conductive material; wherein the first electrically conductive material is selected from a group consisting of aluminum, silver, titanium, gold, Si, SiC, SiO.sub.2 and GaN; and the second electrically conductive material is copper; wherein the component carrier comprises at least one of the following features: wherein the interface structure includes or is an adhesion promoter of one of titanium, copper nitride, tungsten, chromium and nickel, wherein the adhesion promoter has a thickness in the range between 20 nm and 100 nm; and wherein the interface structure comprises or is a diffusion barrier of nickel, wherein the diffusion barrier has a thickness in the range between 150 nm and 500 nm.

2. The component carrier according to claim 1, comprising at least one of the following features: the component carrier includes at least one component being surface mounted on and/or embedded in the component carrier, wherein the at least one component is selected from a group consisting of an electronic component, an electrically non-conductive and/or electrically 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 storage 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, an accumulator, a switch, a camera, an antenna, a magnetic element, a further component carrier, and a logic chip; wherein at least one of the electrically conductive layer structures of the component carrier includes at least one of a group consisting of copper, aluminum, nickel, silver, gold, palladium, and tungsten; wherein the electrically insulating layer structure includes at least one of the group consisting of resin, reinforced or non-reinforced resin, epoxy resin or bismaleimide-triazine resin, FR-4, FR-5, cyanate ester, polyphenylene derivate, glass, prepreg material, polyimide, polyamide, liquid crystal polymer, epoxy-based Build-Up Film, polytetrafluoroethylene, a ceramic, and a metal oxide; wherein the component carrier is shaped as a plate; wherein the component carrier is configured as one of a group consisting of a printed circuit board, a substrate, and an interposer; wherein the component carrier is configured as a laminate-type component carrier.

3. A method of manufacturing a component carrier, comprising: forming a stack including at least one electrically conductive layer structure and/or at least one electrically insulating layer structure, the stack being defined by a stack top surface and a stack bottom surface; embedding a component in the stack, the component comprising a component body having a component body top surface and a component body bottom surface, and a terminal, the terminal being made of a first electrically conductive material and having a terminal uppermost surface being arranged below the stack top surface and a terminal lowermost surface directly arranged on top of the component body top surface, the component and the terminal being embedded in the at least one electrically insulating layer structure of the stack; forming a recess in the stack exposing at least a part of the terminal; forming an interface structure on the at least partially exposed terminal, the interface structure having an interface structure top surface, wherein the interface structure contacts a surface which defines the recess in the stack; and forming an electrically conductive structure at least partly on top of the interface structure top surface and at least partly above the stack top surface, the electrically conductive structure being made of a second electrically conductive material; wherein the second electrically conductive material is different from the first electrically conductive material; wherein the first electrically conductive material is selected from a group consisting of aluminum, silver, titanium, gold, Si, SiC, SiO.sub.2 and GaN; and the second electrically conductive material is copper; wherein the component carrier comprises at least one of the following features: wherein the interface structure includes or is an adhesion promoter of one of titanium, copper nitride, tungsten, chromium and nickel, wherein the adhesion promoter has a thickness in the range between 20 nm and 100 nm; and wherein the interface structure comprises or is a diffusion barrier of nickel, wherein the diffusion barrier has a thickness in the range between 150 nm and 500 nm.

4. The method according to claim 3, wherein forming the interface structure and the electrically conductive structure is carried out simultaneously with forming an interface structure and an electrically conductive structure in a through hole of the stack.

5. The method according to claim 3, wherein at least one of the interface structure and the electrically conductive structure are deposited by a deposition process or a sputter process, a thin film deposition, high-power impulse magnetron sputtering, chemical-vapor deposition, plasma-enhanced chemical-vapor deposition, laser ablation, or electroless deposition.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention.

(2) FIG. 2 illustrates a method of manufacturing a component carrier according to an exemplary embodiment of the invention.

(3) FIG. 3 illustrates a method of manufacturing a component carrier according to an exemplary embodiment of the invention.

(4) FIG. 4 illustrates a method of manufacturing a component carrier according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

(5) The illustrations in the drawings are schematically presented. In different drawings, similar or identical elements are provided with the same reference signs.

(6) FIG. 1 illustrates a cross-sectional view of a component carrier 1 according to an exemplary embodiment of the invention. The component carrier 1 is shaped as a plate. The component carrier 1 can be configured as one of a group consisting of a printed circuit board, a substrate, and an interposer. The component carrier 1 can be configured as a laminate-type component carrier.

(7) The component carrier 1 comprises a stack comprising at least one electrically conductive layer structure and at least one electrically insulating layer structure 2.

(8) The at least one electrically conductive layer structure of the component carrier 1 can comprise at least one of a group consisting of copper, aluminum, nickel, silver, gold, palladium, and tungsten, any of the mentioned materials being optionally coated with supra-conductive material such as graphene.

(9) The electrically insulating layer structure 2 can comprise at least one of the group consisting of resin, in particular reinforced or non-reinforced resin, for instance epoxy resin or bismaleimide-triazine resin, FR-4, FR-5, cyanate ester, polyphenylene derivate, glass, prepreg material, polyimide, polyamide, liquid crystal polymer, epoxy-based build-up film, polytetrafluoroethylene, a ceramic, and a metal oxide.

(10) A component 4 is embedded in the stack. The component 4 can be selected from a group consisting of an electronic component, an electrically non-conductive and/or electrically 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 storage 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, an accumulator, a switch, a camera, an antenna, a magnetic element, a further component carrier, and a logic chip.

(11) The component 4 comprises a terminal 5 which is made of a first electrically conductive material. The first electrically conductive material of the terminal 5 is not necessarily copper.

(12) A recess 6 is provided in the stack so that at least a part of the terminal 5 is exposed. Note that the recess 6 may optionally expose the terminal 5 not only partially but completely. This can be done in order to avoid possible weak adhesion of the surfaces of the terminal 5 and the electrically insulating layer structure 2. The adhesion between the terminal 5 and the electrically insulating layer structure 2 will be solely based on the choice of materials. This issue basically applies to all embodiments. An interface structure 7 is provided on the exposed terminal 5, and an electrically conductive structure 8, which is made of a second electrically conductive material, is provided on the interface structure 7.

(13) The second electrically conductive material is different from the first electrically conductive material. In particular, the first electrically conductive material can be selected from a group consisting of aluminum, silver, titan, copper, gold, Si, SiC, SiO.sub.2 and GaN, and the second electrically conductive material can be copper.

(14) The interface structure 7 can comprise or be an adhesion promoter, in particular one of titanium, copper nitride, tungsten, chromium and nickel. The adhesion promoter has a thickness in the range between 20 nm and 100 nm.

(15) In addition or alternatively, the interface structure 7 can comprise or be a diffusion barrier, in particular nickel. The diffusion barrier has a thickness in the range between 150 nm and 500 nm.

(16) FIG. 2 illustrates a method of manufacturing a component carrier 1 according to an exemplary embodiment of the invention.

(17) In a step S1, a preform of a component carrier 1 is provided. The component carrier 1 is embodied as a PCB which comprises a stack having at least one electrically insulating layer structure 2 and optionally at least one electrically conductive layer structure. The component carrier 1 further comprises a component 4 comprising a terminal 5 made of a first electrically conductive material and being embedded in the stack. The first electrically conductive material of the terminal 5 is not necessarily copper. In particular, the first electrically conductive material can be selected from a group consisting of aluminum, silver, titan, copper, gold, Si, SiC, SiO.sub.2 and GaN. The component carrier 1 further comprises a recess 6 in the stack exposing at least a part of the terminal 5.

(18) The recess 6 can be a laser drilled hole which serves as connection between the outer surface of the component carrier 1 and the component 4. Once the laser hole 6 is formed, the component carrier 1 can optionally be cleaned, for example in a chemical bath, to clean the laser hole 6 and the outer surface of the component carrier 1.

(19) In a step S2, an interface structure 7 is deposited on the exposed terminal 5. The interface structure 7 can be deposited by a metal deposition process or a sputter process, such as thin film deposition, HiPMS (High-power impulse magnetron sputtering), CVD, PECVD, laser ablation, electroless plating, etc. Thereby, the surface of the terminal 5, which is not made of copper, is prepared for a subsequent copper deposition. The interface structure 7 forms an adhesion promoter so that a copper material can adhere to the terminal 5 of the component 4. The adhesion promoter can be selected from a group consisting of titanium, copper nitride, aluminum nitride (AlN), tungsten, and chromium. More general, other oxides, nitrides, metal alloys or metals can be used for the interface structure 7. The adhesion promoter can have a thickness in the range between 20 nm and 100 nm. The interface structure 7 can be deposited not only on the interface structure 7 of the terminal 5 of the component 4, but also on the outer surface of the component carrier 1.

(20) Alternatively or in addition to the adhesion promoter, the interface structure 7 can form a diffusion barrier, in particular if nickel is used therein. The diffusion barrier can have a thickness in the range between 150 nm and 500 nm. The diffusion barrier can also be deposited by a deposition process or a sputter process, such as thin film deposition, HiPMS (High-power impulse magnetron sputtering), CVD, PECVD, laser ablation, electroless deposition, etc.

(21) As a result, the interface structure 7 can either comprise the adhesion promoter, the diffusion barrier or both.

(22) In a step S3, an electrically conductive structure 8 made of a second electrically conductive material is deposited on the interface structure 7 and optionally also on the outer surface of the component carrier 1. The electrically conductive structure 8 can be a copper film (Cu). The electrically conductive structure 8 can also be deposited by a deposition process or a sputter process, such as thin film deposition, HiPMS (High-power impulse magnetron sputtering), CVD, PECVD, laser ablation, electroless deposition, etc.

(23) After step S3, the component carrier 1 may be processed by conventional PCB manufacture steps. For example, a further copper layer can be applied on the electrically conductive structure 8 by galvanic electroplating or electroless deposition. The copper layer can then conventionally be patterned by lithography and etching processes. It is also possible to (completely) fill the recess 6 by copper.

(24) FIG. 3 illustrates a method of manufacturing a component carrier 1 according to an exemplary embodiment of the invention. The method of FIG. 3 is similar to the method of FIG. 2 except for the following difference. The first electrically conductive material of the terminal 5 is gold (Au). The interface structure 7 may comprise nickel (Ni) or titanium or a combination of both as an adhesion promoter between the terminal 5, and a superposed electrically conductive structure 8 made of copper. In this case, the nickel layer as an adhesion promoter can be structured with conventional acid combinations.

(25) The methods of FIGS. 2 and 3 can be modified by an additional masking and lithography step which is carried out before the step S2. The additional masking and lithography step is carried out so that the interface structure 7 will be patterned or structured. A mask can be formed by a photoresist or a dry film. Very thin films can be used as the mask, and in combination with the sputtering processes, very small line-space copper structures can be obtained. A stripping step can be performed after the step S2, where the mask is stripped off. Thereafter, the step S3 can be carried out.

(26) It is also possible to carry out the stripping step after step S3.

(27) FIG. 4 illustrates a method of manufacturing a component carrier 1 according to an exemplary embodiment of the invention. In this embodiment, the terminal 5 of the embedded component 4 does not have an electrical contact surface metallization. This means that the embedded component 4 can initially be provided with naked Si, SiC, SiO.sub.2 or GaN material as the exposed terminal 5. In other words, a contact surface area of the terminal 5 may directly expose a component material of the embedded component 4, in particular Si, SiC, SiO.sub.2 or GaN. This can reduce production costs because several steps of manufacturing the component 4 can be omitted, such as metallization, lithography, cleaning etc. The underlying concept is to produce a contact metallization of the terminal 5 of the component 4 when the same is already embedded in the electrically insulating layer structure 2. A laser process can be calibrated to stop drilling on a component surface, for example on a doped Si or SiO.sub.2 surface. After that, a regular metallization of the terminal 5 of the component 4 can be done, for example by titan and/or copper. After that, the metallization process of the component carrier 1 will continue similar to the previous embodiments.

(28) In a step S10, a recess 6 is formed by laser drilling in an electrically insulating layer structure 2. In this case, the upper surface of the component carrier 1 can be used as a stopping layer for the laser process. An oxide layer can be formed on the component carrier 1 to protect the same (for example a SiO.sub.2 layer if the component carrier 1 is made of Silicon (Si)). A masking and lithography step is carried out so that the interface structure 7 will be patterned or structured.

(29) The steps S11 and S13 correspond to steps S2 and S3 in FIGS. 2 and 3.

(30) In a step S12, a stripping process is carried out where the mask is stripped-off.

(31) The methods of FIGS. 2 to 4 can be modified by a via filling step, where a via (not shown) in the stack of the component carrier 1 is filled during the step S2/S11 and/or the step S3/S13. The parameters for the via filling step are basically an aspect ratio and a sputtering rate. For example, extra layers of gold (Au) or silver (Ag) can be applied in the via filling step. Instead of copper as the second electrically conductive material, gold, silver or any other metal can be used. This process can also be extended to the whole surface of the component carrier 1.

(32) In the methods of FIGS. 2 to 4, the component 4 can be embedded either on a panel level, a wafer level or a PCB level. Centre core embedding and asymmetric embedding are possible.

(33) Further, the sputtering metallization by the interface structure 7 and the electrically conductive structure 8 will allow the implementation of bio-compatible metals to the component carrier 1, such as titanium (Ti) and gold (Au), at any stage.

(34) It should be noted that the term “comprising” does not exclude other elements or steps and the article “a” or “an” does not exclude a plurality. Also, elements described in association with different embodiments may be combined.

(35) Implementation of the invention is not limited to the preferred embodiments shown in the figures and described above. Instead, a multiplicity of variants is possible which use the solutions shown and the principle according to the invention even in the case of fundamentally different embodiments.