COMPONENT CARRIER WITH EMBEDDED COMPONENT AND HORIZONTALLY ELONGATED VIA

Abstract

A component carrier includes a stack with at least one electrically conductive layer structure and at least one electrically insulating layer structure, a component embedded in the stack, and a via formed in the at least one electrically insulating layer structure along a horizontal path having a length being larger than a horizontal width.

Claims

1. A component carrier, comprising: a stack comprising at least one electrically conductive layer structure and at least one electrically insulating layer structure; a component embedded in the stack; and a via formed in at least one of the at least one electrically insulating layer structure along a horizontal path having a length being larger than a horizontal width.

2. The component carrier according to claim 1, wherein the via is at least partially filled with an electrically conductive filling which electrically contacts the embedded component.

3. The component carrier according to claim 1, wherein the via is not filled with an electrically conductive filling.

4. The component carrier according to claim 1, wherein the via is a laser via formed by laser drilling.

5. The component carrier according to claim 1, wherein the via has tapering sidewalls in a depth direction.

6. The component carrier according to claim 1, wherein the via is formed with vertical sidewalls in a depth direction.

7. The component carrier according to claim 1, wherein the via is substantially bathtub shaped.

8. The component carrier according to claim 1, wherein the via is substantially W-shaped.

9. The component carrier according to claim 1, wherein the component is connected with or contacted by the via, in particular by a plurality of vias each formed in at least one of the at least one electrically insulating layer structure along a horizontal path having a length being larger than a horizontal width.

10. The component carrier according to claim 9, wherein each via is at least partially filled with an electrically conductive filling.

11. The component carrier according to claim 1, comprising at least one of the following features: wherein a plurality of vias is provided in a vertically stacked arrangement, each via formed in at least one of the at least one electrically insulating layer structure along a horizontal path having a length being larger than a horizontal width, wherein in particular each via is at least partially filled with an electrically conductive filling; wherein the via is configured for thermally conducting heat out of the component carrier; wherein the via is configured for electrically conducting current and/or signals within the component carrier; wherein the via is formed as a sequence of frustoconical holes in adjacent surface portions of at least one of the at least one electrically insulating layer structure to thereby form connected circular recesses constituting the via; wherein the via has a shape of an oblong slot with straight shape along its length; wherein the via has a curved shape; wherein a ratio between length and width of the via is in a range between 1.5 and 5; wherein a ratio between a depth and the width of the via is in a range between 10% and 90%; wherein, in a plan view, the via has an outline defined by a plurality of longitudinally arranged overlapping circular recesses; wherein the via is configured as a thermal via and is at least partially filled with a thermally conductive filling, wherein in particular the thermal via is electrically inactive; wherein the via extends in a vertical direction from a horizontally extending trace.

12. The component carrier according to claim 1, comprising at least one of the following features: the component is particular 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 optical element, a bridge, 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 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 being optionally coated with supra-conductive material such as graphene; wherein the at least one electrically insulating layer structure comprises 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; wherein the component carrier is shaped as a plate; wherein the component carrier is configured as one of the group consisting of a printed circuit board, a substrate, and an interposer; wherein the component carrier is configured as a laminate-type component carrier.

13. A method of manufacturing a component carrier, the method comprising: providing a stack comprising at least one electrically conductive layer structure and at least one electrically insulating layer structure; embedding a component in the stack; and forming a via in at least one of the at least one electrically insulating layer structure along a horizontal path having a length being larger than a horizontal width.

14. The method according to claim 13, wherein the method comprises forming the via by laser drilling.

15. The method according to claim 13, wherein the method comprises using the via for thermally conducting heat out of the component carrier.

16. The method according to claim 13, wherein the method comprises using the via for conducting electric current and/or signals within the component carrier.

17. The method according to claim 13, wherein the method comprises forming the via by: opening an electrically conductive layer structure above an electrically insulating layer structure of the stack by etching a window in the electrically conductive layer structure and subsequently removing exposed material of the electrically insulating layer structure by laser processing.

18. The method according to claim 13, wherein the method comprises forming the via by: operating a laser source for continuously emitting a laser beam, and moving the laser beam relative to the electrically insulating layer structure during forming the via.

19. The method according to claim 13, wherein the method comprises forming the via by: operating a laser source for moving with respect to the electrically insulating layer structure only between emitting different laser shots in adjacent, in particular overlapping, surface portions of the electrically insulating layer structure, and operating the laser source to be stationary with respect to the electrically insulating layer structure during each individual laser shot.

20. The method according to claim 13, wherein the method comprises electrically and/or thermally contacting or connecting the embedded component by the via.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG. 1 illustrates a lengthwise cross-sectional view and FIG. 2 illustrates a lateral cross-sectional view of a structure obtained during manufacturing a component carrier according to an embodiment of the invention with oblong copper filled laser via.

[0051] FIG. 3 illustrates a lengthwise cross-sectional view and FIG. 4 illustrates a lateral cross-sectional view of a structure obtained during manufacturing a component carrier according to FIG. 1 and FIG. 2.

[0052] FIG. 5 illustrates a lengthwise cross-sectional view and FIG. 6 illustrates a lateral cross-sectional view of a component carrier obtained by manufacturing according to FIG. 1 to FIG. 4.

[0053] FIG. 7 illustrates a plan view of an oblong slot-shaped copper-filled laser via of a component carrier according to an exemplary embodiment of the invention.

[0054] FIG. 8 and FIG. 9 illustrate images of a part of a component carrier according to an embodiment of the invention with oblong copper filled laser via.

[0055] FIG. 10 illustrates a plan view and FIG. 11 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention with oblong copper filled laser via.

[0056] FIG. 12 illustrates a cross-sectional view of a component carrier according to an exemplary embodiment of the invention with stacked oblong copper filled laser vias.

[0057] FIG. 13 illustrates a plan view of a component carrier according to an exemplary embodiment of the invention with oblong copper filled laser vias.

[0058] FIG. 14 illustrates a plan view of a component carrier according to an exemplary embodiment of the invention with electrically conductive trace having integrated oblong copper filled laser vias.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0059] The illustrations in the drawings are schematically presented. It is noted that in different figures, similar or identical elements or features are provided with the same reference signs or with reference signs, which are different from the corresponding reference signs only within the first digit. In order to avoid unnecessary repetitions elements or features which have already been elucidated with respect to a previously described embodiment may not be elucidated again at a later position of the description.

[0060] Further, spatially relative terms, such as “front” and “back”, “above” and “below”, “left” and “right”, et cetera are used to describe an element's relationship to other element(s) as illustrated in the figures. Thus, the spatially relative terms may apply to orientations in use which differ from the orientation depicted in the figures. Obviously, all such spatially relative terms refer to the orientation shown in the figures only for ease of description and are not necessarily limiting as an apparatus according to an embodiment of the invention can assume orientations different from those illustrated in the figures when in use.

[0061] Before, referring to the drawings, exemplary embodiments will be described in further detail, some basic considerations will be summarized based on which exemplary embodiments of the invention have been developed.

[0062] According to an embodiment of the invention, a component carrier with low-ohmic and thus low-loss electric connection of an embedded component may be provided which is based on a blind micro slot via design, the via being filled with an electrically conductive (and preferably also thermally conductive) material such as copper. The latter may be manufactured for instance by a laser direct drill process. Such a blind micro slot via has more contact surface area than a combination of two conventional vias for the same hole size, which allows better electric connection and heat removal of the embedded component. The blind micro slot via can be produced by a laser direct drill process making use of a laser drill machine without the necessity to make any specific adaptations. A correspondingly manufactured component carrier shows a pronounced electric reliability of the embedded component. Any layer design PCB is possible according to exemplary embodiments of the invention.

[0063] According to an exemplary embodiment of the invention, large area copper connections can be formed with a high capability of thermal dissipation for functional dies being embedded in inner layers of a component carrier. Simultaneously, this can be accomplished with low space consumption.

[0064] Exemplary embodiments provide a connection between embedded functional dies and outer layers which provide not only outstanding electric connectivity but also a high ability of thermal dissipation with accurate alignment and variable connection area. A remarkably high ability of thermal dissipation may thus be synergistically combined with an accurate alignment via the connection area.

[0065] FIG. 1 illustrates a lengthwise cross-sectional view and FIG. 2 illustrates a lateral cross-sectional view of a structure obtained during manufacturing a component carrier 100 according to an embodiment of the invention with oblong copper filled laser via 108.

[0066] As shown in FIG. 1, a component 116 is embedded in a stack 102 of layer structures 104, 106. The component 116, for instance embodied as a semiconductor chip, is provided with pads 150 on its top side.

[0067] The stack 102 may be a plate shaped laminate type layer stack composed of one or more electrically conductive layer structures 104 and one or more electrically insulating layer structures 106. For example, the electrically conductive layer structures 104 may comprise patterned copper foils and vertical through connections, for example copper filled laser vias. The electrically insulating layer structures 106 may comprise a resin (such as epoxy resin) and optionally reinforcing particles therein (for instance glass fibers or glass spheres). For instance, the electrically insulating layer structures 106 may be made of FR4 or ABF. In the shown embodiment, the thick central electrically insulating layer structure 106 may be a fully cured core.

[0068] A cavity may be defined by a through-hole in the stack 102 which may be closed on a bottom side by attaching a temporary carrier (not shown) to a lower main surface of the stack 102. The temporary carrier may for instance be a sticky tape. The component 116 may be attached with a main surface opposing to the upwardly oriented pads 150 with direct physical contact on the temporary carrier in the cavity. The function of the temporary carrier is to provide stability until the component 116 is glued in place within the cavity.

[0069] Referring to FIG. 1, the component 116 has been embedded in the stack 102 and has been glued in place by lamination. More specifically, the structure shown in FIG. 1 can be obtained by laminating one or more further electrically insulating layer structures 106 and one or more further electrically conductive layer structures 104 to the upper main surface of the stack 102 with the component 116 in the cavity. For instance, a prepreg layer (as further electrically insulating layer structure 106) and a copper foil (as further electrically conductive layer structure 104) may be laminated on top of the component 116 and the stack 102. During the lamination process, uncured material of the further electrically insulating layer structure 106 may become flowable or melt and may flow in gaps between stack 102, temporary carrier and component 116. Upon curing (for instance cross-linking, polymerizing, etc.) of the material of the further electrically insulating layer structure 106, the filling medium in said gaps may become solid. A resin coated copper (RCC) may also be used for lamination on the top side of the component 116 and the stack 102. As an alternative to the described lamination, it is also possible to glue component 116 in place in the cavity formed in stack 102 by filling liquid adhesive material in the gaps in between (not shown). Upon curing said adhesive material, the component 116 is again glued in place in the cavity.

[0070] After that, the temporary carrier may be removed. When the temporary carrier is a sticky tape, it may be simply peeled off from the lower main surface of the structure shown in FIG. 1 and FIG. 2.

[0071] Hence, FIG. 1 and FIG. 2 show a functional die in form of component 116 embedded in the stack 102. Gaps are filled-up with cured material of a resin sheet.

[0072] FIG. 3 illustrates a lengthwise cross-sectional view and FIG. 4 illustrates a lateral cross-sectional view of a structure obtained during manufacturing a component carrier 100 according to FIG. 1 and FIG. 2.

[0073] The structure shown in FIG. 3 and FIG. 4 may be obtained by lithographically etching the previously continuous electrically conductive layer structure 104 on top of the structure according to FIG. 1 and FIG. 2. As a result, a patterned electrically conductive layer structure 104 is shown on top of FIG. 3 and FIG. 4. Subsequently, it may be possible to remove material of the thereby exposed electrically insulating layer structure 106 by laser drilling, to thereby expose the pads 150 of the embedded component 116. Thus, it may be possible to make the shown opening(s) in the top electrically conductive layer structure 104 with a conformal mask process and to drill slots in the beneath electrically insulating layer structure 106 by a CO.sub.2 laser, to thereby obtain three parallel slot-shaped oblong vias 108.

[0074] Thus, slotted vias 108 are formed in the electrically insulating layer structure 106 along a horizontal path having a length L (see FIG. 4) being larger than a horizontal width W (see FIG. 3). The slotted vias 108 may have vertical or tapering sidewalls in a depth D direction perpendicular to the horizontal plane. As shown, the vias 108 have a shape of an oblong slot with straight shape along its length L. A ratio between length L and width W of the via 108 may be in a range between 1.5 and 5. A ratio between depth D and width W of the via 108 may be in a range between 10% and 90%.

[0075] FIG. 5 illustrates a lengthwise cross-sectional view and FIG. 6 illustrates a lateral cross-sectional view of a component carrier 100 obtained by manufacturing according to FIG. 1 to FIG. 4.

[0076] As shown, it is then possible to fill-up the slot shaped vias 108 with an electrically conductive filling 110, for instance with copper. For example, this may be done with electroless plating, galvanic plating, etc. Thereafter, it is possible to etch exterior pads for designing outer layers.

[0077] As a result, the illustrated component carrier 100 according to an embodiment of the invention is obtained. Said component carrier 100 comprises stack 102 comprising electrically conductive layer structures 104 and electrically insulating layer structures 106. Component 116 is embedded in the stack 102.

[0078] The vias 108 are filled with electrically and thermally conductive filling 110 which electrically contacts the embedded component 116 and removes heat generated by the component 116 during operation of the component carrier 100. The component 116 being embedded in the stack 102 may be electrically contacted by the vias 108 which may simultaneously function for removing and/or spreading heat. In other words, the vias 108 may be configured for thermally conducting heat out of the component carrier 100 and for electrically conducting current and/or signals within the component carrier 100.

[0079] As described, the via 108 may be formed by laser drilling. The vias 108 may have vertical sidewalls, but may also have tapering sidewalls 112 (compare FIG. 8 and FIG. 9). It is also possible that a plurality of vias 108 having the described features are provided in a vertically stacked arrangement (not shown).

[0080] FIG. 7 illustrates a plan view of an oblong copper filled laser via 108 of a component carrier 100 according to an exemplary embodiment of the invention.

[0081] According to FIG. 7, the via 108 is formed as a straight sequence of laser shots in adjacent surface portions of the electrically insulating layer structure 106 of stack 102 to thereby form integrally connected circular recesses 118 constituting the via 108. Each laser shot may form a frustoconical hole. Thus, in the illustrated plan view, the via 108 has an outline defined by the plurality of longitudinally aligned circular recesses 118. Descriptively speaking, the circles of the individual laser shots may overlap to form a straight oblong via 108 with wave-shaped side trajectory. Thus, each of the slot-type vias 108 may be composed of multiple overlapping laser holes filled with copper.

[0082] Referring to FIG. 7, “W” denotes the width or diameter of the laser holes. It is possible to control a partial exposure of conformal mask to get a highly accurate alignment. “A” denotes the pitch size (i.e., the holes' center to center distance). The pitch size may lead to the shape of the slot and its current carrying and removal capacity as well. “L” denotes the length of the slot.

[0083] FIG. 8 and FIG. 9 illustrate images of a part of a component carrier 100 according to an embodiment of the invention with oblong copper filled laser via 108. After CO.sub.2 laser drilling, the slots may be filled through PLB and via filling. Said images correspond to a component carrier region indicated in FIG. 6 with a box 199. For instance, the vias 108 may be substantially bathtub shaped.

[0084] Also, in each of the following embodiments, it is possible that a component 116 is embedded in a stack 102 and is contacted by a via 108 and/or by a trace 151.

[0085] FIG. 10 illustrates a plan view and FIG. 11 illustrates a cross-sectional view of a component carrier 100 according to an exemplary embodiment of the invention with oblong copper filled laser via 108.

[0086] A thermal via 108 is formed as a blind hole in one of the electrically insulating layer structures 106 along a horizontal path, i.e., along a path within a horizontal plane of the component carrier 100. The thermal via 108 has a length L in the horizontal plane being larger than a horizontal width W in the horizontal plane, and has tapering sidewalls 112 in a depth D direction (perpendicular to width direction and length direction). Moreover, the thermal via 108 is filled with a thermally conductive filling 110 such as copper. The via 108 filled with the thermally conductive filling 110 is configured for thermally conducting heat out of the component carrier 100. Additionally, the via 108 may be configured for electrically conducting current and/or signals within the component carrier 100. The via 108 is a laser via formed by laser drilling. As shown in particular in FIG. 2, the via 108 is substantially bathtub shaped. As shown in particular in FIG. 1, the via 108 has a shape of an oblong slot with substantially straight shape along its length L. Alternatively, the via 108 may have a curved shape within the horizontal plane (not shown). A ratio between length L and width W of the via 108 may be in a range between 1.5 and 5. Furthermore, a ratio between depth D and width W of the via 108 may be in a range between 10% and 90%.

[0087] For instance, the via 108 may be formed along a continuous trajectory by a moving laser source or as a sequence of laser shots in adjacent surface portions of the electrically insulating layer structure 106 to thereby form integrally connected circular recesses constituting the via 108.

[0088] The blind micro slot via 108 may have a dimension of 100 μm with 80% of the via bottom being capable to provide 15027 μm.sup.2 of contact area (when dimension “X” is 40 μm). This may be about 50% more than a conventional blind micro via.

[0089] FIG. 12 illustrates a cross-sectional view of a component carrier 100 according to an exemplary embodiment of the invention with stacked oblong copper filled laser vias 108.

[0090] More specifically, FIG. 12 shows a plurality of vias 108 having the described features and being provided in a vertically stacked arrangement. By taking this measure, a larger contact area and thus an increased heat transfer capability may be obtained. The heat removal function is illustrated by arrows in FIG. 12.

[0091] FIG. 13 illustrates a plan view of a component carrier 100 according to an exemplary embodiment of the invention with oblong copper filled laser vias 108. FIG. 13 compares a horizontally aligned and a vertically aligned oblong straight via 108 according to an exemplary embodiment with a conventional array of vias 109 with circular cross-section.

[0092] As shown, the vias 108 of the illustrated exemplary embodiment form a high via density area. Descriptively speaking, it is possible to combine two conventional vias 109 into one via 108. This allows to obtain an enhanced thermal transfer capacity without additional spacing.

[0093] FIG. 14 illustrates a plan view of a component carrier 100 according to an exemplary embodiment of the invention with an electrically conductive trace 151 having integrated oblong copper filled laser vias 108. The electrically conductive trace 151 is connected with a vertically extending land pad 152 and is configured for conducting electric power or an electric signal. The elongate thermal vias 108 being integrally formed with the electrically conductive trace 151 boost the heat removal function of the component carrier 100. Thus, thermal vias 108 with horizontally elongated trajectory may be formed within the trace 151. More specifically, the thermal vias 108 can be drilled within the trace 151. This renders it possible to obtain a better heat transfer without any additional spacing requirement.

[0094] 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.

[0095] Implementation of an embodiment 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 an embodiment of the invention even in the case of fundamentally different embodiments.