Protection Structure for an Aperture for an Optical Component Embedded Within a Component Carrier

Abstract

A component carrier including (a) a stack having at least one electrically conductive layer structure and at least one electrically insulating layer structure; (b) an optical component embedded within the stack, wherein the optical component comprises an optically active portion; (c) an opening formed within the stack, wherein the optical component and the opening are spatially arranged and configured such that an optical communication between the optically active portion and an exterior of the stack is enabled; and (d) a protection structure extending at least partially around the optically active portion and/or the opening. The protection structure protects the optically active portion from a resin flow during an embedding of the optical component in the stack. A method for manufacturing such a component carrier.

Claims

1. A component carrier, comprising: a stack comprising at least one electrically conductive layer structure and at least one electrically insulating layer structure; an optical component embedded within the stack; wherein the optical component comprises an optically active portion; an opening formed within the stack, wherein the optical component and the opening are spatially arranged and configured such that an optical communication between the optically active portion and an exterior of the stack is enabled; and a protection structure extending at least partially around the optically active portion and/or the opening, wherein the protection structure is configured for protecting the optically active portion from a resin flow during an embedding of the optical component in the stack.

2. The component carrier as set forth in claim 1, wherein the optical component is embedded within an interior of the stack; and the opening is an aperture formed by at least one electrically conductive layer structure and/or at least one electrically insulating layer structure of the stack.

3. The component carrier as set forth in claim 1, wherein the opening is a cavity accommodating the optical component.

4. The component carrier as set forth in claim 1, wherein the protection structure extends to the full extent around the optically active portion and/or the opening.

5. The component carrier as set forth in claim 4, wherein the protection structure extends circumferentially around the optically active portion and/or the opening; or the protection structure extends in a rectangular manner around the optically active portion and/or the opening.

6. The component carrier as set forth in claim 1, wherein the protection structure is a part of or is directly attached to the optical component.

7. The component carrier as set forth in claim 1, wherein the protection structure protrudes from an outer main surface of the optical component.

8. The component carrier as set forth in claim 1, wherein the protection structure protrudes from the outer main surface of the optical component by a first protrusion length and sidewalls of the opening protrude from the outer main surface of the optical component by a second protrusion length, wherein the first protrusion length is larger than the second protrusion length.

9. The component carrier as set forth in claim 1, wherein the optical component comprises a redistribution layer structure, wherein the protection structure forms a part of the redistribution layer structure.

10. The component carrier as set forth in claim 1, wherein the protection structure is a protrusion protruding from an outer surface of the stack.

11. The component carrier as set forth in claim 1, wherein the protection structure is a recess extending into a main surface of the stack.

12. The component carrier as set forth in claim 1, wherein the component carrier comprises at least one of the following features: the protection structure is made of metal and/or an electrically insulating material; the protection structure comprises a thickness being the same or being larger than the thickness of a layer of a material encapsulating at least partially the embedded optical component.

13. The component carrier as set forth in claim 2, wherein the aperture is uncovered.

14. The component carrier as set forth in claim 2, wherein the aperture is at least partially filled with an optically transparent medium.

15. The component carrier as set forth in claim 14, wherein the component carrier comprises at least one of the following features: a transmittance value of the optically transparent medium is larger than 80%, preferably larger than 90%; wherein in particular the transmittance value applies for a wavelength range between 250 nm and 1250 nm and in particular for a wavelength range between 300 nm and 1000 nm; the optically transparent medium is formed exclusively within the aperture and optionally within an annular surrounding thereof; the optically transparent medium is formed at an entire main surface of the stack.

16. The component carrier as set forth in claim 1, wherein the optical component is embedded in a core, wherein a buildup comprising a resin layer is formed on the core.

17. The component carrier as set forth in claim 1, wherein the optical component is one of: an optical receiver, in particular a sensor, a photodiode or a camera; an optical transmitter, in particular a light emitting diode or a laser diode; and an optical transceiver, in particular and optical communication module.

18. A method for 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; providing an optical component having an optically active portion; forming a protection structure at the optical component, wherein the protection structure surrounds at least partially the optically active portion; and embedding the optical component within the stack, wherein the optically active portion is protected from a resin flow by means of the protection structure.

19. The method as set forth in claim 18, further comprising: forming an opening within the stack, wherein the optical component and the opening are spatially arranged and configured such that an optical communication between the optically active portion and an exterior of the stack is enabled.

20. The method as set forth in claim 19, wherein forming the opening comprises temporally filling an opening region in the stack with a poorly adhesive material, and removing the poorly adhesive material after having completed the embedding of the optical component within the stack.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0067] FIG. 1A and FIG. 1B show an optical component having a resin flow protection structure formed at an outer main surface of a body of the optical component.

[0068] FIG. 2 shows the optical component after having been embedded into a stack or a core of a component carrier.

[0069] FIG. 3 shows a component carrier with an embedded optical component and an optically transparent medium being locally applied in and around an aperture region.

[0070] FIG. 4 shows a component carrier with an embedded optical component and an optically transparent medium being entirely applied at a main surface of the component carrier.

[0071] FIG. 5 shows a component carrier with an embedded optical component and an avoid aperture region.

[0072] FIG. 6 shows a component carrier with an optical component being embedded within an opening, wherein an outer surface of the component is aligned with an outer surface of the stack.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

[0073] 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, are not elucidated again at a later position of the description.

[0074] 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 another 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 can assume orientations different than those illustrated in the Figures when in use.

[0075] 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.

[0076] Embodiments of the invention relate to a specific feature provided at a surface of an optical component which is (supposed to be) embedded within a stack of a component carrier such as a Printed Circuit Board (PCB). This specific feature is a protection structure which enables a safe and robust embedded packaging process of the optical component. The specific protection structure may be at least a part of a redistribution layer (RDL), which is provided at the body of the optical component. The protection structure is configured for ensuring that an encapsulation resin will not flow and contaminate an optical aperture region which enables an optical communication between (an optically active portion of) the optical component and an exterior of the stack respectively the component carrier. The protection structure may, due to its flow protection function, denominated a (resin) flow guard structure. The protection structure/flow guard structure may have height (along a z-direction) such that it represents the “highest point” (of a RDL) above the respective surface of the optical component in order to ensure a full sealing of the aperture region from unwanted resin flow. Thereby, the z-direction is perpendicular to the interfaces between neighboring layers of the component carrier stack.

[0077] FIG. 1A and FIG. 1B show an optical component 120, which is prepared for being embedded within a non-depicted stack of a component carrier. FIG. 1A is a top view and FIG. 1B is a cross-sectional view of the optical component 120.

[0078] The optical component 120 comprises a body portion 121 and an optical active portion 122. The optical active portion 122 may be at least one of an optoelectronic emitter, e.g., a light emitting diode (LED), and an optoelectronic receiver, e.g., a photodiode (PD). An aperture region 130, which is used by the optical component 120 for transmitting and/or receiving electromagnetic radiation, it is denominated with reference number 130. In order to protect the aperture 130 from an unwanted resin flow during an embedding process, there is provided a protection structure 140, which is configured for blocking such a resin flow into the aperture region 130. The protection structure 140 is elevated from the (lower) main surface of the optical component 120 (see FIG. 1B). It should be understood that such a resin flow could result in resin material which could block or at least attenuate of the electromagnetic radiation propagating through the aperture 130.

[0079] The protection structure 140 may be made of any material which allows for stopping a flow of (at least partially liquid) resin material. Thereby, the resin material may originate from a known encapsulating material which is used for the embedding process. Depending on the specific application the protection structure 140 may be made of metal and/or an electrically insulating material, in particular a plastic material.

[0080] As has already been mentioned above, the protection structure 140 may be at least a part of a RDL, which may be formed anyway at the respective outer main surface of the optical component 120.

[0081] FIG. 2 shows the optical component 120 after having been embedded into a stack 210 of a component carrier 200. According to the exemplary embodiment described here the stack is or comprises a core 210 of the component carrier 200. The core 210 may be made from a dielectric material which has already undergone an at least partial curing process resulting in comparatively large mechanical stability of the core 210.

[0082] A known encapsulating material 250 is used for mounting or attaching the optical component 120 within a cavity formed within the core 120. The encapsulating material 250 comprises a resin. The encapsulation/embedding process of the optical component 120 typically comprises a heat and/or pressure assisted lamination process, during which the encapsulating material 250 is or becomes at least partially liquid. The protection structure 140, which is depicted already in FIGS. 1A and 1B, prevents (liquid) resin material (of the encapsulating material 250) from entering into the aperture region 130. Hence, within the protection structure 140 there is provided a resin free region RF. The aperture region 130 is located within this resin free region RF.

[0083] According to the embodiment described here the optical component 120 comprises two electric connection structures 260, which are formed at the bottom main surface of the optical component 120. The electric connection structures 260 are used for electrically connecting the optical component 120 with other external or internal circuitry.

[0084] Spaced apart from the optical component 120 there are formed two vias 262, one in FIG. 2 at the left side of the optical component 120 and the other one at the right side of the optical component 120.

[0085] FIG. 3 shows the component carrier 200, which is now denominated with reference numeral 300, after at least one further processing step. As can be taken from this Figure, an optically transparent medium 370 has been locally applied in and around the aperture region 130. This optically transparent medium 370 provides a protection of the aperture 130 from being polluted with foreign particles such as, e.g., dust. Hence, the optically transparent medium 370 ensures a long lasting and low attenuation optical communication through the aperture 130.

[0086] Further, as can also be taken from FIG. 3, the component carrier 300 comprises two upper buildup layer structures 380. An upper one of the two buildup layer structures 380 covers the entire upper main surface of the component carrier 300. The lower one of the two buildup layer structures 380 surrounds the locally applied optically transparent medium 370. It is pointed out that when manufacturing the component carrier 300 the lower buildup layer structure 380 may also be formed prior to the optically transparent medium 370. In this case, within the lower buildup layer structure 380, there would be formed a recess and the optically transparent medium 370 would be formed selectively within this recess.

[0087] According to the exemplary embodiment described here the connection structures 260 of the optical component 120 are electrically contacted with respectively one via connection structure 361 extending through the lower buildup layer structure 380. Further, the vias 262 are extended such that two extended via structures 362 are formed which also extend through the lower buildup layer structure 380.

[0088] FIG. 4 shows a component carrier 400 in accordance with a further embodiment. The component carrier 400 basically corresponds to the component carrier 300 shown in FIG. 3. The only difference is that, instead of the (recessed) lower buildup layer structure 380, there is used a complete layer of optically transparent medium 470. This complete layer of optically transparent medium 470 covers the entire lower main surface of the core 210.

[0089] FIG. 5 shows a component carrier 500 in accordance with a further embodiment. The component carrier 500 comprises an embedded optical component 520, which, by contrast to the optical component 120, is electrically contacted from the upper side. As a consequence, via connection structures 561 are provided, which extend through the upper buildup layer structure 380.

[0090] Further, as can be taken from FIG. 5 and by contrast to the component carriers 300 and 400, there is not used any protection for the aperture region 130. Hence, below the core 210 (and the encapsulated component 520) there it is not provided any further layer. Hence, the (extended) vias 562 only extend through (i) the core 210, (ii) the encapsulating material 250 formed above the core 210, and (iii) the upper buildup layer structure 380.

[0091] FIG. 6 shows a component carrier 600 according to a further embodiment. In this embodiment the optical component 120 is embedded within a cavity 630. The cavity 630 is dimensioned such that the component 120, if applicable with not depicted gap filling material, geometrically fits to the cavity 630. Hence, an outer surface of the component 120 is aligned with an outer surface of the stack 210 of the component carrier 600.

[0092] As can be taken from FIG. 6, the protection structure 140 is formed at the lower surface of the stack 210 and defines a protected region. Further, the entire component 120 is located within this protected region.

[0093] As can be further taken from FIG. 6, the outer surface of the optically active portion 122 is also aligned with the outer surface of the stack 210. Hence, there is not provided and also not needed an aperture at least within any outer layer of the stack 210 as it is depicted here. However, it should be clear that this does not hold true for a component carrier which in addition to the stack 210 comprises further build-up layers at its bottom side.

[0094] It should be noted that the term “comprising” does not exclude other elements or steps and the use of articles “a” or “an” does not exclude a plurality. Also, elements described in association with different embodiments may be combined.

[0095] 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 variants use the solutions shown and the principle according to the invention even in the case of fundamentally different embodiments.

LIST OF REFERENCE SIGNS

[0096] 120 optical component [0097] 121 body portion [0098] 122 optical active portion [0099] 130 aperture (region) [0100] 140 protection structure [0101] 200 component carrier [0102] 210 stack/core [0103] 250 encapsulation material [0104] 260 connection structure [0105] 262 via [0106] RF resin free region [0107] 300 component carrier [0108] 361 via connection structure [0109] 362 (extended) via [0110] 370 optically transparent medium (locally applied) [0111] 380 buildup layer structure [0112] 400 component carrier [0113] 470 optically transparent medium (entirely applied) [0114] 500 component carrier [0115] 520 optical component [0116] 561 via connection structure [0117] 562 (extended) via [0118] 600 component carrier [0119] 630 cavity