Component carrier with integrated antenna structure

Abstract

An electronic assembly and a method for fabricating the same are disclosed. The assembly includes a component carrier, a wireless communication component and an antenna structure. The component carrier has at least one dielectric layer and a metallic layer. The wireless communication component is attached to the component carrier. The antenna structure is formed from a metallic material and is electrically connected with the wireless communication component. An opening formed in the component carrier extends from an upper surface into the interior of the component carrier. The antenna structure is formed at least partially at a wall of the opening.

Claims

1. An electronic assembly, comprising: a component carrier, which comprises at least one dielectric layer and a metallic layer, which is attached at the dielectric layer; a wireless communication component, which is attached to or embedded in the component carrier; and an antenna structure, which is formed from a conducting material and which is electrically connected with the wireless communication component; wherein an opening is formed within the component carrier, which opening extends from an upper main surface of the component carrier into the interior of the component carrier, wherein the antenna structure is formed at least partially at a wall of the opening, wherein the opening is at least partially a slit having a first sidewall portion and a second sidewall portion, wherein the second sidewall portion is opposite and parallel to the first sidewall portion, wherein the slit is a groove, which does not extend completely through the component carrier, wherein the two opposing sidewall portions are connected to each other by opposed curved wall portions being a part of the antenna structure, wherein a direction of main extension of the two opposed sidewall portions and the opposed curved wall portions is oriented perpendicular to the directions of main extension of the component carrier, and wherein the two opposed sidewall portions and the opposed curved wall portions are arranged on the same height level in the component carrier.

2. The electronic assembly of claim 1, wherein an upper edge of the opening being located at the upper surface of the component carrier describes a closed line.

3. The electronic assembly of claim 1, wherein the opening is a passage opening which extends from the upper surface to an opposing lower surface of the component carrier.

4. The electronic assembly of claim 1, wherein the opening is a blind opening, which extends from the upper surface of the component carrier into the interior of the component carrier.

5. The electronic assembly of claim 1, wherein the wireless communication component is spatially separated from the opening.

6. The electronic assembly of claim 1, wherein the opening comprises a widening at one end of the slit, wherein a part of the antenna structure is formed at a sidewall of the widening, and wherein the antenna structure is not a horn antenna.

7. The electronic assembly of claim 1, wherein the opening comprises at least one further slit.

8. The electronic assembly of claim 7, wherein the opening comprises a further widening at one end of the further slit, wherein a part of the antenna structure is formed at a further sidewall of the further widening.

9. The electronic assembly of claim 1, further comprising: a protective material arranged in the opening.

10. A method for fabricating an electronic assembly, the method comprising: providing a component carrier, which comprises at least one dielectric layer and a metallic layer, which is attached at the dielectric layer; attaching a wireless communication component to the component carrier, or embedding the wireless component in the component carrier; forming an opening within the component carrier, which opening extends from an upper main surface of the component carrier into the interior of the component carrier; wherein the opening is a slit having a first sidewall portion, a curved sidewall portion and a second sidewall portion, wherein the second sidewall portion is adjacent to the curved sidewall portion and opposite and parallel to the first sidewall portion, and wherein the slit is a groove, which does not extend completely through the component carrier; forming a metallic antenna structure at a wall of the opening so that the curved sidewall portion and two opposing sidewall portions are a part of the antenna structure; and electrically connecting the wireless communication component with the antenna structure; wherein a direction of main extension of the two opposed sidewall portions and the opposed curved wall portions is oriented perpendicular to the directions of main extension of the component carrier, and wherein the two opposed sidewall portions and the opposed curved wall portions are arranged on the same height level in the component carrier.

11. The method for fabricating an electronic assembly of claim 10, further comprising: filling a portion of the opening with a protective material.

12. An electronic assembly, comprising: a component carrier, which comprises from top to bottom in the following order, a first structured metallic layer, a first dielectric layer, a second structured metallic layer, a second dielectric layer, a third structured metallic layer, and a third dielectric layer, wherein the first structured metallic layer, the first dielectric layer, the second structured metallic layer, the second dielectric layer, the third structured metallic layer, and the third dielectric layer are arranged in parallel with each other, wherein each of the structured metallic layers is defined by a respective metallic conductor trace, wherein each metallic conductor trace has a straight trace portion and a curved trace portion, wherein the straight trace portions of the respective metallic conductor traces have all the same length, and wherein the curved trace portions of the respective metallic conductor trace of the respective metallic layers have all different lengths; wherein the curved trace portions of the respective metallic conductor trace have an open end; a wireless communication component, which is attached to or embedded in the component carrier; and an antenna structure, which is formed from the metallic conductor traces of the structured metallic layers and which is electrically connected with the wireless communication component, wherein an opening is formed within the component carrier, which opening extends from an upper surface of the component carrier into the interior of the component carrier, and wherein the antenna structure is formed at least partially at a wall of the opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1a and 1b show in a plan view respectively in a perspective view an electronic assembly having an antenna structure formed at the sidewall of a milled slot.

(2) FIGS. 2a and 2b show in a perspective view electronic assemblies having an antenna structure which extends over at least two patterned metallic layers of a multilayer component carrier.

(3) FIGS. 3a and 3b show in a cross sectional respectively in a plan view a cone shaped antenna structure formed within a multilayer component carrier.

(4) FIGS. 4a and 4b show in a cross sectional respectively in a perspective view an antenna structure formed as a corrugated horn.

(5) FIGS. 5a, 5b and 5c show in plan views different embodiments of antenna structures comprising at least one slit portion and at least two widened portions.

(6) FIGS. 6a and 6b show in a plan view respectively in a cross sectional view an antenna structure being realized with patterned metallic layers each having a different length.

(7) FIG. 7 shows in a cross sectional view an antenna structure with patterned metallic layers each having a different length and all but one being embedded within dielectric layers.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

(8) The illustration in the drawing is presented schematically. 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.

(9) 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 of the invention can assume orientations different than those illustrated in the figures when in use.

(10) FIGS. 1a and 1b show in a plan view respectively in a perspective view an electronic assembly 100 according to a first embodiment of the invention. The depicted electronic assembly 100 comprises a component carrier 110 which is also denominated a printed circuit board (PCB). According to the embodiment described here the component carrier 110 is a so called multilayer component carrier 110 which comprises in an alternating sequence non-depicted metallic layers and non-depicted dielectric layers. In the top view shown in FIG. 1a several conductor paths respectively conductor traces 120 and 122 can be seen which are formed within an upper structured or patterned metallic layer. Each one of the conductor paths 122 ends at a via connection 126 which in a known manner provides an electric contact to lower (structured) metallic layers.

(11) The electronic assembly 100 comprises a wireless communication component respectively an RFID chip 150 which is embedded within the component carrier 110 (see FIG. 1b). The RFID chip 150 comprises two terminals 152 via which the RFID chip 150 is electrically connected to antenna connection conductor paths 170. As can be seen from both FIGS. 1a and 1b, the antenna connection conductor paths 170 extend to an antenna structure 160. As can be seen exclusively from FIG. 1b, the upper surface of the RFID chip 150 is located below the upper surface of the component carrier 110. Since the antenna connection conductor paths 170 are formed on the upper surface of the component carrier 110, each one of the two terminals 152 comprises a via connections extending perpendicular to the surface of the component carrier 110.

(12) The electronic assembly 100 further comprises an opening 130 which according to the embodiment described here extends completely from the upper surface of the component carrier 110 to the lower surface of the component carrier 110. According to the embodiment described here the opening is a milled slot 130 which comprises a sidewall also extending completely through the component carrier 110. At this sidewall of the antenna structure 130 there is applied an appropriate metallization which preferably comprises the metal element copper which may be the same material which is also used for the metallic layers.

(13) It is mentioned that the form or shape of the opening 130 shown in FIGS. 1a and 1b is only exemplary because also other opening designs can be used which provide a sidewall extending along the thickness direction of the component carrier 110. Further, an antenna structure may also be realized by an appropriate metallization of the sidewall of an opening which does not completely extend through the component carrier 110 and which may also called a “blind opening”.

(14) As can be further seen from the Figures showing the electronic assembly 100, the opening 130 is spatially separated from the RFID chip 150. This may in particular provide the advantage that the RFID chip 150 can be fully embedded within the component carrier 110 such that it is protected from negative external impacts.

(15) FIGS. 2a and 2b show in a perspective view electronic assemblies 200a and 200b, which comprise an embedded RFID chip 150 being connected to an antenna structure 260a and 260b, respectively. Both antenna structures 260a, 260b extend over at least two patterned metallic layers of a multilayer component carrier 110.

(16) As can be seen from FIG. 2b, the electronic assembly 200b comprises on its top surface two connection pads 223 which are connected with respectively one conductor path 224 by means of (a) a conductor path 122 formed on the top surface of the component carrier 110 and (b) a via connection 126.

(17) As can be seen from FIG. 2a, the antenna structure 260a comprises a plurality of antenna elements 262, wherein respectively two of the plurality of antenna elements are formed within one and the same metallic layer of the multilayer component carrier 110. The antenna elements 262 are arranged within two vertical stacks, wherein the antenna elements 262 of one stack are connected with one of the terminals 152 of the RFID chip 150. The antenna elements 262 within one stack are interconnected with an antenna connection 264 which according to the embodiment described here is realized by means of a metallized opening extending along the thickness of the component carrier 110.

(18) As can be seen from FIG. 2b, the antenna structure 260b of the electronic assembly 200b comprises two antenna substructures, an upper antenna substructure 266 and a lower antenna substructure 267. The two antenna substructures 266 and 267 are formed by two different patterned metallic layers. According to the embodiment described here, each one of the antenna substructures 266 and 267 comprises two L-shaped conductor paths wherein the two ends of the two L-shaped conductor paths are connected via a conductor path portion having a zig-zag pattern made from a plurality of U-shaped conductor path elements. The upper antenna substructure 266 and the lower antenna substructure 267 are connected by means of antenna connections 264, which are also be realized by means of metallized openings extending along the thickness of the component carrier 110.

(19) FIGS. 3a and 3b show in a cross sectional respectively in a plan view a cutaway of an electronic assembly 300, which comprises the cone shaped antenna structure 360 formed within the multilayer component carrier 110.

(20) As can be seen from FIG. 3a the component carrier 110 comprises five structured metallic layers 311, 313, 315, 317, and 319 and four non-depicted dielectric layer, wherein respectively one dielectric layer is located (sandwiched) between two structured metallic layers.

(21) Within the component carrier 110 there is provided a cone shaped opening 330, which extends from the top of the component carrier 110 almost completely through the component carrier 110 until the upper side of the bottom metallic layer 319. The cone shaped opening 330 is metallized in such a manner that a metallic sidewall portion 366 and a metallic bottom portion 367 are formed. According to the embodiment described here the antenna structure 360 comprises a side wall portion 366 and a bottom portion 367. The non-depicted RFID chip may be connected in particular via the structured metallic layer 319 with the antenna structure 360.

(22) Descriptively speaking, the antenna structure 360 represents a horn antenna which has the well-known advantage that electromagnetic radiation being emitted is focused along one spatial direction. The same holds of course also for the directional sensitivity for receiving electromagnetic (RFID) radiation. As a consequence, the efficiency for an electromagnetic coupling of the non-depicted RFID chip and a non-depicted RFID reader and/or RFID writer will be high.

(23) FIGS. 4a and 4b show in a cross sectional respectively in a perspective view an antenna structure 460 formed as a corrugated horn. By contrast to the cone shaped antenna structure 360 shown in FIG. 3a, in the cross sectional view of FIG. 4a the metallic antenna structure 460 has a step-shaped structure. Further, as can be seen from FIG. 4a, the corrugated horn structure involves only the four structured metallic layers 311, 313, 315, and 317. A non-depicted RFID chip may be connected directly or indirectly with a central portion of the structured metallic layer 317, a part of which forms the bottom of the corrugated horn structure 460.

(24) Realizing the antenna structure 460 as a corrugated horn being formed within the component carrier 110 may also provide the advantage of a directional radiation pattern leading to a directional dependent sensitivity of a RFID data communication between the RFID chip and a non-depicted RFID reader and/or RFID writer.

(25) FIGS. 5a, 5b, and 5c show in plan views different embodiments of antenna structures 560a, 560b, and 560c. The antenna structure 560c is shown together with an RFID chip 150 being connected with the antenna structure 560c by means of two chip terminals 152 and two antenna connection conductor paths 170.

(26) As can be seen from FIG. 5a, the antenna structure 560a comprises a slit portion 561. The slit portion 561 is formed within a non-depicted component carrier for instance by means of a milling procedure. According to the embodiment described here, the slit portion 561 is a gap extending completely through the non-depicted component carrier along its thickness direction. Alternatively, the slit portion 561 may only be a groove, which does not extend completely through the component carrier. The slit portion 561 defines two opposing sidewall portions which are covered with a metallization layer being a part of the antenna structure 560a.

(27) As can be seen from FIG. 5a, the opening 530 further comprises two widened portions 563, wherein respectively one widened portion 563 is located at one end of the slit portion 561. According to the embodiment described here, the widened portions 563 have a circular respectively a cylindrical shape. With the widened portions 563 a proper frequency bandwidth of the antenna structure 560a can be selected by choosing an appropriate geometric design for the slit portion 561 and/or for the widened portions 563.

(28) Further, as has already been mentioned above, choosing an appropriate geometric design for the slit portion 561 and/or for the widened portions 563 may further allow for selecting both a capacitive value and an inductive value of the antenna structure 560a in an appropriate manner depending on an application specific electromagnetic specification. This holds of course also for the antenna structures 560b and 560c which are described in detail in the following paragraphs.

(29) The antenna portion 560b differs from the antenna portion 560a only (a) by a different length and width of the slit portion 561 and (b) by the shape of the widened portion 563, which is now an half circle respectively a half cylinder.

(30) As can be seen from FIG. 5c, the antenna portion 560c comprises an opening 530 having a plurality of slit portions 561 and a plurality of widened portions 563. Respectively one widened portion 563 is located at one end of one slit portion 561. The antenna structure 560c is again realized by means of a proper metallization on the entire sidewall having a complex geometric structure and running along the entire opening 530. Again, the narrow slit portions 561 represent the capacitive part of the antenna structure 560c and the widened portions 563 represent the inductive part of the antenna structure 560c.

(31) Descriptively speaking, the antenna structure 560c has the shape of a “frog finger”, wherein the “fingers” are connected in series with respect to each other. As a consequence, the entire antenna structure 560c radiates preferably into a direction being perpendicular to the plane of drawing.

(32) At this point it is mentioned that the number of “fingers” can deviate from the number “4” as depicted in FIG. 5c. In principle any number of figures is possible. Even an embodiment having only one finger may be appropriate for certain applications.

(33) FIGS. 6a and 6b show in a plan view respectively in a cross sectional view an antenna structure 660 being formed within a component carrier 110 shown in FIG. 6b. The component carrier 110 comprises, from the bottom to the top, the following sequence of layers: (a) a dielectric layer 616, (b) a structured metallic layer 615, (c) a dielectric layer 614, (d) a structured metallic layer 613, (e) a dielectric layer 612, and (f) a structured metallic layer 611. Within the component carrier 110 there is formed a circular respectively a cylindrical opening 630. Of course, also other geometries can be used for the opening. The metallic layers 611, 613, and 615 are structured in such a manner that the antenna structure 660, which extends via these three metallic layers 611, 613, and 615, is defined by metallic conductor traces, wherein each trace has a straight trace portion 668 and a curved trace portion 669.

(34) According to the embodiment described here, the straight trace portions 668 of the various metallic layers 611, 613, and 615 have all the same length. By contrast thereto, the curved trace portions 669 of the various metallic layers 611, 613, and 615 have different lengths. This can best be seen from FIG. 6a, wherein (a) the two curved portions 669 of the metallic layer 611 encircle only little more than one half of the circular opening 630, (b) the two curved portions 669 of the metallic layer 613 encircle approximately three quarter of the circular opening 630, and (c) the two curved portions 669 of the metallic layer 615 encircle almost the entire circular opening 630. The three dashed lines connecting FIGS. 6a and 6b represent an “optical guidance” for assigning with each other corresponding edge structures depicted in the two Figures.

(35) As can be seen in particular from FIG. 6b, according to the embodiment described here the dielectric layers 612, 614, and 616 have different lengths. Specifically, the length of each one of these layers 612, 614, and 616 corresponds to the length of this metallic layer 611, 613, and 615, respectively, which is located above the respective dielectric layer 612, 614, or 616.

(36) FIG. 7 shows in a cross sectional view a further embodiment of an antenna structure 760, which differs from the antenna structure 660 shown in FIG. 6b only in that the two lower metallic layers 613 and 615 are embedded within the dielectric layers 612, 614, and 616.

(37) 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. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

REFERENCE SIGNS

(38) 100 electronic assembly 110 component carrier/printed circuit board (PCB) 120 conductor paths 122 conductor paths 126 via connections 130 opening/milled slot 150 wireless communication component/RFID chip 152 terminals 160 antenna structure 170 antenna connection conductor paths 200a electronic assembly 200b electronic assembly 223 connection pad 224 inner conductor paths 260a antenna structure 260b antenna structure 262 antenna elements 264 antenna connections 266 upper antenna substructure 267 lower antenna substructure 300 electronic assembly 311 structured metallic layer 313 structured metallic layer 315 structured metallic layer 317 structured metallic layer 319 structured metallic layer 330 opening (cone shaped) 360 antenna structure 366 side wall portion 367 bottom portion 460 antenna structure/corrugated horn structure 430 opening (stepwise) 530 opening 560a antenna structure 560b antenna structure 560c antenna structure 561 slit portion 563 widened portion/widening 611 structured metal layer 612 dielectric layer 613 structured metal layer 614 dielectric layer 615 structured metal layer 616 dielectric layer 630 opening 660 antenna structure 668 straight trace portion 669 curved trace portion 760 antenna structure