Partially Filling a Component Carrier Opening in a Controlled Manner

Abstract

A component carrier includes a layer stack with at least one electrically insulating layer structure and/or at least one electrically conductive layer structure, at least one opening in the layer stack, a first curable dielectric element arranged at least partially on the opening, and a second curable dielectric element arranged adjacent to the first curable dielectric element, so that there is an interface region in between. A part of the first curable dielectric element extends partially into the opening.

Claims

1. A component carrier, comprising: a layer stack with at least one electrically insulating layer structure and/or at least one electrically conductive layer structure; at least one opening in the layer stack; a first curable dielectric element arranged at least partially on the opening; and a second curable dielectric element arranged adjacent to the first curable dielectric element, so that there is an interface region in between; wherein a part of the first curable dielectric element extends partially into the opening.

2. The component carrier according to claim 1, wherein the cure state of the first curable dielectric element is more cured than the cure state of the second curable dielectric element during component carrier manufacturing, and wherein this difference in the cure state is determinable at the interface region as an interface pattern.

3. The component carrier according to claim 2, wherein the interface pattern comprises at least one of the group which consists of at least one cut fiber, in particular a cut glass fiber, an alignment shift, a smearing, a colour shift, a tapering.

4. The component carrier according to claim 1, wherein the part of the first curable dielectric element extends into the opening to a specific filling height, in particular wherein the filling height corresponds to 5% or more of the opening volume, and/or wherein the filling height corresponds to 50% or less of the opening volume.

5. The component carrier according to claim 1, wherein the part of the first curable dielectric element that extends into the opening comprises a shaped main surface, in particular a hemisphere-like shape, more in particular a concave or convex shape.

6. The component carrier according to claim 1, wherein the part of the first curable dielectric element that extends into the opening essentially comprises no glass-fibers, in particular, wherein a glass fiber of the first curable dielectric element forms a wave-like structure at the opening main surface.

7. The component carrier according to claim 1, wherein the opening comprises at least one of the group which consists of a blind hole, a through hole, a cavity, a trench, a recess between traces.

8. The component carrier according to claim 1, wherein sidewalls of the opening are at least partially covered by an electrically conductive material.

9. The component carrier according to claim 1, wherein a diameter of the opening exposed at a layer stack main surface, in particular an opening main surface, is larger than a diameter of the opening which is not exposed at the layer stack main surface, in particular wherein the diameter at the opening main surface is a backdrill-opening.

10. The component carrier according to claim 1, wherein the opening is a fluid-filled, in particular gas-filled, more in particular air filled, cavity embedded in the layer stack.

11. A component carrier arrangement, comprising: a component carrier having a layer stack with at least one electrically insulating layer structure and/or at least one electrically conductive layer structure; at least one opening in the layer stack; a first curable dielectric element arranged at least partially on the opening; and a second curable dielectric element arranged adjacent to the first curable dielectric element, so that there is an interface region in between; wherein a part of the first curable dielectric element extends partially into the opening; and a further component carrier or a further component comprising a protruding element; wherein the further component carrier or the further component is stacked on the component carrier; and wherein the protruding element is at least partially inserted into the opening in order to connect the component carrier with the further component carrier or the further component.

12. A method of manufacturing a component carrier, the method comprising: providing a layer stack with at least one electrically insulating layer structure and/or at least one electrically conductive layer structure; forming at least one opening in the layer stack; arranging a first curable dielectric element with a first cure state at least partially on the opening; and arranging a second curable dielectric element with a second cure state adjacent to the first curable dielectric element, thereby forming an interface region in between; wherein the first cure state is more cured than the second cure state.

13. The method according to claim 12, further comprising: extending a part of the first curable dielectric element into the opening.

14. The method according to claim 13, wherein extending comprises: flowing material of the first curable dielectric element into the opening in a controlled manner, in particular with respect to at least one of the group which consists of filling depth, amount of flow material, speed of flow material, shape of the flow material.

15. The method according to claim 12, further comprising: arranging the second curable dielectric element to provide a cut-out region on the opening; and arranging the first curable dielectric element in the cut-out region.

16. The method according to claim 12, further comprising: predefining a cure state criterion, in particular including at least one of viscosity and filling height; and tuning the first curable dielectric element so that the first cure state fulfills the cure state criterion.

17. The method according to claim 12, further comprising: laminating a further electrically insulating layer structure and/or a further electrically conductive layer structure on the first curable dielectric element, in particular wherein the first cure state and the second cure state are different after lamination or wherein the first cure state and the second cure state are the same after lamination.

18. The method according to claim 12, further comprising: back-drilling the opening at an opening main surface that is exposed to a layer stack main surface.

19. The method according to claim 12, further comprising: interconnecting a further component carrier or a further component at the opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] FIG. 1 shows a side view of a component carrier according to an exemplary embodiment of the invention.

[0081] FIG. 2A, FIG. 2B, FIG. 2C and FIG. 2D show a method of manufacturing a component carrier according to an exemplary embodiment of the invention.

[0082] FIG. 3A, FIG. 3B, FIG. 3C and FIG. 3D respectively show an interface pattern according to exemplary embodiments of the invention.

[0083] FIG. 4 shows a side view of a component carrier with a component in a cavity according to an exemplary embodiment of the invention.

[0084] FIG. 5 shows a side view of a component carrier with a component in a cavity according to another exemplary embodiment of the invention.

[0085] FIG. 6 shows a side view of a component carrier with a fluid-filled cavity according to an exemplary embodiment of the invention.

[0086] FIG. 7 shows a side view of two different filling heights in the opening according to an exemplary embodiment of the invention.

[0087] FIG. 8 shows a component carrier arrangement according to an exemplary embodiment of the invention.

[0088] FIG. 9A, FIG. 9B, and FIG. 9C show side views of a specifically shaped part of the first curable dielectric element in the opening, respectively, according to exemplary embodiments of the invention.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

[0089] The illustrations in the drawings are schematically presented. In different drawings, similar or identical elements are provided with the same reference signs.

[0090] FIG. 1 shows a side view of a component carrier 100 according to an exemplary embodiment of the invention. The component carrier 100 comprises a layer stack 101 with an electrically insulating layer structure 102 (for example a core layer) and thin electrically conductive layer structures 104 that sandwich the electrically insulating layer structure 102. A plurality of openings 110 in the form of through holes are formed in the layer stack 101 and through the electrically insulating layer structure 102. The through holes 110 are plated with an electrically conductive material 111, e.g., copper. It can be seen that, at the top of each through hole 110, the opening diameter is larger than the further diameter of the through holes, which is not the opening diameter (the hole diameter at the main surface of the layer stack 101 is enlarged).

[0091] A first curable dielectric element 120, being in this example a pre-cured prepreg (a glass fiber enforced epoxy resin, e.g., FR4) that is formed as a sheet, is arranged on top of the openings 110. A part 121 of the first curable dielectric element 120 extends partially into the openings 110. This extension is down to a predetermined filling depth. The first curable dielectric element 120 is in a first cure state (for example with a cross-linking state of 30%), wherein the cure state has been pre-determined (and fulfills a predetermined cure state criterion) in order to achieve a controlled flow of curable dielectric material 121 into the openings 110.

[0092] In this example, the through holes 110 serve for establishing a press-fit connection to a further component carrier. A protruding element of the further component carrier (not shown) will be pressed into the component carrier openings 110 (in this view from below) up to a specific height. However, during a further lamination step on top of the component carrier 100, layer stack 101, the through holes 110 would be completely filled with insulating material (e.g., resin). Conventional plugin pastes are generally not reliable enough and would fill the through holes 110 too little or too much. However, with the described first curable dielectric element 120, which has a predetermined cure state and hence a controllable flow viscosity, enables a reliable and robust partial filling of the through holes 110.

[0093] The component carrier 100 further comprises two second curable (essentially not pre-cured) dielectric elements 130 that are arranged adjacent (side-by-side) with the first curable dielectric element 120, so that there are two respective interface regions 150 in between. The cure state of the first curable dielectric element 120 is more cured than the cure state of the second dielectric element 130, i.e., being more viscos and/or more cross-linked. Besides the difference in the cure state, the first curable dielectric element 120 and the second curable dielectric elements 130 comprise the same material, e.g., a prepreg. The difference in the cure state is also determinable at the interface region 150 as an interface pattern. The second dielectric element 130 is not arranged on top of the openings 110.

[0094] FIGS. 2A to 2D show a method of manufacturing a component carrier 100 according to an exemplary embodiment of the invention.

[0095] As illustrated in FIG. 2A, a layer stack 101 with an electrically insulating layer structure 102 and electrically conductive layer structures 104 is provided. Openings in the form of through holes 110 are formed in the electrically insulating layer structure 102 of the layer stack 101.

[0096] As shown in FIG. 2B, two second curable dielectric elements 130 with a second cure state have been arranged on the top of the layer stack 101. In between the two second curable dielectric elements 130, there is a cut-out region 132. Either the two second curable dielectric elements 130 have been arranged separately adjacent to the cut-out region 132 or there has been arranged one second curable dielectric element 130 and a part of it has been cut-out.

[0097] In FIG. 2C a first curable dielectric element 120 with a first cure state is arranged on top of the plurality of through holes 110 and in the cut-out region 132 between the two second curable dielectric elements 130, thereby forming two interface regions 150.

[0098] In FIG. 2D the first curable dielectric element 120 extends partially into the openings 110, wherein extending comprises flowing material 121 of the first curable dielectric element 120 into the openings 110 in a controlled manner regarding filling depth and the amount of flowing material. This control is enabled by a predetermined first cure state. For example, the cure state of the first curable dielectric element 120 (and the second curable dielectric element 130) is analyzed in advance to determine and adapt/adjust the first cure state to a (predetermined) cure state criterion.

[0099] In a further step, a further electrically insulating layer structure 140 is laminated on top of the first curable dielectric element 120 and the second curable dielectric elements 130. The openings 110 are not completely filled by the lamination step due to the first curable dielectric element 120 that partially fills the openings 110 to a specific predetermined depth.

[0100] FIGS. 3A to 3D respectively show an interface pattern 155 according to exemplary embodiments of the invention. Different materials can be observed due to the different color, material structure and composition, also that there may be a cut seen in the glass fiber. Depending on the materials, different (material) analysis method can be applied.

[0101] FIG. 4 shows a side view of a component carrier 100 with a component 160 in a cavity 110 according to an exemplary embodiment of the invention. The component carrier 100 comprises a layer stack 101 with a plurality of electrically insulating layer structures 102 and electrically conductive layer structures 104. In the center (in a horizontal direction) of the layer stack 101, there is arranged a cavity 110 in a lower electrically insulating layer structure 102. The electric component 160 is placed in the cavity 110 and is electrically connected to an electrically conductive layer structure at the bottom outer main surface of the component carrier 100. On top of the lower electrically insulating layer structure 102, there are arranged two second curable dielectric element segments 130. These are respectively adjacent to two first curable dielectric element segments 120 that cover the tops of the sidewalls of the cavity 110 and slightly overlap in a region above the cavity 110.

[0102] The electric component 160 is not covered by the first curable dielectric elements 120. On the curable dielectric elements 120, 130, there is arranged an upper electrically insulating layer structure 102 with respective conductive layer structures 104. Depending on the desired functionality, the first cure state can be chosen such that a part of the first curable dielectric elements 120 extends into the cavity 110 and partially fills it. Hereby, the embedded component 160 can be partially encapsulated, for example the region between the cavity sidewalls and the component sidewalls can be filled in a controlled manner. In another example, the first cure state is already very hard and there will be essentially no flow into the cavity 110.

[0103] FIG. 5 shows a side view of a component carrier 100 with a component 160 in a cavity 110 according to another exemplary embodiment of the invention. This example is very similar to the one shown in FIG. 4 with the difference being that the electric component 160 is covered by the first curable dielectric element 120. Further, the top of the sidewall of the cavity 110 is not covered by the first curable dielectric element 120. In this configuration, a part of the first curable dielectric element 120 can flow in a controlled manner into the cavity 110 and (at least partially) fill it. In a further example, a part of the first curable dielectric element 120 flows down to cover the tops of the sidewalls of the cavity 110. In another example, the first cure state is already very hard and there will be essentially no flow into the cavity 110.

[0104] FIG. 6 shows a side view of a component carrier 100 with a fluid-filled cavity 110 according to an exemplary embodiment of the invention. This example is very similar to the ones shown in FIGS. 4 and 5 above. However, there is no electric component arranged in the cavity 110. The first curable dielectric element 120 covers the cavity 110 and also covers the tops of the sidewalls of the cavity 110. Depending on the predetermined first cure state, a part 121 of the first curable dielectric element 120 flows into the cavity 110 and partially fills it. For example, the sidewalls of the cavity 110 can be covered with dielectric material. In another example, the first cure state is already very hard and there will be essentially no flow into the cavity 110.

[0105] FIG. 7 shows a side view of two different filling heights in the opening 110 according to an exemplary embodiment of the invention. The left hole 110a is partially filled by a part 121 of the first curable material 120, that extends into the opening 110a, to a filling height of around 20% of the opening (volume). The right hole 110b is filled by another part 121 of the first curable material 120, that extends into the opening 110b to a filling height of around 5% of the opening (volume).

[0106] FIG. 8 shows a component carrier arrangement 200 according to an exemplary embodiment of the invention. The component carrier arrangement 200 comprises a component carrier 100, being the component carrier 100 described in the previous examples, and a further component carrier or further component 250. The further component (carrier) 250 comprises protruding elements 210 that are configured to establish a press-fit connection together with the openings 110 of the component carrier 100. For this purpose, the first curable dielectric element 120 extends only partially 121 into the openings 110 to a specific filling height h.

[0107] FIGS. 9A to 9C show side views of a specifically shaped part of the first curable dielectric element 120 in the opening 110. For example, due to surface tension, applied pressure and friction at the side walls, a shaped portion can be achieved.

[0108] FIG. 9A shows a hemispherical shape of a convex main surface 122 of the part 121 that extends into the opening 110.

[0109] FIG. 9B shows a further example of a part 121 with a deeper filling height. It is indicated that an angle α can be determined between the opening sidewall and the curved shape.

[0110] FIG. 9C shows a side view of a part 121 of the first curable dielectric element 120 that extends into the opening 110 and comprises no glass-fibers. In contrast, the part that does not extend comprises a glass fiber 123 which is wave-like formed at the opening main surface 112.

[0111] 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.

[0112] Implementation of the invention is not limited to the preferred embodiments shown in the figures and described above. Instead, a multiplicity of variants are possible which variants use the solutions shown and the principle according to the invention even in the case of fundamentally different embodiments.

REFERENCE SIGNS

[0113] 100 Component carrier
101 Layer stack
102 Electrically insulating layer structure
104 Electrically conductive layer structure
110 Opening, through hole, cavity
111 Electrically conductive material
112 Opening main surface

113 Backdrill-opening

[0114] 120 First curable dielectric element
121 Extending part of first curable dielectric element
122 Extending part shaped main surface
123 Glass fiber
130 Second curable dielectric element
132 Cut-out region
140 Further electrically insulating layer structure
150 Interface region
155 Interface pattern
160 Electronic component
200 Component carrier arrangement
210 Protruding element
250 Further component carrier, further component