Component carrier with a solid body protecting a component carrier hole from foreign material ingression

Abstract

A component carrier includes (a) a first stack with at least one first electrically conductive layer structure and/or at least one first electrically insulating layer structure; (b) a hole formed within the first stack; and (c) a non-deformable solid body closing a portion of the hole and being spaced with respect to side walls of the hole by a gap. A component carrier assembly includes (a) a component carrier as described above; (b) a second stack having at least one second electrically conductive layer structure and/or at least one second electrically insulating layer structure; and (c) a connection piece connecting the first stack with the second stack. Further described are methods for manufacturing such a component carrier and such a component carrier assembly.

Claims

1. A component carrier, comprising: a first stack comprising at least one first electrically conductive layer structure and/or at least one first electrically insulating layer structure; a hole formed within the first stack, the hole comprising a first hole portion and a second hole portion; and a non-deformable solid body closing the second hole portion and being spaced with respect to side walls of the hole by a gap, wherein the second hole portion comprises an electrically conductive side wall and the first hole portion is free from an electrically conductive side wall.

2. The component carrier as set forth in claim 1, wherein the non-deformable solid body is a ball.

3. The component carrier as set forth in claim 1, wherein the non-deformable solid body comprises glass.

4. The component carrier as set forth in claim 1, wherein the non-deformable solid body comprises resin.

5. The component carrier as set forth in claim 1, wherein the non-deformable solid body comprises copper.

6. The component carrier as set forth in claim 1, further comprising: a fixing medium located at least partially within the hole, wherein the fixing medium is in contact with the non-deformable solid body.

7. The component carrier as set forth in claim 6, wherein the fixing medium comprises a curable or cured paste.

8. The component carrier as set forth in claim 1, wherein at least a portion of the hole comprises an electrically conductive inner side wall.

9. The component carrier as set forth in claim 8, further comprising: an electric connector, wherein the electrically conductive inner side wall is electrically contacted with a contact terminal of the connector.

10. The component carrier as set forth in claim 9, wherein the hole has a first hole portion and a second hole portion being directly connected to each other, and the first hole portion has a first diameter larger than a diameter of the non-deformable solid body and the second hole portion has a second diameter smaller than the diameter of the non-deformable solid body.

11. The component carrier as set forth in claim 1, further comprising: at least one further hole formed in the first stack; and at least one further non-deformable solid body closing a portion of the at least one further hole and being spaced with respect to side walls of the at least one further hole by a gap.

12. The component carrier as set forth in claim 11, wherein the non-deformable solid body comprises a first spatial dimension and at least one of the at least one further non-deformable solid body comprises a second spatial dimension being different from the first spatial dimension.

13. The component carrier as set forth in claim 6, wherein the fixing medium is a paste.

14. The component carrier as set forth in claim 13, wherein a characteristic of the paste changes upon being exposed to ultraviolet radiation.

15. A method for manufacturing a component carrier, the method comprising: forming a first stack comprising at least one first electrically conductive layer structure and/or at least one first electrically insulating layer structure; forming a hole within the first stack, the hole comprising a first hole portion and a second hole portion; and closing the second hole portion by inserting a non-deformable solid body in the hole, wherein the non-deformable solid body is spaced with respect to side walls of the hole by a gap, wherein the second hole portion comprises an electrically conductive side wall and the first hole portion is free from an electrically conductive side wall.

16. The method as set forth in claim 15, further comprising: forming a further hole within the first stack; and closing at least a portion of the further hole by inserting a further non-deformable solid body in the further hole, wherein the further non-deformable solid body is spaced with respect to side walls of the further hole by a gap.

17. The method as set forth in claim 15, wherein forming the first stack is carried out on a tape and wherein the method further comprises: forming, next to the first stack, an additional first stack on the tape, the additional first stack comprising at least one additional first electrically conductive layer structure and/or at least one additional first electrically insulating layer structure; forming an additional hole within the additional first stack; and closing at least a portion of the additional hole by inserting an additional non-deformable solid body in the additional hole, wherein the additional non-deformable solid body is spaced with respect to side walls of the additional hole by a gap.

18. The method of claim 13, further comprising: introducing a fixing medium in the hole before the step of closing.

19. The method of claim 18, further comprising: exposing the fixing medium to ultraviolet radiation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A, FIG. 1B, FIG. 1C, FIG. 1D, FIG. 1E, FIG. 1F and FIG. 1G illustrate method steps for manufacturing a component carrier assembly comprising a laminate of a first stack and a second stack with an intermediate resin connection piece between the first stack and the second stack.

(2) FIG. 2 shows an alternative solution for fixing a non-deformable solid body within a hole of the component carrier.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

(3) 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.

(4) FIG. 1A, FIG. 1B, FIG. 1C, FIG. 1D, FIG. 1E, FIG. 1F and FIG. 1G illustrate method steps for manufacturing a component carrier assembly 160 comprising a laminate of a first stack and a second stack with an intermediate resin connection piece between the first stack and the second stack.

(5) As can be taken from FIG. 1A, the method for manufacturing a component carrier assembly starts with providing a first stack 110. The first stack 110 is a laminated (and cured) core comprising an alternating sequence of first electrically conductive layer structures 112 and first electrically insulating layer structures 114. Further, a through hole 120 is formed within the first stack 110. The through hole 120 has been plated by means of a known plating procedure such that the hole 120 comprises an electrically conductive inner side wall 128.

(6) It is mentioned that in most applications the first stack 110 comprises more than one hole 120. However, for the sake of clarity of illustration only one hole 120 is depicted in the drawings.

(7) As can be taken from FIG. 1B, in a next step an upper first hole portion 122 of the hole 120 is widened by means of a so called back-drilling. This means that a drill with a slightly larger diameter is used for widening the first hole portion 122. A lower second hole portion 124 is not drilled because the wider drill is not inserted completely within the hole 120 along a not depicted vertical z-direction. Hence, the diameter of the lower second hole portion 124 is the (original) diameter of the hole 120 as depicted in FIG. 1A. Due to the two different diameters a step or a ledge 125 is formed in the transition region between the first hole portion 122 and the second hole portion 124.

(8) It is mentioned that the described back-drilling can also be realized by means of an appropriate laser drilling. Thereby, the necessary larger diameter of a laser beam can be set by means of a proper de-focusing.

(9) As can be taken from FIG. 1C, in a next step a non-deformable solid body 130 is inserted into the upper first hole portion 122. The non-deformable solid body 130, which in the depicted embodiment is a ball made from glass, has a diameter which is smaller than the diameter of the upper first hole portion 122 but larger than the diameter of the lower second hole portion 124. Hence, the glass ball 130 rests on the above-mentioned ledge 125.

(10) According to the nomenclature of this document the structure shown in FIG. 1C including the glass ball 130 is denominated a component carrier 100.

(11) As can be taken from FIG. 1D, in a next step the glass ball 130 is fixed by means of a viscous fixing medium 132. The fixing medium may be for instance a (not yet cured) resin. In this respect it is mentioned that the presence of the fixing medium is optional. In case of a smooth handling of the component carrier 100, when performing a further processing, it may not be necessary to hold the glass ball 130 in position by means of the fixing medium 132. For instance, in other embodiments the glass ball 130 can be fixed when applying a next (prepreg) layer structure 140 (see FIG. 1E) on top of it as there might be a fixing medium from this (prepreg) layer structure 140 flowing into the gap and surrounding and holding in place the upper part of the glass ball 130.

(12) As can be taken from FIG. 1E, in a next step a later re-lamination procedure is prepared. Thereby, a connection piece 140 is arranged above the component carrier 100 and a second stack 150 is arranged above the connection piece 140.

(13) The connection piece 140 may be a resin layer which optionally comprises reinforcement particles such as non-depicted glass fibers or glass balls (with a significantly smaller diameter than the glass ball 130). In some embodiments the connection piece 140 is a semi-finished product. Preferably, the connection piece is an at least partially uncured prepreg layer 140.

(14) The second stack 150 is a laminated (and cured) core comprising an alternating sequence of second electrically conductive layer structures 152 and second electrically insulating layer structures 154. According to the embodiment described here the second stack 150 comprises at least one hole, a through hole and/or a blind hole which is used in a known manner for realizing an electrically conductive interconnect between different second electrically conductive layer structures 152. However, for the ease of illustration such hole(s), which are optional, are not depicted in the drawings.

(15) As can be taken from FIG. 1F, in a next step the re-lamination procedure already mentioned above is accomplished. According to the exemplary embodiment described here the entire arrangement of the component carrier 100, the connection piece 140, and the second stack 150 is heated up. Thereby, the resin comprised in the connection piece 140 is cured at least partially and a permanent connection between the component carrier 100 and the second stack 150 is realized.

(16) During the re-lamination the non-deformable solid body 130 represents a barrier for viscous resin originating from the connection piece 140 and entering the lower second hole portion 124.

(17) As can be taken from FIG. 1G, in a next step an electric connector 170, e.g., a SERDES connector, is attached at the component carrier 100. Thereby, a contact terminal 172 of the electric connector 170 is inserted into the second hole portion 124. Due to the above-described sealing of the second hole portion 124 by means of the non-deformable solid body 130 the second hole portion 124 is free from any (resin) intrusions. Hence, the contact terminal 172 will have a good and reliable electric contact with the electrically conductive inner side wall 128 of the second hole portion 124.

(18) According to the nomenclature of this document the entire structure shown in FIG. 1G is denominated a component carrier assembly 160.

(19) It is again mentioned that a typical connector comprises more than one contact terminal. However, again for the sake of clarity of illustration only the one contact terminal 172 is shown in the drawing.

(20) FIG. 2 shows an alternative solution for fixing the non-deformable solid body 130 within the hole of the component carrier (compare FIG. 1D). The component carrier is now designated with reference numeral 200. Again, the non-deformable solid body is formed as a glass ball 130 which rests on a step within the hole. In FIG. 2 this step, which is located at the transition between the upper first hole portion 122 and the lower second hole portion 124, is not designated with a reference numeral.

(21) By contrast to the solution illustrated in FIG. 1D, in this embodiment the fixing medium 232 has been inserted into the upper first hole portion 122 before the glass ball 130 is inserted. Hence, the fixing medium 232 is located below the glass ball 130. According to the exemplary embodiment described here the glass ball 130 does not displace the fixing medium 232 to such an extent that it comes into direct mechanical contact with the edge of the step.

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

(23) 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.

REFERENCE SIGNS

(24) 100 component carrier 110 first stack 112 first electrically conductive layer structure(s) 114 first electrically insulating layer structure(s) 120 hole 122 first hole portion 124 second hole portion 125 step/ledge 128 electrically conductive inner side wall 130 non-deformable solid body/glass ball 132 fixing medium 140 connection piece/prepreg layer 150 second stack 152 second electrically conductive layer structure(s) 154 second electrically insulating layer structure 160 component carrier assembly 170 electric connector 172 contact terminal 200 component carrier 232 fixing medium