Abstract
A component carrier and a method of manufacturing the component carrier are presented. The component carrier comprises a stack having at least one electrically conductive layer structure and at least one electrically insulating layer structure, wherein the stack comprises i) a support layer structure comprising at least one through-hole; ii) a metal paste filling material in the through-hole; and iii) a metal pad provided on and extending from an exterior main surface of the support layer structure. The metal paste filling material in the through hole and the metal pad comprise at least partially the same material.
Claims
1. A component carrier, comprising: a stack having at least one electrically conductive layer structure and at least one electrically insulating layer structure, wherein the stack comprises: a support layer structure comprising at least one through-hole; a metal paste filling material in the through-hole; and a metal pad provided on and extending from an exterior main surface of the support layer structure; wherein the metal paste filing material in the through hole and the metal pad comprise at least partially the same material.
2. The component carrier according to claim 1, wherein a ratio between a thickness of the support layer structure and a minimum width of the through-hole is at least 5.
3. The component carrier according to claim 1, wherein the support layer structure is configured as a support plate.
4. The component carrier according to claim 1, wherein the support layer structure comprises or consists of one of the following: glass, ceramic, a semiconductor.
5. The component carrier according to claim 1, wherein the thickness of the support layer structure is at least 500 m.
6. The component carrier according to claim 1, wherein the metal paste filling material is in direct physical contact with sidewalls of the support layer structure delimiting the through-hole.
7. The component carrier according to claim 1, wherein the metal pad is a plating pad or wherein the component carrier further comprises a plating pad on top of the metal pad.
8. The component carrier according to claim 1, wherein at least one of the following features applies: wherein the through-hole has slanted sidewalls along its entire extension; wherein the through-hole has an hourglass shape; wherein the through-hole has a continuously tapering shape.
9. The component carrier according to claim 1, further comprising: a further metal pad on an opposing main surface of the support layer structure and on an opposing end of the metal paste filling material.
10. The component carrier according to claim 9, wherein the further metal pad is a plating pad or wherein the component carrier further comprises a further plating pad on top of the further metal pad.
11. The component carrier according to claim 1, wherein the metal paste filling material comprises metal particles and at least one of the following features: the metal paste filling material comprises nano metal particles; at least some of the metal particles are bound to each other; the metal paste filling material comprises or consists of sintered particles; at least some metal particles have a different material than the material of the metal pad; the metal paste filling material is a porous material.
12. The component carrier according to claim 1, configured as an inlay for a further component carrier layer stack.
13. The component carrier according to claim 1, wherein a portion of the metal paste filling material extends into the metal pad; and/or wherein a portion of the material of the metal pad extends into the metal paste filling material.
14. The component carrier according to claim 13, wherein the portion of the metal paste filling material extending into the metal pad or the portion of the metal pad extending into the metal paste filling material comprises a round shape along the stack thickness direction; and/or wherein the portion of the metal paste filling material extending into the metal pad or the portion of the metal pad extending into the metal paste filling material at least partially fills a void caused by an external roughness of the corresponding metal pad or metal paste filling material.
15. The component carrier according to claim 1, wherein the metal pad is made of the same material as the metal paste filling material.
16. A method of manufacturing a component carrier, wherein the method comprises: providing a stack with at least one electrically conductive layer structure, at least one electrically insulating layer structure, and a support layer structure; forming a through-hole in the support layer structure; filling the through-hole with a metal paste filling material, comprising metal particles and a bonding material; and forming a metal pad on and extending from an exterior main surface of the support layer structure; wherein the metal paste filling material in the through hole and the metal pad comprise at least partially the same material.
17. The method according to claim 16, further comprising: sintering the metal paste filling material after filling the metal paste filling material in the through-hole.
18. The method according to claim 17, further comprising: sintering or plating the metal pad.
19. The method according to claim 16, further comprising: forming a plating pad on top of the metal pad.
20. The method according to claim 16, wherein filling the through-hole with the metal paste filling material is performed by a roll coating machine.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0071] The aspects defined above, and further aspects of the present disclosure are apparent from the examples of embodiment to be described hereinafter and are explained with reference to these examples of embodiment.
[0072] FIG. 1A, FIG. 1B, and FIG. 1C show a method of manufacturing a component carrier according to an exemplary embodiment of the present disclosure. FIG. 1C illustrates a component carrier according to an exemplary embodiment of the present disclosure.
[0073] FIG. 2A, FIG. 2B, FIG. 2C, FIG. 2D, FIG. 2E, FIG. 2F, FIG. 2G, FIG. 2H, FIG. 21, FIG., 2J, and FIG. 2K show a method of manufacturing a component carrier according to an exemplary embodiment of the present disclosure in more detail.
[0074] FIG. 3 shows a roll coating machine for performing a method of manufacturing a component carrier according to an exemplary embodiment of the present disclosure.
[0075] FIG. 4, FIG. 5, and FIG. 6 respectively show a connection between metal paste filling material and metal pad according to exemplary embodiments of the present disclosure.
DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
[0076] The illustrations in the drawings are schematically presented. In different drawings, similar or identical elements are provided with the same reference signs.
[0077] Portions A to C of FIG. 1, i.e., FIG. 1A through FIG. 1C show a method of manufacturing a component carrier 100 according to an exemplary embodiment of the present disclosure.
[0078] FIG. 1A shows a support layer structure 110 (being here a component carrier preform 101) is provided that is configured as a glass core layer structure. Through holes 115 are formed through support layer structure 110 along the vertical direction (Z), being perpendicular to the directions (X, Y) of main extension of the component carrier 100. In this example, the through holes 115 have slanted sidewalls 112 (e.g., from laser drilling) and have been formed in two steps respectively: a first hole portion is formed from top to bottom, while a second hole portion is formed from bottom to top, thereby connecting to the first hole portion. Since the sidewalls 112 are tapering towards the center of the support layer structure 110, an hour-glass-like structure is obtained. The through-holes 115 have slanted sidewalls 112 along its entire extension and are continuously tapering.
[0079] FIG. 1B illustrates a metal paste filling material 120 is provided in the through holes 115 by roller coating or electroless deposition combined with electroplating, thereby filling them up completely. Besides the through-holes 115, a layer 132 of the metal paste filling material 120 is deposited on the top main surface 111 and the bottom main surface of the support layer structure 110. The layer 132 could comprise a seed metal layer formed by electroless deposition or sputtering.
[0080] FIG. 1C shows that the layer 132 of the metal paste filling material 120 is patterned, so that on top (and bottom) of each filled through-hole 115 a metal paste filling material pad 130 is arranged and in direct contact with the metal paste filling material 120 located in the through-hole 115. Further, on top of the metal paste filling material 120 (in particular the pad 130), a metal pad 140 is formed. Below the metal paste filling material 120 (in particular a further pad 131) at the bottom side, a further metal pad 141 is formed. The metal pad 140 and the metal paste filling material 120 comprise at least partially the same material, e.g., metal (copper) particles. In one example, the metal pad 140 is formed from a metal paste material, while in another example, the metal pad 140 is formed by plating. In another example, the extension of the metal pad 140 in main extension (along the plane defined by the X,Y directions) is the same as the extension of the further metal pad 141. Alternatively, the extension of the metal pad 140 in main extension (X,Y) is larger than the extension of the further metal pad 141 (not shown). The metal paste filling material 120 is sintered to form a stable interconnection through the support layer structure 110. The support layer structure 110 forms part of a layer stack (not shown) in the final component carrier product 100. The metal paste filling material 120 is in direct physical contact with sidewalls 112 of the support layer structure 110 delimiting the through-hole 115 without a plating structure (or a seed layer) in between.
[0081] In other words, the metal paste filling material is connecting with sidewalls 112 through another thin metal layer formed by electroless deposition or sputtering (the thin metal layer is directly connecting with the sidewall and the thin metal layer is directly connecting with the metal paste filling material). With such a method, the electrical conductivity of the component carrier or the support layer structure (it could be a glass core) will be improved.
[0082] It can be seen that a ratio between a thickness t of the support layer structure 110 and a minimum width w of the through-hole 115 is at least 5, i.e., there is a high aspect ratio. In a specific example, the thickness t of the support layer structure 110 is at least 500 m, in particular in a range from 500 m to 2000 m.
[0083] FIG. 2A through FIG. 2K illustrate show a method of manufacturing a component carrier 100 according to an exemplary embodiment of the present disclosure in more detail.
[0084] As shown in FIG. 2A there is provided a support layer structure 110 (being a glass substrate or glass core) as a component carrier preform 101. Through-holes 115 are formed as described above using a laser (e.g., CO.sub.2, UV, excimer). An optional surface pre-treatment can be performed (e.g., SiN, coupling, plasma, roughening, etc.).
[0085] FIG. 2B shows that the through-holes 115 are filled with metal paste filling material (so-called plugging) 120, comprising, e.g., copper nano metal particles (NMP) and a bonding material, such as resin or other material to improve adhesion among all the elements or compounds inside of the metal paste filling material and mechanical stability of the metal paste filling material. Additionally, the metal paste filling material can also comprise a solvent. Then, a (vacuum) sintering step is performed to sinter the metal paste filling material 120 in the through-holes 115. Thereby, the compounds of metal paste filling material will be bonded together and the material will realize the electrical conductivity as conductors.
[0086] FIG. 2C shows further metal paste filling material 120 is provided on the top and the bottom main surface of the support layer structure 110, thereby forming a layer 132 of metal paste filling material. The provision can be done for example by roll coating (see FIG. 3).
[0087] FIG. 2D illustrates a further (vacuum) sintering step is performed to sinter also the layer 132 of metal paste filling material. Then, a metal layer (e.g., copper) 142 is formed on top of the layer 132 of metal paste filling material. The formation of the metal layer 142 can be done in an electro-less manner and/or by plating. Plating can also be done on an electro-less seed layer (not shown).
[0088] FIG. 2E shows that in order to pattern the metal layer 142, a dielectric film 145 is provided by lamination as a protection at the locations where the metal layer 142 should remain.
[0089] FIG. 2F illustrates that at the location where no dielectric film 145 is situated, the metal layer 142 and the layer 132 of metal paste filling material is removed, e.g., by etching. Then, the dielectric film 145 is stripped. The remaining component carrier 100 is comparable to the one shown in FIG. 1C where on top (and bottom) of each through-hole 115 (being filled by sintered metal paste filling material 120), there is arranged a metal paste filling material pad 130 and a metal pad 140. In this embodiment, the metal pad 140 is a plating pad that originates from patterning the metal layer 142.
[0090] FIG. 2G through FIG. 2J illustrate an alternative manufacturing process.
[0091] In FIG. 2G the two main surfaces of the support layer structure 110 are covered respectively with a dielectric image film 145 (e.g., thinner than 10 m) at surface portion between the through-holes 115.
[0092] In FIG. 2H the through-holes 115 are filled with the metal paste filling material 120 and metal paste filling material pads 130 are formed at the surface portions not covered by the dielectric image film 145. A sintering step (e.g., CO.sub.2 laser sintering or oven cure) is performed to sinter the metal paste filling material 120 in the through-holes 115.
[0093] In FIG. 21 the main surfaces of the support layer structure 110 are grinded to make the metal paste filling material pads 130 flush with the dielectric image film 145.
[0094] In FIG. 2J the dielectric image film 145 is stripped, leaving behind the metal paste filling material pads 130. In this example, the metal paste filling material pads 130 can also be seen as metal pads 140. The obtained component carrier 100 is comparable with the one shown in FIG. 2F with the difference that the metal paste filling material pads 130 can be seen as the metal pads 140, while in FIG. 2F, the metal pads 140 are separate structures formed on the metal paste filling material pads 130.
[0095] FIG. 2K illustrates a process step of filling the through-holes 115 with the metal paste filling material 120 using a stencil 152 and a screen.
[0096] FIG. 3 shows a roll coating machine 150 for performing a method of manufacturing a component carrier 100 according to an exemplary embodiment of the present disclosure. A component carrier preform 101 (e.g., a panel comprising the support layer structure 110) is moved through the roll coating machine 150 in a process direction P, in this example in the vertical direction (from bottom to top). However, the process direction P (coating direction) can also be different, for example in the horizontal direction (perpendicular). By applying the coating in two directions together, the thickness of the coating layer could be more uniform.
[0097] The roll coating machine 150 comprises two rubber rollers 151 that rotate respectively and thereby transport the component carrier preform 101 in the process direction P. Squeegees 152 are used to provide metal paste filling material 120 to the rubber rollers 151, respectively, which transfer the metal paste filling material 120 to the component carrier preform 101 and press it into the through holes 115 thereof.
[0098] FIGS. 4 to 6 respectively show a connection between metal paste filling material 120 and metal pad 140 according to exemplary embodiments of the present disclosure.
[0099] FIG. 4 illustrates an embodiment of the component carrier 100 where the support layer structure 110 with a through-hole 115 is filled with the metal paste filling material 120. On the upper main surface 111 of the support layer structure 110, a metal seed layer 160 has been deposited and on top of the metal paste filling material 120, a metal pad 140 (here a plated metal pad) is arranged. A portion 146 of the material of the metal pad 140 extends into the metal paste filling material 120 in a dome-like shape (convex) and internally with respect to the exterior main surface 111 of the support layer structure 110 (into the support layer structure 110). During the manufacturing process, a metal paste filling material layer 132 (see, e.g., FIG. 2C) has been removed from the exterior main surface 111 by grinding, thereby roughening said exterior main surface 111. The metal seed layer 160 can thus adhere to the support layer structure 110 in a stable manner. Yet, less metal paste filling material 120 than that required to entirely fill the through-hole 115 is provided, resulting in a dimple/recess. The metal seed layer 160 follows the shape of the dimple, however, this defect is cured by the portion 146 of the material of the metal pad 140 that extends into the metal paste filling material 120. In other words, the portion 146 of the metal pad 140 extending into the metal paste filling material 120 at least partially fills a void caused by an external roughness of the corresponding metal paste filling material 120.
[0100] FIG. 5 illustrates an embodiment of the component carrier 100 where the support layer structure 110 with a through-hole 115 is filled with the metal paste filling material 120 and an exterior main surface 111 is covered with a metal paste filling material layer 132 (compare FIG. 2C). In this specific example, a seed layer 160 has been applied at the through-hole sidewalls and the exterior main surface 111. The optional seed layer 160 can be provided, e.g., by sputtering and can promote adhesion between the support layer structure (glass) and the metal paste filling material 120. On top of the metal paste filling material 120, a metal pad 140 (here a plated metal pad) is arranged. Like in the example of FIG. 4, an undesired dimple/recess has been formed between the metal paste filling material 120 and the metal pad 140. However, this defect is cured by the portion 146 of the material of the metal pad 140 that extends into the metal paste filling material 120.
[0101] FIG. 6 illustrates an embodiment of the component carrier 100 which is very similar to the one described for FIG. 5, yet with the difference being that an excess amount of the metal paste filling material 120 is present at the top of the through-hole 115. Accordingly, a concave dome-like shape (a round shape along the stack thickness direction Z), of metal paste filling material 120 is formed and said portion 130 (can be seen as a metal paste filling material pad) of the metal paste filling material 120 extends into the metal pad 140.
REFERENCE SIGNS
[0102] 100 Component carrier [0103] 101 Component carrier preform, panel [0104] 111 Exterior main surface [0105] 115 Through hole [0106] 120 Metal paste filling material [0107] 130 Metal paste filling material pad [0108] 131 Further metal paste filling material pad [0109] 132 Metal paste filling material layer [0110] 140 Metal pad [0111] 141 Further metal pad [0112] 142 Metal/plating layer [0113] 145 Dielectric film [0114] 146 Extension of metal pad [0115] 150 Roll coating machine [0116] 151 Rubber roller [0117] 152 Squeegee [0118] 160 Seed layer
