Package substrate including core with trench vias and planes
Embodiments disclosed herein comprise package substrates and methods of forming package substrates. In an embodiment, a package substrate comprises a core substrate. A hole is disposed into the core substrate, and a via is disposed in the hole. In an embodiment, the via completely fills the hole. In an embodiment, a method of forming a package substrate comprises exposing a region of a core substrate with a laser. In an embodiment, the laser changes the morphology of the exposed region. The method may further comprise etching the core substrate, where the exposed region etches at a faster rate than the remainder of the core substrate to form a hole in the core substrate. The method may further comprise disposing a via in the hole.
1 . A package substrate, comprising:
a core substrate;
a hole into the core substrate, and a trench into the core substrate, the trench laterally spaced apart from the hole, wherein the hole does not pass entirely through a thickness of the core substrate;
a via in the hole, wherein the via completely fills the hole, and wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
a via plane in the trench.
2 . The package substrate of claim 1 wherein the core substrate comprises a glass, a silicon, a ceramic, or a nonconductive semiconductor.
3 . The package substrate of claim 2 , wherein the core substrate comprises the glass, and wherein the glass is a photo-definable glass.
4 . The package substrate of claim 1 , wherein the hole passes entirely through a thickness of the core substrate.
5 . The package substrate of claim 1 , wherein the hole has sidewalls that are sloped.
6 . The package substrate of claim 5 , wherein the sidewalls have a slope that is approximately 10° or less.
7 . The package substrate of claim 5 , wherein the sidewalls form an hourglass shaped cross-section.
8 . The package substrate of claim 1 wherein the hole is elongated to form a trench into the core substrate.
9 . The package substrate of claim 1 , wherein the hole is circular.
10 . The package substrate of claim 1 , wherein the hole is rectangular.
11 . The package substrate of claim 1 , wherein the hole is rectangular with rounded ends.
12 . The package substrate of claim 1 , further comprising a second hole and a second via filling the second hole.
13 . The package substrate of claim 12 , wherein the second hole intersects the first hole.
14 . The package substrate of claim 1 , further comprising:
a buildup layer over a surface of the core substrate.
15 . The package substrate of claim 1 , wherein the core substrate has a thickness that is approximately 200 μm or greater, and wherein a diameter of the hole is approximately 50 μm or smaller.
16 . A method of forming a package substrate, comprising:
exposing a region of a core substrate with a laser, wherein the laser changes the morphology of the exposed region;
etching the core substrate, wherein the exposed region etches at a faster rate than the remainder of the core substrate to form a hole in the core substrate, and to form a trench into the core substrate, the trench laterally spaced apart from the hole;
forming a via in the hole, wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
forming a via plane in the trench.
17 . The method of claim 16 , wherein a first surface of the core substrate and a second surface of the core substrate are exposed with the laser.
18 . The method of claim 17 , wherein the hole has an hourglass shaped cross-section.
19 . The method of claim 16 , wherein the hole passes through an entire thickness of the core substrate.
20 . The method of claim 16 , wherein the hole does not pass through an entire thickness of the core substrate.
21 . An electronic package, comprising:
a package substrate, wherein the package substrate comprises:
a core substrate that comprises a glass section with a via through the glass section, wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate, and the glass section having a via plane through the glass section, the via plane laterally spaced apart from the via; and
a buildup layer over the core substrate; and
a die coupled to the package substrate, wherein the die is electrically coupled to the via; and
a board, wherein the package substrate is coupled to the board.
22 . The electronic package of claim 21 , wherein the glass section is embedded within the core substrate.
23 . The electronic package of claim 21 , wherein an entirety of the core substrate comprises the glass section.
24 . The electronic package of claim 21 , wherein the via has an hourglass shaped cross-section.
25 . A package substrate, comprising:
a core substrate, wherein the core substrate comprises a glass, and wherein the glass is a photo-definable glass;
a hole into the core substrate, and a trench into the core substrate, the trench laterally spaced apart from the hole;
a via in the hole, wherein the via completely fills the hole, and wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
a via plane in the trench.
26 . A package substrate, comprising:
a core substrate;
a hole into the core substrate, wherein the hole has sidewalls that are sloped, and a trench into the core substrate, the trench laterally spaced apart from the hole;
a via in the hole, wherein the via completely fills the hole, and wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
a via plane in the trench.
27 . The package substrate of claim 26 , wherein the sidewalls have a slope that is approximately 10° or less.
28 . The package substrate of claim 26 , wherein the sidewalls form an hourglass shaped cross-section.
29 . A package substrate, comprising:
a core substrate;
a hole into the core substrate, wherein the hole is elongated to form a trench into the core substrate, and a trench into the core substrate, the trench laterally spaced apart from the hole;
a via in the hole, wherein the via completely fills the hole, and wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
a via plane in the trench.
30 . A package substrate, comprising:
a core substrate;
a hole into the core substrate, wherein the hole is rectangular, and a trench into the core substrate, the trench laterally spaced apart from the hole;
a via in the hole, wherein the via completely fills the hole, and wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
a via plane in the trench.
31 . A package substrate, comprising:
a core substrate;
a hole into the core substrate, wherein the hole is rectangular with rounded ends, and a trench into the core substrate, the trench laterally spaced apart from the hole;
a via in the hole, wherein the via completely fills the hole, and wherein the via has an outermost surface at a same level as an outermost surface of the core substrate, the outermost surface of the via having a maximum diameter less than a vertical thickness of the via through the core substrate; and
a via plane in the trench.