Multilayer substrate structure

Abstract

A multilayer substrate structure is provided, comprising a first substrate, a second substrate, a first conductive pillar, a second conductive pillar, and a first seed layer. The first substrate has a first through-hole, and the second substrate overlaps the first substrate and has a second through-hole corresponding to the first through-hole. The first conductive pillar at least partially fills the first through-hole, and the surface of the first conductive pillar facing the second through-hole has a first recess, the bottom of which is located on the side of a first virtual extension plane at the interface between the first and second substrates, closer to the first substrate. The second conductive pillar at least partially fills the second through-hole and extends into the first recess. The first seed layer is at least partially disposed between the second conductive pillar and the first recess and comprises a mixed metal.

Claims

1. A multilayer substrate structure, comprising: A first substrate having a first through hole; A second substrate, which overlaps with the first substrate and has a second through hole, the position of which corresponds to the first through hole; A first conductive post, at least partially filling the first through-hole, the surface of the first conductive post facing the second through-hole having a first recess, the bottom of the first recess being located on one side of a first virtual extension plane at the interface between the first substrate and the second substrate, near the first substrate; a second conductive post, at least partially filling the second through-hole and extending into the first recess; and a first seed layer, at least partially disposed between the second conductive post and the first recess, and comprising a mixed metal.

2. The multilayer substrate structure of claim 1, wherein the first seed layer comprises: a base at least partially connected to the base of the first recess, and the base having an inclination angle of less than 30 degrees relative to the first virtual extension plane; and a sidewall at least partially connected to the second substrate, and the sidewall having an inclination angle of greater than or equal to 30 degrees relative to the first virtual extension plane.

3. The multilayer substrate structure of claim 2, wherein the base is located on the side of the first virtual extension plane close to the first substrate.

4. The multilayer substrate structure of claim 1, wherein the width of the second conductive post in a direction parallel to one of the first virtual extension planes increases as it moves away from the first conductive post.

5. The multilayer substrate structure of claim 1, wherein the second conductive post is recessed into the interior of the second through hole relative to the side of the inner wall of the second through hole.

6. The multilayer substrate structure of claim 1, wherein the first conductive post comprises a plurality of interconnected metal grains, wherein the average diameter of the portion of the metal grains closer to the first recess is smaller, and the average diameter of another portion of the metal grains farther from the first recess is larger.

7. The multilayer substrate structure of claim 1, wherein the first conductive pillar and the second conductive pillar comprise copper, and the first seed layer comprises titanium and copper.

8. The multilayer substrate structure of claim 1, wherein the surface of the second substrate facing the first substrate has a second recess, and the first conductive post extends at least partially into the second recess.

9. The multilayer substrate structure of claim 8, wherein the first conductive post further includes a lug disposed in the second recess and sandwiched between the first substrate and the second substrate, the lug extending axially outward relative to the first through hole, and the depth of the first recess being greater than the thickness of the lug in the stacking direction of the first substrate and the second substrate.

10. The multilayer substrate structure of claim 1, further comprising: a third substrate disposed on the side of the first substrate away from the second substrate, the third substrate having a third through-hole, the third through-hole being positioned corresponding to the first through-hole; a third conductive post at least partially filling the third through-hole; and a second seed layer at least partially disposed between the third conductive post and the first conductive post and comprising a mixed metal, wherein... The surface of the first conductive post facing the third perforation has a third recess. The bottom of the third recess is located on one side of a second virtual extension plane near the first substrate at the interface between the first substrate and the third substrate. The third conductive post extends into the third recess, and the second seed layer connects to the third recess.

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