Method for fabricating package structure

Abstract

A package structure is provided, which includes: a frame having a cavity penetrating therethrough; a semiconductor chip received in the cavity of the frame, wherein the semiconductor chip has opposite active and inactive surfaces exposed from the cavity of the frame; a dielectric layer formed in the cavity to contact and fix in position the semiconductor chip, wherein a surface of the dielectric layer is flush with a first surface of the frame toward which the active surface of the semiconductor chip faces; and a circuit structure formed on the surface of the dielectric layer flush with the first surface of the frame and electrically connected to the active surface of the semiconductor chip, thereby saving the fabrication cost and reducing the thickness of the package structure.

Claims

1. A method for fabricating a package structure, comprising the steps of: disposing at least a semiconductor chip on a carrier; disposing a cover board on the carrier, wherein the cover board has a recessed portion facing the carrier for receiving the semiconductor chip therein; removing a portion of the cover board to expose the semiconductor chip, such that a remaining portion of the cover board forms a frame having a cavity formed from the recessed portion, wherein the carrier has opposite first and second surfaces, the frame is formed on the first surface of the carrier and the cavity exposes a portion of the first surface of the carrier, the frame and the carrier are not integrally formed, the semiconductor chip is received in the cavity of the frame and disposed on the first surface of the carrier and has an inactive surface attached to the first surface of the carrier and an active surface opposite to the inactive surface, and a dielectric layer is filled in the cavity to contact and fix in position the semiconductor chip; forming a circuit structure on the dielectric layer, wherein the circuit structure is electrically connected to the active surface of the semiconductor chip; and removing the carrier to expose the inactive surface of the semiconductor chip.

2. The method of claim 1, before removing the carrier, further comprising forming a plurality of conductive elements on and electrically connected to the circuit structure.

3. The method of claim 2, before removing the carrier, further comprising disposing a substrate on and electrically connected to the conductive elements.

4. The method of claim 1, further comprising: after removing the portion of the cover board to expose the semiconductor chip, forming in the cavity of the frame the dielectric layer with at least a portion of the active surface of the semiconductor chip exposed therefrom.

5. The method of claim 4, wherein the cover board is disposed on the carrier by fusion bonding or adhesion.

6. The method of claim 1, wherein a plurality of the semiconductor chips are received in the cavity of the frame and have same or different heights.

7. The method of claim 1, wherein the semiconductor chip is disposed on the first surface of the carrier through a die attachment film, and removing the carrier further comprises removing the die attachment film.

8. The method of claim 1, wherein the semiconductor chip is disposed on the first surface of the carrier through a promoter layer and a photosensitive material layer sequentially formed on the first surface of the carrier, and removing the carrier further comprises removing the promoter layer and the photosensitive material layer.

9. The method of claim 8, wherein the photosensitive material layer is made of a photosensitive spin-on dielectric (PSOD) material, a photodefinable material or a photosensitive patternable material.

10. The method of claim 1, wherein the frame is higher than the semiconductor chip and the dielectric layer covers the frame and the semiconductor chip, or the frame is higher than the semiconductor chip, but the dielectric layer only covers the semiconductor chip and is flush with a surface of the frame toward which the active surface of the semiconductor chip faces.

11. The method of claim 1, wherein the frame and the semiconductor chip have the same height, and the dielectric layer is flush with a surface of the frame toward which the active surface of the semiconductor chip faces.

12. The method of claim 1, wherein the circuit structure is in contact with the active surface of the semiconductor chip or is electrically connected to the active surface of the semiconductor chip through a plurality of conductors.

13. The method of claim 12, wherein the circuit structure is electrically connected to the active surface of the semiconductor chip through a plurality of conductors, and the circuit structure has at least a circuit layer that is formed simultaneously with or separately from the conductors.

14. The method of claim 1, wherein the dielectric layer is made of an organic or inorganic material.

15. The method of claim 14, wherein the organic material is polyimide, PBO (Polybenzobisoxazole) or BCB (Benzocyclobutene), and the inorganic material is silicon oxide or silicon nitride.

16. The method of claim 1, further comprising the steps of: coupling the semiconductor chip to a bottom surface of the recessed portion, such that the cover board is positioned over and not in contact with the carrier; forming the dielectric layer in the recessed portion and between the cover board and the carrier to contact and fix in position the semiconductor chip; and after forming the dielectric layer in the recessed portion and between the cover board and the carrier, removing the portion of the cover board to expose the semiconductor chip, such that the remaining portion of the cover board forms the frame having the cavity formed from the recessed portion.

17. The method of claim 16, wherein the circuit structure is in contact with the active surface of the semiconductor chip or is electrically connected to the active surface of the semiconductor chip through a plurality of conductors.

18. The method of claim 1, after forming the circuit structure, further comprising performing a singulation process.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic cross-sectional view of a conventional package structure having a silicon interposer;

(2) FIGS. 2A to 2L are schematic cross-sectional views showing a method for fabricating a package structure according to the present invention, wherein FIG. 2C shows another embodiment of FIG. 2C, FIGS. 2D and 2D show different embodiments of FIG. 2D, FIG. 2L shows a package structure continued from FIG. 2D, and FIG. 2L shows another embodiment of the package structure;

(3) FIGS. 3A to 3B are schematic cross-sectional views showing different embodiments of the package structure of the present invention; and

(4) FIGS. 4A to 4E are schematic cross-sectional views showing another method for fabricating a package structure according to the present invention, wherein FIGS. 4D and 4E show different embodiments of FIGS. 4D and 4E, respectively.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(5) The following illustrative embodiments are provided to illustrate the disclosure of the present invention, these and other advantages and effects can be apparent to those in the art after reading this specification.

(6) It should be noted that all the drawings are not intended to limit the present invention. Various modifications and variations can be made without departing from the spirit of the present invention. Further, terms such as first, second, on, a etc. are merely for illustrative purposes and should not be construed to limit the scope of the present invention.

(7) FIGS. 2A to 2L are schematic cross-sectional views showing a method for fabricating a package structure according to the invention, wherein FIG. 2C shows another embodiment of FIG. 2C, and FIGS. 2D and 2D show different embodiments of FIG. 2D.

(8) Referring to FIG. 2A, a carrier 20 and a cover board 21 are provided. The carrier 20 has a first surface 20a and a second surface 20b opposite to the first surface 20a. The cover board 21 has a recessed portion 210. The carrier 20 and the cover board 21 are not integrally formed.

(9) The carrier 20 and the cover board 21 can be made of an organic material such as BCB (Benzocyclobutene) or polyimide, or an inorganic material such as SiC or SiO.sub.2. The carrier 20 and the cover board 21 can be made of metal, glass, ceramic, or a semiconductor material such as Si or GaAs.

(10) Referring to FIG. 2B, one or more semiconductor chips 22 are disposed on the first surface 20a of the carrier 20. The semiconductor chips 22 can have different sizes and thicknesses (also called heights). Each of the semiconductor chips 22 has opposite active and inactive surfaces 22a, 22b and is disposed on the first surface 20a of the carrier 20 via the inactive surface 22b thereof. In an embodiment, an adhesive layer or a die attachment film (not shown) is formed for disposing the semiconductor chips 22 on the first surface 20a of the carrier 20. In another embodiment, a promoter layer (not shown) and a photosensitive material layer (not shown) are sequentially formed on the first surface 20a of the carrier 20 for disposing the semiconductor chips 22 on the first surface 20a of the carrier 20. The promoter layer causes the photosensitive material layer such as polybenzobisoxazole (PBO) to be more adhesive to the carrier 20 than to the semiconductor chips 22.

(11) The photosensitive material layer can be a photosensitive spin-on dielectric (PSOD) material such as a photodefinable polybenzobisoxazole (PBO) precursor, or a photodefinable material such as polyimide precursor, or a photosensitive patternable material such as a polysilsesquiazane composition.

(12) Then, the cover board 21 is disposed on the carrier 20, with the recessed portion 210 facing the carrier 20 for receiving the semiconductor chips 22 therein. The cover board 21 is disposed on the carrier 20 by fusion bonding or adhesion.

(13) Referring to FIG. 2C, the cover board 21 is partially removed by grinding so as to expose the semiconductor chips 22. The remaining portion of the cover board 21 is used to form a frame 21 having a cavity 210 formed from the recessed portion 210, allowing a portion of the first surface 20a of the carrier 20 to be exposed from the cavity 210. In the present embodiment, the frame 21 is higher than the semiconductor chips 22.

(14) In another embodiment, referring to FIG. 2C, the frame 21 and the semiconductor chips 22 have the same height.

(15) Referring to FIG. 2D, a dielectric layer 23 is formed on the frame 21 and the active surfaces 22a of the semiconductor chips 22 and filled in the cavity 210 so as to cover the frame 21 and the semiconductor chips 22. The dielectric layer 23 can be a photosensitive dry film. The dielectric layer 23 can be made of an organic material such as polyimide, PBO (Polybenzobisoxazole) or BCB (Benzocyclobutene), or an inorganic material such as silicon oxide or silicon nitride.

(16) In another embodiment, referring to FIG. 2D, the frame 21 and the dielectric layer 23 of FIG. 2D are partially removed by grinding so as to make a surface of the dielectric layer 23 flush with a first surface of the frame 21 toward which the active surfaces 22a of the semiconductor chips 22 faces.

(17) In a further embodiment, referring to FIG. 2D, the frame 21 is higher than the semiconductor chips 22, such that the dielectric layer 23 covers the active surface 22a of the semiconductor chips 22 and a surface of he dielectric layer 23 is flush with the first surface of the frame 21 toward which the active surfaces 22a of the semiconductor chips 22 faces. Alternatively, the dielectric layer 23 of FIG. 2D can be partially removed by grinding so as for a surface of the dielectric layer 23 to be flush with the surface of the frame 21 toward which the active surfaces 22a of the semiconductor chips 22 faces.

(18) Referring to FIG. 2E, continued from FIG. 2D, a plurality of openings 230 are formed in the dielectric layer 23 to expose the active surfaces 22a of the semiconductor chips 22.

(19) Referring to FIG. 2F, a plurality of conductors 24 are formed in the openings 230 and electrically connected to the active surfaces 22a of the semiconductor chips 22.

(20) Referring to FIG. 2G, a circuit structure 25, for example, a redistribution layer, is formed on the dielectric layer 23 and electrically connected to the conductors 24 and the active surfaces 22a of the semiconductor chips 22. The redistribution layer can have a single circuit layer or a plurality of circuit layers, for example, three circuit layers of FIG. 2G. The conductors 24 and the first circuit layer in contact with the conductors 24 can be separately formed as in FIGS. 2F and 2G or simultaneously formed.

(21) Referring to FIG. 2H, an insulating layer 26 having a plurality of openings 260 is formed on the circuit structure 25.

(22) Referring to FIG. 2I, a plurality of conductive elements 27 such as solder balls are formed in the openings 260 of the insulating layer 26.

(23) Referring to FIG. 2J, a singulation process is performed to form a package structure of the invention.

(24) Referring to FIG. 2K, a substrate 28 is disposed on and electrically connected to the circuit structure 25 through the conductive elements 27. The substrate 28 can be a packaging substrate.

(25) Referring to FIG. 2L, the carrier 20 is removed to expose the inactive surfaces 22b of the semiconductor chips 22. As such, a carrier-free package structure is obtained. In addition, if the die attachment film, the promoter layer or the photosensitive material layer is formed in FIG. 2B, removing the carrier 20 further includes removing these materials.

(26) In another embodiment, a package structure of FIG. 2L is obtained if the process is continued from FIG. 2D. Referring to FIG. 2L, the dielectric layer 23 is flush with the surface of the frame 21 at the side of the active surfaces 22a of the semiconductor chips 22 and covers the active surfaces 22a of the semiconductor chips 22. A plurality of conductors 24 are formed in the dielectric layer 23 and electrically connected to the active surfaces 22a of the semiconductor chips 22. The circuit structure 25 contacts the dielectric layer 23 and is electrically connected to the conductors 24. In a further embodiment, referring to FIG. 2L, the package structure further has the carrier 20 that is disposed on the frame 21, the dielectric layer 23 and the inactive surfaces 22b of the semiconductor chips 22. The frame 21 and the carrier 20 are not integrally formed.

(27) FIGS. 3A to 3B are schematic cross-sectional views showing different embodiments of the package structure of the invention. Referring to FIG. 3A that is continued from step of FIG. 2D, after the dielectric layer 23 is formed, a built-up dielectric layer 23 is formed on the active surfaces 22a of the semiconductor chips 22 and the frame 21 and a plurality of conductors 24 are formed in the built-up dielectric layer 23. Thereafter, the steps of FIGS. 2G to 2L are performed to form the circuit structure 25 electrically connecting the conductors 24, the insulating layer 26 and the conductive elements 27 and disposing on the substrate 28.

(28) FIG. 3B shows another embodiment of FIG. 3A. Referring to FIG. 3B, the built-up dielectric layer 23 and the conductors 24 of FIG. 3A are dispensed with, and the circuit structure 25 is directly electrically connected to the active surfaces 22a of the semiconductor chips 22. In the present embodiment, both the active and inactive surfaces 22a, 22b of the semiconductor chips 22 are completely exposed from the dielectric layer 23, and the circuit structure 25 is in contact and electrical connection with the active surfaces 22a of the semiconductor chips 22.

(29) Further, referring to FIGS. 3A and 3B, the package structure has the carrier 20.

(30) FIGS. 4A to 4E are schematic cross-sectional views showing a method for fabricating a package structure according to another embodiment of the invention.

(31) Referring to FIG. 4A, a carrier 20 is provided, which has a plurality of semiconductor chips 22 disposed thereon and a cover board 21 having a recessed portion 210 facing the carrier 20. The semiconductor chips 22 are received in the recessed portion and attached to a bottom surface of the recessed portion 210 of the cover board 21 so as to allow the cover board 21 to be positioned over and not in contact with the carrier 20.

(32) Referring to FIG. 4B, a dielectric layer 23 is formed in the recessed portion 210 and between the cover board 21 and the carrier 20 so as to contact and fix in position the semiconductor chips 22.

(33) Referring to FIG. 4C, the cover board 21 is partially removed to expose the semiconductor chips 22. The remaining portion of the cover board 21 forms a frame 21.

(34) Then, referring to FIG. 4D, a circuit structure 25, an insulating layer 26 and a plurality of conductive elements 27 are sequentially formed on the dielectric layer 23.

(35) Alternatively, referring to FIG. 4D, a built-up dielectric layer 23 is formed on the dielectric layer 23 first and then a circuit structure 25, an insulating layer 26 and a plurality of conductive elements 27 are sequentially formed on the built-up dielectric layer 23.

(36) Referring to FIGS. 4E and 4E, a substrate 28 is disposed on and electrically connected to the circuit structure 25 through a plurality of conductive elements 27 and then the carrier 20 is removed to expose the inactive surfaces 22b of the semiconductor chips 22. As such, a package structure of the invention is obtained.

(37) The invention further provides a package structure, which has: a frame 21 having a cavity 210 penetrating therethrough; at least a semiconductor chip 22 received in the cavity 210 of the frame 21, wherein the semiconductor chip 22 has opposite active and inactive surfaces 22a, 22b exposed from the cavity 210 of the frame 21; a dielectric layer 23 formed in the cavity 210 to contact and fix in position the semiconductor chip 22, wherein a surface of the dielectric layer 23 is flush with a first surface of the frame 21 toward which the active surface 22a of the semiconductor chip 22 faces; and a circuit structure 25 formed on the surface of the dielectric layer 23 flush with the first surface of the frame 21 and electrically connected to the active surface 22a of the semiconductor chip 22.

(38) In an embodiment, referring to FIGS. 2J and 2K, the package structure further has a carrier 20 disposed on a second surface of the frame 21, the dielectric layer 23 and the inactive surface 22b of the semiconductor chip 22, wherein the frame 21 and the carrier 20 are not integrally formed.

(39) In an embodiment, referring to FIG. 2L, the dielectric layer 23 covers the active surface 22a of the semiconductor chip 22. The package structure further has a plurality of conductors 24 formed in the dielectric layer 23 and electrically connected to the active surface 22a of the semiconductor chip 22. The circuit structure 25 contacts the dielectric layer 23 and is electrically connected to the conductors 24.

(40) Referring to FIG. 2L, the dielectric layer 23 covers the active surface 22a of the semiconductor chip 22 and is flush with the surface of the frame 21 at the side of the active surface 22a of the semiconductor chip 22. The package structure further has a carrier 20, and a plurality of conductors 24 formed in the dielectric layer 23 and electrically connected to the active surface 22a of the semiconductor chip 22. The circuit structure 25 contacts the dielectric layer 23 and is electrically connected to the conductors 24.

(41) In another embodiment, both the active and inactive surfaces 22a, 22b of the semiconductor chip 22 are completely exposed from the dielectric layer 23. The package structure further has a built-up dielectric layer 23 formed on the dielectric layer 23 at the side of the active surface 22a of the semiconductor chip 22 and a plurality of conductors 24 formed in the built-up dielectric layer 23. The circuit structure 25 is formed on the built-up dielectric layer 23 and electrically connected to the active surface 22a of the semiconductor chip 22 through the conductors 24. In the present embodiment, referring to FIG. 3A, the frame 21, the semiconductor chip 22 and the dielectric layer 23 have the same height. In an alternative embodiment, referring to FIG. 4E, the frame 21 is less in thickness than the semiconductor chip 22, and the dielectric layer 23 is further formed on the second surface of the frame 21 toward which the inactive surface 22b of the semiconductor chip 22 faces.

(42) In another embodiment, both the active and inactive surfaces 22a, 22b of the semiconductor chip 22 are completely exposed from the dielectric layer 23. The circuit structure 25 is in contact and electrical connection with the active surface 22a of the semiconductor chip 22. Referring to FIG. 3B, the frame 21, the semiconductor chip 22 and the dielectric layer 23 have the same height. In an alternative embodiment, referring to FIG. 4E, the frame 21 is less in thickness than the semiconductor chip 22, and the dielectric layer 23 is further formed on the second surface of the frame 21 toward which the inactive surface 22b of the semiconductor chip 22 faces.

(43) Referring to FIG. 3A, the package structure has a carrier 20. Both the active and inactive surfaces 22a, 22b of the semiconductor chip 22 are completely exposed from the dielectric layer 23. The package structure further has a built-up dielectric layer 23 formed between the dielectric layer 23 and the circuit structure 25 and a plurality of conductors 24 formed in the built-up dielectric layer 23. The circuit structure 25 formed on the built-up dielectric layer 23 is electrically connected to the active surface 22a of the semiconductor chip 22 through the conductors 24.

(44) Referring to HG 3B, the package structure has a carrier 20. Both the active and inactive surfaces 22a, 22b of the semiconductor chip 22 are completely exposed from the dielectric layer 23. The circuit structure 25 is in contact and electrical connection with the active surface 22a of the semiconductor chip 22.

(45) The package structure can further have a plurality of conductive elements 27 formed on the circuit structure 25 and electrically connected the circuit structure 25.

(46) The package structure can further have a substrate 28 disposed on and electrically connected to the circuit structure 25 through the conductive elements 27.

(47) Therefore, the invention replaces the conventional interposer with a cheap circuit structure and dispenses with the conventional solder balls formed between the semiconductor chip and the interposer, thereby effectively reducing the fabrication cost and the thickness of the package structure. Further, since the carrier provides a rigid support to the package structure during formation of the circuit structure or disposing of the substrate, the invention avoids warpage of the package structure. Furthermore, the inactive surface of the semiconductor chip can be exposed for heat dissipation. In addition, since the semiconductor chip is fixed by the frame of the invention, the invention prevents positional deviation of the semiconductor chip during the fabrication process.

(48) The above-described descriptions of the detailed embodiments are only to illustrate the preferred implementation according to the present invention, and it is not to limit the scope of the present invention. Accordingly, all modifications and variations completed by those with ordinary skill in the art should fall within the scope of present invention defined by the appended claims.