Package substrate and fabricating method thereof

Abstract

A packaging substrate includes a circuit structure having opposing ball-mounted and layer-adding sides, a wiring structure formed on the layer-adding side of the circuit structure, and a fixing structure extending from and through the circuit structure to prevent interlayer delamination of the packaging substrate and improve the yield and reliability of the packaging substrate. This disclosure also provides a method for manufacturing the packaging substrate.

Claims

1. A packaging substrate, comprising: The circuit structure has opposing ball-planting sides and add-on sides, and the circuit structure includes: a core layer having opposing first and second sides, a plurality of through holes communicating with the first and second sides, and at least one fixing hole; a bonding layer formed on the first and second sides of the core layer, the walls of the through holes and the fixing hole; a plurality of conductive posts formed in each of the through holes; and a circuit layer formed on the opposing first and second sides of the core layer and electrically connected to the conductive posts, wherein the first side corresponds to the ball-planting side, and the second side corresponds to the add-on side; a wiring structure formed on the add-on side of the circuit structure; and a fixing structure including a support portion formed in the fixing hole, an extension portion located in the wiring structure and correspondingly formed on the support portion, such that the fixing structure extends from the circuit structure and through the wiring structure, wherein the support portion is not electrically connected to the circuit layer.

2. The packaging substrate as described in claim 1, wherein, The circuit structure includes an insulating layer formed on the bonding layer and filled in the plurality of through holes and the fixing hole, wherein the plurality of conductive pillars penetrate the insulating layer in the plurality of through holes, and the fixing structure penetrates the insulating layer in the fixing hole.

3. The packaging substrate as described in claim 2, wherein, The fixing structure includes a plurality of fastening portions formed on the extension and between the support and the extension, wherein the width of the fastening portion between the support and the extension is greater than the diameter of the support.

4. The packaging substrate as described in claim 3, wherein, The outermost wiring layer on the added layer side has a plurality of electrical contact pads, and the width of the plurality of electrical contact pads is smaller than the width of the plurality of fastening portions. The package substrate also includes a plurality of solder resist layers, which are respectively formed on the outermost side of the circuit structure and wiring structure to cover the fastening portions of the outermost wiring layer.

5. The packaging substrate as described in claim 1, wherein, The bonding layer is an organic or inorganic coating, wherein the material forming the organic coating is a polymer and the thickness of the organic coating is 1 nanometer to 100 micrometers, and the material forming the inorganic coating is silica fume with a diameter of 20 to 50 micrometers and a roughness Ra of 1 to 200 micrometers.

6. The packaging substrate as described in claim 5, wherein, The polymer is selected from at least one of the group consisting of polyoxymethylene, polyamide and parylene.

7. The packaging substrate as described in claim 2, wherein, The insulating layer contains dielectric material or ink material.

8. The packaging substrate as described in claim 7, wherein, The dielectric material is selected from at least one of the group consisting of polybenzoxazole (PBO), polyimide (PI), prepreg (PP) and Ajinomoto Build-up Film (ABF), and the ink material includes epoxy ink composites.

9. The packaging substrate as described in claim 7, wherein, The ink material has a viscosity of 25 to 55 Pa·s and a glass transition temperature (Tg) of 145 to 180°C.

10. The packaging substrate as described in claim 1, wherein, The fixed structure is in the form of rivets, grids, or frames.

11. A method for manufacturing a packaging substrate, comprising: A circuit structure is provided, having opposing ball-planting side and add-layer side, and the circuit structure includes: a core layer having opposing first and second sides, a plurality of through holes communicating with the first and second sides, and at least one fixing hole; a bonding layer formed on the first and second sides of the core layer, the walls of the through holes and the fixing hole; a plurality of conductive posts formed in each of the through holes and a support portion formed in the fixing hole; and a circuit layer formed on the opposing first and second sides of the core layer and electrically connected to the conductive posts, wherein the first side corresponds to the ball-planting side, and the second side corresponds to the add-layer side, wherein the support portion is not electrically connected to the circuit layer; and a wiring structure is formed on the add-layer side of the circuit structure, and an extension portion is formed in the wiring structure corresponding to the support portion to form a fixing structure extending from and through the wiring structure, including a support portion formed in the fixing hole and an extension portion located in the wiring structure and correspondingly formed on the support portion.

12. The method for manufacturing a package substrate as described in claim 11 further includes, before forming the wiring structure, attaching the ball-planting sides of the two wiring structures to opposite sides of a carrier, and after forming the wiring structure on the layer-addition side of the wiring structure, removing the carrier to perform a dicing process to obtain a plurality of package substrates.

13. The method for manufacturing the packaging substrate as described in claim 11, wherein, The steps for fabricating the circuit structure include forming a bonding layer on the first and second sides of the core layer, the walls of the through holes and the fixing holes; forming an insulating layer on the bonding layer and filling it into the plurality of through holes and the fixing holes; and forming a plurality of conductive pillars penetrating the insulating layer in the plurality of through holes and forming a support portion penetrating the insulating layer in the fixing holes.

14. The method of manufacturing the packaging substrate as described in claim 11 further includes forming a plurality of fasteners on the extension and between the support and the extension after forming the support portion and the extension portion, wherein the width of the fastener between the support portion and the extension portion is greater than the diameter of the support portion.

15. The method for manufacturing the packaging substrate as described in claim 14, wherein, The outermost wiring layer on the added layer side has a plurality of electrical contact pads, and the width of the plurality of electrical contact pads is smaller than the width of the plurality of fasteners. The manufacturing method includes forming solder resist layers on the outermost sides of the circuit structure and the wiring structure to cover the fasteners of the outermost wiring layer.

16. The method for manufacturing the packaging substrate as described in claim 11, wherein, The bonding layer is an organic or inorganic coating, wherein the material forming the organic coating is a polymer and the thickness of the organic coating is 1 nanometer to 100 micrometers, and the material forming the inorganic coating is silica fume with a diameter of 20 to 50 micrometers and a roughness Ra of 1 to 200 micrometers.

17. The method for manufacturing the packaging substrate as described in claim 16, wherein, The polymer is selected from at least one of the group consisting of polyoxymethylene, polyamide and parylene.

18. The method for manufacturing the packaging substrate as described in claim 13, wherein, The insulating layer contains dielectric material or ink material.

19. The method for manufacturing the packaging substrate as described in claim 18, wherein, The dielectric material is selected from at least one of the group consisting of polybenzoxazole (PBO), polyimide (PI), prepreg (PP) and Ajinomoto Build-up Film (ABF), and the ink material includes epoxy ink composites.

20. The method for manufacturing the packaging substrate as described in claim 18, wherein, The ink material has a viscosity of 25 to 55 Pa·s and a glass transition temperature (Tg) of 145 to 180°C.

21. The method for manufacturing the packaging substrate as described in claim 11, wherein, The fixed structure is in the form of rivets, grids, or frames.

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