Micro-through-hole filled substrate and manufacturing method thereof

Abstract

[Problem] The present invention provides a micro-via filled substrate and a method for manufacturing the same. The micro-via filled substrate is a high-reliability substrate formed by filling metal in micro-vias, which can achieve high-density mounting and high reliability. [Solution] The above problem is solved as follows: it is a micro-via filled substrate (10) in which a plurality of micro-vias (2) formed on a substrate (1) are filled. The micro-vias (2) are filled with a conductive layer (at least (3b)) formed on its inner wall surface and a metal solder layer (3c) formed on the conductive layer. The conductive layer is a conductive layer formed by forming a copper plating layer (3b) on the side of the aforementioned metal solder layer. The metal solder layer (3c) is a metal solder layer filled with nickel-containing molten solder treated with an organic fatty acid solution.

Claims

1. A micro-via-filled substrate, comprising a plurality of micro-vias formed on a substrate and filled therein, wherein the micro-vias are filled by a conductive layer formed on its inner wall surface and a metal solder layer formed on the conductive layer, wherein the conductive layer is a conductive layer formed by forming a copper plating layer on the side of the metal solder layer, and the metal solder layer is a metal solder layer filled with nickel-containing molten solder treated with an organic fatty acid solution.

2. The micro-via filled substrate as described in claim 1, wherein, The substrate is a quartz substrate or a glass substrate.

3. The micro-via filled substrate as described in claim 1 or 2, wherein, An intermetallic compound layer is formed on the conductive layer side of the metal solder layer, which combines with the copper component constituting the conductive layer to prevent copper corrosion.

4. A micro-via filled substrate as described in claim 1 or 2, wherein, The metal solder layer contains at least tin as the main component and nickel as a secondary component.

5. A micro-via filled substrate as described in claim 1 or 2, wherein, The conductive layer is composed of a first conductive layer formed on the inner wall surface and a second conductive layer formed on the first conductive layer, wherein the second conductive layer is a copper plating or a copper alloy plating.

6. The micro-via filled substrate as described in claim 5, wherein, The first conductive layer is a conductive material selected from ITO, Cr, Ti, Al, Au, Ag, Cu, Ni and Mo or a composite material thereof.

7. A method for manufacturing a micro-via-filled substrate, wherein the micro-via-filled substrate is a micro-via-filled substrate in which a plurality of micro-vias formed on a substrate are filled by a metal solder layer, the manufacturing method comprising the following steps: a conductive layer forming step, wherein a conductive layer composed of a copper plating layer or a copper alloy plating layer is formed on the inner wall surface of the micro-vias on the side of the metal solder layer; and a metal solder layer forming step, wherein a liquid flow of nickel-containing molten solder treated with an organic fatty acid solution is supplied to the conductive layer on the inner wall surface, and the micro-vias are filled with the metal solder layer.

8. A method for manufacturing a micro-via-filled substrate as described in claim 7, wherein, The metal solder layer formation process includes a molten solder removal process, which removes excess molten solder after the molten solder supply process that supplies the liquid flow of the nickel-containing molten solder.

9. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The substrate is a quartz substrate or a glass substrate.

10. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The molten solder contains at least tin as the main component and nickel as a secondary component.

11. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The organic fatty acid solution is a solution containing palmitic acid with 16 carbon atoms.

12. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, After the conductive layer formation process and before the solder layer formation process, there is an organic fatty acid solution immersion process in which an organic fatty acid solution is immersed into the micro-through holes.

13. A method for manufacturing a micro-via-filled substrate as described in claim 12, wherein, The organic fatty acid solution immersion process includes a liquid immersion process, in which a cleaning solution or surface treatment solution is immersed into the micro-through holes before the organic fatty acid solution is immersed into the micro-through holes.

14. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The viscosity of the molten solder is above 0.002 Pa·s and below 0.004 Pa·s.

15. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The metal solder layer formation process is carried out in a vapor atmosphere containing an organic fatty acid solution.

16. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The metal solder layer formation process involves spraying the molten solder toward the micro-through hole or at a predetermined angle.

17. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The molten solder removal process is carried out by spraying a liquid stream containing an organic fatty acid solution.

18. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, When the conductive layer is formed on both the inner wall surface of the micro-through hole and the substrate surface, a conductive layer removal process is performed before the metal solder layer formation process to remove the conductive layer formed on the substrate surface.

19. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The conductive layer forming process includes the following steps: a first conductive layer forming process for forming a first conductive layer on the inner wall surface; and a second conductive layer forming process for forming a second conductive layer composed of a copper plating layer or a copper alloy plating layer on the first conductive layer.

20. A method for manufacturing a micro-via-filled substrate as described in claim 19, wherein, The first conductive layer formation process is performed by PVD or CVD, wherein the PVD or CVD process forms a conductive material or a composite material selected from ITO, Cr, Ti, Al, Au, Ag, Cu, Ni and Mo.

21. A method for manufacturing a micro-via-filled substrate as described in claim 7 or 8, wherein, The conductive layer formation process is a process of forming a chemically plated copper layer or a chemically plated copper alloy layer after a chemical plating catalyst is placed on the inner wall surface.

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