MANUFACTURING INSULATED SPHERICAL WELD GOLD WIRE FOR INTEGRATED CIRCUIT DOUBLE-LAYER STACKED PACKAGE

Abstract

The present invention discloses a method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package, which relates to the technical field of microelectronic packaging spherical weld gold wires, and specifically comprises the following steps: alloy sheet preparation; alloy rod preparation; stretching; annealing treatment; activation treatment; sputtered insulating coating; multi-winding and sub-packaging, since the polyaryletherketone insulating coating is provided on the surface of the spherical weld gold wire in a scaled integrated circuit and the double-layer stacked package of the present invention, the spherical weld gold wire is allowed to contact and cross during packaging, without affecting the product performance, cost and quality; two high-hardness and high-conductivity materials of cobalt and germanium are added, which greatly enhances the tensile strength of the material.

Claims

1. A method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package, comprising the following steps: step S1: alloy sheet preparation: preparing a gold-cobalt alloy sheet, a gold-lanthanum alloy sheet, a gold-cerium alloy sheet and a gold-germanium alloy sheet according to weight percentages, respectively; step S2: alloy rod preparation: preparing a gold-cobalt-lanthanum-cerium-germanium gold alloy rod with a diameter of 8 mm from the gold-cobalt alloy sheet, gold-lanthanum alloy sheet, gold-cerium alloy sheet and gold-germanium alloy sheet prepared in step S1; step S3: stretching: successively subjecting the 8 mm gold-cobalt-lanthanum-cerium-germanium gold alloy rod prepared in step S2 to rough stretching, medium stretching, fine stretching, and micro-stretching to form a spherical weld gold wire with a diameter of 0.011 mm-0.050 mm; step S4: annealing treatment: placing the spherical weld gold wire prepared in step S3 in a continuous annealing system, using high-purity nitrogen as a protective gas, at a temperature of 300° C.-600° C. and a speed of 40 m-80 m/min to perform a continuous annealing treatment; step S5: activation treatment: placing the annealed spherical weld gold wire in a continuous activation treatment system, wherein the wire passes through an activation acid solution with a concentration of 3%-10%, wherein the solution temperature is 50° C.-120° C.; meanwhile, applying ultrasonic waves with a power of P045 and a frequency of 8 KHZ-40 KHZ to the solution, performing activation treatment at a speed of 40 m-80 m/min, and performing drying treatment during winding, wherein the drying temperature is 100° C.-120° C.; step S6: sputtering an insulating coating: diluting the high-performance polyaryletherketone coating to a concentration of 8%45% using acetone, and adjusting the sputtering pressure to be 0.1 Mpa-0.3 Mpa; passing the wire through an annular outlet with a pressure of 0.15 Mpa-0.2 Mpa at a speed of 100 m/min-200 m/min, performing high-performance polyaryletherketone coating sputtering on wire surface at 360 degrees at constant velocity and pressure at the annular outlet to uniformly form a protective coating, adjusting the sputtering pressure and the running speed of the wire, and controlling the thickness of the coating to be 0.3 nm-1 nm; step S7: sputtered insulating coating curing treatment: passing the wire after sputter coating through a U-shaped curing device with a length of 500 mm and a heating temperature of 300° C.-400° C. at a speed of 100 m/min-200 m/min to cure the high-performance polyaryletherketone coating so that the coating firmly adheres to the surface of the wire; and step S8: multi-winding and sub-packaging: sizing the wire treated in step S7 in a single roll, controlling tension 0.8 g-8.0 g, and sizing in a single roll of 500 or 1000.

2. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 1, wherein in step S1, the gold-cobalt alloy sheet is prepared by: placing 0.1%-0.5% cobalt and 99.9%-99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.-1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min-90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cobalt alloy ingot; and rolling the alloy ingot into a sheet having a thickness of 0.2 mm to 0.5 mm in several passes to obtain a gold-cobalt alloy sheet.

3. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 2, wherein in step S1, the gold-lanthanum alloy sheet is prepared by: placing 0.1%-0.5% lanthanum and 99.9%-99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.-1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min-90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-lanthanum alloy ingot; and rolling the alloy ingot into a sheet having a thickness of 0.2 mm to 0.5 mm in several passes.

4. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 3, wherein in step S1, the gold-cerium alloy sheet is prepared by: placing 0.1%-0.5% cerium and 99.9%-99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.-1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min-90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cerium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of 0.2 mm to 0.5 mm in several passes.

5. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 1, wherein in step S1, the gold-germanium alloy sheet is prepared by: placing 0.1%-0.5% germanium and 99.9%-99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.-1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min-90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-germanium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of 0.2 mm to 0.5 mm in several passes.

6. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 1, wherein in step S2, the gold-cobalt-lanthanum-cerium-germanium gold alloy rod is prepared by: placing the gold ingot with a purity of ≥99.99% and the gold-cobalt alloy sheet, the gold-lanthanum alloy sheet, the gold-cerium alloy sheet and the gold-germanium alloy sheet prepared in step S1 in a high-purity graphite crucible by weight percentage, placing same in a vacuum pull-down continuous casting furnace, vacuumizing and heating same to 1100° C.-1350° C., preserving the temperature for 15 min-60 min after the materials are completely melted, and performing electromagnetic stirring; refining same for 10 min-60 min after stirring, and obtaining a gold rod with the diameter of φ8 mm through pull-down continuous casting using a directional solidification method with a traction speed being controlled at 50 mm/min-120 mm/min.

7. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 6, wherein in step S2, the gold-cobalt-lanthanum-cerium-germanium gold alloy rod is composed of 0.0001%-1.5% of cobalt, 0.0005%-0.001% of lanthanum, 0.0005%-0.001% of cerium, and balance of gold.

8. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 1, wherein the purity of cobalt, lanthanum, cerium, and germanium is ≥99.99%, and the purity of gold is ≥99.999%.

9. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 1, wherein the density of graphite is ≥1.65 g/cm.sup.3 and the density of ash is ≤100 ppm in high-purity graphite crucible and graphite mold.

10. The method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to claim 9, wherein in step S6, the protective coating has a thickness of 0.3 nm to 1 nm.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0030] The present invention will now be further described more fully hereinafter with reference to the accompanying drawings.

[0031] FIG. 1 is a schematic structural flow diagram of a method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package according to the present invention;

[0032] FIG. 2 is a schematic view showing the structure of the dot-like distribution of the elements of the insulated spherical weld gold wire;

[0033] FIG. 3 is a schematic view showing the structure of the fine wire-drawn surface of the insulated spherical weld gold wire.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present invention are shown. It is to be understood that the embodiments described are only a few, but not all embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without inventive effort fall within the scope of the present invention.

Embodiment 1

[0035] With reference to FIG. 1, the present invention is a method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package, comprising the following steps:

[0036] Step S1, Alloy Sheet Preparation: [0037] placing 0.1% cobalt and 99.9% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cobalt alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.2 mm in several passes to obtain a gold-cobalt alloy sheet; [0038] placing 0.1% lanthanum and 99.9% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-lanthanum alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.2 mm in several passes; [0039] placing 0.1% cerium and 99.9% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cerium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.2 mm in several passes; and [0040] placing 0.1% germanium and 99.9% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1100° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 30 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-germanium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.2 mm in several passes.

[0041] Step S2, Alloy Rod Preparation: [0042] placing the gold ingot with a purity of ≥99.99% and the gold-cobalt alloy sheet, the gold-lanthanum alloy sheet, the gold-cerium alloy sheet and the gold-germanium alloy sheet prepared in step S1 in a high-purity graphite crucible by weight percentage, placing same in a vacuum pull-down continuous casting furnace, vacuumizing and heating same to 1100° C., preserving the temperature for 15 min after the materials are completely melted, and performing electromagnetic stirring; refining same for 10 min after stirring, and obtaining a gold rod with the diameter of φ8 mm through pull-down continuous casting using a directional solidification method with a traction speed being controlled at 50 mm/min; [0043] wherein the composition of the gold-cobalt-lanthanum-cerium-germanium gold alloy rod is 0.0001% cobalt, 0.0005% lanthanum and 0.0005% cerium, and balance of gold; [0044] the purity of cobalt, lanthanum, cerium, germanium is ≥99.99% and the purity of said gold is ≥99.999%; [0045] step S3: stretching: successively subjecting the 8 mm gold-cobalt-lanthanum-cerium-germanium gold alloy rod prepared in step S2 to rough stretching, medium stretching, fine stretching, and micro-stretching to form a spherical weld gold wire with a diameter of 0.011 mm; [0046] step S4: annealing treatment: placing the spherical weld gold wire prepared in step S3 in a continuous annealing system, using high-purity nitrogen as a protective gas, at a temperature of 300° C. and a speed of 40 m/min to perform a continuous annealing treatment; [0047] step S5: activation treatment: placing the annealed spherical weld gold wire in a continuous activation treatment system, wherein the wire passes through an activation acid solution with a concentration of 3%, and the solution temperature is 50° C.; meanwhile, applying ultrasonic waves with a power of P045 and a frequency of 8 KHZ to the solution, and operating at a speed of 40 m to perform activation treatment, and performing drying treatment during winding, wherein the drying temperature is 100° C.; [0048] step S6: sputtering an insulating coating: diluting the high-performance polyaryletherketone coating to a concentration of 8% using acetone, and adjusting the sputtering pressure to be 0.1 Mpa; passing the wire through an annular outlet with a pressure of 0.15 Mpa at a speed of 100 m/min, performing high-performance polyaryletherketone coating sputtering on wire surface at 360 degrees at constant velocity and pressure at the annular outlet to uniformly form a protective coating, adjusting the sputtering pressure and the running speed of the wire, and controlling the thickness of the coating to be 0.3 nm, and the thickness of the protective coating to be 0.3 nm; [0049] step S7: sputtered insulating coating curing treatment: passing the wire after sputter coating through a U-shaped curing device with a length of 500 mm and a heating temperature of 300° C. at a speed of 100 m/min to cure the high-performance polyaryletherketone coating so that the coating firmly adheres to the surface of the wire; and [0050] step S8: multi-winding and sub-packaging: sizing the wire treated in step S7 in a single roll, controlling tension 0.8 g, and sizing in a single roll of 500 or 1000; [0051] in high-purity graphite crucibles and graphite molds, the graphite density is ≥1.65 g/cm.sup.3 and the ash powder is ≤100 ppm.

Embodiment 2

[0052] a method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package, comprising the following steps:

[0053] Step S1, Alloy Sheet Preparation: [0054] placing 0.2% cobalt and 99.8% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1200° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 50 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cobalt alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.35 mm in several passes to obtain a gold-cobalt alloy sheet; [0055] placing 0.2% lanthanum and 99.8% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1200° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 60 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-lanthanum alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.3 mm in several passes; [0056] placing 0.3% cerium and 99.7% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1200° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 60 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cerium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.3 mm in several passes; and [0057] placing 0.2% germanium and 99.8% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1200° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 60 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-germanium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.3 mm in several passes.

[0058] Step S2, Alloy Rod Preparation: [0059] placing the gold ingot with a purity of ≥99.99% and the gold-cobalt alloy sheet, the gold-lanthanum alloy sheet, the gold-cerium alloy sheet and the gold-germanium alloy sheet prepared in step S1 in a high-purity graphite crucible by weight percentage, placing same in a vacuum pull-down continuous casting furnace, vacuumizing and heating same to 1200° C., preserving the temperature for 30 min after the materials are completely melted, and performing electromagnetic stirring; refining same for 30 min after stirring, and obtaining a gold rod with the diameter of φ8 mm through pull-down continuous casting using a directional solidification method with a traction speed being controlled at 90 mm/min; [0060] wherein the composition of the gold-cobalt-lanthanum-cerium-germanium gold alloy rod is 0.0005% cobalt, 0.0007% lanthanum and 0.0007% cerium, and balance of gold; [0061] the purity of cobalt, lanthanum, cerium, germanium is ≥99.99% and the purity of said gold is ≥99.999%; [0062] step S3: stretching: successively subjecting the 8 mm gold-cobalt-lanthanum-cerium-germanium gold alloy rod prepared in step S2 to rough stretching, medium stretching, fine stretching, and micro-stretching to form a spherical weld gold wire with a diameter of 0.03 mm; [0063] step S4: annealing treatment: placing the spherical weld gold wire prepared in step S3 in a continuous annealing system, using high-purity nitrogen as a protective gas, at a temperature of 400° C. and a speed of 50 m/min to perform a continuous annealing treatment; [0064] step S5: activation treatment: placing the annealed spherical weld gold wire in a continuous activation treatment system, wherein the wire passes through an activation acid solution with a concentration of 6%, and the solution temperature is 70° C.; meanwhile, applying ultrasonic waves with a power of P045 and a frequency of 20 KHZ to the solution, and operating at a speed of 60 m/min to perform activation treatment, and performing drying treatment during winding, wherein the drying temperature is 110° C.; [0065] step S6: sputtering an insulating coating: diluting the high-performance polyaryletherketone coating to a concentration of 10% using acetone, and adjusting the sputtering pressure to be 0.2 Mpa; passing the wire through an annular outlet with a pressure of 0.018 Mpa at a speed of 150 m/min, performing high-performance polyaryletherketone coating sputtering on wire surface at 360 degrees at constant velocity and pressure at the annular outlet to uniformly form a protective coating, adjusting the sputtering pressure and the running speed of the wire, and controlling the thickness of the coating to be 0.6 nm, and the thickness of the protective coating to be 0.6 nm; [0066] step S7: sputtered insulating coating curing treatment: passing the wire after sputter coating through a U-shaped curing device with a length of 500 mm and a heating temperature of 350° C. at a speed of 150 m/min to cure the high-performance polyaryletherketone coating so that the coating firmly adheres to the surface of the wire; and [0067] step S8: multi-winding and sub-packaging: sizing the wire treated in step S7 in a single roll, controlling tension 4 g, and sizing in a single roll of 500 or 1000; [0068] in high-purity graphite crucibles and graphite molds, the graphite density is ≥1.65 g/cm.sup.3 and the ash powder is ≤100 ppm.

Embodiment 3

[0069] a method for manufacturing an insulated spherical weld gold wire for integrated circuit double-layer stacked package, comprising the following steps:

[0070] Step S1, Alloy Sheet Preparation: [0071] placing 0.5% cobalt and 99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cobalt alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.5 mm in several passes to obtain a gold-cobalt alloy sheet; [0072] placing 0.5% lanthanum and 99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-lanthanum alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.5 mm in several passes; [0073] placing 0.5% cerium and 99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-cerium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.5 mm in several passes; and [0074] placing 0.5% germanium and 99.5% gold by weight percentage into a high-purity graphite crucible, respectively, and placing same in a vacuum alloy furnace, vacuumizing and heating same to 1300° C.; after the material is completely melted, filling high-purity argon as protection, preserving the temperature for 90 min, and pouring the alloy melt into a graphite mold to obtain a massive gold-germanium alloy ingot; and rolling the alloy ingot into a sheet having a thickness of to 0.5 mm in several passes.

[0075] Step S2, Alloy Rod Preparation: [0076] placing the gold ingot with a purity of ≥99.99% and the gold-cobalt alloy sheet, the gold-lanthanum alloy sheet, the gold-cerium alloy sheet and the gold-germanium alloy sheet prepared in step S1 in a high-purity graphite crucible by weight percentage, placing same in a vacuum pull-down continuous casting furnace, vacuumizing and heating same to 1350° C., preserving the temperature for 60 min after the materials are completely melted, and performing electromagnetic stirring; refining same for 60 min after stirring, and obtaining a gold rod with the diameter of φ8 mm through pull-down continuous casting using a directional solidification method with a traction speed being controlled at 120 mm/min; [0077] wherein the composition of the gold-cobalt-lanthanum-cerium-germanium gold alloy rod is 1.5% cobalt, 0.001% lanthanum and 0.001% cerium, and balance of gold; [0078] the purity of cobalt, lanthanum, cerium, germanium is ≥99.99% and the purity of said gold is ≥99.999%; [0079] step S3: stretching: successively subjecting the 8 mm gold-cobalt-lanthanum-cerium-germanium gold alloy rod prepared in step S2 to rough stretching, medium stretching, fine stretching, and micro-stretching to form a spherical weld gold wire with a diameter of 0.050 mm; [0080] step S4: annealing treatment: placing the spherical weld gold wire prepared in step S3 in a continuous annealing system, using high-purity nitrogen as a protective gas, at a temperature of 600° C. and a speed of 80 m/min to perform a continuous annealing treatment; [0081] step S5: activation treatment: placing the annealed spherical weld gold wire in a continuous activation treatment system, wherein the wire passes through an activation acid solution with a concentration of 10%, and the solution temperature is 120° C.; meanwhile, applying ultrasonic waves with a power of P045 and a frequency of 40 KHZ to the solution, and operating at a speed of 80 m/min to perform activation treatment, and performing drying treatment during winding, wherein the drying temperature is 120° C.; [0082] step S6: sputtering an insulating coating: diluting the high-performance polyaryletherketone coating to a concentration of 15% using acetone, and adjusting the sputtering pressure to be 0.3 Mpa; passing the wire through an annular outlet with a pressure of 0.2 Mpa at a speed of 200 m/min, performing high-performance polyaryletherketone coating sputtering on wire surface at 360 degrees at constant velocity and pressure at the annular outlet to uniformly form a protective coating, adjusting the sputtering pressure and the running speed of the wire, and controlling the thickness of the coating to be 1 nm, and the thickness of the protective coating to be 1 nm; [0083] step S7: sputtered insulating coating curing treatment: passing the wire after sputter coating through a U-shaped curing device with a length of 500 mm and a heating temperature of 400° C. at a speed of 200 m/min to cure the high-performance polyaryletherketone coating so that the coating firmly adheres to the surface of the wire; and [0084] step S8: multi-winding and sub-packaging: sizing the wire treated in step S7 in a single roll, controlling tension 8.0 g, and sizing in a single roll of 500 or 1000; [0085] in high-purity graphite crucibles and graphite molds, the graphite density is 1.65 g/cm.sup.3 and the ash powder is ≤100 ppm.

[0086] Referring to FIGS. 2 and 3, the spherical weld gold wire for integrated circuit double-layer stacked package obtained by the method of the present invention has a smooth solder joint surface without golf balls and strawberry balls when bonding a wire, and a vacuum directional solidification method is used to control the crystallization temperature and speed of the material, so that each of cobalt, lanthanum, cerium and germanium are distributed in a spot shape and uniformly in gold, which results in a relatively high material density, a smooth surface quality after fine wire drawing, and an excellent surface quality, and avoiding the phenomenon of burning small balls and sliding balls when bonding a wire, thereby improving the bonding smoothness.

[0087] While one embodiment of the present invention has been described in detail, the description is merely a preferred embodiment of the invention and should not be construed as limiting the scope of the invention. All changes and modifications that come within the meaning and range of equivalence of the claims are to be embraced within their scope.