Method for copper filling of a hole in a component carrier

• US 10,455,704 B2
• Filed: 07/30/2018
• Issued: 10/22/2019
• Est. Priority Date: 07/31/2017
• Status: Expired due to Fees

• Current Assignee: AT&S Austria Technologie & Systemtechnik AG
• Original Assignee: AT&S Austria Technologie & Systemtechnik AG
• Inventors: Wang, Ares, Ling, Yee-Bing, Tay, Annie
• Primary Examiner(s): Nguyen, Donghai D
• Application Number:
  US16/049,512
• Publication Number:
  US 20190037703A1
• Time in Patent Office: 449 Days
• Field of Search: 29846, 29852
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• CPC Class Codes: H05K 2201/0344 Electroless sublayer, e.g. Ni, Co, Cd or Ag; Transferred electroless sublayer
• CPC Class Codes: H05K 2201/09563 Metal filled via plated through-hole filled with insulating material H05K2201/0959
• CPC Class Codes: H05K 2203/1476 Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: H05K 3/0026 by laser ablation
• CPC Class Codes: H05K 3/0055 After-treatment, e.g. cleaning or desmearing of holes
• CPC Class Codes: H05K 3/0094 Filling or covering plated through-holes or blind plated vias, e.g. for masking or for mechanical reinforcement
• CPC Class Codes: H05K 3/241 characterised by the electroplating method; means therefor, e.g. baths or apparatus
• CPC Class Codes: H05K 3/244 Finish plating of conductors, especially of copper conductors, e.g. for pads or lands selective plating methods H05K3/243; finish plating of conductors made by printing techniques H05K3/246; solder as finish H05K3/3457, e.g. by plating H05K3/3473
• CPC Class Codes: H05K 3/423 characterised by electroplating method
• CPC Class Codes: H05K 3/4644 by building the multilayer layer by layer, i.e. build-up multilayer circuits making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

A method of filling a hole formed in a component carrier with copper is disclosed. The method comprises i) forming a layer of an electrically conductive material covering at least part of a surface of a wall, wherein the wall delimits the hole, and subsequently ii) covering at least partially the layer and filling at least partially an unfilled volume of the hole with copper using a plating process including a bath. Hereby, the bath comprises a concentration of a copper ion, in particular Cu²⁺, in a range between 50 g/L and 75 g/L, in particular in a range between 60 g/L and 70 g/L.

Claims

1. A method of filling a hole formed in a component carrier with copper, the method comprising:

forming a layer of an electrically conductive material covering at least part of a surface of a wall, wherein the wall delimits the hole; and

subsequently, covering at least partially the layer and filling at least partially an unfilled volume of the hole with copper using a plating process including a bath,

wherein the bath comprises a concentration of a copper ion in a range between 50 g/L and 75 g/L, and

wherein at least partially covering the layer and at least partially filling the hole are done by flash-plating.

2. The method according to claim 1, further comprising:

supplying the bath with copper sulfate (CuSO₄) and/or copper sulfate pentahydrate (CuSO₄*5H₂O).

3. The method according to claim 1, wherein the bath further comprises:

sulfuric acid (H₂SO₄) with a concentration in a range between 80 g/L and 110 g/L.

4. The method according to claim 1, wherein the bath further comprises:

at least one of the group consisting of iron ions, chloride (Cl⁻

) a brightening agent, and a leveler agent.

5. The method according to claim 1, further comprising:

filling at least partially a remaining volume of the hole with copper using a further plating process including a further bath, wherein the further bath comprises at least approximately the same composition of chemical ingredients and/or at least approximately the same concentration of chemical ingredients as the first bath.

6. The method according to claim 1, further comprising:

filling at least partially a remaining volume of the hole with copper using a further plating process including a further bath, wherein the further bath comprises a different composition of chemical ingredients and/or a different concentration of chemical ingredients as the first bath.

7. The method according to claim 1, wherein a formed layer of electrically conductive material comprises a thickness in a range between 0.1 μ

m and 1 μ

m, and/or

wherein a copper material, which has been formed above the formed layer of electrically conductive material, comprises a thickness in a range between 0.3 μ

m and 15 μ

m.

8. The method according to claim 1, wherein forming the layer of electrically conductive material is done by electro-less plating.

9. The method according to claim 1, further comprising:

drilling the hole with a laser; and

removing waste products caused by laser drilling.

10. The method according to claim 1, further comprising:

drilling the hole with a laser; and

wherein the forming of the layer is performed without previously removing waste products caused by laser drilling.

11. The method according to claim 1, wherein an aspect ratio of the hole is in a range between 0.5 and 1.5.

12. The method according to claim 1, wherein the hole is configured as a through hole or as a blind hole.

13. The method according to claim 1, wherein the electrically conductive material comprises at least one of the group consisting of copper, aluminum, and nickel.

14. The method according to claim 1, wherein the copper ion is Cu²⁺.

15. The method according to claim 1, wherein the bath comprises a concentration of the copper ion in a range between 60 g/L and 70 g/L.