Method and Apparatus for Performing Immersion Tin Process or Copper Plating Process in the Production of a Component Carrier

Abstract

A method of performing an immersion tin process in the production of a component carrier is provided which includes immersing at least a part of a copper surface of the component carrier in a composition containing Sn(II) in an immersion tin unit, while passing a non-oxidizing gas through the immersion tin unit, wherein at least part of the non-oxidizing gas is recycled. In addition, an apparatus for performing an immersion tin process in the production of a component carrier, a method of performing a copper plating process in the production of a component carrier and an apparatus for performing a copper plating process in the production of a component carrier are provided.

Claims

1. A method of performing an immersion tin process in the production of a component carrier, the method comprising: immersing at least a part of a copper surface of the component carrier in a composition containing Sn(II) in an immersion tin unit, while passing a non-oxidizing gas through the immersion tin unit, wherein at least part of the non-oxidizing gas is recycled.

2. The method of performing an immersion tin process in the production of a component carrier according to claim 1, wherein the composition containing Sn(II) further contains a complexing agent for copper and an acid.

3. The method of performing an immersion tin process in the production of a component carrier according to claim 2, wherein the complexing agent for copper comprises thiourea and/or wherein the acid comprises methanesulfonic acid.

4. The method of performing an immersion tin process in the production of a component carrier according to claim 1, wherein the immersing step is carried out at a temperature of from 50 to 95° C., in particular 60 to 85° C., in particular 70 to 75° C.; and/or wherein the immersing step is carried out under elevated gas pressure, in particular 1.02 to 1.2 times atmospheric pressure.

5. The method of performing an immersion tin process in the production of a component carrier according to claim 1, wherein the non-oxidizing gas comprises at least 95 vol % of nitrogen.

6. The method of performing an immersion tin process in the production of a component carrier according to claim 1, wherein at least part of the non-oxidizing gas is recycled and re-used, in particular re-introduced into the immersion tin unit.

7. The method of performing an immersion tin process in the production of a component carrier according to claim 1, further comprising: circulating at least part of the non-oxidizing gas through at least one of a fluid driving unit, a gas-gas heat exchanger, a gas-water heat exchanger, a water removing unit, and/or a H.sub.2S removing unit.

8. An apparatus for performing an immersion tin process in the production of a component carrier, the apparatus comprising: at least one non-oxidizing gas generation unit; at least one immersion tin unit; at least one fluid driving unit; at least one gas-gas heat exchanger; at least one gas-water heat exchanger; at least one water removing unit upstream and/or downstream of the gas-water heat exchanger; at least one H.sub.2S removing unit.

9. The apparatus for performing an immersion tin process in the production of a component carrier according to claim 8, wherein the apparatus is configured for circulating more than 100 m.sup.3/h, in particular more than 200 m.sup.3/h, of non-oxidizing gas; and/or wherein the at least one non-oxidizing gas generation unit and the at least one immersion tin unit are located in the same compartment.

10. A method of performing a copper plating process in the production of a component carrier, the method comprising: plating at least a part of a surface of the component carrier with copper in a copper plating unit, while passing a non-oxidizing gas through the copper plating unit, wherein at least part of the non-oxidizing gas is recycled.

11. The method of performing an immersion tin process in the production of a component carrier according to claim 10, wherein the plating step is carried out under elevated gas pressure, in particular 1.02 to 1.2 times atmospheric pressure; and/or wherein the non-oxidizing gas comprises at least 95 vol % of nitrogen.

12. The method of performing an immersion tin process in the production of a component carrier according to claim 10, wherein at least part of the non-oxidizing gas is recycled and re-used, in particular re-introduced into the copper plating unit.

13. An apparatus for performing a copper plating process in the production of a component carrier, the apparatus comprising: at least one non-oxidizing gas generation unit; at least one copper plating unit; and at least one fluid driving unit.

14. The apparatus for performing a copper plating process in the production of a component carrier according to claim 13, further comprising at least one of: at least one gas-water heat exchanger; at least one water removing unit; at least one gas filter unit; and at least one cooling water supply unit.

15. The apparatus for performing a copper plating process in the production of a component carrier according to claim 13, wherein the at least one non-oxidizing gas generation unit and the at least one copper plating unit are located in the same compartment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0092] FIG. 1 illustrates an apparatus for performing an immersion tin process according to an exemplary embodiment of the invention.

[0093] FIG. 2 illustrates an apparatus for performing a copper plating process according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0094] The illustrations in the drawings are schematically presented. In different drawings, similar or identical elements are provided with the same reference signs.

[0095] FIG. 1 illustrates an apparatus 100 for performing an immersion tin process according to an exemplary embodiment of the invention. The apparatus 100 comprises an immersion tin unit 120 where the actual immersion tin plating is performed by immersing at least a part of a copper surface of a component carrier (not shown) in a composition containing Sn(II), while passing a non-oxidizing gas through the immersion tin unit 120. In the embodiment shown in FIG. 1 a stream of 320 m.sup.3/h of non-oxidizing gas (basically comprising nitrogen) enters into the immersion tin unit 120. Hereof, 20 m.sup.3/h of excessive nitrogen gas is exhausted into the surrounding environment, whereas the majority of the gas stream (more specifically 300 m.sup.3/h) having a temperature of 60° C. and significant water and H.sub.2S contents is circulated (recycled). To this end, a fluid driving unit 130 drives the circulating stream of the non-oxidizing gas. In FIG. 1, the fluid driving unit 130 is depicted directly downwards of the immersion tin unit 120. As will be appreciated by a person skilled in the art, the fluid driving unit 130 may also be arranged at other positions of the circulating system and it may also be possible to arrange two or more fluid driving units 130 at different positions of the circulating system. The still warm circulating stream of non-oxidizing gas containing water (steam) and H.sub.2S is then passed through a gas-gas heat exchanger 140, where the warm and water-saturated circulating stream of non-oxidizing gas is pre-cooled, while at the same time dry non-oxidizing gas stream after water removal is heated. Due to the pre-cooling, water may be condensed and removed from the circulating stream of non-oxidizing gas in a water removing unit 160, such as a cyclone. Subsequently, the partially dried circulating stream of non-oxidizing gas may be further fed to a gas-water heat exchanger 150 where the circulated stream of non-oxidizing gas is further cooled, so as to cause a further condensation and removal of water in a further water removing unit 160, such as an additional cyclone, downstream of the gas-water heat exchanger 150. The thus dried stream of non-oxidizing gas is then fed into a H.sub.2S removing unit 170 where H.sub.2S is absorbed by for instance iron oxide (Fe.sub.2O.sub.3) and thus eliminated from the circulated stream of non-oxidizing gas. The dry non-oxidizing gas stream freed from H.sub.2S may then be warmed in the same gas-gas heat exchanger 140 discussed above and returned to the immersion tin unit 120. Excess nitrogen gas (in the depicted embodiment, 20 m.sup.3/h) supplied by a nitrogen generation unit 110 may be fed to the non-oxidizing gas stream prior to entering into the immersion tin unit 120 so as to provide for an elevated gas pressure within the immersion tin unit 120 thereby avoiding the penetration of air (and thus oxygen) into the immersion tin unit 120. As a result, an immersion tin process with a circulating non-oxidizing gas atmosphere may be carried out in a stable and cost-efficient manner with significantly reduced maintenance efforts and downtimes.

[0096] FIG. 2 illustrates an apparatus 200 for performing a copper plating process according to an exemplary embodiment of the invention. The apparatus 200 comprises a copper plating unit 220 where the actual copper plating is performed involving plater chemistry, while passing a non-oxidizing gas through the copper plating unit 220. More specifically, a stream of non-oxidizing gas (basically comprising nitrogen) enters into the copper plating unit 220. Hereof, a small part of for instance 10 to 20 m.sup.3/h of excessive nitrogen gas is exhausted into the surrounding environment, whereas the majority of the gas stream having a significant water content is circulated (recycled). To this end, a fluid driving unit 230 drives the circulating stream of the non-oxidizing gas. In FIG. 2, the fluid driving unit 230 is depicted (directly) downwards of the copper plating unit 220. As will be appreciated by a person skilled in the art, the fluid driving unit 230 may also be arranged at other positions of the circulating system and it may also be possible to arrange two or more fluid driving units 230 at different positions of the circulating system. The circulating stream of non-oxidizing gas containing water (steam) is then passed through a gas-water heat exchanger 250 where the circulated stream of non-oxidizing gas is cooled, so as to cause condensation and removal of water in a water removing unit 260, such as a water splitter, downstream of the gas-water heat exchanger 250. Cool water may be supplied to gas-water heat exchanger 250 by means of a cooling water supply unit 280. The thus dried stream of non-oxidizing gas is then passed through a gas filter unit 270 containing for instance active carbon or zeolite and returned to the copper plating unit 220. Excess nitrogen gas (in the depicted embodiment, about 10 to 20 m.sup.3/h) supplied by a nitrogen generation unit 210 may be fed to the non-oxidizing gas stream prior to entering into the copper plating unit 220 so as to provide for an elevated gas pressure within the copper plating unit 220 thereby avoiding the penetration of air (and thus oxygen) into the copper plating unit 220. As a result, a copper plating process with a circulating non-oxidizing gas atmosphere may be carried out in a stable and cost-efficient manner with significantly reduced maintenance efforts and downtimes.

[0097] Implementation of the invention is not limited to the preferred embodiments shown in the figures and described above. Instead, a multiplicity of variants is possible which variants use the solutions shown and the principle according to the invention even in the case of fundamentally different embodiments.