US20040134786A1

US20040134786A1 - Mold for a V-groove fiber array base block and fabrication method thereof

Info

Publication number: US20040134786A1
Application number: US10/703,536
Authority: US
Inventors: Chung-I Chiang; Ming-Jen Wang; Kun-Hsien Cheng; Chun-Han Wu; Jui-Yi Cheng
Original assignee: Ritek Corp
Current assignee: Ritek Corp
Priority date: 2002-08-28
Filing date: 2003-11-10
Publication date: 2004-07-15
Also published as: TW590999B

Abstract

A V-groove mold fabrication method is disclosed. The method for fabricating a V-groove mold includes the following steps: (a) providing a matrix substrate having a plurality of V-grooves, and then forming a metal layer on said matrix substrate; immersing said matrix substrate having said metal layer thereon with an electroforming metal ion solution and forming a father mold by an electroforming process; and separating said father mold from said matrix substrate.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for fabricating a V-groove mold and, more particularly, to a method for fabricating a mold for further mass-producing V-groove fiber array base blocks.

2. Description of Related Art

Owing to the booming high-volume communication through optical fibers, the fiber array modules are in great demand now. Basically, the fiber array modules are made by bonding optical fibers on base blocks having a plurality of grooves. For meeting the great demand for fiber array modules, improvements for mass-producing base blocks have become necessary. Generally speaking, a base block used for fiber array generally is a glass substrate or a silicone substrate having V-grooves. Traditionally, these substrates for base blocks are made by forming grooves through cutting or carving by knives. However, this traditional method for making base blocks not only takes a long time but also results in damage on the substrate. Moreover, the process for carving grooves is complex and is not suitable for mass production. Alternatively, photolithography is suggested for forming V-shaped grooves on the substrate of base blocks. However, only a silicon substrate for a fiber array module can be processed. It is difficult to manufacture the glass substrate having V-grooves through photolithography. Recently, new glass and plastic materials used for manufacturing fiber array base block by injection moldings or press moldings have been reported. Nevertheless, a method for efficiently fabricating a suitable mold for the fiber array base block is still not found. Furthermore, fabricating a mold for a fiber array base block always involves a huge amount of time and this inevitably makes the existing fiber array base blocks uneconomic. There is a need for improvement of the fabrication process of the mold.

Therefore, it is desirable to provide a mold fabrication method for fiber array base blocks that eliminates the aforesaid drawback.

SUMMARY OF THE INVENTION

It is the main object of the present invention to provide a fabrication method of a mold having V-grooves for simplifying the mass-production of said molds and shortening the time involved for fabricating said molds.

Another object of the present invention is to provide a V-groove mold, which can be used in fabricating a substrate of a fiber array base block by injection moldings or press moldings.

To achieve these and other objects of the present invention, the method for fabricating a mold for fiber array base blocks comprises the steps of: providing a matrix substrate having a plurality of V-grooves, and then forming a metal layer on said substrate; immersing said matrix substrate having said metal layer formed thereon with an electroforming metal ion solution and forming a father mold by an electroforming process; and separating said father mold from said matrix substrate. The metal of the metal layer is unlimited. Preferably, the metal of the metal layer is selected from the group consisting of copper, nickel, silver, gold, and alloys thereof. More preferably, the metal of the metal layer is copper, silver, or alloys thereof. Preferably, the electroforming metal of the father mold of present invention is selected from the group consisting of nickel, nickel-containing alloys, silver, copper, gold, chromium, and aluminum. Most preferably, the nickel-containing electroforming metal of the father mold is nickel-iron alloy, nickel-cobalt alloy, nickel-tungsten alloy, nickel-manganese alloy, Ni—SiC (nickel-siliconcarbide alloy), or Ni—Fe—TiO ₂alloy.

The fabrication method may selectively further comprise fabricating a mother V-groove mold by the foregoing method. The method of the present invention optionally further comprises the steps of forming a passive layer on the father mold surface; forming a mother mold on said passive layer by an electroforming process in an electroforming metal ion solution; and separating said mother mold from said father mold.

The present invention also relates to a V-groove mold having an electroforming layer to a thickness between about 0.3 mm to about 30 mm. Preferably, the electroforming metal is selected from the group consisting of nickel, nickel-contained alloys, silver, copper, gold, chromium, and aluminum.

Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing showing a process flow of one embodiment for fabricating a V-groove mold of the present invention. [0012]
FIG. 2 is a schematic drawing showing a process flow of another embodiment for fabricating a V-groove mold of the present invention. [0013]
FIG. 3 is a schematic drawing showing a process flow of another embodiment for fabricating a V-groove mold of the present invention.[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a mold for fabricating a V-groove fiber array base block and a mold fabrication method suitable for mass production. The mold has an electroforming layer in a V-groove shape. The material of metal layer is unlimited. Preferably, the metal of the metal layer is selected from the group consisting of copper, nickel, silver, gold, and alloys thereof. More preferably, the metal of the metal layer is copper, silver, or alloys thereof formed by evaporation or sputtering. The metal layer is in order to make the matrix substrate more conductive for conducting further electroforming. Preferably, the electroforming metal of the mold of present invention is selected from the group consisting of nickel, nickel-contained alloys, silver, copper, gold, chromium, and aluminum. More preferably, the nickel-containing electroforming metal of the mold is nickel-iron alloy, nickel-cobalt alloy, nickel-tungsten alloy, nickel-manganese alloy, Ni—SiC, or Ni—Fe—TiO[0015] ₂alloy. The thickness of the electroforming layer is not limited. Preferably, the thickness of the electroforming layer ranges from 0.3 mm to about 30 mm.
The mold fabrication method comprises the steps of: [0016]
(A) providing a matrix substrate having a plurality of V-grooves, and then forming a metal layer on said matrix substrate; [0017]
(B) immersing said matrix substrate having said metal layer formed thereon with an electroforming metal ion solution and forming a father mold by an electroforming process; and [0018]
(C) separating said father mold from said matrix substrate. [0019]
The fabrication method may optionally further comprise the following steps in order to improve throughput, if necessary. [0020]
(D) forming a passive layer on said father mold; [0021]
(E) forming a mother mold on said passive layer by an electroforming process in an electroforming metal ion solution; and [0022]
(F) separating said mother mold from said father mold. [0023]
The passivation process in step (D) facilitates the release of the electroforming layer (the mother mold) from the V-groove father mold and further prevents the electroforming layer from combining with the V-groove father mold when proceeding in step (E). By repeating the process from step (D) to step (F), lots of mother molds can be produced. But the construction of the mother mold may not be equal to that of the father mold. The fiber array base blocks can not be produced directly by the mother mold so a son mold, constructed equal to the father mold for mass-producing fiber array base blocks, is produced from the mother mold by passivation and electroforming processes. To be more specific, the son molds can be achieved through the following steps. [0024]
(G) forming a passive layer on said mother mold; [0025]
(H) forming a son mold on said passive layer by an electroforming process in an electroforming metal ion solution; and [0026]
(I) separating said son mold from said mother mold. [0027]
The son mold can be taken as a father mold for producing more mother molds from step (D) to step (F). A V-groove fiber array base block can be produced by either the son or father molds. The thickness of the metal layer, preferably silver or copper, may be between about 40 nm to about 200 nm. More preferably, the thickness of metal layer is between about 40 nm to about 80 nm. Preferably, the electroforming metal ion solution is a nickel-containing solution. More preferably, the nickel-containing electroforming solution used to conduct the electroforming process in steps (B), (E) and (H) is Ni(NH[0028] ₂SO₃) 4H₂O or NiSO₄. The passivation process at steps (D) and (G) is exposing to plasma or immersing the mold surface with a passivation reagent. The passivation reagent is unlimited. Preferably, the passivation reagent comprises a K₂Cr₂O₇solution or a basic solution, such as Na₂CO₃or NaOH, to form a passive layer by a chemical method. Optionally, the passivation reagent may further include surfactant. Of course, the chemical method for forming a passive layer can be replaced by a plasma process to form an oxide layer on the surface of the mold. The thickness of the oxide layer is unlimited, but can not result in an adverse effect on the performance of the further electroforming process in steps (E) or (H). Preferably, the thickness of the oxide layer is particularly thin so that all the electroforming performances in steps (B), (E) and (H) are similar. The method of separating the electroformed mother mold from the father mold in step (F) is unlimited. The method of separating the electroformed son mold from the mother mold in step (I) is also unlimited. Preferably, the method in step (F) and (I) can be achieved by hand.
The application of the molds produced by the method of the present invention is not limited. Preferably, the V-groove mold of the present invention is applied for fabricating a fiber array base block by injection moldings or press moldings, especially for a glass or plastic substrate. [0029]
The following embodiments of the present invention are examples of a V-groove mold by using the fabrication method of the present invention. [0030]

EXAMPLE 1

Fabrication for a Single V-Groove Mold

With reference to FIG. 1, a process indicating the sequence for fabricating a V-groove mold of the present invention is shown. A [0031] silicon substrate 100 is used as a matrix substrate in the present embodiment. A silver metal layer 110 is formed on the substrate 100 by sputtering. The sputtering is achieved in a Denton Vacuum Desk II equipment under a pressure of 75 mtorr and at an electric current of 45 mA. Then a silver metal layer 110 of a thickness between about 40 nm to 80 nm is obtained.

In one aspect, the

substrate

100 having the silver metal layer 110 proceeds in an electroforming process. According to the electroforming operating conditions in Table 1, a current density ranging from 2 ASD to 3 ASD is applied for 27 to 40 hours, and then the current is increased to a range between about 12 ASD to about 14 ASD for 8 days. A nickel-containing electroformed layer 120 of a thickness of 30 mm is obtained.

	TABLE 1


	Items	Operating conditions

Concentration of Ni(NH₂SO₃)4H₂O	450	g/L
Concentration of NiCl₂6H₂O	6	g/L
Concentration of H₃BO₃	40	g/L
pH value	4.0
Temperature	50°	C.
Current density	1-10	ASD
Surfactant	0.05-0.1	g/L
Concentration of STAR FUTURON
Stress relieving agent (STAR CS)	1-10	ml/L

The nickel-containing electroformed layer is then separated from the matrix substrate and taken as a V-groove father mold. There may be silicon residuals adhering to the father mold surface after mold separation. Additional etching processes may be applied to remove both the silicon residual and the metal layer on the father mold. The etching solution includes NH[0033] ₄OH and H₂O₂. The V-groove profile on the surface of the father mold will be improved after the etching process.

EXAMPLE 2

Mass Production for V-Groove Molds

With reference to FIG. 2, a sequence of the manufacturing process for mass-producing the mother molds of the present invention is shown. As shown in FIG. 2, a mother mold is obtained from the V-groove father mold (i.e. nickel-containing electroformed layer) [0034] 120 fabricated in example 1. A passive surface 125 is subsequently formed on the V-groove father mold 120 by a passivation process. The passivation process is performed by immersing the V-groove father mold 120 in a solution having a passivation reagent such as a solution of Na₂CO₃and a surfactant. An oxide layer (i.e. a passive surface) 125 is formed on the surface of the V-groove father mold 120 by a chemical method. The operating conditions for the passivation process are shown in Table 2.

TABLE 2

Items Operating conditions

Concentration of 12.5 g/L

Na₂CO₃solution

Temperature 60° C.

Type of cathode Titanium Mesh

Area ratio of cathode to anode 1:1

Current density for 1-3 ASD

cathode and anode

Reaction time 0.2-1 mins
When the V-[0035] groove father mold 120 is exposed to the passive solution, the cathode of the power supply is connected to the V-groove father mold 120 and the anode is connected to a titanium mesh. A degreasing process is executed for 30 seconds at the current equal to 2 ASD. By exchanging the location of the V-groove father mold 120 with that of titanium mesh, (i.e. connecting the anode of the power supply to the V-groove father mold 120 and connecting the cathode to the titanium mesh), the passivation process is achieved after being conducted for 30 seconds at the current equal to 2 ASD.
By repeating the electroforming process described in example 1, a nickel-containing electroformed layer (i.e. a mother mold) [0036] 140 is formed on the passive surface 125. The passive layer is then separated or released from the V-groove father mold.
With reference to FIG. 3, a sequence of the manufacturing process for mass-producing the father molds of the present invention is shown. As shown in FIG. 3, a [0037] son mold 150 is obtained from the V-groove mother mold 140. A passive surface 145 is subsequently formed on the V-groove mother mold 140 by a passivation process. The passivation process is performed by immersing the V-groove mother mold 140 in a solution having a passivation reagent such as a solution of Na₂CO₃and a surfactant. An oxide layer (i.e. a passive surface) 145 is formed on the surface of the V-groove mother mold 140 by a chemical method. The operating conditions for the passivation process are same as those shown in Table 2.
By repeating the electroforming process described in example 1, a nickel-containing electroformed layer (i.e. a son mold) [0038] 150 is formed on the passive surface 145. The passive layer is then separated or released from the V-groove mother mold 140. The son mold 150 can be taken as another nickel-containing father mold for further application of mass-production. According to this method, every nickel-containing metal mold can be treated as a mold to duplicate another mold.

EXAMPLE 3

Fabrication for a Single V-Groove Mold

With reference to FIG. 1, a process indicating the sequence for fabricating a V-groove mold of the present invention is shown. A Pyrex Substrate (i.e. a glass substrate) [0039] 100 is used as a matrix substrate in the present embodiment. A nickel metal layer 110 is formed on the substrate 100 by sputtering. The sputtering is achieved in a Denton Vacuum Desk II equipment under a pressure of 75 mtorr and at an electric current of 45 mA. Then a nickel metal layer 110 of a thickness between about 0.04 μm to 0.08 μm is obtained.

In one aspect, the

substrate

100 having the nickel metal layer 110 proceeds in an electroforming process. According to the electroforming operating conditions in Table 3, a current density ranges from 2 ASD to 3 ASD is applied for 27 to 40 hours, and then the current is increased to a range between about 12 ASD to about 14 ASD for 8 days. A nickel-containing (a nickel-iron alloy) electroformed layer 120 of a thickness of 30 mm is obtained.

	TABLE 3


	Items	Operating conditions

Concentration of Ni(SO₄) 6H₂O	200	g/L
Concentration of Fe₂(SO₄)₃	8	g/L
Concentration of H₃BO₃	25	g/L
Concentration of FeCl₃	5	g/L
Saccharin	3	g/L
pH value	2.8-4.2
Temperature	50-65°	C.
Current density	0.1-8	ASD
Surfactant	5	ml/L
Surface tension	27	mN/m

The nickel-containing electroformed layer is then separated from the matrix substrate and taken as a V-groove father mold. [0041]

EXAMPLE 4

Mass Production for V-Groove Molds

With reference to FIG. 2, a sequence of the manufacturing process for mass-producing the mother molds of the present invention is shown. As shown in FIG. 2, a mother mold is obtained from the V-groove father mold (i.e. nickel-containing electroformed layer) [0042] 120 fabricated in example 3. A passive surface 125 is subsequently formed on the V-groove father mold 120 by a passivation process. The passivation process is performed by immersing the V-groove father mold 120 in a solution having a passivation reagent such as a solution of K₂Cr₂O₇and a surfactant. An oxide layer (i.e. a passive surface) 125 is formed on the surface of the V-groove father mold 120 by a chemical method. The operating conditions for the passivation process are shown in Table 4.

TABLE 4

Items Operating conditions

Concentration of 0.6 g/L

K₂Cr₂O₇solution

Concentration of a passivation 50 ml/L

reagent for Nickel-iron alloy

Temperature 25-40° C.

Type of cathode Titanium Mesh

Area ratio of cathode to anode 1:1

Current density for 1-5 ASD

cathode and anode

Reaction time 0.2-1 mins
When the V-[0043] groove father mold 120 is exposed to the passive solution, the cathode of the power supply is connected to the V-groove father mold 120 and the anode is connected to a titanium mesh. A degreasing process is executed for 30 seconds at the current equal to 2 ASD. By exchanging the location of the V-groove father mold 120 with that of titanium mesh, (i.e. connecting the anode of power supply to the second V-groove mold 120 and connecting the cathode to the titanium mesh), the passivation process is achieved after being conducted for 30 seconds at the current equal to 2 ASD.
By repeating the electroforming process described in example 3, a nickel-containing (a nickel-iron alloy) electroformed layer (i.e. a mother mold) [0044] 140 is formed on the passive surface 125. The passive layer is then separated or released from the V-groove father mold. The nickel-containing electroformed layer (i.e. a mother mold) 140 can be taken as another nickel-containing mold for further application of mass-production by repeating the passivation process and electroforming process described above. According to this method, every nickel-containing metal mold can be treated as a mold to duplicate another mold.
The present invention provides a V-groove mold, which is used in fabricating a glass substrate or a silicon substrate of a fiber array base block through injection moldings or press moldings. Meanwhile, the present invention also provides a novel method for duplicating this V-groove mold rapidly by passivation process. In other words, the fabrication method facilitates the mass production of the glass substrates and silicon substrate by simplifying the duplication of plural copies of the same molds used for injecting molding (or press molding) in a short period. [0045]
Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. [0046]

Claims

What is claimed is:

1. A method for fabricating a mold for a fiber array base block comprising the steps of:

(a) providing a matrix substrate having a plurality of V-grooves, and then forming a metal layer on said matrix substrate;

(b) immersing said matrix substrate having said metal layer thereon with an electroforming metal ion solution and forming a father mold by an electroforming process; and

(c) separating said father mold from said matrix substrate.

2. The method as claimed in claim 1, further comprising:

(d) forming a passive layer on said father mold;

(e) forming a mother mold on said passive layer by an electroforming process in an electroforming metal ion solution; and

(f) separating said mother mold from said father mold.

3. The method as claimed in claim 2, further comprising:

(g) forming a passive layer on said mother mold;

(h) forming a son mold on said passive layer by an electroforming process in an electroforming metal ion solution; and

(i) separating said son mold from said mother mold;

wherein said son mold is taken as a father mold for mass-production.

4. The method as claimed in claim 1, wherein the material of said metal layer is selected from the group consisting of copper, nickel, silver, gold, and alloys thereof.

5. The method as claimed in claim 1, wherein said metal of said mold formed by said electroforming process is selected from the group consisting of nickel, nickel-containing alloys, silver, copper, gold, chromium, and aluminum.

6. The method as claimed in claim 2, wherein said metal of said mold formed by said electroforming process is selected from the group consisting of nickel, nickel-containing alloys, silver, copper, gold, chromium, and aluminum.

7. The method as claimed in claim 3, wherein said metal of said mold formed by said electroforming process is selected from the group consisting of nickel, nickel-containing alloys, silver, copper, gold, chromium, and aluminum.

8. The method as claimed in claim 5, wherein said nickel-containing alloys comprise nickel-iron alloy, nickel-cobalt alloy, nickel-tungsten alloy, nickel-manganese alloy, Ni—SiC, or Ni—Fe—TiO₂alloy.

9. The method as claimed in claim 6, wherein said nickel-containing alloys comprise nickel-iron alloy, nickel-cobalt alloy, nickel-tungsten alloy, nickel-manganese alloy, Ni—SiC, or Ni—Fe—TiO₂alloy.

10. The method as claimed in claim 7, wherein said nickel-containing alloys comprise nickel-iron alloy, nickel-cobalt alloy, nickel-tungsten alloy, nickel-manganese alloy, Ni—SiC, or Ni—Fe—TiO₂alloy.

11. The method as claimed in claim 1, wherein said electroforming metal ion solution used for electroforming in step (b) is a solution of Ni(NH₂SO₃) 4H₂O or NiSO₄.

12. The method as claimed in claim 2, wherein said passive layer is formed by exposing said surface of said father mold to plasma, a K₂Cr₂O₇solution or a basic solution.

13. The method as claimed in claim 12, wherein said basic solution is Na₂CO₃or NaOH.

14. The method as claimed in claim 3, wherein said father mold or son mold is applied for injection molding fiber array base blocks.

15. The method as claimed in claim 3, wherein said father mold or son mold is applied for press molding fiber array base blocks.

16. The method as claimed in claim 1, wherein the thickness of said metal layer ranges from 0.04 μm to 0.2 μm.

17. The method as claimed in claim 2, wherein said passive layer is a metal oxide layer.

18. The method as claimed in claim 1, wherein sputtering or evaporation forms said metal layer.

19. The method as claimed in claim 1, further comprising step (c1) etching said metal layer remaining on said father mold using H₂O₂and NH₄OH after step (c).