JPH04280991A - Local plating device - Google Patents

Abstract

PURPOSE:To form a bump for connecting the inner lead of TAB and a semiconductor chip with high quality and precision. CONSTITUTION:A fiber 12 is introduced into a nozzle 11 for forming the jet 4a of a plating soln. 4, and the part to be plated is directly irradiated with a laser beam 9 from the selected part of the fiber 12 without totally reflecting the beam in the jet 4a.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The inventions according to claims 1 to 4 are, for example, TAB (Tape Automated
The present invention relates to a local plating device for plating and forming contacts and electrodes on parts of electronic equipment components, such as bumps for connecting inner leads of bonding and semiconductor chips.

0002

2. Description of the Related Art FIG. 5 is a sectional view showing a conventional local plating method for electrical terminals, which is disclosed in, for example, Japanese Patent Publication No. 60-45278. In the figure, a material to be plated 2 such as an electrical terminal is provided on the surface of a cathode 1. A mask 3 is provided around the material 2 to be plated. Further, a nozzle 5 that forms a jet stream 4a of plating solution is provided facing the material to be plated 2.

In such a conventional jet-type local plating method, a voltage is applied between the cathode 1 and an anode (not shown) to blow out a jet 4a of plating solution onto the area to be plated. With this method, it became possible to perform local plating at high speed without masking each material 2 to be plated.

Next, the conventional laser-assisted jet plating method was developed to improve the jet plating method.
-Enhanced Jet Plating) will be explained. Figure 6, for example, is from ``Electrochemical Science and Technology'' (J.Electro
chem. Soc: “Electrochemica
lScience And Technology”
, Vol. 132) It is a sectional view showing the conventional laser-assisted jet plating method shown in November 1985, pages 2575 to 2581. In the figure, a plating bath 6 having a nozzle 5 is made of quartz through which a laser 9 passes. An anode 7 is provided within the plating tank 6. Furthermore, the plating tank 6 is provided with an air blender 6a and a plating solution feeding port 6b. Outside the plating tank 6,
A lens 8 is provided, and the lens 8 focuses the laser 9 near the nozzle 5 of the plating solution 4.

In this method, a voltage is applied between the anode 7 and the cathode 1 to blow out a jet 4a of the plating solution 4 onto the plating area, and a laser 9 is focused into the plating solution 4 by a lens 8. There is. Due to the difference in refractive index between the plating solution 4 and the surrounding atmosphere, the irradiated laser 9 is
It reaches the part of the material to be plated 2 to be plated while being totally reflected within a. The plated material 2 irradiated with the laser 9 becomes partially hot, so the plating speed increases and
A dense plating film can be obtained.

[0006]

[Problem to be solved by the invention] In the conventional jet plating method that does not use a laser as described above, the plating film tends to be granular, and cracks occur at the interface between the plating film and the material to be plated 2. There were some problems, such as: In addition, in the laser-assisted jet plating method as described above, when the jet 4a is disturbed, the laser 9 is no longer totally reflected within the jet 4a, causing fluctuations in the laser output that reaches the plating area, resulting in variations in plating quality. There was a problem.

The inventions according to claims 1 to 4 have been made with the aim of solving the above-mentioned problems, and are aimed at stabilizing the laser output reaching the plating part and making the plating quality uniform. The purpose is to obtain a local plating device that can perform the following steps.

[0008]

[Means for Solving the Problems] The local plating device of the invention according to claim 1 introduces a fiber for directly irradiating a laser beam onto a plating area inside a nozzle for forming a jet of plating solution. This is what I did. The local plating device of the invention according to claim 2 is one in which a fiber for directly irradiating the plating portion with a laser is provided outside the nozzle and separately from the nozzle for forming a jet of plating solution. . The local plating apparatus of the invention according to claim 3 uses a laser transmission nozzle made of a material that transmits the laser as a nozzle for forming a plating solution jet, and directly irradiates the plating portion with the laser through the laser transmission nozzle. This is what I did. The local plating device of the invention according to claim 4 is made of a material that transmits the laser, and the laser transmission mask is used to completely reflect the laser internally and transmit it to directly irradiate the plating area. It is installed around the plated part of the material.

[0009]

In the invention according to claim 1, the laser is directly irradiated onto the plating portion from the tip of the fiber introduced into the nozzle without being totally reflected within the jet of plating solution. In the invention according to claim 2, the laser is directly irradiated onto the plating portion from the tip of the fiber provided separately outside the nozzle without causing total reflection within the jet of the plating solution. In the invention according to claim 3, the laser is transmitted through total reflection within the wall of the laser transmission nozzle, and the laser is transmitted from the end of the laser transmission nozzle to the plating portion without being totally reflected within the jet of the plating solution. irradiate directly. In the invention according to claim 4, the laser is transmitted by total reflection within the laser transmission mask, and from the end of the laser transmission mask,
Laser is directly irradiated onto the plating area without total reflection within the jet of plating solution.

0010

Embodiments Hereinafter, embodiments of the invention according to claim 1 will be described with reference to the drawings. FIG. 1 shows an embodiment of the invention according to claim 1 (
7 is a configuration diagram showing a local plating apparatus according to the first embodiment, in which the same or equivalent parts as in FIG. 6 are denoted by the same reference numerals, and the explanation thereof will be omitted. In the figure, a nozzle 11 provided facing the material to be plated 2 is provided with a fiber introduction port 11a. A fiber 12 is introduced into the nozzle 11 through this fiber introduction port 11a. The tip of this fiber 12 is located at the tip of the nozzle 11. Further, the base end of the fiber 12 is connected to a laser oscillator 14 via a laser input optical system 13.

In the local plating apparatus configured as described above, a voltage is applied between the cathode 1 and the anode (not shown) so that a current flows through the jet 4a, and the plating solution 4 flows through the nozzle 11. It is sprayed from the tip onto the plating portion of the material to be plated 2. In addition, the laser 9 oscillated by the laser oscillator 14
is input into the fiber 12 by the laser input optical system 13 so as to be totally reflected within the fiber 12. The incident laser beam 9 is transmitted through the fiber 12 and is irradiated onto a portion to be plated, that is, a plating portion, simultaneously with the injection of the plating solution 4, with an arbitrary time delay, or intermittently. This increases the plating speed and provides a dense plating film. In addition, in this local plating device, there is no need to totally reflect the laser 9 within the jet 4a, and the laser 9 is directly irradiated from the tip of the fiber 12 to the area to be plated, so even if the jet 4a is disturbed, The output of the laser 9 that reaches the plating portion is always stable, so variations in plating quality are suppressed.

The laser 9 used in the above embodiment is Y
It was an AG laser fundamental wave, second harmonic, and argon ion laser, and the oscillation output was 20W to 40W. Further, the oscillation time was 1 to 2 seconds for continuous waves and 2 to 3 seconds for pulsed waves. As plating solution 4, a cyan-based gold plating solution was used, and the gold content was 12 g/l. The current density of plating is 8A/cm2 to 15A/cm2.
It was cm2. The distance between the tip of the nozzle 11 and the material to be plated 2 was 1 mm to 5 mm, but since the laser 9 irradiated from the fiber 12 has a divergence angle, the narrower the distance, the smaller the diameter. The plated metal portion 15 could be formed. For example, when the above-mentioned interval was 1 mm, the diameter of the plated metal portion 15 was 1.03 mm, and the thickness of the plated metal portion 15 was 15 μm to 35 μm.

In the above embodiment, the fiber 12 is arranged at the center of the nozzle 11, and by constricting the tip of the nozzle 11, the flow of the plating solution 4 is made into a jet 4a.
The jet stream 4a is also directed toward the center of the jet stream 4a, thereby realizing a jet stream 4a without hollow holes. Therefore, it goes without saying that the shape of the nozzle 11 needs to be changed depending on the location of the fiber 12.

Next, an embodiment of the invention according to claim 2 will be explained with reference to the drawings. FIG. 2 is a configuration diagram showing a local plating apparatus according to an embodiment (second embodiment) of the invention according to claim 2. In the figure, a fiber 12 that transmits the laser beam 9 and irradiates the plated portion has its tip facing the plated portion at right angles. In the vicinity of the fiber 12, first and second nozzles 21 and 22, each of which sprays a jet stream 4a of the plating solution 4 onto the plating portion, are arranged so as to sandwich the fiber 12 therebetween. The tips of the first and second nozzles 21 and 22 each face the plating portion at a predetermined angle. Further, the fiber 12 and each nozzle 21, 22 are provided with a movable mechanism (not shown) for independently moving each nozzle.
is provided.

In such a local plating apparatus, a voltage is applied between the cathode 1 and the anode (not shown) so that a current flows through the jet stream 4a, and the plating solution 4 is supplied to each nozzle 21.
, 22 onto the plating portion of the material to be plated 2. At the same time, the laser 9 is emitted from the tip of the fiber 12.
is irradiated directly onto the plating area. The type of laser 9, irradiation method, oscillation output, oscillation time, etc. at this time are the same as in the first embodiment. Further, the type of plating solution 4 and the current density for plating are also the same as in the first embodiment. Also in the local plating apparatus of this embodiment, since the laser 9 is directly irradiated onto the plating area, the same effect as that in FIG. 1 can be obtained. Also,
By moving the fiber 12 and each nozzle 21, 22 independently, the plating jet conditions and the power density conditions of the laser 9 can be easily and independently controlled.

Next, an embodiment of the invention according to claim 3 will be explained with reference to the drawings. FIG. 3 is a configuration diagram showing a local plating apparatus according to an embodiment (third embodiment) of the invention according to claim 3. In the figure, a liquid feeding tube 2 for feeding plating solution 4 is shown.
At the tip of 3, a jet 4 of plating solution 4 is applied to the plating part.
A laser transmission nozzle 24 for spraying a is connected. The liquid sending tube 23 is made of a material that is opaque to the wavelength of the laser 9 emitted by the laser oscillator 14, such as sintered alumina. Further, the laser transmission nozzle 24 is made of a material that transmits the laser 9, such as fused silica, and its entrance end face 24a and exit end face 24b are each processed to be optically smooth with respect to the laser 9. Furthermore, a laser beam 9 is provided on the inner peripheral surface of the laser transmission nozzle 24.
Gold plating may be applied to increase the transmission efficiency. Furthermore, the emission end face 24b is narrowed down so that the laser beam 9 is concentrated at one point.

In the local plating apparatus configured as described above, the method of applying voltage to the jet 4a, the method of applying voltage to the jet 4a,
The injection method, the type of laser 9, the type of plating solution 4, the plating current density, etc. are the same as in the first embodiment. The laser 9 oscillated by the laser oscillator 14 is incident into the laser transmission nozzle 24 from an entrance end face 24 a provided on a part of the end face of the laser transmission nozzle 24 by the laser entrance optical system 13 . The incident laser beam 9 is transmitted while being totally reflected within the wall of the laser transmission nozzle 24, and is emitted from the other end surface, the output end surface 24b.

In the local plating apparatus of this embodiment, the laser beam 9 is transmitted through the wall of the laser transmission nozzle 24 and directly irradiates the plating area without being totally reflected within the plating solution 4. The same effect can be obtained. Note that in the case of the third embodiment, the laser 9 is used rather than using a fiber.
Since the transmission efficiency of the second embodiment is rather low, it was necessary to increase the laser oscillation output or the laser oscillation time by 20% to 30% compared to the first embodiment.

Next, an embodiment of the invention according to claim 4 will be described with reference to the drawings. FIG. 4 is a configuration diagram showing a local plating apparatus according to an embodiment (fourth embodiment) of the invention according to claim 4. In the figure, around the plating part of the plated material 2,
Laser-transmissive masks 25 and 26 made of a material transparent to the laser 9, for example fused silica, are provided. These laser transmission masks 25 and 26 are for locally covering the material 2 to be plated.

[0020] In the above-mentioned local plating apparatus,
The method of applying voltage to the jet 4a, the method of ejecting the jet 4a, the type of laser 9, the type of plating solution 4, the plating current density, etc. are the same as in the first embodiment. Laser oscillator 1
The laser 9 oscillated in step 4 is input into the laser transmission mask 25 by the laser incidence optical system 13 from the incidence end face 25 a provided on a part of the end face of the laser transmission mask 25 . The incident laser beam 9 is transmitted through the laser transmission mask 25 while being totally reflected, and is emitted from the other end surface, the output end surface 25b.

In the local plating apparatus of this embodiment, the laser beam 9 is transmitted through the laser transmission mask 25 and directly irradiates the plating area without being totally reflected in the plating solution 4, so that it is similar to that in FIG. The effect of this can be obtained. In addition, the above 4th
In the case of this embodiment, since the transmission efficiency of the laser 9 is slightly lower than that of using a fiber, the laser oscillation output or laser oscillation time is reduced by 30% compared to the first embodiment, although it depends on the width of the laser transmission mask 25. needed to be increased by ~40%. Further, in each invention, the number and shape of nozzles and fibers are not particularly limited.

[0022]

Effects of the Invention As explained above, the local plating apparatus of the invention according to claim 1 introduces a fiber into a nozzle,
Since the laser is directly irradiated from the tip of the fiber to the plating area without total reflection within the jet of plating solution, the laser output reaching the plating area can be stabilized even when the jet is turbulent. This has the effect of suppressing variations in plating quality and uniformly improving it. In addition, the local plating apparatus of the invention according to claim 2 has a fiber for directly irradiating the plating portion with a laser outside the nozzle and is separate from the nozzle, so that the effect of the invention according to claim 1 is not achieved. In addition, there is also the effect that it becomes easier to independently control the jet flow conditions of the plating solution and the power density conditions of the laser. Furthermore, the local plating apparatus of the invention according to claim 3 uses a laser transmission nozzle made of a material that transmits laser, and the laser is directly irradiated to the plating area through this laser transmission nozzle. In addition to the effects of the invention, there is also the effect of simplifying the device configuration. Furthermore, the local plating apparatus of the invention according to claim 4 is provided with a laser transmission mask that is made of a material that transmits laser and that completely internally reflects the laser and transmits it to directly irradiate the plating area. Since it is provided around the section, in addition to the effect of the invention according to claim 1, there is also an effect that the device configuration is simplified.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the invention according to claim 1.

FIG. 2 is a configuration diagram showing an embodiment of the invention according to claim 2.

FIG. 3 is a configuration diagram showing an embodiment of the invention according to claim 3.

FIG. 4 is a configuration diagram showing an embodiment of the invention according to claim 4.

FIG. 5 is a cross-sectional view for explaining a conventional jet-type local plating method.

FIG. 6 is a cross-sectional view for explaining a conventional laser-assisted jet plating method.

[Explanation of symbols]

2 Plated material 4 Plating solution 4a Jet stream 9 Laser 11 Nozzle 12 Fiber 21 First nozzle 22 Second nozzle 24 Laser transmission nozzle 25 Laser transmission mask

Claims (4)

[Claims] 1. In a local plating device that irradiates a laser while spraying a jet of plating solution onto a plating portion of a material to be plated, the laser is directly irradiated onto the plating portion within a nozzle that forms the jet. A local plating device characterized in that a fiber is introduced for the purpose of plating. 2. In a local plating device that irradiates a laser while spraying a jet of plating solution onto a plating part of a material to be plated, the laser is directly applied to the plating part outside the nozzle that forms the jet. A local plating device characterized in that a fiber for irradiation is provided separately from the nozzle. 3. A local plating device that irradiates a plating part of a material to be plated with a laser while spraying a jet of a plating solution, the device being made of a material that transmits the laser, and forming the jet and irradiating the plating solution with a laser. 1. A local plating apparatus comprising a laser transmission nozzle for totally reflecting and transmitting a laser beam within a wall portion and directly irradiating the plating portion. 4. A local plating device that irradiates a laser beam while spraying a jet of plating solution onto a plated portion of a material to be plated, wherein the device is provided around the plated portion of the material to be plated, and that A local plating apparatus comprising a laser transmission mask made of a transparent material and configured to completely internally reflect and transmit the laser beam to directly irradiate the plating area.