JP3664572B2 - Joining method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for bonding a crystal or glass material for use in, for example, manufacturing a lens used in an optical instrument or a glass micromachine.
[0002]
[Prior art]
In the case of bonding a glass lens used for an optical device, an ultraviolet curable resin adhesive is generally used. As an example of the joining process, first, a thin film such as an antireflection film is coated on the surface of a lens material optically polished in a vacuum, once taken out into the atmosphere, applied with an ultraviolet curable resin, and then again adhered in a vacuum. Take the process.
[0003]
On the other hand, as a bonding method used for micromachine fabrication, 1% HF is infiltrated into the interface of the superposed substrates, and the substrates are pressurized at a pressure of 4 kPa at room temperature and left for 2 hours to obtain a quartz substrate A method of joining together has been announced (Proceedings of Micro Eelctro Mechanical System '97 pp.299). In this method, a bonding pressure of 4 MPa is obtained.
[0004]
In addition to the bonding method used for micromachine fabrication, there has been reported a method of bonding by irradiating water ions onto the surface of the material to be bonded in a vacuum vessel to make it adhere, heat, and pressurize.
[0005]
[Problems to be solved by the invention]
First, for the joining method with UV curable resin,
(1) After the process performed in a vacuum, the process was complicated by a process of exposing to the atmosphere once, applying an ultraviolet curable adhesive, and joining again in a vacuum.
(2) Since the ultraviolet curable resin is applied in the air, fine dust in the air adheres to the resin, resulting in poor yield.
(3) Optical characteristics such as transmittance, reflectance, and refractive index deteriorate due to the presence of the ultraviolet curable resin layer.
(4) The optical characteristics are deteriorated due to misalignment due to curing of the ultraviolet curable resin.
There were problems such as.
[0006]
Next, in the method in which 1% HF is infiltrated into the interface of the substrates and the quartz substrates are bonded to each other, there is a problem in productivity because the bonding takes 2 hours. Further, when a large number of fine particles such as fine dust and dust floating in the air exist on the surface of the material to be joined, there is a problem that joining does not occur and yield decreases.
[0007]
Finally, after irradiating the surface of the material to be joined in the vacuum container with water ions, bonding is performed by heating, pressurizing, and water ions are radiated to the surrounding circuit, affecting the electrical characteristics. There was a problem of giving.
[0008]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a bonding method and apparatus capable of performing high-quality bonding with a high yield without using an adhesive. .
[0009]
[Means for Solving the Problems]
The invention described in claim 1 includes a step of HF-treating a bonded surface of a crystal or glass sample that is a bonded material, a step of irradiating a bonded surface of the bonded material in a vacuum container with a high-speed atomic beam, The materials to be joined after irradiation with high-speed atomic beams are heated and pressurized with HF (hydrogen fluoride) treated materials in purified air, inert gas, or nitrogen (N ₂ ) atmosphere. A bonding method characterized by comprising a step of bonding.
[0010]
With this configuration, by directly bonding in an inert atmosphere such as argon (Ar) or nitrogen (N ₂ ), the cleaned surface does not react with active gas molecules, resulting in a decrease in bonding yield or bonding. The deterioration of the quality of the part can be suppressed. Further, since the bonding is performed in an atmosphere with very few fine particles floating in the space, the fine particles are hardly mixed on the surface, and this can also suppress the yield reduction and the quality deterioration of the bonded portion. Furthermore, since it can join directly, without using adhesives, such as resin, the deterioration of the optical characteristic by presence of a resin layer and the fall of productivity by the position shift at the time of resin hardening are also prevented. By heating, the bonding time can be shortened and the treatment can be performed in a controlled atmosphere in a short time, so that there is no reduction in yield due to the adhesion of minute dust.
[0011]
The invention described in claim 2 includes a step of HF-treating a bonded surface of a crystal or glass sample that is a bonded material, a step of irradiating a bonded surface of the bonded material in a vacuum vessel with a high-speed atomic beam, A method of manufacturing a micromachine comprising a step of bonding materials to be bonded after irradiation with high-speed atomic beams by heating and pressurizing each other in a purified air, inert gas, or nitrogen atmosphere. is there.
[0012]
With this configuration, as in the case of claim 1, the cleaned surface reacts with active gas molecules, and the mixing of fine particles into the surface is prevented, thereby suppressing a decrease in bonding yield and a decrease in quality of the bonded portion. be able to. Similarly, the optical characteristics are degraded due to the presence of the resin layer, and the productivity is not lowered due to misalignment when the resin is cured, so that the bonding time can be shortened, and the yield is reduced due to the adhesion of minute dust. Absent.
[0013]
The present invention includes a step of HF-treating a bonded surface of a crystal or glass sample that is a bonded material, a step of irradiating a bonded surface of the bonded material in a vacuum vessel with a high-speed atomic beam, A bonding method characterized by comprising a step of heating and pressurizing the materials to be bonded to each other in a purified air, inert gas, or nitrogen (N ₂ ) atmosphere. By applying fast atomic beam (FAB) irradiation, the bonding surface can be instantly activated, enabling more efficient bonding, and in accordance with this, bonding time can be shortened or bonding conditions such as temperature can be reduced. Can be loosened. In addition, since the fast atomic beam is a neutral beam, the electrical characteristics of the surrounding circuits are not affected.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
(Example 1)
Joining was performed under the following conditions in a vacuum vessel maintained in a predetermined atmosphere by a vacuum pump.
(1) Synthetic quartz glass and synthetic quartz glass (15mm × 20mm × 0.5t)
(2) Synthetic quartz glass (15mm x 20mm x 0.5t) and cover glass (25mm x 25mm)
(3) Cover glass and cover glass (25mm × 25mm)
[0016]
First, the sample substrate was washed with acetone and lightly treated with 1% HF, and then the substrates were overlapped to allow 1% HF to permeate the interface. Then, it was possible to join in 5 minutes by pressurizing at a pressure of 10 kPa and heating to 100 ° C.
[0017]
(Example 2)
In joining of synthetic quartz glass and synthetic quartz glass, the surfaces to be joined between the samples were washed with acetone, lightly treated with 1% HF, and then left in a container filled with Ar for 24 hours. Thereafter, the samples were stacked in this container and pressurized at a pressure of 10 kPa, and joined after 2 hours.
[0018]
(Example 3)
FIG. 1 shows a bonding apparatus for carrying out the method of the present invention using high-speed atomic beam irradiation. This apparatus includes a pressure bonding device 20 disposed in the vacuum vessel 10 and a fast atomic beam source 30 disposed on the upper portion of the vacuum vessel 10.
[0019]
The crimping device 20 has a structure in which holders 23 a and 23 b are attached to sample holders 22 a and 22 b provided facing the stage 21. The sample bars W ₁ and W ₂ are held by the holders 23a and 23b with their joint surfaces facing substantially perpendicularly, and fast atom atoms from the upper fast atom beam source 3 from an angle close to 0 degrees with respect to the joint surface. It is intended to receive radiation. If two fast atomic beam sources are installed in an oblique direction, the fast atomic beam can be irradiated obliquely. At least one of the sample holders 22a and 22b can be moved toward the other by the driving device 24 and can be pressurized with a predetermined pressure.
[0020]
A heater H is attached so as to surround the periphery of the sample holders 23a and 23b. The heater H heats the holders 22a and 22b by heat radiation and further transfers heat to the sample by heat conduction. In this apparatus, a high-speed atomic beam is irradiated from an angle close to 0 degrees with respect to the bonding surface to activate the bonding surface, and heating is performed with a heater H to bond.
[0021]
The parallel plate electrode type fast atomic beam source 30 is a tripolar type as shown in detail in FIG. This has an outer cylinder 31 made of an insulating material (ceramics), and an upper portion thereof is covered with a top plate 33 having an introduction path 32 for introducing a gas G, and a plate-like cathode 35 having a gas introduction port 34 below it. A plate-like anode 37 having an anode hole 36 and a plate-like cathode 39 having an atom emission hole 38 are sequentially provided in parallel.
[0022]
In the fast atomic beam source 30, a DC voltage is applied between the three plate electrodes 35, 37 and 37, 39. As a result, positive ions in the plasma generated between the electrodes are accelerated by the electrode 39 and neutralized by exchanging charges with residual gas molecules when passing through the atom emission hole 38. During neutralization, the ion beam does not lose its energy, so it becomes a fast atom beam FAB and is emitted into the vacuum.
[0023]
The parallel plate electrode type fast atomic beam source 30 having such an ion acceleration and neutralization mechanism has an advantage that it can emit a beam superior in straightness as compared with the conventional fast atomic beam source. In addition, since the parallel plate electrode type fast atomic beam source 30 can arbitrarily control the neutralization rate depending on the shape of the fast atom emission electrode 39, the sample can be cleaned and activated efficiently.
[0024]
Below, a joining process is demonstrated. First, the sample to be joined is attached to the holding part. An elastic member for buffering may be attached to one of the holding portions. Then, a fast atomic beam of Ar is irradiated to the bonding surfaces of the samples W ₁ and W _{2 for} a predetermined time. Then, the atmosphere in the container is set to a vacuum, an inert gas atmosphere of a predetermined pressure, or an air atmosphere depending on the case, and the sample is heated with a heater at a predetermined temperature (depending on the material to be bonded, generally 70% of the melting point of the bonded sample). After heating to the following absolute temperature), the drive mechanism is operated to bring the bonding surfaces into contact with each other and gradually approach each other.
[0025]
In a sample of synthetic quartz glass, the sample substrate was first washed with acetone, lightly treated with 1% HF, and then irradiated with a fast atomic beam using Ar gas for 2 minutes. Thereafter, the samples were overlapped and joined when pressurized at a pressure of 10 kPa.
[0026]
【The invention's effect】
According to the present invention, a quartz or glass substrate can be bonded by treating the surface of quartz or glass with HF and then heating and pressurizing in a clean gas atmosphere such as Ar or in vacuum. Good optical elements and the like can be manufactured with a high yield.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing one embodiment of a bonding method of the present invention.
FIG. 2 is a diagram schematically showing a fast atomic beam source of the embodiment of FIG.
[Explanation of symbols]
10 Vacuum vessel 20 Crimping device 30 High-speed atomic beam source H Heater W ₁ and W ₂ materials to be joined

Claims (2)

A step of HF-treating a surface to be bonded of a crystal or glass sample to be bonded;
Irradiating a bonding surface of the material to be bonded with a high-speed atomic beam in a vacuum vessel;
A bonding method comprising a step of heating and pressurizing bonding materials to be bonded after irradiation with high-speed atomic beam in a purified air, an inert gas, or a nitrogen atmosphere. A step of HF-treating a surface to be bonded of a crystal or glass sample to be bonded;
Irradiating a bonding surface of the material to be bonded with a high-speed atomic beam in a vacuum vessel;
The the bodies to each other after the fast atom beam irradiation, cleaned air, or an inert gas or in a nitrogen atmosphere, a pressurized heating method micromachined characterized by having a step of pressurizing bonding.

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