JP4147678B2 - Anodic bonding equipment - Google Patents

Description

【００２８】
この結果、実施例１、すなわち酸化チタンTiO2のみのコーティングによるカーボンヒータでは、十分な表面抵抗が得られなかったが、実施例２、すなわち酸化チタンTiO2に＋ニッケルNiを３０％含有したものにおいては、前記記載の目的に用いるのに十分な結果が得られた。
【００２９】
次に、表２に、剥離強度の測定結果を示す。ここでは、実施例１及び実施例２を施したカーボンヒータに、粘着テープ（900g/20mm）を貼付け、これを剥離してカーボン基材とコーティングとの密着性を確認した。
【００３０】
【表２】

【００３１】
結果、何れの実施例においても、ヒートサイクルの前及び後において剥離は見られなかった。また、カーボンヒータを割った際にも、その破断面近傍のコーティングが剥がれるようなことがなかった。これに対し、同程度のヒートサイクルを行った後のカーボンコーティングを施したカーボンヒータは、表面が変色し、更にコーティングが剥離した部分が多く確認されている。また、部分的に基材のカーボンまで損傷していた箇所も確認されている。従って、従来のカーボンヒータに施されたカーボンコーティングに比べ、実施例１及び２のコーティングは、基材と被膜の密着性に優れ、また、ヒートサイクルを繰り返しても被膜自体が劣化しにくいことが確認された。
【００３２】
また、実施例１及び２のカーボンヒータ上に、ステンレス鋼板製（ＳＵＳ製）、重さ１．０ｋｇ、板状の金属治具を摺接させて、その耐摩耗性を確認した。その結果、何れの実施例においても、１５０往復程度では表面のコーティングが摩耗したり剥離したりしないことが確認された。一方、従来のカーボンコーティングでは、１往復の摺接でカーボンヒータのコーティングが部分的に摩擦し、剥離することが確認されている。
【００３３】
表３は、従来のカーボンコーティングと上記実施例１及び２の温度分布特性を測定したグラフである。測定は、各カーボンヒータ上にシリコンウェハを載置し、この内部温度を測定することによって行った。
【００３４】
【表３】

【００３５】
これより、本実施例１及び２における温度特性が、従来のものに劣ることがないことが確認された。
【００３６】
【発明の効果】
以上の如く本発明によって、カーボンヒータ本来の良好な熱伝導特性を損なわず、耐摩耗性及び剥離強度が優れたカーボンヒータを備えた陽極接合装置を提供することができる。
【００３７】
また、酸化チタンTiO2を主成分とした皮膜に、ニッケルNiを含有したものを用いるカーボンヒータを備えた本発明においては、さらにその導電性が良好となり、従って例えば、カーボンヒータを陽極接合における電極として好適に用いることができる。
【図面の簡単な説明】
【図１】本発明に係る陽極接合装置によって陽極接合されるガラス基板とキャビティプレートの一例を示す斜視図である。
【図２】陽極接合されるガラス基板とキャビティプレートを治具に納めてなる組立体の側面図である。
【図３】本発明の一実施形態に係る陽極接合装置の概略構成図である。
【図４】本発明の陽極接合装置で用いられるカーボンヒータの平面図及び側断面図である。
【符号の説明】
１０ ガラス基板
１１ キャビティプレート
２０ 治具
２１、２２ 金属板
２３ 締結部材
２５ 組立体
３０ 陽極接合装置
３１ 密閉室
３２ カーボンヒータ
３２、３３ カーボンヒータ
３４ スペーサ
３５ 交流電圧源
３６ 直流電圧源
３７ 電極端子
４０ カーボンヒータ
４１ 基材
４２ 皮膜[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an anodic bonding apparatus for bonding a semiconductor substrate and a glass substrate without using an adhesive.
[0002]
[Prior art]
Anodic bonding is widely used as a technique for bonding silicon and other semiconductor substrates and glass substrates precisely and reliably in the manufacture of semiconductor devices and the like. An anodic bonding apparatus used for realizing anodic bonding includes a structure for applying a DC voltage of several hundred volts to an assembly in which a semiconductor substrate and a glass substrate are brought into contact with each other. And a structure for heating the assembly to several hundred degrees. By using the apparatus configured in this manner, the assembly is heated and a DC voltage is applied to the assembly, so that sodium positive ions Na + in the glass substrate (Pyrex glass) move to the cathode side, and the glass A space charge layer is formed at the bonding interface of the substrate, and a high electric field is generated. This high electric field generates an electrostatic attractive force at the bonding interface (between the substrates), leading to bonding. For example, as such an anodic bonding apparatus, one disclosed in JP-A-8-88154 is known.
[0003]
On the other hand, as an anodic bonding apparatus, one using a heating apparatus using a carbon heater for heating the assembly is known. Carbon heaters generally have the advantages of high responsiveness to rapid heating and rapid cooling, and uniform surface temperature distribution. For anodic bonding that requires uniform and highly controlled heating of the assembly, Very convenient.
[0004]
Conventionally, as a carbon heater used in a heating device, in order to increase its heat resistance and service life, carbon C is generally used on its surface, and also silicon carbide SiC, silicon nitride SiN, boron nitride BN, aluminum nitride AlN. Etc. (JP-A-5-135858) is used.
[0005]
[Problems to be solved by the invention]
However, in the anodic bonding apparatus provided with the conventional carbon heater with the coating, the following problems have occurred.
[0006]
(1) In a certain kind of anodic bonding apparatus, an assembly to be heated may be mounted on a plate-like carbon heater directly or via a jig. In this case, the coating applied to the surface of the carbon heater may be peeled off or worn due to friction between the carbon heater and the assembly (or jig) due to the insertion and removal of the assembly. Moreover, carbon may precipitate from the part from which the said coding peeled by repetition of rapid heating or rapid cooling of a carbon heater. The peeled surface coating material and the deposited carbon are dispersed as fine particles in the anodic bonding apparatus, contaminating the atmosphere, thereby deteriorating the yield of the workpiece (assembly).
[0007]
(2) In some types of anodic bonding apparatuses, the carbon heater may function as one of electrodes for applying a DC voltage to an assembly mounted on the carbon heater. However, the coating material other than carbon C does not have sufficient conductivity as an electrode necessary for the voltage application.
[0008]
An object of the present invention is to solve the above-mentioned conventional problems and provide an anodic bonding apparatus provided with a carbon heater provided with a coating excellent in wear resistance, peel strength, conductivity, etc. without impairing the original performance of the carbon heater. Is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an anodic bonding apparatus for bonding a semiconductor substrate and a glass substrate, which are provided as an assembly having their surfaces in contact with each other, without using an adhesive. A first electrode for applying a DC voltage from the DC voltage source to the semiconductor substrate side of the assembly; and a second electrode for applying a DC voltage from the DC voltage source to the glass substrate side of the assembly. A carbon heater for heating the electrode and the assembly, wherein the surface of the base material mainly composed of carbon C is coated with a film mainly composed of titanium oxide TiO2, and the carbon heater is heated. Therefore, an AC voltage source for applying an AC voltage thereto is provided.
[0010]
According to the experiments by the inventors, the film mainly composed of titanium oxide TiO2 in the carbon heater is inferior in the conductive performance as compared with the conventional carbon coating, but has excellent wear resistance and peel strength, Thus, it was confirmed that the good thermal characteristics of the carbon heater were not impaired. Therefore, the degree of film peeling and wear due to friction with the assembly and other parts can be extremely reduced, and the risk of contamination of the atmosphere in the apparatus due to film peeling and wear can be minimized. it can.
[0011]
In the present invention, the carbon heater has a mounting surface on which the assembly is mounted, and the film has conductivity, and is configured to function as either the first electrode or the second electrode. be able to.
[0012]
In this case, it is preferable that the film of the carbon heater contains nickel Ni. According to experiments by the inventors, it has been confirmed that by including nickel Ni in the coating, the conductivity of the surface of the carbon heater is improved, and the carbon heater is suitably used as an electrode in anodic bonding.
[0013]
Here, the content of titanium oxide TiO2 and nickel Ni in the film of the carbon heater is preferably about 7 to 3.
[0014]
Moreover, it was confirmed that sufficient thickness (abrasion resistance, heat resistance, temperature characteristics) can be obtained when the thickness of the film is about 100 μm. In addition, when placing the workpiece directly on the carbon heater, it is more preferable to make the surface of the coating smoother in order to improve heat transferability. In this case, titanium oxide TiO ₂ or titanium oxide TiO After spraying ₂ and nickel Ni on the surface of the substrate, it is necessary to carry out a finishing process such as relatively large polishing. The surface roughness obtained by performing only thermal spraying and simple post-treatment is Ra = 4.0-6.0 μm, Rmax = 30-50 μm, but even this level of surface roughness is sufficient. It was confirmed that temperature characteristics were obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an anodic bonding apparatus used in manufacturing a head in an ink jet printer will be described. FIG. 1 shows a glass substrate 10 to be anodically bonded by this apparatus and a cavity plate 11 made of silicon Si. A groove 10a is formed in the glass substrate 10, and an electrode for driving the ink jet head is provided on the bottom wall. Grooves 11 a and the like are formed in the cavity plate 11, and an electrostatic actuator (vibration plate and electrode) for discharging ink is formed by bonding the cavity plate 11 on the glass substrate 10. A lid substrate (not shown) is further bonded onto the cavity plate 11 to form a nozzle, an ink chamber, and an ink path.
[0016]
The glass substrate 10 and the cavity plate 11 are aligned and overlapped with high accuracy, and are mounted on an anodic bonding apparatus in a state of being placed in a predetermined jig 20 as shown in FIG. The jig 20 includes a pair of rectangular metal plates 21 and 22 sandwiching the glass substrate 10 and the cavity plate 11 in an overlapped state, and is fixed to each other by insulating fastening members 23 provided at the four corners. .
[0017]
The jig 20 maintains the alignment of the glass substrate 10 and the cavity plate 11 with high accuracy. The opposing surfaces of the metal plates 21 and 22 are in surface contact with the outer surfaces of the glass substrate 10 and the cavity plate 11, respectively. Therefore, as described later, a DC voltage applied by the anodic bonding apparatus of the present invention is applied to the metal plate. By applying to 21 and 22, it is ensured that a voltage is applied to the substrate. In this specification, the glass substrate 10 and the cavity plate 11 held by the jig 20 are collectively referred to as an assembly 25.
[0018]
FIG. 3 is a schematic configuration diagram of an anodic bonding apparatus according to an embodiment of the present invention. The anodic bonding apparatus 30 has a sealed chamber 31 sealed from the outside air. The inside of the sealed chamber 31 is highly dust-free and is filled with nitrogen gas when anodic bonding is performed. A pair of upper and lower carbon heaters 32 and 33 are disposed in the sealed chamber 31 and are fixed in the sealed chamber 31 by any attachment means (not shown). Each carbon heater 32 and 33 has a substantially rectangular shape, and a predetermined interval is maintained by spacers 34 on both sides thereof. The assembly 25 which is a workpiece is placed on the lower carbon heater 32 and held between the carbon heaters 32 and 33 as shown in the figure. Although not shown in the drawing, a positioning pin protrudes from the upper surface of the lower carbon heater 32, and the assembly 25 is slid on the carbon heater 32 so that the two sides are brought into contact with the pin. By making contact, the assembly 25 is positioned.
[0019]
As shown in the figure, both poles of the AC voltage source 35 are grounded on both sides of the lower carbon heater 32, and an AC voltage is applied for heating. The carbon heaters 32 and 33 are heated to a predetermined temperature by the application of the AC voltage. At this time, the spacer 34 is preferably formed of copper or other metal having a low resistivity. The assembly 25 is heated to a predetermined temperature by heating while controlling the carbon heaters 32 and 33.
[0020]
The anodic bonding apparatus 30 further includes a DC voltage source 36 for applying a DC voltage to the assembly 25. The anode of the DC voltage source 36 is connected to the electrode terminal 37. The electrode terminal 37 is in contact with the metal plate 21 (on the cavity plate 11 side) above the assembly 25 and applies a voltage for anodic bonding thereto. On the other hand, the cathode of the DC voltage source 36 is connected to the lower carbon heater 32. As will be described in detail later, since the carbon heater 32 is coated with a conductive member, the DC voltage from the DC voltage source 36 passes through the carbon heater 32 and below the assembly 25 placed thereon. It is applied to the metal plate 22. In this way, a DC voltage of several hundred volts is applied to both metal plates of the assembly 25 and is applied between the glass substrate 10 and the cavity plate 11 held therebetween. In one embodiment, anodic bonding of the glass substrate 10 and the cavity plate 11 was performed by applying a DC voltage of 800 V for 5 minutes in a nitrogen atmosphere having a temperature of about 340 ° C.
[0021]
FIG. 4 shows the external shape of a carbon heater (32 or 33) used in the anodic bonding apparatus 30. The carbon heater 40 has a substantially rectangular shape when seen in a plan view, and its four corners are largely cut off. In the figure, the hatched regions 40 a on both sides indicate the grounding region of the spacer 34. That is, the spacer 34 has a trapezoidal cross section along the hatched area 40a, and the end surface thereof is brought into surface contact with the spacer 34 during assembly. In one embodiment, the outer dimensions of the carbon heater 40 are width 340 × depth 220 × thickness 6.5 mm.
[0022]
As shown in FIG. 5B, the carbon heater 40 is formed by coating the surface of a base material 41 made of carbon with a film 42 containing 30% nickel Ni in titanium oxide TiO2. . In the example, the coating 42 was applied except for the region 40a. As will be shown in later examples, the film 42 is excellent in wear resistance, adhesion to a substrate, heat resistance, conductivity, and the like. In the anodic bonding apparatus 30, the surface of the carbon heater 40 needs to be able to withstand friction when the assembly 25 is taken in and out. Moreover, it is necessary that the material does not peel off due to repeated rapid temperature changes. Furthermore, it must be applied to the assembly 25 without reducing the applied DC voltage. The carbon heater 40 coated with the film 42 meets these requirements and enables high-quality bonding by the anodic bonding apparatus 30.
[0023]
As mentioned above, although one embodiment of the present invention has been described with reference to the drawings, the present invention is not limited to the matters shown in the embodiment, and the description of the claims and the detailed description of the invention, as well as the well-known technology Based on the above, a range in which those skilled in the art can make changes and applications thereof is included. In the anodic bonding apparatus shown in the above embodiment, a DC voltage is applied via a carbon heater, but the upper electrode terminal is configured in the same manner, and the electrode terminal is directly connected to the lower metal plate. You may make it contact. In this case, since the carbon heater does not necessarily require conductivity, a carbon film that does not contain nickel Ni may be used as the coating on the surface.
[0024]
【Example】
The inventors created two types of carbon heaters according to the present invention and measured their performance. In the experiment, titanium oxide TiO2 (Example 1) and titanium oxide TiO2 containing 30% nickel Ni (Example 2) are sprayed on the surface of a carbon substrate generally used for a carbon heater. The surface resistance, peel strength, abrasion resistance, and temperature distribution characteristics were measured.
[0025]
In addition, when the surface roughness of the sprayed coating was measured before these measurements, Ra = 4.0 to 6.0 μm and Rmax = 30 to 50 μm. For measurement of surface resistance, peel strength, wear resistance, and temperature distribution characteristics, each sample was subjected to 6 heat cycles of 450 ° C x 7h in a nitrogen atmosphere to obtain data over time. The surface resistance and peel strength were measured before and after that. The conditions of the above heat cycle are the same as or slightly severer than the conditions in which a conventional carbon coating-coated carbon heater is confirmed to have a peeled portion on the surface coating.
[0026]
Table 1 shows the measurement results of the surface resistance before and after the heat cycle.
[0027]
[Table 1]

[0028]
As a result, in Example 1, that is, a carbon heater coated only with titanium oxide TiO2, sufficient surface resistance could not be obtained, but in Example 2, that is, titanium oxide TiO2 containing 30% nickel + Ni. Sufficient results were obtained for the purposes described above.
[0029]
Next, Table 2 shows the measurement results of peel strength. Here, the adhesive tape (900g / 20mm) was affixed on the carbon heater which applied Example 1 and Example 2, this was peeled, and the adhesiveness of a carbon base material and coating was confirmed.
[0030]
[Table 2]

[0031]
As a result, in any of the examples, no peeling was observed before and after the heat cycle. Further, when the carbon heater was broken, the coating near the fracture surface was not peeled off. On the other hand, in the carbon heater that has been subjected to the carbon coating after the same degree of heat cycle, the surface has been discolored and many portions where the coating has peeled off have been confirmed. Moreover, the location which was partially damaged to the carbon of the base material was also confirmed. Therefore, compared with the carbon coating applied to the conventional carbon heater, the coatings of Examples 1 and 2 are excellent in adhesion between the base material and the film, and the film itself is not easily deteriorated even after repeated heat cycles. confirmed.
[0032]
Further, on the carbon heaters of Examples 1 and 2, a stainless steel plate (made of SUS), a weight of 1.0 kg, and a plate-shaped metal jig were slidably contacted to confirm the wear resistance. As a result, in any of the examples, it was confirmed that the surface coating did not wear or peel off after about 150 reciprocations. On the other hand, in the conventional carbon coating, it has been confirmed that the coating of the carbon heater partially rubs and peels in one reciprocal sliding contact.
[0033]
Table 3 is a graph obtained by measuring the temperature distribution characteristics of the conventional carbon coating and Examples 1 and 2 described above. The measurement was performed by placing a silicon wafer on each carbon heater and measuring the internal temperature.
[0034]
[Table 3]

[0035]
From this, it was confirmed that the temperature characteristics in Examples 1 and 2 were not inferior to the conventional ones.
[0036]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an anodic bonding apparatus including a carbon heater excellent in wear resistance and peel strength without impairing the original good heat conduction characteristics of the carbon heater.
[0037]
In addition, in the present invention provided with a carbon heater using a nickel oxide-containing film containing titanium oxide TiO2 as a main component, the conductivity is further improved. For example, the carbon heater is used as an electrode in anodic bonding. It can be used suitably.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a glass substrate and a cavity plate that are anodically bonded by an anodic bonding apparatus according to the present invention.
FIG. 2 is a side view of an assembly in which a glass substrate to be anodically bonded and a cavity plate are placed in a jig.
FIG. 3 is a schematic configuration diagram of an anodic bonding apparatus according to an embodiment of the present invention.
FIG. 4 is a plan view and a side sectional view of a carbon heater used in the anodic bonding apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Glass substrate 11 Cavity plate 20 Jigs 21 and 22 Metal plate 23 Fastening member 25 Assembly 30 Anodic bonding device 31 Sealed chamber 32 Carbon heater 32 and 33 Carbon heater 34 Spacer 35 AC voltage source 36 DC voltage source 37 Electrode terminal 40 Carbon Heater 41 Base material 42 Coating

Claims (4)

In an anodic bonding apparatus for bonding a semiconductor substrate and a glass substrate provided as an assembly in contact with each other without using an adhesive,
A DC voltage source;
A first electrode for applying a DC voltage from the DC voltage source to the semiconductor substrate side of the assembly;
A second electrode for applying a DC voltage from the DC voltage source to the glass substrate side of the assembly;
A carbon heater for heating the assembly, wherein the surface of the base material mainly composed of carbon C is coated with a film mainly composed of titanium oxide TiO2,
An AC voltage source for applying an AC voltage to the carbon heater to heat the carbon heater;
An anodic bonding apparatus comprising: The carbon heater has a mounting surface on which the assembly is mounted, and its film has conductivity, and functions as either the first or second electrode. 1. The anodic bonding apparatus according to 1. The anodic bonding apparatus according to claim 1 or 2, wherein the film of the carbon heater contains nickel Ni. 4. The anodic bonding apparatus according to claim 3, wherein the content of titanium oxide TiO2 and nickel Ni in the film of the carbon heater is about 7 to 3.

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