JPH09283392A - Method and device for laminating substrates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To materialize a method of laminating two sheets of substrates in condition that there is no flexion or distortion and inner stress does not remain, in a method and a device for laying one on top of the other before joining two sheets of substrates. SOLUTION: An upper mechanism 20 is composed of a support disc 21 supported capable of ascent and descent by a drive means, suction heads 22 and 23 fixed to the bottom of this support disc 21, a lifting cylinder 24 fixed to the bottom of the support disc 21, a mobile plate 25 connected and fixed to the mobile rod of the lifting cylinder 24, and a press pin 26 supported by the mobile plate 25. Exhaust ports 22a and 23a are made, respectively, at the suction heads 22 and 23, and the suction heads are equipped with a plurality of openings at the the suction faces 22b and 23b. The press pin 26 is passed freely to ascent and descent in the passage hole made in the mobile plate 25, and it is energized downward by a coil spring 27, and the surface of the pin head 26a at the tip is made in hemispherical form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for stacking substrates, and more particularly, when bonding a semiconductor substrate and a glass substrate or bonding semiconductor substrates to each other, the substrates are brought into contact with each other in advance and stacked. The present invention relates to a technique suitable as a method and device for matching.

[0002]

2. Description of the Related Art Conventionally, various techniques for bonding semiconductor substrates to each other or bonding a semiconductor substrate and a glass substrate are known. Among them, for example, in the field of micromachining, a silicon wafer (hereinafter referred to as a semiconductor substrate) and a borosilicate glass substrate (hereinafter referred to as a glass substrate) are brought into contact with each other, and in this state, the semiconductor substrate and the glass substrate are anodically bonded. There is a technique for joining and, and by this technique, attempts have been made to manufacture various micro parts such as a pressure sensor and an inkjet head.

The anodic bonding technique is, for example, 300 to 4 when the bonding surfaces of a semiconductor substrate and a glass substrate are in contact with each other.
By heating to 00 ° C. and applying a positive potential to the semiconductor substrate and a negative potential to the glass substrate to apply a DC voltage, the two can be permanently bonded.

FIG. 10 shows a manufacturing process of an ink jet head using such an anodic bonding technique. A large number of surface recesses 11a are formed on the surface of the glass substrate 11 in a state of being arranged vertically and horizontally. A semiconductor substrate 12 made of a silicon wafer is stacked on the glass substrate 11.

Etching grooves 12 are formed in the semiconductor substrate 12.
a is formed, and the thin portion 12b is formed by the etching groove 12a, which is a so-called diaphragm type semiconductor substrate used also for a pressure sensor or the like. A glass substrate 13 is further stacked on the semiconductor substrate 12.

The semiconductor substrate 12 and the glass substrates 11 and 13
Since the joint surface of is extremely flat and is formed on a clean surface, it can be closely adhered only by bringing them into contact with each other. In this way, the glass substrate 11 and the semiconductor substrate 12
In a state where the glass substrate 13 and the glass substrate 13 are stacked, they are fixed to each other by a holding jig (not shown). The holding jig is provided with an application electrode so that a predetermined voltage can be applied to each of the glass substrate 11, the semiconductor substrate 12, and the glass substrate 13.

By connecting the above-mentioned applying electrode to the power source 14, first, a direct current voltage of several hundred V is applied between the glass substrate 11 and the semiconductor substrate 12 to perform anodic bonding, and then the semiconductor substrate 12 and the glass substrate. The power supply 15 is connected to the substrate 13 and anodic bonding is similarly performed. By bonding the glass substrates 11 and 13 to both sides of the semiconductor substrate 12 in this manner, a bonded body having a large number of inkjet heads having the thin portion 12b as a vibrating portion is completed. This bonded body is later separated into individual inkjet heads by dicing or the like.

[0008]

However, in the above-mentioned anodic bonding, it is necessary to position the substrates with respect to each other in advance, and to bring them into contact with each other so that they are overlaid, but conventionally, the semiconductor substrate is manually placed on the glass substrate. It was placed on the substrate, and this state was held and fixed by a jig. However, since the surface of the semiconductor substrate or the glass substrate is formed to have high flatness and cleanliness, it is extremely difficult to make a close contact with each other once they come into contact with each other and slide them on each other. Therefore, when the two substrates are brought into contact with each other, the contact state of the two substrates is determined. For example, if one of the substrates is brought into contact with the substrate being bent, the bending state of the substrate is not canceled and the bonding is performed as it is. Will cause a space between the boards,
There is a problem that a defective joint region remains.

Here, fine irregularities are formed on the surface of the semiconductor substrate by various patterning, etching, deposition techniques and the like, and particularly when a pressure sensor, an ink jet head or the like is formed, the semiconductor substrate is extremely thin. Since a thin portion may be formed, when the semiconductor substrate is placed on the glass substrate, the semiconductor substrate may be slightly bent or distorted, so that internal stress remains between the two substrates after joining. However, there is a problem in that the characteristics of forming elements such as micro components are deteriorated.

Therefore, the present invention solves the above-mentioned problems. The problem is that the two substrates are not bent or distorted before the bonding between the substrates as described above, and no internal stress remains. It is to realize a method and apparatus for superposing in a state.

[0011]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the means taken by the present invention is to adsorb and hold at least a plurality of portions of a first substrate, and to dispose the first substrate opposite to a second substrate. Is supported from the back side of the first substrate so as to have a convex shape with respect to the second substrate of the first substrate.
The protrusion region that is most protruded from the substrate is brought into contact with the second substrate, and the convex shape is eliminated in the contact region between the first substrate and the second substrate, while gradually increasing from the protrusion region to its adjacent region. The first substrate and the second substrate are brought into contact with each other by bringing the first substrate into contact with the second substrate.
A method of stacking substrates is characterized in that the substrates are stacked.

According to this means, the first substrate is held in a convex shape, firstly brought into contact with the second substrate from the projecting region, and then gradually brought into contact with the adjacent region, whereby the first substrate is formed.
Since the boards can be brought into contact smoothly without being flexed or distorted carelessly, they can be overlapped without leaving any bending or distortion, and internal stress remains even after joining. No bonded body can be formed.

Here, the first substrate may be a semiconductor wafer, and the second substrate may be a glass substrate.

In this case, the first substrate may be a diaphragm type semiconductor substrate having a thin portion locally. In this case, the presence of the thin portion is likely to cause bending or distortion in the semiconductor substrate, and the bending or distortion of the thin portion is likely to adversely affect the manufactured device characteristics, which is particularly effective.

Next, as a substrate stacking apparatus, a plurality of suction holding portions that suction-hold at least a plurality of peripheral regions of the first substrate and the first substrate are supported from the back surface side of the first substrate. A supporting / holding unit that enables the holding and a driving unit that allows the held first substrate to come into contact with and separate from the second substrate that is arranged to face each other are provided. In this case, in particular, various fine structures are often formed on the semiconductor substrate, but since the fine structure can be avoided and held by sucking and holding the peripheral region, a machine applied to the semiconductor substrate It is possible to reduce the physical influence.

Further, a plurality of suction holding portions configured to hold the surface of the first substrate by suction and move the suction holding surfaces thereof in the normal direction to each other, and the first suction holding portion.
There may be a case where a driving unit that can be brought into contact with and separated from the second substrate arranged so as to face the substrate is provided.

In these cases, the first substrate is held so as to have a convex shape with respect to the second substrate, and the second substrate is projected from a projecting region of the first substrate that is most projecting with respect to the second substrate. The first substrate is brought into contact with the substrate, and the convex shape is eliminated in the contact region between the first substrate and the second substrate, while the first region is gradually moved from the protruding region to the adjacent region.
It is preferable that the first substrate and the second substrate are superposed by bringing the substrate into contact with the second substrate.

Further, it is desirable that the support holding portion or the suction holding portion is directly or indirectly attached to the driving means in a state of being biased toward the first substrate.

According to this means, since the support holding portion or the suction holding portion is attached to the drive means while being biased toward the first substrate, the first substrate is brought into contact with the second substrate. At this time, there is no fear that stress will be applied to these substrates more than necessary, and after the first substrate comes into contact with the second substrate, the support holding part or the suction holding part is moved against the urging force thereof. Therefore, since the convex shape of the first substrate is naturally eliminated, it is possible to bring the first substrate into contact with the second substrate and superimpose them without performing fine position control.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of a substrate superposing method and apparatus according to the present invention will be described with reference to the accompanying drawings. Each embodiment shown below is a method or apparatus for superposing a semiconductor substrate and a glass substrate configured for use in manufacturing an inkjet head, and after superposing the substrates by the method or apparatus,
This is performed on the premise that they are bonded by anodic bonding.

However, in the present invention, not only the superposition of the semiconductor substrate and the glass substrate, but also the semiconductor substrates,
The present invention can be applied to the superposition of glass substrates or substrates made of other materials, and as the joining method after the superposition, various other joining methods than the anodic joining can be applied.

(First Embodiment) FIG. 1 is a schematic vertical sectional view (a) showing a structure of a superposing apparatus in a first embodiment and a schematic bottom view (b) of an upper mechanism. The present embodiment is composed of a bottom plate 16 and an upper mechanism 20 arranged above the bottom plate 16 so as to be able to move up and down. The upper mechanism 20 includes a support plate 21 connected to be movable up and down by a driving mechanism (not shown) such as a linear slider, a fluid pressure cylinder, a ball screw, and a pair of left and right suction plates fixed to the bottom surface of the support plate 21. Heads 22 and 23 and this suction head 2
A lift cylinder 24 fixed to the bottom surface of the support board 21 at a position between 2 and 23 and operated by air pressure or hydraulic pressure.
And a movable plate 25 connected and fixed to a movable rod of the lifting cylinder 24, and a pressing pin 26 supported by the movable plate 25.

Exhaust holes 22a and 23a are formed in the suction heads 22 and 23, respectively.
Is connected to an exhaust device via an exhaust tube (not shown). The exhaust holes 22a and 23a are attached to the suction heads 22 and 2, respectively.
The three suction surfaces 22b and 23b have a plurality of openings.

The pressing pin 26 is vertically inserted through an insertion hole formed in the movable plate 25 and is urged downward by a coil spring 27. The surface of the pin head 26a at the tip of the pressing pin 26 is formed in a hemispherical shape.

In the mechanism 20, first, the glass substrate 11 is sucked and held by the suction heads 22 and 23 from the substrate supply unit (not shown) as shown by the chain line in the figure, and the alignment marks formed on the bottom plate 16 and the glass substrate 11 are shown. Positioning is carried out by a known method such as image processing with reference to, and it is placed on the bottom plate 16. Next, as shown in FIG. 2, the semiconductor substrate 12 is similarly suction-held by the suction heads 22 and 23. At this time, the elevating cylinder 24 is operated to lower the movable plate 25 so that the pin head 26a of the pressing pin 26 contacts the substantially central portion of the back surface (upper surface) of the semiconductor substrate 12.

At this time, the pressing pin 26 is the coil spring 27.
Since the semiconductor substrate 12 is biased downward by the pin head 26a, the semiconductor substrate 12 is pressed by the weight of the pressing pin 26 and the elastic force of the coil spring 27, and is slightly curved so as to be convex downward as illustrated. To do. The pressing force of the pressing pin 26 can be sufficiently curved in advance on the semiconductor substrate 12 by appropriately adjusting the weight of the pressing pin 26 and the elastic force of the coil spring 27, and the degree of the bending. Can be suppressed to such an extent that the semiconductor substrate 12 is not damaged or the semiconductor substrate 12 is not strained.

Next, as shown in FIG. 3, the entire upper mechanism 20 is lowered by a driving means (not shown), and after alignment is performed in the same manner as described above, the upper mechanism 20 is formed at a substantially central portion of the bonding surface of the semiconductor substrate 12. The protruding region (the most protruding part of the convex shape formed by the bending due to the pressing of the pressing pin 26) is brought into contact with the surface of the glass substrate 12 placed on the bottom plate 16. At this time, the pressing pin 26 is pushed back upward against the elastic force of the coil spring 27 due to the contact of the semiconductor substrate 12 with the glass substrate 11, and this is attached to the pin head 26a and the base portion 26b engaging with the movable plate 25. 3 is detected by a pressure sensor etc.
In this state, the driving means can be temporarily stopped.

Next, when the upper mechanism 20 is further lowered by the driving means, the semiconductor substrate 12 comes into contact with the surface of the glass substrate 11 in order from the center portion which was in contact first with the periphery. At this time, in the contact region of the semiconductor substrate 12 with respect to the glass substrate 11 (the part that is already in contact), the pin head 26a is pushed back upward as the upper mechanism 20 descends, whereby the convex shape is eliminated in the contact region. As it goes, it naturally comes into close contact with the glass substrate 11.

Thus, finally, as shown in FIG. 4, when the semiconductor substrate 12 is sufficiently close to the state where the semiconductor substrate 12 is entirely in contact with the surface of the glass substrate 11, the suction head 22,
When the suction of 23 is released and the semiconductor substrate 12 is released, the semiconductor substrate 12 is naturally placed on the glass substrate 11.

According to the present embodiment, the semiconductor substrate 12 has a convex curved surface shape with a substantially central portion protruding, and the central portion is first brought into contact with the glass substrate 11, and thereafter, the periphery thereof is sequentially covered with the surface of the glass substrate 11. Since the semiconductor substrate 12 and the glass substrate 11 are superposed on each other, the bending and deformation of the substrate are hardly left, and the residual internal stress (strain) can be significantly reduced even after the bonding. .

Further, since the semiconductor substrate 12 is deformed into a convex curved surface shape by the elastic force of the pressing pin 26, the semiconductor substrate 12 is not applied with an unnecessarily large pressing force. In addition to being able to prevent it, the displacement of the drive means can be absorbed by the elastic force, so that the semiconductor substrate 12 is not required to perform fine position control.
Can be brought into contact with the glass substrate 11.

(Second Embodiment) Next, a second embodiment according to the present invention
An embodiment will be described. In this embodiment,
As shown in FIG. 5, an upper mechanism 30 is arranged above the bottom plate 16, and the upper mechanism 30 is provided with a support plate 31 configured to be able to move up and down by a driving unit (not shown) and an insertion hole formed in the support plate 31. A screw shaft 32 which is vertically inserted into the hole, has a screw groove formed on the outer surface thereof, and has an exhaust hole 32a formed in the center thereof; and a positioning nut 33 screwed to the upper end of the screw shaft 32. The screw shaft 32 includes a spring lock nut 34 screwed into the lower end portion thereof, and a coil spring 35 elastically mounted between the support plate 31 and the spring lock nut 34.

As shown in FIG. 5B, the assembly consisting of the screw shaft 32, the positioning nut 33, the spring lock nut 34, and the coil spring 35 has a central portion of the support board 31 and four peripheral portions, respectively, for a total of five locations. Installed. Screw shaft 32
The exhaust hole 32a is connected to an exhaust device via an exhaust tube (not shown), and has an opening on a suction surface 32b formed at the tip of the screw shaft 32.

In the present embodiment, first, similarly to the first embodiment, the glass substrate 11 is positioned and placed on the bottom plate 16, and the semiconductor substrate 12 is brought into contact therewith. At this time, as shown in FIG.
The semiconductor substrate 1 is arranged so that A is located slightly downward and the end 12B opposite to the end 12A is located slightly upward.
It is adsorbed and held so that the joint surface of 2 is slightly inclined from the horizontal plane.

To do this, the screw shaft 32 on the end 12A side is moved downward by the rotation of the positioning nut 33, and the screw shaft 32 on the end 12B side is moved to the positioning nut 3.
It may be moved upward by the rotation of 3. Here, in order to make the elastic force of the coil spring 35 uniform, it is necessary to rotate the spring lock nut 34 so as to cancel the movement amount of the screw shaft 32 and keep the gap between the support plate 31 and the spring lock nut 34 constant. Good.

Here, the semiconductor substrate 12 needs to be slightly curved so as to have a convex shape with respect to the glass substrates 11 to be stacked, that is, to have a convex shape downward in this embodiment. This is because, if the semiconductor substrate 12 is curved in a slightly concave shape so as to be convex upward, a non-contact area is likely to occur between the glass substrate 11 and the semiconductor substrate 12 that are overlapped with each other, resulting in poor bonding. This will cause

Next, the upper mechanism 30 is lowered by a driving means (not shown) so that the protruding region near the end 12A of the semiconductor substrate 12 is brought into contact with the surface of the glass substrate 11. At this time, even if stress is applied to the screw shaft 32 on the side of the contacted end 12A from the glass substrate 11 via the semiconductor substrate 12, the screw shaft 32 moves upward due to the elasticity of the coil spring 35. No stress is applied to the semiconductor substrate 12 beyond the weight of the positioning nut 33 and the screwing nut 34 and the elastic force of the coil spring 35.

At this time, similarly to the first embodiment, a sensor or the like detects that the portion of the semiconductor substrate 12 on which the screw shafts 32 are attracted is in contact with the glass substrate 11 to control the driving means. It is also possible.

Next, the upper mechanism 3 is further driven by the driving means.
When 0 is lowered, the semiconductor substrate 12 gradually contacts the glass substrate 11 from the end portion 12A toward the central portion, and the central portion contacts as shown in FIG. 8, and the upper mechanism 30 is further lowered. Then, as shown in FIG. 9, the semiconductor substrate 12 contacts the glass substrate 11 up to the vicinity of the end 12B. In this state, the suction of the screw shaft 32 is released, the semiconductor substrate 12 is released from the upper mechanism 30, and the remaining portions are naturally brought into contact with each other, whereby the superposition of the glass substrate and the semiconductor substrate is completed.

In this way, the semiconductor substrate 12 can be gradually brought into contact with the surface of the glass substrate 11 from one end to the other end of the semiconductor substrate 12 in a slightly convex curved shape.
Similar to the first embodiment, the two substrates can be superposed on each other without causing the semiconductor substrate 12 to bend, distort, or deform, and the residual amount of the internal stress after bonding can be significantly reduced.

In each of the above-described embodiments, the semiconductor substrate 12 is contacted from the substantially central portion or the end portion, but it may be contacted from any other location. In this case, one substrate surface is made to have a convex curved surface shape from the first contact point, and is gradually brought into contact with the other substrate surface, whereby a separated region or a defective joint region is formed between the two substrates. It can be superposed without causing any bending and distortion.

In each of the above-described embodiments, the case where the semiconductor substrate 12 is superposed on the glass substrate 11 has been described as an example, but thereafter, a plurality of strip-shaped glass substrates 13 are superposed on the semiconductor substrate 12 in the same manner. Finally, the glass substrate 11, the semiconductor substrate 12, and the glass substrate 13 are finally held and fixed in a laminated state, and anodic bonding is performed as shown in FIG. 10 to form a bonded body for manufacturing an inkjet head. can do.

[0043]

As described above, according to the present invention, the following effects can be obtained.

According to the first and the sixth aspects, by holding the first substrate in a convex shape, first contacting the second substrate from the protruding region, and gradually contacting the adjacent region with the second substrate, Since the first substrate can be smoothly brought into contact with each other without being flexed or distorted carelessly, the first substrate can be superposed without leaving any bending or distortion, and the internal stress remains even after the bonding. It is possible to form a joint body without

According to the third aspect of the invention, the presence of the thin portion easily causes the semiconductor substrate to bend or distort, and the bending or strain of the thin portion easily affects the manufactured device characteristics, which is particularly effective. Is.

According to claim 4 or claim 5, the first
The substrate is held so as to have a convex shape with respect to the second substrate, and the first substrate is brought into contact with the second substrate from a projecting region most projecting with respect to the second substrate.
The first substrate is gradually brought into contact with the second substrate from the protruding region to the adjacent region while eliminating the convex shape in the contact region between the substrate and the second substrate. A substrate and the second substrate can be superposed. Particularly, in the case of claim 4, although various fine structures are often formed on the semiconductor substrate, the fine structure can be avoided and held by adsorbing and holding the peripheral region. The mechanical influence exerted can be reduced.

According to the seventh or eighth aspect, since the support holding portion or the suction holding portion is attached to the drive means in a state of being urged toward the first substrate, the first substrate is attached to the first substrate. There is no risk of applying unnecessary stress to these substrates when they are brought into contact with the two substrates, and after the first substrate comes into contact with the second substrate, the support holding portion or the suction holding portion resists the urging force. Since the convex shape of the first substrate is naturally eliminated because the first substrate is moved, the first substrate is brought into contact with the second substrate without performing fine position control and the like.
Can be stacked.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view (a) and a schematic bottom view (b) of an upper mechanism showing a first embodiment according to the present invention.

FIG. 2 is a schematic vertical sectional view showing a state before overlapping in the first embodiment.

FIG. 3 is a schematic vertical sectional view showing a state in the middle of superposition in the first embodiment.

FIG. 4 is a schematic vertical sectional view showing a state at the time of completion of superposition in the first embodiment.

FIG. 5 is a schematic vertical sectional view (a) showing a second embodiment according to the present invention and a schematic bottom view (b) of an upper mechanism.

FIG. 6 is a schematic vertical sectional view showing a state before overlapping in the second embodiment.

FIG. 7 is a schematic vertical sectional view showing a state in the middle of superposition in the second embodiment.

FIG. 8 is a schematic vertical sectional view showing a state in the middle of superposition in the second embodiment.

FIG. 9 is a schematic vertical sectional view showing a state at the time of completion of superposition in the second embodiment.

FIG. 10 is a schematic explanatory diagram showing a state of substrate bonding by anodic bonding in the manufacturing process of the inkjet head.

[Explanation of symbols]

 11, 13 Glass substrate 12 Semiconductor substrate 16 Bottom plate 20 Upper mechanism 21 Support plate 22,23 Adsorption head 24 Elevating cylinder 25 Movable plate 26 Pressing pin 26a Pin head

Claims (8)

[Claims] 1. At least a plurality of portions of a first substrate are adsorbed and held, and the first substrate is disposed to face a second substrate.
The substrate is supported from the back surface side of the first substrate so as to have a convex shape, and is brought into contact with the second substrate from a protruding region of the first substrate that most projects with respect to the second substrate,
By eliminating the convex shape in the contact region between the first substrate and the second substrate, gradually contacting the first substrate with the second substrate from the protruding region to the adjacent region. A method of stacking substrates, wherein the first substrate and the second substrate are stacked. 2. The method of stacking substrates according to claim 1, wherein the first substrate is a semiconductor wafer and the second substrate is a glass substrate. 3. The method for stacking substrates according to claim 2, wherein the first substrate is a diaphragm-type semiconductor substrate locally having a thin portion. 4. A plurality of suction-holding units that suction-hold at least a plurality of peripheral regions of the first substrate, a support-holding unit that can support the first substrate from the back surface side of the first substrate, and a holding unit. And a driving means for enabling the separated first substrate to come into contact with and separate from the oppositely arranged second substrate. 5. A plurality of suction holding portions configured to hold the surface of the first substrate by suction and move the suction holding surfaces of the first substrate in the normal direction to each other, and the suction holding portions on the first substrate. A substrate stacking device, comprising: a driving unit that can be brought into contact with and separated from a second substrate that is disposed so as to face each other. 6. The method according to claim 4 or 5, wherein the first substrate is held so as to have a convex shape with respect to the second substrate, and most protrudes from the second substrate in the first substrate. The first substrate is contacted with the second substrate from the protruding region,
The first substrate is gradually brought into contact with the second substrate from the protruding region to the adjacent region while eliminating the convex shape in the contact region between the substrate and the second substrate. A substrate superposing apparatus, characterized in that the substrate and the second substrate are superposed on each other. 7. The substrate according to claim 4, wherein the support holding portion is directly or indirectly attached to the drive means in a state of being urged toward the first substrate. Overlay device. 8. The substrate according to claim 5, wherein the suction holding portion is directly or indirectly attached to the driving means in a state of being urged toward the first substrate. Overlay device.