JP3901529B2 - Joining device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for bonding objects to be bonded, and particularly to an optimal bonding apparatus applied to a mounting apparatus or the like for bonding a chip to a substrate.
[0002]
[Prior art]
In an apparatus for mounting a chip on a substrate or an apparatus for bonding wafers, the relative positional relationship between objects to be bonded is kept within a predetermined accuracy, and the head holding one object to be bonded is used as the other object to be bonded. It drives toward and joins both objects to be joined.
[0003]
This head drive mechanism usually has a structure in which a feed mechanism that transmits a pressure driving force from a drive source is connected to a head side mechanism that includes a parallelism adjustment mechanism and holds an object to be joined via a guide mechanism. It is configured. Since these feed mechanism, guide mechanism, and head side mechanism are usually arranged side by side, a certain distance exists between the axis of the feed mechanism and the joining center (pressure center) of the workpiece. The moment is generated by the pressure applied from the mechanism side and the weight of the head side mechanism.
[0004]
Such a moment affects the positioning accuracy during pressure bonding, especially the accuracy of adjusting the parallelism between the objects to be joined. Therefore, the rigidity of the guide mechanism and the head side mechanism is usually increased, and the head side mechanism, In particular, a measure is taken so that the bonded object holding portion is not greatly displaced.
[0005]
[Problems to be solved by the invention]
However, in order to achieve high-accuracy positioning, if the influence of the moment as described above is to be suppressed to an extremely low level, extremely high rigidity is required for the guide mechanism and the like. And the like are large-sized and heavy-weight, so that the degree of freedom in designing the entire apparatus is greatly limited. In addition, since it is difficult to completely cancel the influence of the moment, there is a limit to positioning accuracy.
[0006]
In addition, when a high-rigidity guide mechanism is used, the sliding resistance of the guide portion generally increases, so that there is a problem that it is difficult to control the low pressurizing force when joining the objects to be joined.
[0007]
The object of the present invention is to pay attention to the problems in the conventional mechanism as described above, particularly to eliminate the adverse effects caused by the generation of moments, and to perform highly accurate positioning without using a particularly high-rigidity guide mechanism. Another object of the present invention is to provide a structure of a joining device that can be easily controlled to a low pressure.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, a joining device according to the present invention is a device for joining objects to be joined, and means for holding one object to be joined and the holding means in the joining direction of the objects to be joined. A feeding mechanism and a driving source of the feeding mechanism are arranged in series on the same axis, and the holding means and the feeding mechanism are connected via a slide member that is moved in the vertical direction in a high-precision guide. The holding means comprises a low sliding resistance cylinder means capable of pressurizing the held article to be joined in the joining direction , and the holding means is a spherical bearing having a junction point of the article to be joined as a spherical center And an actuator for supporting the holding member and controlling the posture of the holding member .
[0009]
The feed Ri mechanism Te The joining apparatus smell, for example, can employ a high-precision ball screw, the drive source of the feed mechanism, for example using a servo motor or the like.
[0010]
As the upper Symbol low sliding resistance cylinder means, for example using an air bearing cylinder.
[0012]
In the joining apparatus according to the present invention as described above, the holding means for the object to be joined, the feeding mechanism of the holding means, and the drive source of the feeding mechanism are arranged in series on the same axis , and the holding means and the above-mentioned Since the feed mechanism is connected via a slide member that is moved in the vertical direction in the high-precision guide, when the applied force is transmitted from the drive source of the feed mechanism to the holding means via the feed mechanism, the moment is Does not occur. Therefore, the moment is not generated due to the shaft misalignment of the feed mechanism and the holding means or the dead weight as in the conventional mechanism, and the influence of the moment on the positioning accuracy of the holding means is almost completely eliminated. Therefore, the desired high-accuracy positioning is possible without using a particularly high-rigidity feed mechanism or the like. In particular, if the drive source of the feed mechanism such as a servo motor is also arranged on the same axis, the drive source and the feed mechanism do not pass through an elastic body such as a belt, so high accuracy in both position accuracy and pressure accuracy can be expected.
[0013]
Further, since it is not necessary to use a high-rigidity feed mechanism, the sliding resistance of the feed mechanism can be kept low, and control can be easily performed up to a low applied pressure. In particular, since the holding means is provided with a low sliding resistance cylinder means (for example, an air bearing cylinder) , when a relatively large applied pressure is required, the above-mentioned feed mechanism itself exerts the applied pressure. Is required, the pressurizing force is controlled by the low sliding resistance cylinder means in a state where the operation of the feed mechanism is fixed, whereby the low pressurizing force can be controlled with high accuracy.
[0014]
Further, since the holding means is configured to have a holding member for a workpiece having a spherical bearing with the joint point of the workpiece as a spherical center, and an actuator for controlling the posture of the holding member, In addition, it is possible to make the structure arranged coaxially up to the joint point of the object to be joined, and it becomes possible to prevent the generation of the moment as described above from the positioning to the joining, and with higher accuracy. Positioning and joining are possible. Moreover, in this structure, posture control such as parallelism is performed using a spherical bearing with the joint point of the article to be joined as the center of the sphere, so that the joint point of the article to be joined is substantially maintained at a predetermined position ( It is possible to perform posture adjustment while keeping the position on the same axis), and even in the posture adjustment mechanism itself, it is possible to prevent the occurrence of moments and inconveniences such as displacement due to multi-axis adjustment. Accurate positioning is possible.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a mounting apparatus 1 as a joining apparatus according to an embodiment of the present invention. In FIG. 1, the case where one is a chip 2 and the other is a substrate 3 is illustrated as an object to be bonded. The chip 2 is held on the lower surface of a heat tool 5 having a built-in heater provided at the lower portion of the head portion 4 as a workpiece holding means, and the substrate 3 is held on the stage 6. In this embodiment, the stage 6 can be adjusted in position in the X, Y direction (horizontal direction) and / or the rotation direction (θ direction), and the heat tool 5 can be adjusted in position in the Z direction (up and down direction). The posture can be adjusted in the Y direction (tilting direction), and by these adjustments, the relative positional relationship including the parallelism of both objects to be joined is adjusted and controlled before joining.
[0016]
In the above description, the chip 2 refers to all of the IC chip, semiconductor chip, optical element, surface mount component, wafer, and the like on the side to be bonded to the substrate 3 regardless of the type and size. Moreover, the board | substrate 3 points out all the things by the side joined to the chip | tip 2 irrespective of a kind and magnitude | size, such as a resin substrate, a glass substrate, a film substrate, a chip | tip, a wafer, for example.
[0017]
The stage 6 and the heat tool 5 as described above are generally mounted so as to be movable in parallel and / or rotatable, but may be mounted in a form in which they are combined with lifting and lowering as necessary. Further, with respect to the alignment of the chip 2 and the substrate 3, the apparatus may be configured such that the tool 5 is lowered after the alignment of the chip 2 and the substrate 3.
[0018]
The head unit 4 is connected to a feed mechanism 7 that feeds the head unit 4 in the chip bonding direction, and the head unit 4 and the feed mechanism 7 are arranged in series on the same axis 8. The feed mechanism 7 includes a ball screw mechanism, and the ball screw mechanism includes a ball screw shaft 9 and a nut 10 screwed thereto. As the ball screw shaft 9 rotates, the nut 10 is moved in the vertical direction in the figure. The nut 10 is connected to the head portion 4 via a slide member 11 having a rotation prevention mechanism, and when the vertical movement of the nut 10 is transmitted to the head portion 4, the head portion 4 The chip 2 is determined at a height position for bonding with the substrate 3. The slide member 11 is moved in the vertical direction within the high-accuracy guide 12 composed of a slide roller mechanism. A linear servo actuator and a voice coil actuator can be used as the feed mechanism, and a slide ball and an air bearing slider can be used as the high-precision guide.
[0019]
The upper part of the ball screw shaft 9 of the feed mechanism 7 is rotatably supported by a bearing 13 capable of receiving a thrust load. An output shaft of a drive source 15 for rotating the ball screw shaft 9 is connected to an upper end portion of the ball screw shaft 9 via a coupling 14, and in this embodiment, the drive source 15 is constituted by a servo motor. . Under the control of the drive source 15, the height position of the head unit 4 is determined via the feed mechanism 7, and pressure is applied by the following air cylinder means. In this embodiment, this drive source 15 is also arranged in series with the feed mechanism 7 on the above-described coaxial axis 8.
[0020]
In the present embodiment, the head unit 4 is configured as follows. The head unit 4, Eabe A ring cylinder 16 is incorporated as a low sliding resistance cylinder means. The Eabe A ring cylinder 16, the pressure port 18a for supplying air pressure of the pressurized side to the piston 17, together with the balance port 18b supplies the air pressure increase side (balanced side) the piston 17 is provided An air slide guide 19 is provided for guiding the piston 17 in the sliding direction with a very low sliding resistance by the static pressure of air. The air bearing cylinder 16 is applied with high precision in a low pressure region by controlling air pressure from the pressure port 18a and the balance port 18b with extremely low sliding resistance (substantially zero resistance) by the air slide guide 19. The pressure can be controlled.
[0021]
Further, between the piston 17 lower and heat tool 5 of Eabe A ring cylinder 16, the parallelism adjusting mechanism 20 having a spherical bearing structure is provided. The parallelism adjusting mechanism 20 includes a spherical bearing composed of a spherical seat member 21 that forms a concave spherical surface downward and a convex spherical member 22 that forms a convex spherical surface upward, and the heat tool 5 below. Are connected to each other to constitute the holding member 23 of the object to be joined as a whole, and the plate 24 interposed between the convex spherical member 22 and the heat tool 5 at three points around the actuator (parallelism) Adjustment actuators) 25 (for example, actuators equally spaced 120 °). The actuator may be a highly accurate one such as a piezo, servo motor, linear motor, or stepping motor.
[0022]
Further, in this embodiment, as shown in FIGS. 2 and 3, the spherical bearing is configured as an air bearing mechanism, and when adjusting the parallelism, the concave spherical surface of the spherical seat member 21 and the convex spherical member 22 An air bearing mechanism with a minute gap is formed between the convex spherical surface and relative movement between the two members (relative position adjustment) is possible. After positioning, the lock cylinder 26 can be fixed to the adjusted position. It has become. In order to make the operation of the air bearing mechanism smooth, in this embodiment, a magnet 27 is embedded in the spherical seat member 21 to draw the convex spherical member 22 toward the spherical seat member 21.
[0023]
In this parallelism adjusting mechanism 20, as shown in FIGS. 2 and 3, by controlling the operation amounts of the three actuators 25 in the unlocked state (FIG. 2), the lower surface of the heat tool 5 via the plate 24 is controlled. By controlling the posture, the parallelism between the chip 2 held by the heat tool 5 and the lower substrate 3 (or the parallelism between the lower surface of the heat tool 5 and the upper surface of the stage 6) is within a predetermined accuracy. Control. After the positioning, as shown in FIG. 3, the locking cylinder 26 is locked and fixed in the post-positioning state. At the time of this adjustment, in the spherical bearing, the convex spherical surface of the convex spherical member 22 is rotated along the concave spherical surface of the spherical seat member 21, and the convex spherical surface is seated on the concave spherical surface after positioning. Since the center (rotation center) 28 is set to the joining point of the chip 2 (joining point of the object to be joined), that is, the joining center, the convex spherical member 22 is centered on the joining point of the chip 2 with respect to the spherical seat member 21. The position is adjusted after being rotated. Therefore, the parallelism can be adjusted without moving the joining point of the workpieces. In this embodiment, it is arranged on the above-described coaxial 8 up to this junction (spherical center 28).
[0024]
In the mounting apparatus 1 according to the present embodiment configured as described above, the head portion 4 (heat tool 5) that holds the chip 2 and the feed mechanism 7 of the holding means are arranged in series on the coaxial 8. When transmitting the pressing force from the feed mechanism 7 to the head portion 4, no moment is generated as in the conventional mechanism. Therefore, the influence of the moment on the positioning accuracy at the head portion 4 is almost completely eliminated. Therefore, the desired high-accuracy positioning is possible without using a particularly high-rigidity feed mechanism or the like.
[0025]
In this embodiment, the drive source 15 and the feed mechanism 7 are arranged on the same axis 8 up to the drive source 15 of the feed mechanism 7 composed of a servo motor. Therefore, the drive source 15 and the feed mechanism 7 are connected without an elastic body such as a belt. As a result, high accuracy can be expected in both position accuracy and pressure accuracy.
[0026]
In addition, since no moment is generated, there is no need to use an exceptionally rigid guide mechanism as in the past. First, the sliding resistance of the guide mechanism can be kept low from this surface. You will be able to control. In particular, in this embodiment, since the high-precision guide 12 composed of the slide roller mechanism is used as the guide mechanism, it is possible to suppress the desired low sliding resistance and to ensure high rigidity compared to the slide ball mechanism. Considered.
[0027]
In this embodiment, since the air bearing cylinder 16 is incorporated as the low sliding resistance cylinder means in the head portion 4 as the holding means, the feed mechanism 7 is used when a relatively large pressure is required. When the pressure is exerted by itself and a low pressure is required, the pressure can be controlled by the air bearing cylinder 16 with the operation of the feed mechanism 7 fixed. Since the air bearing cylinder 16 can receive the sliding of the piston 17 by the air slide guide 19 using the air pressure when the piston 17 is operated, the piston 17 can be operated with an extremely low sliding resistance. It has become. Therefore, it becomes possible to control with high accuracy to an extremely low pressurizing force, which has been difficult in the past, and it is possible to perform pressurization control with high accuracy over a wide range from a high pressurizing force to an extremely low pressurizing force.
[0028]
Furthermore, in this embodiment, since the parallelism adjusting mechanism 20 having a spherical bearing structure is provided between the air bearing cylinder 16 of the head portion 4 and the heat tool 5 holding the chip 2, FIG. As shown in FIG. 3, the parallelism can be adjusted with the joint point of the chip 2 as the center. Moreover, it arrange | positions on the above-mentioned coaxial 8 to this junction. As a result, positioning with extremely high accuracy becomes possible, and it becomes possible to prevent the generation of moments from positioning to pressure bonding, thereby enabling higher accuracy bonding.
[0031]
Incidentally, the upper you embodiments with has been described as being applied to the mounting device of the present invention, the present invention is not limited to a mounting device such as described above, in the alignment device and a mounter or the like of various objects to be bonded is applied it can.
[0032]
【The invention's effect】
As described above, according to the joining apparatus according to the present invention, at least the holding means for the object to be joined and the feeding mechanism for the holding means are arranged in series on the same axis without generating a moment, and Without using a special high-rigidity guide mechanism, it is possible to accurately apply the desired pressure to a low pressure and eliminate the influence of the moment on the positioning accuracy during pressure bonding. It becomes possible to perform positioning with higher accuracy.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a mounting apparatus as a joining apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged schematic configuration diagram of a spherical bearing mechanism portion in the apparatus of FIG.
3 is a schematic configuration diagram showing a positional relationship with a joint point in the spherical bearing mechanism portion of FIG. 2;
[Explanation of symbols]
Mounting Device as 1 Joining Device 2 Chip 3 Substrate 4 Head 5 Heat Tool 6 Stage 7 Feeding Mechanism 8 Coaxial 9 Ball Screw Shaft 10 Nut 11 Slide Member 12 High Precision Guide 13 Bearing 14 Coupling 15 Drive Source 16 Low Sliding Resistance Cylinder Eabe a ring cylinder 17 piston 18a pressure port 18b balanced port 19 air slide guide 20 spherical parallelism adjusting mechanism having a bearing structure 21 spherical seat member 22 convex spherical surface member 23 to be bonded holding member 24 plate 25 actuator 26 for locking the means Cylinder 27 Magnet 28 Joining point of the tip that is the center of the spherical bearing (joint point of the workpiece)

Claims (2)

An apparatus for joining objects to be joined, wherein a means for holding one object to be joined, a feed mechanism for feeding the holding means in the joining direction of the work pieces, and a drive source for the feed mechanism are coaxially connected. The holding means and the feed mechanism are connected via a slide member that is moved in the vertical direction in the high-precision guide, and the holding means adds the held object to be joined in the joining direction. A low-sliding resistance cylinder means capable of being pressed, and the holding means supports a holding member for a workpiece having a spherical bearing with the joint point of the workpiece as a spherical center, and supports the holding member And an actuator for controlling the posture of the holding member .   2. A joining apparatus according to claim 1, wherein said low sliding resistance cylinder means comprises an air bearing cylinder.

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