JP5373725B2 - Conductive ball capturing apparatus, conductive ball capturing method, and conductive ball mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive ball trapping device, a conductive ball trapping method, and a conductive ball mounting method, which enable a ball loading operation to be accurately performed even in the case of a minute conductive ball. <P>SOLUTION: A conductive ball trapping device 10 includes: a bar electrode 11; a dielectric layer 12 including a contact surface 12A coming into contact with a tip of the bar electrode 11, and a trapping surface 12B on the other side of the contact surface 12A by which a conductive ball 1 is trapped; and an auxiliary electrode 14 disposed on the contact surface 12A so as to surround the bar electrode 11. The conductive ball 1 is trapped by using the conductive ball trapping device 10 and mounted in a desired position on a substrate. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a conductive ball capturing device, a conductive ball capturing method, and a conductive ball mounting method, and more particularly to a conductive ball capturing device, a conductive ball capturing method, and a conductive ball mounting method using electrostatic force.

  As a method of forming a bump for electrically connecting a semiconductor chip and a mounting substrate, for example, a plating method using a photoresist film, a printing method using a metal mask, and a ball bump method in which conductive balls are mounted at predetermined locations. It has been known.

  In the ball bump method, for example, there is a method in which a conductive ball is sucked with a suction machine and the conductive ball is dropped at a predetermined position and mounted. However, in the ball bump method, a conductive ball mounting error (for example, (Mounting leakage, mounting position deviation) may occur.

  The mounting mistake of the conductive ball can be detected by inspecting the mounting state of the conductive ball after mounting the ball. When there is a ball mounting error, a treatment (hereinafter referred to as repair) for individually mounting the conductive ball is performed at the position where the mounting error occurred. Generally, an apparatus including a suction tube capable of individually mounting conductive balls is used for repair (see, for example, Patent Document 1).

JP 2007-294835 A

  However, according to the apparatus provided with the suction tube, there is a problem that it is difficult to produce an extremely fine suction tube in accordance with the miniaturization of the conductive ball. In addition, if the tip of the suction tube is missing, the suction position of the conductive ball will become inconsistent and the accuracy of the ball mounting operation will be reduced. The position where you want to drop the ball by biting into the hole of the suction tube (the position you want to mount) ) Can not drop the ball.

  Accordingly, an object of the present invention is to provide a conductive ball trapping device, a conductive ball trapping method, and a conductive ball mounting method capable of accurately performing a ball mounting operation even with a small conductive ball. .

In order to achieve the above object, the present invention comprises an electrode and a dielectric layer having a contact surface in contact with the tip of the electrode and a capture surface opposite to the contact surface in which a conductive ball is captured. the electrode is rod-shaped electrode, the said tip portion provides a conductive ball catching device according to claim Rukoto that having a large curvature than zero.

  In addition, in order to achieve the above object, the present invention includes a step of charging the conductive ball positively or negatively, a contact surface that contacts the tip of the electrode by applying a first voltage to the electrode, and the conductive By charging a dielectric layer having a capture surface opposite to the contact surface on which the ball is captured, a charge opposite to that of the conductive ball is charged on the capture surface side, thereby electrostatically charging the conductive ball. There is provided a method for capturing a conductive ball, comprising the step of capturing on the capture surface by force.

  In order to achieve the above object, the present invention includes a step of mounting the conductive ball captured by the conductive ball capturing method of the present invention at a desired position on a substrate. Provide mounting method.

  According to the present invention, it is possible to provide a conductive ball capturing device, a conductive ball capturing method, and a conductive ball mounting method capable of accurately performing a ball mounting operation even with a small conductive ball.

It is a figure which shows schematic structure of the conductive ball capture | acquisition apparatus which concerns on 1st Embodiment. It is a figure which shows schematic structure of the modification of the conductive ball | bowl capture apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the conductive ball capture | acquisition method which concerns on 1st Embodiment. It is a figure for demonstrating the conductive ball mounting method which concerns on 1st Embodiment. It is a figure for demonstrating the conductive ball mounting method which concerns on 1st Embodiment. It is a figure which shows schematic structure of the conductive ball capture apparatus which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the modification of the electroconductive ball capture apparatus which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the conductive ball capturing apparatus which concerns on an Example. It is a correlation diagram of the electrostatic force which acts on a conductive ball, and the thickness of a dielectric material layer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
[First Embodiment]
(Configuration of conductive ball catcher)
FIG. 1 shows a schematic configuration of a conductive ball capturing apparatus according to the first embodiment.
The conductive ball capturing device 10 includes a dielectric layer having a rod-shaped electrode 11, a contact surface 12A that contacts the tip of the rod-shaped electrode 11, and a capture surface 12B opposite to the contact surface 12A that captures the conductive ball 1. 12. Moreover, the rod-shaped electrode 11 and the dielectric layer 12 are fixed to each other, and provided with a connecting portion 13 for connecting them, they can be moved together in a fixed state. The rod-shaped electrode 11 may have another shape, but in the present embodiment, it is preferable to use a rod-shaped electrode that is an electrode provided with a support portion. It is preferable that the rod-shaped portion is a columnar rod-shaped electrode.

  The rod-shaped electrode 11 preferably has a tip portion having a curvature (convex curved surface) larger than 0, and more preferably the tip portion is hemispherical. It is preferable that the hemispherical tip and the cylindrical rod-shaped portion have the same diameter and are smoothly connected. The diameter of the hemispherical tip is preferably 1/5 to 5 times the diameter of the ball to be captured, and more preferably 1/2 to 2 times the diameter of the ball.

  The rod-shaped electrode 11 may be made of a conductor, for example, copper, steel, aluminum, or the like.

  The dielectric layer 12 has a curvature larger than 0 whose center of curvature is the contact surface 12A side (that is, the rod-shaped electrode 11 side). The curvature of the dielectric layer 12 is preferably smaller than the curvature of the tip of the rod-shaped electrode 11. The curvature is preferably 1/5 to 1/20 times or more, more preferably 1/10 to 1/20 times the curvature of the tip of the rod-shaped electrode 11.

  As a material of the dielectric layer 12, for example, plastic, glass, ceramic, mica (mica) or the like can be used.

  For example, the thickness of the dielectric layer 12 is preferably 0.01 to 2 mm, more preferably 0.1 to 1 mm, and still more preferably 0.2 to 0.5 mm.

  The conductive ball 1 is a metal ball, for example, a solder ball, an iron ball, a gold ball, or a copper ball. A resin ball, a ceramic ball or the like formed with a conductive film may be used.

  In the present embodiment, the conductive ball 1 having any size can be used in accordance with its application / conditions, etc., but the apparatus is provided with a small conductive ball, particularly a conventional suction tube. However, it is difficult to accurately mount a conductive ball within the range of 10 to 300 μm in diameter, more specifically within the range of 30 to 300 μm, and more limited within the range of 50 to 250 μm. Thus, this embodiment is excellent.

  The conductive ball capturing device 10 may further include an electrode plate 2 that is a conductive ball charging electrode that charges the conductive ball 1.

  As a material of the electrode plate 2, for example, copper, stainless steel, or conductive treatment resin can be used.

(Configuration of Modified Example of Conductive Ball Capturing Device)
FIG. 2 is a diagram showing a schematic configuration of a modified example of the conductive ball capturing apparatus according to the first embodiment.
The conductive ball capturing device 10 preferably further includes an auxiliary electrode 14 disposed so as to surround the rod-shaped electrode 11 on the contact surface 12A.
The auxiliary electrode 14 has, for example, a donut shape, a hollow square shape, and the like, and in the vicinity of the rod electrode 11, specifically, 3 to 50 times the diameter of the rod electrode 11, more preferably 5 to 20 times, a rod shape. The electrode 11 is disposed on the contact surface 12 </ b> A so as to surround the rod-shaped electrode 11 apart from the electrode 11.

  The material of the auxiliary electrode 14 may be a conductor, and for example, copper, stainless steel, aluminum, or the like can be used.

(Conductive ball capture method)
FIG. 3 is a diagram for explaining the conductive ball capturing method according to the first embodiment. FIG. 3A is a diagram illustrating a state before capturing the conductive ball, and FIG. 3B is a diagram illustrating a state after capturing the conductive ball.

The method for capturing a conductive ball according to the first embodiment includes a step of charging the conductive ball 1 positively or negatively, applying a _first voltage V ₁ to the rod-shaped electrode 11, By charging the dielectric layer 12 having the contact surface 12A that contacts and the capture surface 12B opposite to the contact surface 12A where the conductive ball 1 is captured, the charge opposite to that of the conductive ball 1 is obtained on the capture surface 12B side. And charging the conductive ball 1 onto the capture surface 12B by electrostatic force.

In FIG. 3, the conductive ball catching device 10 of FIG. 1 is illustrated and described. However, when the conductive ball catching device 10 of FIG. 2 is used, as shown in FIG. is applied with one of voltages V _1, a positive voltage is applied to the first voltage V ₁ and the same direction (both in Figure 2 each electrode to the auxiliary electrode 14 disposed on the contact surface 12A so as to surround the rod-like electrodes 11 applying a second voltage V ₂ direction) to be. The first voltage V ₁ applied to the rod-shaped electrode 11 is higher than the second voltage V ₂ applied to the auxiliary electrode 14. Second voltage _{V 2} is preferably first is a 0.1 to 0.95 times the voltage _{V 1,} more preferably from 0.3 to 0.9 times, 0.5 to 0. More preferably, it is 8 times.

Step of charging a conductive ball 1 positive or negative, but the method is not particularly limited, is preferably the same process of applying a first voltage V _1, the rod-shaped electrode 11 and the conductive It is preferable that the first voltage V ₁ be applied between the electrode plate 2 which is a conductive ball charging electrode. For example, when a negative voltage is applied to the electrode plate 2, the conductive ball 1 on the electrode plate 2 is charged with a negative charge. When the conductive ball trapping device 10 of FIG. 2 is used, as shown in FIG. 2, the first voltage V ₁ is applied to the rod-shaped electrode 11 and the second electrode is interposed between the auxiliary electrode 14 and the electrode plate 2. it is preferably performed by applying a voltage V ₂ of.

Next, a specific operation example will be described.
As shown in FIG. 3A, the conductive ball capturing device 10 is moved to a position almost directly above the conductive ball 1. More preferably, the rod-shaped electrode 11 is moved so as to be positioned almost immediately above the conductive ball 1. The movement of the conductive ball capturing apparatus 10 can be controlled by a CPU or the like. The distance between the capture surface 12B of the dielectric layer 12 of the conductive ball capturing device 10 and the conductive ball 1 is preferably about 1 to 2 times the diameter of the conductive ball 1.

Next, the first voltage V ₁ is applied between the rod-shaped electrode 11 and the electrode plate 2. The first voltage V ₁ is, for example, +200 to +600 V when the diameter of the conductive ball 1 is 100 μm, and +100 to +300 V when the diameter of the conductive ball 1 is 50 μm. When the conductive ball capturing device 10 of FIG. 2 is used, the first voltage V ₁ is applied, and the second voltage V ₂ is applied between the auxiliary electrode 14 and the electrode plate 2. Second voltage _{V 2,} for example, when the diameter of the conductive ball 1 is 100 [mu] m, + 150 to + and 550 V, the diameter of the conductive ball 1 is the case of 50 [mu] m, and + 90 to + 280 V.

  As a result, as shown in FIG. 3B, the conductive ball 1 charged positively or negatively (negative in the figure) is captured by the electrostatic force on the capture surface 12B charged positively or negatively (positive in the figure). . The conductive ball 1 is captured at a position directly below the rod-shaped electrode 11.

  After capture, the captured state of the conductive ball 1 is maintained even when the voltage is turned off.

(Conductive ball mounting method)
4 and 5 are views for explaining the conductive ball mounting method according to the first embodiment.
The conductive ball mounting method according to the first embodiment includes a step of mounting the conductive ball 1 captured by the conductive ball capturing method according to the first embodiment at a desired position on the substrate 3. . The desired position is, for example, a position where there is a mounting error of the conductive ball 1.

Further, in the conductive ball mounting method according to the first embodiment, after the step of mounting the conductive ball 1 at a desired position on the substrate 3, the step of removing the dielectric layer 12 and / or the rod-shaped electrode 11. the first and the voltages V ₁ may include the step of applying a reverse voltage to.

A specific operation example of the conductive ball mounting method will be described below.
FIG. 4A is a diagram illustrating a state in which the conductive ball capturing device 10 that has captured the conductive ball 1 is moved to a desired position where the conductive ball 1 is to be mounted. The movement of the conductive ball capturing device 10 to a desired position can be controlled by a CPU or the like.

FIG. 4B is a diagram illustrating a state in which the conductive ball 1 is mounted at a desired position.
The conductive ball capturing device 10 that has moved to the position immediately above the position where the mounting mistake of the conductive ball 1 on the substrate 3 is moved in the direction of the substrate 3, and the conductive ball 1 is placed at the position where the flux is applied in advance. Press.

FIG. 4C is a diagram showing a state where the mounting of the conductive ball 1 at a desired position is completed.
After an appropriate time (for example, several hundred milliseconds) has passed since the conductive ball 1 was pressed, the conductive ball capturing device 10 is returned to the original position. As a result, the conductive ball 1 is separated from the conductive ball capturing device 10 by the adhesive force (tack force) of the flux, and is transferred onto the substrate 3. At this time, since the adhesive force (tack force) of the flux is sufficiently larger than the adhesion force to the capture surface 12B, the conductive ball 1 is transferred onto the substrate 3.

FIG. 5 is a diagram illustrating a process of discharging the dielectric layer 12 with a static eliminator.
After the conductive ball 1 is mounted at a desired position, the conductive ball trapping device 10 is moved to the position of a static eliminator (for example, a corona discharge type using AC) to erase the residual charge on the dielectric layer 12. Then, remove the static electricity. Alternatively, static elimination may be performed by applying a voltage in the direction opposite to the first voltage V ₁ to the rod-shaped electrode 11 of the conductive ball capturing device 10. Of course, both of these static elimination processes may be performed. Thereby, the conductive ball capture device 10 from which the conductive ball 1 is separated can be used again.

[Second Embodiment]
(Configuration of conductive ball catcher)
FIG. 6 is a diagram showing a schematic configuration of a conductive ball capturing apparatus according to the second embodiment.
The conductive ball catching device 20 according to the second embodiment shown in FIG. 6 has the same configuration as the conductive ball catching device 10 according to the first embodiment shown in FIG. This is different from the first embodiment in which the dielectric layer 22 having a curvature larger than 0 is used in that the dielectric layer 22 is used. The material, thickness, and the like other than the shape of the dielectric layer 22 are the same as those of the dielectric layer 12.

(Configuration of Modified Example of Conductive Ball Capturing Device)
FIG. 7 is a diagram showing a schematic configuration of a modified example of the conductive ball capturing apparatus according to the second embodiment.
The conductive ball catching device 20 according to the modified example of the second embodiment shown in FIG. 7 has the same configuration as the conductive ball catching device 10 according to the modified example of the first embodiment shown in FIG. However, this embodiment is different from the modification of the first embodiment in which the dielectric layer 12 having a curvature larger than 0 is used in that the flat dielectric layer 22 is used. The material, thickness, and the like other than the shape of the dielectric layer 22 are the same as those of the dielectric layer 12.

  Since the conductive ball capturing method and the conductive ball mounting method according to the second embodiment are the same as the conductive ball capturing method and the conductive ball mounting method according to the first embodiment, description thereof is omitted.

[Effect of the embodiment of the present invention]
(1) It is possible to provide a conductive ball capturing device, a conductive ball capturing method, and a conductive ball mounting method capable of accurately performing a ball mounting operation even with a small conductive ball.
(2) According to each modification including the auxiliary electrode 14, the electrostatic force acting on the conductive ball is increased as compared with the embodiment not including the auxiliary electrode 14, and the flying force of the conductive ball is increased. It is easy to trap the conductive ball in the dielectric layer.
(3) According to the first embodiment, since the dielectric layer has a curvature larger than 0, when the conductive ball is mounted at the position of the mounting error, the surrounding mounting on the substrate is completed. Since the conductive ball trapping device is less likely to contact the conductive ball, it is suitable for repair in the manufacture of a semiconductor device that is smaller and denser than the second embodiment.

(Conductive ball capture experiment 1)
FIG. 8 is a diagram illustrating a schematic configuration of the conductive ball capturing apparatus according to the embodiment.
Conductive balls were captured using the following conductive ball trapping device.
A steel ball having a diameter d = 1 mm was used as the conductive ball 1, and stainless steel was used as the electrode plate 2. Further, as the rod-shaped electrode 11, a rod-shaped electrode made of stainless steel having a length of 5 cm having a hemispherical (diameter R = 0.7 mm, curvature: 2.9 / mm) tip portion and a columnar rod-shaped portion having the same diameter. A transparent resin plate having a thickness of 0.3 mm was used as the dielectric layer 12. The distance L between the rod-shaped electrode 11 and the conductive ball 1 was 1.0 mm. The illustrations of the devices that support and fix each of them are omitted.

  When a voltage of 3000 V was applied between the rod-shaped electrode 11 and the electrode plate 2, the conductive ball 1 flew and was captured by the dielectric layer 12 at a position immediately below the rod-shaped electrode 11.

(Capture experiment 2 of conductive ball)
FIG. 9 is a correlation diagram between the electrostatic force acting on the conductive ball and the thickness of the dielectric layer.
Conductive balls were captured using the following conductive ball trapping device.
A steel ball having a diameter d = 1 mm was used as the conductive ball 1, and stainless steel was used as the electrode plate 2. Further, as the rod-shaped electrode 11, a hemispherical (diameter R = 0.1, 0.2, 0.5, 1.0, 2.0, 5.0 mm) tip portion and a columnar rod-shaped portion having the same diameter, A rod-shaped electrode made of stainless steel having a length of 5 cm was used. When the dielectric layer 12 is not used and used, experiments are conducted. When the dielectric layer 12 is used, the dielectric layer 12 has a relative dielectric constant of 2 and a thickness of 0.1, 0.2, 0.3 mm. A transparent resin plate was used. The distance L between the rod-shaped electrode 11 and the conductive ball 1 was 1.0 mm. The distance between the rod-shaped electrode 11 and the electrode plate 2 was 0.5 mm.

  The electrostatic force F (N) acting on the conductive ball 1 when a voltage of 3000 V was applied between the rod-shaped electrode 11 and the electrode plate 2 was measured. The measurement results are shown in FIG.

As can be seen from FIG. 9, when the distance between the electrodes is constant, the electrostatic force F (N) acting on the conductive ball 1 increases as the thickness of the dielectric layer 12 increases. It can also be seen that the electrostatic force F (N) acting on the conductive ball 1 increases as the diameter R of the hemispherical tip of the rod electrode 11 at the tip of the rod electrode 11 increases.
In each case where the dielectric layer 12 was used, the conductive ball 1 was captured by the dielectric layer 12 at a position immediately below the rod-shaped electrode 11, but when the dielectric layer 12 was not used, Also in this case, the conductive ball 1 could not be captured at a position immediately below the tip of the rod-shaped electrode 11.

(Capture experiment 3 of conductive ball)
A solder ball having a diameter d = 100 μm was used as the conductive ball 1, the interval L between the rod-shaped electrode 11 and the conductive ball 1 was set to 0.1 mm, and a capture experiment was performed in the same manner as the conductive ball capture experiment 1. . When a voltage of 300 V was applied between the rod-shaped electrode 11 and the electrode plate 2, the conductive ball 1 flew and was captured by the dielectric layer 12 at a position immediately below the rod-shaped electrode 11.

1: conductive ball, 2: electrode plate, 3: substrate 10, 20: conductive ball trapping device 11: rod-shaped electrode, 12, 22: dielectric layer, 13: connecting portion, 14: auxiliary electrodes 12A, 22A: contact Surface, 12B, 22B: capture surface

Claims (10)

An electrode, and a dielectric layer having a contact surface in contact with the tip of the electrode and a capture surface opposite to the contact surface in which a conductive ball is captured ,
The electrode is rod-shaped electrode, the said tip portion, the conductive ball catching device according to claim Rukoto that having a large curvature than zero. Conductive ball capturing apparatus according to claim 1, characterized in that it comprises an auxiliary electrode which is arranged to surround the electrode on the contact surface. Said dielectric layer, the conductive ball catching device according to claim 1 or claim 2 that the center of curvature and having a large curvature of from 0 the a contact surface side (the rod-shaped electrode side). The conductive ball capturing device according to claim 3 , wherein a curvature of the dielectric layer is smaller than a curvature of a tip portion of the electrode. Conductive ball catching device according to any one of claims 1 to 4, characterized in that it comprises a conductive ball charging electrode for charging the conductive ball. Charging the conductive ball positively or negatively;
Applying a first voltage to the electrode to charge a dielectric layer having a contact surface that contacts the tip of the electrode and a capture surface opposite to the contact surface where the conductive ball is captured A method for capturing a conductive ball, comprising a step of charging a charge opposite to the conductive ball on the capture surface side and capturing the conductive ball on the capture surface by electrostatic force. A first voltage is applied to the electrode, and a second voltage in the same direction as the first voltage is applied to the auxiliary electrode disposed on the contact surface so as to surround the electrode. The method for capturing a conductive ball according to claim 6 . The step of charging the conductive ball positively or negatively is the same as the step of applying the first voltage, and the first voltage is applied between the electrode and the conductive ball charging electrode. The conductive ball capturing method according to claim 6, wherein the method is performed. A method for mounting a conductive ball, comprising the step of mounting the conductive ball captured by the method for capturing a conductive ball according to any one of claims 6 to 8 at a desired position on a substrate. . After the step of mounting the conductive ball at a desired position on the substrate, the method includes a step of neutralizing the dielectric layer and / or a step of applying a voltage in the direction opposite to the first voltage to the electrode. The method for mounting a conductive ball according to claim 9 .

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