WO2005011927A1 - Work transfer means - Google Patents

Abstract

PROBLEMS TO BE SOLVED: To detect the lower dead point of a suction section simply and reliably in a work transfer means used in picking up work, such as a semiconductor chip, without constructing the suction section so that the latter is capable of lifting and lowering by separating the main body and the suction section and even if the suction section is composed of an elastic body. SOLUTION: A work transfer means (10) has a suction section (12) fixed to the lower end of a main body (11), with a flow rate sensor (14) placed somewhere between the ends of a pipe (13) that supplies a vacuum suction force or compressed air to the suction section (12). The work transfer means (10) is lowered while supplying a vacuum suction force or compressed air to the suction section (12), until the suction section (12) contacts an object, such as a semiconductor chip, whereupon the flow rate sensor (14) detects a change in the flow rate of ambient air, nitrogen or compressed air caused by the vacuum suction force; thus, the work transfer means (10) reaching the lower dead point can be detected.

Description

 Details Work transfer means Technology field

The present invention relates to a work transfer means, for example, the bottom dead center when a work is sucked by a suction part when a semiconductor chip is picked up by a die bonder depends on the material of the suction part and the thickness of the work. The present invention relates to a work transfer means capable of detecting a workpiece without being detected. 2. Description of the Related Art In general, semiconductor devices bond the back surface of a semiconductor chip (die) to a board such as a lead frame or a printed board through a bonding material such as soft solder, hard solder, silver paste, or wood. ).

 As shown in FIG. 5, the collet 30 of the die bonder for bonding such a semiconductor chip (die) to a substrate is composed of a collet body 31 and a suction device attached to a tip end of the collet body 31. Part 32 is provided. Then, as shown in FIG. 6 (A), a vacuum suction force is applied to the collet 30 at the pickup position of the semiconductor chip P, and the semiconductor chip P is adsorbed by the adsorbing section 32. As shown in (B), after bonding the semiconductor chip P at the bonding position of the semiconductor chip P, a compressed gas is supplied to the collet 30 to release the semiconductor chip P from the suction portion 32. .

By the way, when picking up the semiconductor chip P with the collet 30, detecting the bottom dead center where the collet 30 contacts the semiconductor chip P means that the collet 30 contacts the semiconductor chip P despite the contact with the semiconductor chip P. As 30 continues to fall, excessive stress is applied to the semiconductor chip P to damage the semiconductor chip P, or the collect 30 stops descending even though the collect 30 is not in contact with the semiconductor chip P. And the semiconductor chip P may be sucked incorrectly. It is extremely important to prevent the collet 30 and to operate the collet 30 at high speed.

 For this reason, conventionally, for example, as shown in a collet 40 shown in FIG. 7, the collet body 41 and the suction portion 42 are separated, and the suction portion 42 is separated from the collet body 41 by the shaft 43. The suction section 42 is always urged downward by the elastic force of the compression spring 44 so that it can be moved up and down, and the proximity sensor 4 is located between the upper part of the collect body 41 and the upper part of the shaft 43. 5 (45 a, 45 b) is provided, and when the suction part 42 rises against the elastic force of the compression spring 44 when the suction part 42 contacts the semiconductor chip P, the proximity sensor It has been proposed to detect that the suction section 42 has reached the bottom dead center by the separation of 45 (45a, 45b).

 Also, although it does not detect the lower branch of the suction section, when the work on the chip is suctioned by the suction port at the tip of the suction transfer nozzle and transferred to a predetermined location, the presence of the suction work in the suction port is not detected. In the work presence / absence detection device of the suction / conveyance nozzle for detecting the presence / absence, a pressure sensor is interposed in a vacuum suction pipe between the suction / conveyance nozzle and a vacuum source, and the suction port is pressed against a predetermined work. At the same time, there has been proposed a device for detecting the presence or absence of a work with a suction conveyance nozzle in which the work is vacuum-sucked by driving a vacuum source so that the work is vacuum-sucked to a suction port (for example, see Patent Document 1).

Patent Document 1: Japanese Unexamined Utility Model Publication No. 5-388776 Disclosure of the Inventions of FIGS. 1 and 2 Problems to be Solved by the Invention However, the collet 40 shown in FIG. The suction part 42 is separated from the suction part 42 so that the suction part 42 can be moved up and down and the compression spring 44 must be interposed, so that the structure is complicated and the collet 40 is expensive. Become. In addition, the suction section 42 is made of various materials such as super steel, polymer resin, and polymer rubber according to a request of a semiconductor device maker for the purpose of use, and the bottom dead center of the suction section 42 is set. There is a problem that it is difficult to detect I got it.

 For example, when the suction portion 42 is made of an elastic material such as a polymer rubber, as shown in FIG. 8, even after the suction portion 42 comes into contact with the semiconductor mounting chip P, the collet 40 is not removed. As shown by the two-dot chain line in the figure, the suction sensor 42 is compressed and deformed by the dimension h, and the proximity sensors 45 (45a, 45b) do not separate from each other. The bottom dead center of the suction section 42 could not be detected with high accuracy.

 Further, although the work presence / absence detection device described in Patent Document 1 can detect the presence / absence of work suction, the vacuum source is driven after the suction port contacts the work. The bottom dead center of the detection device cannot be detected.

 Therefore, the present invention does not separate the main body and the suction section and does not configure the suction section to be able to move up and down. Further, even when the suction section is formed of an elastic body, for example, An object of the present invention is to provide a work transfer means capable of reliably detecting a bottom dead center. Means for Solving the Problems In order to solve the above-mentioned problems, the work transfer means of the present invention is a work transfer means having a suction part for vacuum-sucking a work, wherein a fluid supply means for supplying a fluid to the suction part. And a sensor for detecting a change in the flow state of the fluid supplied to the adsorbing section, so that the fluid flows to the adsorbing section before the adsorbing section comes into contact with the object, and the adsorbing section contacts the object The sensor is characterized in that the bottom dead center of the suction portion is detected by detecting a change in the flow state of the fluid at the time of the detection. Further, the work transfer means of the present invention is characterized in that the sensor is a flow rate sensor interposed in a fluid supply pipe between the fluid supply means and the suction part.

 Further, the workpiece transfer means of the present invention is characterized in that the sensor is a pressure sensor connected to a pipe branching from the middle of a fluid supply pipe between the fluid supply means and the suction unit.

Further, the work transfer means of the present invention is characterized in that the adsorbing section adsorbs a semiconductor chip or a substrate. Effect of the Invention According to the workpiece transfer means of the present invention, the fluid flows to the suction section before the suction section comes into contact with the target object, and the suction section is lowered so that the suction section contacts the work. The sensor detects changes in the flow state of the fluid that occur at this time, and the bottom dead center of the suction part can be detected, so that the main body and the suction part are separated and the suction part is moved up and down with respect to the main body as in the past. There is no need to make it possible, and the configuration is significantly simplified. Even if the suction section is made of an elastic body, the sensor detects a change in the fluid flow state caused by the object blocking the vacuum suction I hole of the suction section before the suction section is deformed. The bottom dead center of the suction part can be easily and reliably detected. In addition, before the suction section is deformed, the lowering operation of the work transfer means can be stopped and the operation can be shifted to the next operation, so that the work transfer means can be uselessly operated and the high-speed operation of the work transfer means can be performed. Will be possible. Furthermore, even when the target object is a work and the thickness is different, the bottom dead center can be reliably detected. Further, according to the work transfer means of the present invention, since the flow rate sensor is interposed in the pipe for supplying the fluid to the suction section, when the suction section reaches the bottom dead center, the flow rate change of the fluid is immediately changed. Can be detected by the flow sensor.

 Further, according to the work transfer means of the present invention, since the pressure sensor is connected to the pipe branched from the pipe for supplying the fluid, when the suction section reaches the bottom dead center, the pressure in the pipe due to the change in the flow rate of the fluid is immediately changed. A pressure change can be detected by a pressure sensor.

 According to the work transfer means of the present invention, works such as a semiconductor chip, a lead frame, and a printed circuit board can be easily and reliably transferred at a high speed, and a high-precision and high-speed operation in a die bonder or the like is possible. become. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic front view of a work transfer means according to a first embodiment of the present invention.

FIG. 2 (A) is a main part front view of a state in which the suction portion has not reached the bottom dead center when a vacuum suction force is supplied to the work transfer means of FIG. FIG. 2 (B) is a main part front view of the state in which the suction section has reached the bottom dead center when a vacuum suction force is supplied to the work transfer means of FIG.

 FIG. 2 (C) is a front view of the main part in a state where the suction section has not reached the bottom dead center when the compressed gas is supplied to the work transfer means of FIG.

 'FIG. 2 (B) is a front view of a main part in a state where the suction section has reached the bottom dead center when the compressed gas is supplied to the work transfer means of FIG.

 FIG. 3 is a schematic front view of the work transfer means according to the second embodiment of the present invention.

 FIG. 4 (A) is a front view of a main part in a state where the suction part has not reached the bottom dead center when a vacuum suction force is supplied to the work transfer means of FIG.

 FIG. 4 (B) is a main part front view of the state in which the suction part has reached the bottom dead center when a vacuum suction force is supplied to the work transfer means of FIG.

 FIG. 4 (C) is a front view of the main part in a state where the suction section has not reached the bottom dead center when the compressed gas is supplied to the work transfer means of FIG.

 FIG. 4B is a main part front view of the state in which the suction section has reached the bottom dead center when the compressed gas is supplied to the work transfer means of FIG.

 FIG. 5 is a schematic front view of a conventional collet.

 FIG. 6 (A) is a schematic front view of a main part in a state where a vacuum suction force is supplied to the collet of FIG. 5 to adsorb the semiconductor chip.

 FIG. 6 (B) is a schematic front view of an essential part in a state where compressed gas is supplied to the collet of FIG. 5 to detach the semiconductor chip from the suction part. '

 FIG. 7 is a schematic front view of a conventional bottom dead center detection type collet.

FIG. 8 is a schematic front view of an essential part for explaining a problem of the collet shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a work transfer means according to the present invention will be described with reference to the drawings. (First Embodiment) As shown in FIG. 1, the workpiece transfer means 10 includes a main body 11 and a fl binding portion 12, and a suction portion 12 is fixed to a lower end of the main body 11, and A flow sensor 14 is interposed in the middle of a pipe 13 for supplying a vacuum suction force or a compressed gas to 2.

 Next, the operation of the work transfer means 10 will be described with reference to FIGS. 2 (A) to 2 (D). First, as shown in Fig. 2 (A), when a vacuum suction force is supplied to the pipe 13 and the suction unit 12 reaches the bottom dead center and does not contact the object, the suction unit 12 Since the air or nitrogen 15 is sucked and flows through the pipe 13, the flow sensor 14 detects the flow of air or nitrogen, and can detect that the adsorption section 12 has not reached the bottom dead center.

 With the vacuum suction force being supplied to the pipe 13, the work transfer means 10 descends, and as shown in FIG. 2 (B), when the suction portion 12 comes into contact with an object, for example, a semiconductor chip P. Since the semiconductor chip P closes the suction hole of the suction section 12, the flow of air and nitrogen in the pipe 13 disappears, and the flow rate sensor 14 detects the flow, and the suction section 12 detects the bottom dead center. Can be detected. The suction section 12 vacuum-adsorbs the semiconductor chip P, so that the pickup can be performed as it is. As shown in Fig. 2 (C), when the compressed gas 16 is supplied to the pipe 13 and the suction section 12 reaches the bottom dead center and does not contact the target, the pipe 13 Since the compressed gas 16 flows and the compressed gas 16 is ejected from the adsorbing section 12, the flow sensor 14 detects the flow of the compressed gas 16 and the adsorbing section 12 has not reached the bottom dead center. Can be detected.

 With the compressed gas 16 supplied to the pipe 13, the work transfer means 10 descends, and as shown in FIG. 2 (D), the suction portion 12 contacts the object, for example, the semiconductor chip P. Then, since the semiconductor chip P blocks the suction hole of the suction section 12, the compressed gas 16 does not flow in the pipe 13, and the flow rate sensor 14 detects it, so that the suction section 12 is It can be detected that the bottom dead center has been reached. In the case of picking up the semiconductor chip P, if a vacuum suction force is supplied to the pipe 13, the semiconductor chip P can be vacuum-sucked by the suction section 12 and picked up.

 (Second embodiment)

As shown in FIG. 3, the workpiece transfer means 20 includes a main body 21 and a suction section 22, and the suction section 22 is fixed to a lower end of the main body 21, and the work transfer section 20 is attached to the suction section 22. A pressure sensor 25 is connected to a pipe 24 branching from the middle of a pipe 23 for supplying a vacuum suction force or a compressed gas. Next, the operation of the work transfer means 20 will be described with reference to FIGS. First, as shown in Fig. 4 (A), when vacuum suction is supplied to the pipe 23, if the suction part 22 does not reach the bottom dead center, the surrounding air or nitrogen 15 Is sucked and flows through the pipe 23, so that the pressure sensor 25 hardly detects the pressure, so that it can be detected that the suction section 12 has not reached the bottom dead center.

 With the vacuum suction force being supplied to the pipe 23, the work transfer means 20 descends, and as shown in FIG. 4B, when the suction portion 22 comes into contact with an object, for example, a semiconductor chip P. Since the semiconductor chip P closes the suction hole of the suction portion 22, air and nitrogen 15 do not flow in the pipe 23, and the pressure in the pipes 23 and 24 decreases. Can detect that the suction section 22 has reached the bottom dead center. Since the suction part 22 suctions the semiconductor chip P by vacuum, it can be picked up as it is.

 Also, as shown in FIG. 4 (C), when the compressed gas 16 is supplied to the pipe 23, the compressed gas 16 flows through the pipe 23 unless the suction part 22 reaches the bottom dead center. Since the compressed gas 16 is ejected from the suction section 22, almost no pressure is applied to the pipes 23 and 24, and the pressure sensor 25 does not detect the pressure. Can be detected that has not reached the bottom dead center.

 With the compressed gas 16 supplied to the pipe 23, the work transfer means 20 descends, and as shown in FIG. 4 (D), the suction portion 22 is attached to the target object, for example, the semiconductor chip: P. When contact is made, the semiconductor chip P closes the suction hole of the suction section 22, so that the compressed gas 16 does not flow in the pipe 23, and the pressure in the pipes 23, 24 increases. The sensor 14 detects this, and it can be detected that the suction section 22 has reached the bottom dead center. In the case of picking up the semiconductor chip P, if a vacuum suction force is supplied to the pipe 23, the semiconductor chip P can be picked up by suctioning the semiconductor chip P in the suction section 22.

 The above embodiment has been described with respect to a specific embodiment of the present invention, and the present invention is not limited to this embodiment, and various modifications are possible.

For example, in the above embodiment, the case where the object is a semiconductor chip has been described, but a work such as a lead frame or a printed board may be used. Also, for example, a workpiece picker In the case where the bottom dead center is detected before the work transfer means, the object may be a bottom dead center detection table or the like.

 Further, in the above-described embodiment, the case where the work transfer means 10, 20 is a single unit has been described. For example, in the case of transferring a large-sized work such as a lead frame or a printed circuit board, The work transfer means may have a plurality of suction sections. In such a case, only one flow sensor or pressure sensor needs to be provided for a common pipe that supplies a vacuum suction force or a compressed gas to a plurality of suction sections.

 Further, the work transfer means of the present invention is particularly suitable when the suction section is made of an elastic body such as a polymer rubber, but the suction section is made of super steel or a polymer resin. Can also be applied to

 INDUSTRIAL APPLICABILITY The work transfer means of the present invention is particularly useful in a die bonder for a semiconductor chip. However, the die transfer means for various types of electronic parts such as a resistor chip and a capacitor chip, and a resin mold. The present invention can also be applied to means for transferring electronic components such as individual semiconductor devices, semiconductor integrated circuit devices, resistors, capacitors, and the like, or for transferring other workpieces.

Claims

The scope of the claims 1. In the work transfer means having a suction part for vacuum suction of the work,  Fluid supply means for supplying a fluid to the adsorption section,  A sensor that detects a change in the flow state of the fluid supplied to the suction unit,  Before the suction section contacts the object, the fluid flows to the suction section, and the sensor detects the flow state fluctuation of the fluid when the suction section contacts the object, so that the bottom dead center of the suction section can be set. Work transfer means characterized by detection.  2. The work transfer means according to claim 1, wherein the sensor is a flow sensor interposed in a fluid supply pipe between the fluid supply means and the suction part.  3. The work transfer means according to claim 1, wherein the sensor is a pressure sensor connected to a pipe branched from the middle of a fluid supply pipe between the fluid supply means and the suction unit.  4. The work transfer device according to claim 1, wherein the suction unit is configured to suction a semiconductor chip or a substrate.