JP2004132335A - Paste ejecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paste ejecting device having a compact and simple mechanism, which can be maintained by an easy maintenance work. <P>SOLUTION: In a pump mechanism of the paste ejecting device, a first rotary member 34 and a second rotary member 35 are concentrically disposed at a housing member 33 having a first fixing part 33b and a second fixing port 33c at upper and lower positions to be individually normally or reversely rotatably engaged with each other. The member 35 is rotated in a state in which a peripheral protrusion 35b is disposed along a first inner peripheral surface 34e so that the volumes of a first space 37 and second space 38 can be increased or decreased. The rotations of the members 34 and 35 are controlled to increase or decrease the volumes of the spaces 37, 38 and to communicate the spaces with the ports 33b, 33c to thereby suck/discharge the paste via the ports. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a paste discharging device that discharges a paste such as a conductive paste.
[0002]
[Prior art]
As a method of joining an electronic component such as a semiconductor chip to a printed board, a lead frame, or the like, a resin adhesive is often used. As a type of the resin adhesive, a conductive paste in which a conductive portion such as a metal powder is added to a resin to give a conductive property to a joint portion is known. The conductive paste has a function as an adhesive and can electrically connect the bonding portion. Therefore, the conductive paste is used for fixing the semiconductor element to the substrate and for connecting the semiconductor element to an electrode of the substrate.
[0003]
The application device for applying the conductive paste is provided with a discharge device that discharges the conductive paste. Conventionally, a plunger-type discharge device that sucks and discharges the conductive paste into the cylinder chamber by reciprocating the plunger has been used. It is known (for example, see Patent Document 1).
[0004]
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. 2-78773 [0005]
[Problems to be solved by the invention]
This plunger type discharge device requires a port switching mechanism for sucking and discharging the paste into and from the cylinder, together with a housing part constituting the cylinder and reciprocating means for reciprocating the plunger. For this reason, the structure of the discharge device is complicated and it is difficult to reduce the size of the discharge device, and the disassembling and assembling work at the time of the maintenance work that is frequently performed becomes complicated, which requires time and labor.
[0006]
Therefore, an object of the present invention is to provide a paste discharge device that is configured with a compact and simple mechanism and that facilitates maintenance work.
[0007]
[Means for Solving the Problems]
The paste discharge device according to claim 1, wherein the paste discharge device discharges a paste, and a housing portion provided with a circular fitting hole, and an outer peripheral surface rotatably fitted into the fitting hole and in sliding contact therewith. A first rotating member having a first inner diameter and a first central angle provided concentrically with the outer circumferential surface on the first rotating member and within a range of a first central angle. A second inner peripheral surface provided with a second inner diameter smaller than the first inner diameter concentrically with the first inner peripheral surface; and a first rotating member provided near both ends of the first inner peripheral surface. A first moving port and a second moving port which are located and penetrated in the radial direction, and a first outer peripheral surface which is in sliding contact with the first inner peripheral surface is smaller than a first central angle. A second rotating member having a convex portion provided in a range of the central angle of 2 and a second outer peripheral surface slidably contacting the second inner peripheral surface; A first space and a second space formed between a first inner peripheral surface and a second outer peripheral surface on both sides of the protrusion, a first rotating member and a second rotating member First and second rotation driving means for individually rotating the first and second rotation ports respectively, and a first movement port and a second rotation port provided at the housing portion at a specific rotation position of the first rotation member. A first fixed port and a second fixed port that respectively communicate with the moving ports of the first and second rotation driving means, and control the first rotation driving means and the second rotation driving means of the first space and the second space. By increasing / decreasing the volume and connecting the first space and the second space to the first fixed port and the second fixed port, the suction and suction of the paste via the first fixed port and the second fixed port. Suction and discharge to perform discharge operation And control means.
[0008]
According to the present invention, a first rotating member having two inner peripheral surfaces having concentric and different diameters is relatively rotatably combined with a second rotating member having two outer peripheral surfaces slidingly contacting these inner peripheral surfaces. By forming a first space and a second space having variable volumes for paste suction / discharge, a pump mechanism can be configured with a compact and simple mechanism, and a paste discharge device that is easy to maintain is provided. Can be realized.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a die bonding apparatus according to one embodiment of the present invention, FIG. 2 is a side view of a paste discharging apparatus according to one embodiment of the present invention, and FIG. 3 is a paste discharging apparatus according to one embodiment of the present invention. 4 (a) is a perspective view of a first rotating member of the paste discharge device according to one embodiment of the present invention, and FIG. 4 (b) is a paste according to one embodiment of the present invention. FIG. 5 is a perspective view of a second rotating member of the discharge device, FIG. 5 is a front sectional view of a pump mechanism of the paste discharge device of one embodiment of the present invention, and FIGS. 6 and 7 are paste discharge of one embodiment of the present invention. It is operation | movement explanatory drawing of an apparatus.
[0010]
First, the structure of the die bonding apparatus will be described with reference to FIG. In FIG. 1, a wafer sheet 2 is held by a chip supply unit 1 by a holding table (not shown). A large number of chips 3 as semiconductor elements are adhered to the wafer sheet 2. A transport path 5 is provided on the side of the chip supply unit 1, and the transport path 5 transports a lead frame 6, which is a substrate, and positions the lead frame 6 at a paste application position and a bonding position. A bonding head 4 is provided above the chip supply unit 1, and the bonding head 4 is moved horizontally and vertically by a moving mechanism (not shown).
[0011]
A paste application section 9 is provided on the side of the transport path 5. The paste application unit 9 is configured by mounting an application nozzle 18 on a moving table 10 via an L-shaped bracket 15. The application nozzle 18 is connected to the paste discharge device 16 by a tube 17 that is a flexible tube member.
[0012]
The paste discharge device 16 is further connected to the syringe 19 via a tube 20. A conductive paste (hereinafter simply referred to as “paste”) is stored in the syringe 19. This paste is obtained by mixing a conductive metal powder with a resin adhesive such as an epoxy resin as a main component, a curing agent for curing the epoxy resin, and a curing accelerator. Silver powder is frequently used as the metal powder, and is supplied in a slurry form in which silver powders of various shapes such as granules and flakes are mixed in order to improve conductivity.
[0013]
The paste is supplied to the paste discharge device 16 by the syringe 19 at a predetermined press-in pressure, and the supplied paste is sucked by the paste discharge device 16 and is then pressure-fed to the application nozzle 18 through the tube 17 at a predetermined discharge pressure. . The ink is discharged from an application port provided at the lower end of the application nozzle 18 and applied to the application area 6 a of the lead frame 6.
[0014]
The moving table 10 is configured by stacking an X-axis table 12 on a Y-axis table 11 and further vertically connecting a Z-axis table 14 via an L-shaped bracket 13. The Y-axis table 11, the X-axis table 12, and the Z-axis table 14 include a Y-axis motor 11a, an X-axis motor 12a, and a Z-axis motor 14a, respectively. By driving the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a, the application nozzle 18 moves horizontally and vertically on the lead frame 6. Therefore, the moving table 10 serves as moving means for moving the application nozzle 18 relatively to the lead frame 6.
[0015]
The mounting position of the chip 3 on the upper surface of the lead frame 6 is an application area 6a where the paste 7 is applied. The application nozzle 18 is positioned in the application area 6a, and the application nozzle 18 is moved while discharging the paste 7 from the application nozzle 18, whereby the paste 7 for chip bonding is drawn in a predetermined drawing pattern in the application area 6a. Applied.
[0016]
After this paste application, the lead frame 6 is sent to the bonding position 8 on the transport path 5 and positioned. Then, the chip 3 picked up from the chip supply unit 1 is bonded by the nozzle 4a of the bonding head 4 onto the paste 7 applied in the application area 6a.
[0017]
Next, the structure of the paste discharge device 16 will be described with reference to FIG. In FIG. 2, the paste discharge device 16 has a configuration in which a pump mechanism 30 driven by two motors 23 and 24 is disposed on a base plate 21. At both ends of the base plate 21. Two brackets 22 are provided upright, and motors 23 and 24 are fixed to the brackets 22. A pump mechanism 30 is fixed to a central portion of the base plate 21 via a bracket 25, and rotation shafts 23a and 24a of motors 23 and 24 are coupled to the pump mechanism 30. The motors 23 and 24 are controlled by the control unit 26, and the pump mechanism 30 discharges the paste sucked through the tube 20 through the tube 17 when the motors 23 and 24 perform a predetermined rotation operation.
[0018]
Next, the structure of the pump mechanism 30 will be described with reference to FIGS. In the pump mechanism 30, the first fixed port 33b that sucks the paste through the tube 20 and the second fixed port 33c that discharges the paste through the tube 17 are symmetrical in the vertical direction (180 ° equidistant with respect to the center). A first rotating member 34 and a second rotating member 35 are rotatably mounted in a concentric arrangement on a housing portion 33 provided at (position).
[0019]
In FIG. 3, two holding members 31 and 32 are connected to a U-shaped bracket 25. The holding members 31 and 32 hold the housing portion 33 by sandwiching the housing portion 33 from both sides, and have circular fitting holes (the inner holes shown in FIG. 5) provided through the holding members 31 and 32 and the housing portion 33 in the horizontal direction. A first rotating member 34 and a second rotating member 35 are fitted concentrically on the peripheral surface 33a), and the outer peripheral surfaces of the first rotating member 34 and the second rotating member 35 Rotatably slidably contact the inner peripheral surface 33a of the fitting hole provided in the first hole.
[0020]
The rotating shafts 23a and 24a of the motors 23 and 24 are respectively coupled to the first rotating member 34 and the second rotating member 35. By driving the motors 23 and 24, the first rotating member 34 and the second rotating member 35 are driven. The second rotating member 35 is pivotally supported by the holding members 31 and 32 and the housing portion 33 and rotates individually. The motors 23 and 24 serve as first rotation driving means and second rotation driving means for individually rotating the first rotating member 34 and the second rotating member 35 forward and backward, respectively.
[0021]
On the outer peripheral surface of the first rotating member 34 and the second rotating member 35, a seal member 36 is attached at a position of a contact surface between the holding members 31 and 32 and the housing portion 33. In addition, at the time of paste suction / discharge operation due to rotation of the second rotating member 35, the paste is prevented from leaking to the outside. In FIG. 3, a bearing mechanism and an axial holding mechanism that support the first rotating member 34 and the second rotating member 35 are not shown.
[0022]
Next, the shapes of the first rotating member 34 and the second rotating member 35 will be described with reference to FIGS. FIG. 5 shows an AA cross section of FIG. 3, where the dimensional ratio in the radial direction is different between FIG. 3 and FIG. 5 for convenience of illustration. As shown in FIG. 4A, the first rotating member 34 has a structure in which a concave processed portion 34a having a depth D that is recessed in the axial direction is formed on one surface of a columnar member. As shown in FIG. 5, the inner side surface of the concave processed portion 34a has two inner peripheral surfaces provided concentrically with the outer peripheral surface 34d, that is, a first central angle θ1 (here, θ1 = 180 °) with a radius r1. (Set), and a second inner peripheral surface 34f having a radius r2 smaller than r1.
[0023]
At the boundary position between the first inner peripheral surface 34e and the second inner peripheral surface 34f in the vicinity of both ends, the first moving port 34b and the second moving port 34c are arranged at equal angles of 180 ° in the radial direction. It is provided through. The first moving port 34b and the second moving port 34c communicate with the first fixed port 33b and the second fixed port 33c provided in the housing portion 33 at a specific rotation position of the first rotating member 34. I do.
[0024]
As shown in FIG. 4 (b), the second rotating member 35 is formed on one surface of the cylindrical member by forming a convex processing portion 35a protruding in the axial direction at a height H equal to the depth D of the concave processing portion 34a. It has a formed structure. As shown in FIG. 5, the outer surface of the convex processed portion 35 a is in contact with two outer surfaces that are in sliding contact with the two inner surfaces of the first rotating member 34, that is, the first outer surface that is in sliding contact with the first inner surface 34 e. Has an outer peripheral surface 35c and a second outer peripheral surface 35d which is in sliding contact with the second inner peripheral surface 34f. Here, the first outer peripheral surface 35c is provided in a range of a second central angle θ2 (here, θ2 = 90 ° is set) smaller than the first central angle θ1. The range of the outer peripheral surface 35e is a peripheral convex portion 35b (convex portion) that protrudes in the radial direction from the second outer peripheral surface 34d along the circumferential direction.
[0025]
In a state where the convex processing portion 35a of the second rotating member is fitted into the concave processing portion 34a of the first rotating member 34, since θ2 is smaller than θ1, as shown in FIG. A first space 37 and a second space 38 sandwiched between the first inner peripheral surface 34e and the second outer peripheral surface 35d are formed on both sides of the first inner peripheral surface 34e and the second outer peripheral surface 35d. Then, by rotating the second rotating member 35 relative to the first rotating member 34, the volumes of the first space 37 and the second space 38 increase or decrease.
[0026]
Since the first space 37 and the second space 38 communicate with the first movement port 34b and the second movement port 34c, respectively, the first movement port 34b and the second movement port 34c are The first space 37 and the second space 38 are formed by rotating the first rotating member 34 together with the second rotating member 35 to a position where they communicate with the first fixed port 33b and the second fixed port 33c, respectively. Can be selectively communicated with either the first fixed port 33b or the second fixed port 33c.
[0027]
Therefore, by increasing the volume of the first space 37 in a state where the first space 37 is communicated with the first fixed port 33b, the paste from the first fixed port 33b is inserted into the first space 37. Is sucked. Then, the paste is discharged from the second fixed port 33c by reducing the volume of the first space 37 in a state where the first space 37 in which the paste is sucked is communicated with the second fixed port 33c. You. This paste suction / discharge operation is performed in the second space 38 in the same manner.
[0028]
The above-described paste suction / discharge operation can be performed by controlling the motors 23 and 24 by the control unit 26 to perform a predetermined rotation operation. That is, the control unit 26 controls the motors 23 and 24 to increase or decrease the volume of the first space 37 and the second space 38 and to connect the first space 37 and the second space 38 to the first fixed port. By communicating with the fixed port 33b and the second fixed port 33c, a suction / discharge control means for performing a suction / discharge operation of the paste via the first fixed port 33b and the second fixed port 33c is provided.
[0029]
In the above configuration, an example is shown in which the first central angle θ1 and the second central angle θ2 are set to 180 ° and 90 °, respectively. However, the first moving port, the second moving port, and the first As long as the relative positional relationship between the fixed port and the second fixed port is appropriately set, the first central angle θ1 may be set to an angle other than 180 °. Then, the second central angle θ2 is determined based on the relationship between the set first central angle θ1 and the required fixed volume discharge volume.
[0030]
Next, the suction / discharge operation of the paste will be described with reference to FIGS. FIG. 6A shows a state in which the paste suction operation is started. In this state, the first moving port 34b communicates with the first fixed port 33b. The circumferential protrusion 35b is located at the moving end on the first moving port 34b side, and is located at a position where the volume of the first space 37 becomes zero. The paste 7 is supplied from the syringe 20 to the first fixed port 33b at a predetermined pressure.
[0031]
FIG. 6B shows a state after the start of suction, that is, a state in which the second rotating member 35 is rotated counterclockwise, and the circumferential projection 35b is moving in the direction of the arrow. By this movement, the volume of the first space 37 increases, and the paste 7 is sucked into the first space 37 via the first fixed port 33b and the first movement port 34b. FIG. 6C shows a state in which the suction operation has been completed. That is, the circumferential protrusion 35b reaches the moving end on the second moving port 34c side, whereby the volume of the first space 37 sucking the paste 7 becomes maximum and the volume of the second space 38 becomes zero. .
[0032]
FIG. 6D shows a port switching operation for shifting from the suction operation to the discharge operation. At the time of the port switching, the first rotating member 35 and the second rotating member 35 are rotated in a clockwise direction in synchronization with each other, and the first moving port 34b communicating with the first space 37 is moved to the second fixed port. Move toward 33c. FIG. 7A shows a state in which the port switching operation is completed and the paste discharging operation can be started.
[0033]
From this state, the volume of the first space 37 is reduced by rotating the second rotating member 35 clockwise and moving the circumferential projection 35b in the direction of the arrow as shown in FIG. 7B, Thereby, the paste 7 contained in the first space 37 is discharged through the first moving port 34b and the second fixed port 33c. Along with the discharge of the paste 7, the paste 7 is sucked into the second space 38 via the first fixed port 33b and the second moving port 34c, and the suction and the discharge are simultaneously performed. FIG. 7C shows a state in which the discharge of the paste 7 contained in the first space 37 and the suction of the paste 7 into the second space 38 have both been completed.
[0034]
Thereafter, port switching for shifting to a new paste suction / discharge operation is performed again. That is, as shown in FIG. 7 (d), the first moving member 35 and the second rotating member 35 are synchronously rotated together in the counterclockwise direction, and the second moving port communicated with the first space 38. 34c is moved toward the second fixed port 33c. As a result, the state returns to the state shown in FIG. 6A, and the paste contained in the second space 38 can be discharged and the paste can be sucked into the first space 37. Thereafter, by repeating the same suction / discharge operation, the paste discharge from the paste discharge device 16 is continuously performed.
[0035]
As described above, in the paste discharge device described in the present embodiment, the first rotating member 34 having two concentric and different diameter inner peripheral surfaces has two outer peripheral surfaces that are in sliding contact with these inner peripheral surfaces. The second rotating member 35 is rotatably combined with each other to form a first space 37 and a second space 38 having variable volumes for paste suction / discharge.
[0036]
Then, by individually rotating the first rotating member 35 and the second rotating member 35 in the forward and reverse directions, the volumes of the first space 37 and the second space 38 are increased and decreased, and the first space 37 and the The second space 38 can communicate with the first fixed port 33b and the second fixed port 33c.
[0037]
Therefore, compared with the conventional plunger-type paste discharging apparatus, a compact and simple pump mechanism is realized, and it is frequently required when using a slurry paste containing metal powder such as silver powder. Maintenance work can be simplified.
[0038]
【The invention's effect】
According to the present invention, a first rotating member having two inner peripheral surfaces having concentric and different diameters is relatively rotatably combined with a second rotating member having two outer peripheral surfaces slidingly contacting these inner peripheral surfaces. By forming a first space and a second space having variable volumes for paste suction / discharge, a pump mechanism can be configured with a compact and simple mechanism, and a paste discharge device that is easy to maintain is provided. Can be realized.
[Brief description of the drawings]
FIG. 1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention; FIG. 2 is a side view of a paste discharging apparatus according to an embodiment of the present invention; FIG. FIG. 4 (a) is a perspective view of a first rotating member of the paste discharge device according to one embodiment of the present invention; FIG. 4 (b) is a perspective view of a first rotating member of the paste discharge device according to one embodiment of the present invention; FIG. 5 is a perspective view of a second rotating member. FIG. 5 is a front sectional view of a pump mechanism of the paste discharging device according to one embodiment of the present invention. FIG. 6 is an operation explanatory diagram of the paste discharging device according to one embodiment of the present invention. FIG. 7 is an explanatory diagram of the operation of the paste discharge device according to one embodiment of the present invention.
7 Paste 16 Paste discharge device 23, 24 Motor 26 Control unit 30 Pump mechanism 33 Housing unit 33b First fixed port 33c Second fixed port 34 First rotating member 34a Concave processing unit 34b First moving port 34c Second Moving port 34d outer peripheral surface 34e first inner peripheral surface 34f second inner peripheral surface 35 second rotating member 35a convex processing portion 35b peripheral convex portion 35c first outer peripheral surface 35d second outer peripheral surface 37 first Space 38 Second space

Claims (1)

A paste discharging device for discharging paste, a first rotating member having a housing portion provided with a circular fitting hole, and an outer peripheral surface rotatably fitted in said fitting hole and slidably contacting said housing portion; The first rotating member is concentric with the outer peripheral surface. The first inner peripheral surface and the first rotating member are provided concentrically with the first inner peripheral surface and have a first inner diameter within a range of a first central angle. A second inner peripheral surface provided with a second inner diameter smaller than the first inner diameter, and a radially penetratingly provided at the first rotating member near both ends of the first inner peripheral surface; The first and second moving ports and the first outer peripheral surface slidingly contacting the first inner peripheral surface are provided in a range of a second central angle smaller than the first central angle. A second rotating member having a convex portion and a second outer peripheral surface slidably contacting the second inner peripheral surface; a first inner peripheral surface on both sides of the convex portion; A first space and a second space formed between the first rotation member and the outer circumference of the first rotation member; a first rotation driving means for individually rotating the first rotation member and the second rotation member in forward and reverse directions; A second rotation drive unit, a first fixed port and a second fixed port provided on the housing portion and communicating with the first and second movement ports at a specific rotation position of the first rotation member , And the first and second rotation driving means are controlled to increase or decrease the volumes of the first and second spaces and to reduce the volume of the first and second spaces. Suction and discharge control means for communicating with the first fixed port and the second fixed port to perform a suction / discharge operation of the paste via the first fixed port and the second fixed port. Features Paste ejection apparatus.

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