A material handling unit and a die bonder

Abstract

The present invention relates to a material taking unit and a crystal bonding machine, which also includes a driving device, a parallelism adjustment device and a material taking head, wherein the parallelism adjustment device includes a first mounting plate and a second mounting plate, wherein the first mounting plate is arranged on the output end of the driving device, and the parallelism between the first mounting plate and the second mounting plate is adjustable, and the material taking head is fixed on the second mounting plate, and the driving device can drive the material taking head to perform linear reciprocating motion. By adjusting the parallelism between the first mounting plate and the second mounting plate, the present invention can timely adjust the parallelism between the mounting surface of the wafer and the carrier, prevent the wafer from being skewed, and prevent the wafer from being loosely attached to the carrier, thereby improving the yield rate of wafer attachment and ensuring product quality.

Description

Technical Field

[0001] The present invention relates to the technical field of chip bonding, and in particular to a material taking unit and a bonding machine. Background Art

[0002] Semiconductor packaging refers to the process of processing tested wafers into independent chips according to product models and functional requirements. The specific packaging process is to cut the wafer into small chips through a dicing process, and then glue the cut chips to the corresponding islands on the substrate frame. Ultra-fine metal wires or conductive resins are used to connect the bonding pads of the chips to the corresponding pins of the substrate to form the required circuit. The independent chips are then packaged and protected with a plastic shell. After plastic sealing, the packaging is completed through inspection, testing, and packaging.

[0003] The pick-up device is the core component of the die bonder. Its function is to pick up the separated wafers on the wafer, transfer and place them on a carrier (such as a lead frame and PCB board), and then paste or weld them. To this end, the pick-up device is generally designed as a mechanism with two degrees of freedom (Y-axis direction and Z-axis direction). It needs to move back and forth between the pick-up point and the bonding point accurately and smoothly to complete the actions of picking up wafers, transferring wafers, and bonding wafers.

[0004] During the wafer bonding process, the wafer needs to be aligned with the mounting surface of the carrier and then placed to prevent the wafer from tilting and the wafer from not being firmly attached to the carrier. At this time, the spatial angle between the material picking head and the carrier needs to be adjusted, so a design is required for this. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to adjust the parallelism between the wafer and the mounting surface of the carrier when the wafer is placed.

[0006] The technical solution adopted by the present invention to solve the above technical problems is:

[0007] A material picking unit also includes a driving device, a parallelism adjustment device and a material picking head, the parallelism adjustment device includes a first mounting plate and a second mounting plate, the first mounting plate is arranged on the output end of the driving device, the parallelism between the first mounting plate and the second mounting plate is adjustable, the material picking head is fixed on the second mounting plate, and the driving device can drive the material picking head to perform linear reciprocating motion.

[0008] In a preferred embodiment, a pressure sensor is further included, and the pressure sensor can detect the force of the material picking head to place the material on the carrier.

[0009] In a preferred embodiment, the pressure sensor is arranged between the first mounting plate and an output end of the drive device.

[0010] In a preferred embodiment, the first mounting plate is slidably connected to the output end of the driving device, and the sliding direction of the first mounting plate relative to the output end of the driving device is parallel to the direction of the linear reciprocating motion of the material taking head.

[0011] In a preferred embodiment, a first sliding pair is further included, and the first mounting plate is connected to the output end of the driving device through the first sliding pair.

[0012] In a preferred embodiment, the parallelism adjustment device also includes a ball, a first elastic element and a set screw, the ball is clamped between the first mounting plate and the second mounting plate, the second mounting plate can rotate around the ball, the first elastic element gives the second mounting plate an elastic force close to the first mounting plate, the set screw is threadedly connected to the first mounting plate, and one end of the set screw is abutted against the second mounting plate.

[0013] In a preferred embodiment, the parallelism adjustment device also includes a screw, the first elastic element is a first spring, a through hole is provided on the first mounting plate, and after the screw passes through the through hole, it is threadedly connected to the second mounting plate, the first spring is sleeved on the screw, one end of the first spring is abutted against a side of the first mounting plate away from the second mounting plate, and the other end of the first spring is abutted against the screw.

[0014] In a preferred embodiment, two set screws are provided, and the axis of one set screw and the plane where the center of the ball is located are perpendicular to the axis of the other set screw and the plane where the center of the ball is located.

[0015] A crystal bonding machine comprises the above-mentioned material taking unit.

[0016] In a preferred embodiment, a fixing seat is further included, the driving device is a voice coil motor, the voice coil motor includes a mounting frame, a coil and a magnet, the mounting frame is provided with a receiving groove, the coil is fixed in the receiving groove, and the magnet is fixed on the fixing seat.

[0017] In a preferred embodiment, the material taking units are provided with two or more, the mounting frames respectively belonging to the two or more voice coil motors are arranged in parallel on the fixing seat, and the magnets span the coils respectively belonging to the two or more voice coil motors.

[0018] In a preferred embodiment, two or more coils are provided.

[0019] The beneficial effects of the present invention are:

[0020] The present invention is provided with a parallelism adjustment device, which includes a first mounting plate and a second mounting plate. The first mounting plate is arranged on the output end of the driving device, and the parallelism between the first mounting plate and the second mounting plate is adjustable. The material picking head is fixed on the second mounting plate. By adjusting the parallelism between the first mounting plate and the second mounting plate, the parallelism between the mounting surfaces of the chip and the carrier can be adjusted in time to prevent the chip from being skewed and the chip from being loosely attached to the carrier, thereby improving the yield rate of chip attachment and ensuring product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 is an axonometric view of a die bonder according to an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 The right side view of the die bonder in FIG.

[0024] Figure 3 yes Figure 1 Partial exploded view of the die bonder in the figure;

[0025] Figure 4 yes Figure 1 A top view of the die bonder in FIG.

[0026] Figure 5 yes Figure 4 Cross-sectional view along section AA. DETAILED DESCRIPTION

[0027] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that each technical feature and the overall technical solution of the present invention can be understood intuitively and figuratively, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0028] In the description of the present invention, if it involves a description of orientation, such as "upper", "lower", "front", "back", "left", "right", etc., the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. When a feature is referred to as "set", "fixed", or "connected" to another feature, it can be directly set, fixed, or connected to the other feature, or it can be indirectly set, fixed, or connected to the other feature.

[0029] In the description of the present invention, if "several" is involved, it means one or more, if "multiple" is involved, it means more than two, if "greater than", "less than" or "exceed" is involved, it should be understood as not including the number itself, if "above", "below" or "within" is involved, it should be understood as including the number itself. If "first" or "second" is involved, it should be understood as being used to distinguish technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0030] In addition, unless otherwise defined, the technical terms and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art. The terms used in the present invention are only for describing specific embodiments, not for limiting the present invention.

[0031] Reference Figures 1 to 3 , Figure 1 is an axonometric view of a die bonding machine according to an embodiment of the present invention, Figure 2 yes Figure 1 The right side view of the die bonder in the figure. Figure 3 yes Figure 1 Partial exploded view of the crystal bonding machine in the figure. The crystal bonding machine of this embodiment includes a frame 1 and a material picking unit 2, the material picking unit 2 is arranged on the frame 1, and the material picking unit 2 includes a second elastic element 20, a second sliding pair 21, a driving device 22, a connecting seat 23, a pressure sensor 24, a first sliding pair 25, a parallelism adjustment device 26, a material picking head 27, a grating ruler 28 and a photoelectric sensor assembly 29, the output end of the driving device 22 is connected to the frame 1 through the second sliding pair 21, the parallelism adjustment device 26 is fixed to the output end of the driving device 22 through the connecting seat 23, and the material picking head 27 is arranged on the parallelism adjustment device 26. Under the drive of the driving device 22, the material picking head 27 can make reciprocating linear motion. In this embodiment, the sliding direction of the second sliding pair 21 is arranged along the Y-axis direction, and the direction of the reciprocating linear motion of the material picking head 27 is the Y-axis direction.

[0032] The frame 1 includes a fixed seat 11, a connecting plate 12 and a third mounting plate 13. In this embodiment, the second elastic element 20 is a second spring, the upper end of the second spring is fixed on the fixed seat 11, and the lower end of the second spring is fixed on the output end of the driving device 22. The second spring gives the driving device 22 an elastic force along the positive direction of the Y axis. The spring force can offset the gravity of the load fixed on the output end of the driving device 22, thereby reducing the burden on the driving device 22 and saving energy.

[0033] In this embodiment, the driving device 22 is selected to be a special voice coil motor, which includes a mounting frame 221, a coil 222 and a magnet 223. A receiving groove 224 is provided on the mounting frame 221, and the coil 222 is fixed in the receiving groove 224. The fixing method can be glued or the coil 222 is embedded in the receiving groove 224. The mounting frame 221 is connected to the fixed seat 11 through the second sliding pair 21, and the magnet 223 is fixed on the frame 1. When the coil 222 is energized, under the action of the magnetic field of the magnet 223, the coil 222 drives the mounting frame 221, that is, drives the material picking head 27 to make reciprocating linear motion in the Y-axis direction.

[0034] In order to improve the working efficiency of the die bonding machine and save the installation space of the die bonding machine, two material picking units 2 are provided, and the mounting frames 221 respectively belonging to the two voice coil motors are arranged in parallel on the fixing base 11, and the material picking heads 27 respectively belonging to the two voice coil motors are located on the same side, and the magnets 223 span the coils 222 respectively belonging to the two voice coil motors. In this embodiment, four magnets 223 are provided, two of which are fixed on the fixing base 11, and the other two are fixed on the third mounting plate 13, and the coils 222 respectively belonging to the two voice coil motors are located between the magnets 223 arranged oppositely.

[0035] Through this design, coils 222 belonging to two voice coil motors can be installed in the magnetic field of a magnet 223, thereby saving installation space and realizing independent driving of two material picking heads 27; in addition, a single voice coil motor is provided with two coils 222, which can provide greater power to the material picking head 27.

[0036] The magnet 223 and the coil 222 of this embodiment are both rectangular and regular in shape. When more material taking heads 27 need to be driven, the magnet 223 is lengthened and the coil 222 is added to realize independent driving of multiple material taking heads 27.

[0037] In addition, when multiple material taking heads 27 are provided, the material taking heads 27 can be of the same type or of different types. Thus, when mounting different chips, it is not necessary to prepare multiple die bonding machines, which can improve the die bonding efficiency and reduce the manufacturing cost.

[0038] In other embodiments, the driving device 22 may also be a rod-shaped motor.

[0039] In addition, in order to detect the displacement of the material picking head 27, a grating ruler 28 is provided. The grating ruler 28 includes a scale grating and a grating reading head. The scale grating is fixed on the mounting frame 221 of the voice coil motor, and the grating reading head is fixed on the third mounting plate 13. By setting the grating ruler 28, the displacement, speed and acceleration of the material picking head 27 can be detected in time and utilized. For example, when the material picking head 27 starts to move toward the carrier, the power of the voice coil motor can be increased to make the material picking head 27 move quickly. When the material picking head 27 is close to the carrier, the material picking head 27 can be decelerated in advance to prepare for crystal bonding.

[0040] In order to detect whether the material picking head 27 has reached the correct position along the positive direction of the Y-axis, a photoelectric sensor assembly 29 is provided. The photoelectric sensor assembly 29 includes a shading sheet 291 and a photoelectric sensor 292. The shading sheet 291 is fixed on the mounting frame 221 of the voice coil motor, and the photoelectric sensor 292 is fixed on the third mounting plate 13. When the material picking head 27 has reached the correct position along the positive direction of the Y-axis, the shading sheet 291 triggers the photoelectric sensor 292. At this time, it can be determined that the material picking head 27 has obtained the chip, or that the material picking head 27 has placed all the chips.

[0041] Reference Figure 3 , Figure 4 and Figure 5 , Figure 4 yes Figure 1 A top view of the die bonder in Figure 1. Figure 5 yes Figure 4 In the sectional view along section AA, the parallelism adjustment device 26 of this embodiment includes a first mounting plate 261, a ball 262, a second mounting plate 263, a set screw 264, a screw 265 and a first elastic element. In this embodiment, the first elastic element is a first spring, the first mounting plate 261 is arranged on the connecting seat 23, the ball 262 is clamped between the first mounting plate 261 and the second mounting plate 263, and the second mounting plate 263 can rotate around the ball 262.

[0042] Specifically, arc grooves can be set on the first mounting plate 261 and the second mounting plate 263 respectively, and the ball 262 is placed in the arc groove. By controlling the diameter of the ball 262 and the depth of the arc groove, a gap is created between the first mounting plate 261 and the second mounting plate 263.

[0043] A through hole 266 is provided on the first mounting plate 261, and the screw 265 is loosely matched with the through hole 266. After passing through the through hole 266, the screw 265 is threadedly connected to the second mounting plate 263. The first spring is sleeved on the screw 265, and the lower end of the first spring abuts against the upper surface of the first mounting plate 261, and the upper end of the first spring abuts against the head of the screw 265. Therefore, the first spring gives the first mounting plate 261 an elastic force close to the second mounting plate 263, and because of the connecting effect of the screw 265, the first mounting plate 261 and the second mounting plate 263 will not be separated from each other.

[0044] The set screw 264 is threadedly connected to the first mounting plate 261, and the lower end of the set screw 264 abuts against the second mounting plate 263. By rotating the set screw 264, the set screw 264 can be extended from the first mounting plate 261, and the point on the second mounting plate 263 that abuts against the set screw 264 will be away from the first mounting plate 261, or the set screw 264 is retracted into the second mounting plate 263, and the point on the second mounting plate 263 that abuts against the set screw 264 will be close to the first mounting plate 261.

[0045] In this embodiment, two groups of set screws 264, screws 265 and first springs are provided, the axis of one set screw 264 and the center of the ball 262 are located in the XY plane, and the axis of the other set screw 264 and the center of the ball 262 are located in the YZ plane, and the two are perpendicular to each other. Therefore, by controlling the two set screws 264, the second mounting plate 263 can have two degrees of freedom of rotation around the X axis and around the Z axis. The material picking head 27 is fixed on the second mounting plate 263, thereby adjusting the parallelism between the chip fixed on the material picking head 27 and the mounting surface of the carrier, so that the chip and the carrier are more firmly attached, and the yield rate of the solid crystal is high.

[0046] In this embodiment, the material removal head 49 is a vacuum nozzle, the material of the vacuum nozzle is rubber, bakelite, ceramic or tungsten steel, the vacuum nozzle is connected to the negative pressure gas source, so as to adsorb the chip, when the negative pressure in the vacuum nozzle disappears, the chip is released.

[0047] The vacuum nozzle can be fixed on the second mounting plate 263 by fasteners.

[0048] In another embodiment, the material removal head 49 can also use the clamping technology of water surface tension adsorption. The specific method is to stick the mesh foam polyurethane cloth to the surface of the stainless steel sample tray and use the water tension on the foam polyurethane surface to adsorb the chip.

[0049] In another embodiment, the first elastic element may also be a bellows.

[0050] In order to detect the force of the material picking head 27 to place the chip on the carrier, a pressure sensor 24 is provided. To facilitate the installation of the pressure sensor 24, the pressure sensor 24 is arranged between the first mounting plate 261 and the connecting seat 23. By arranging the pressure sensor 24, the force of the chip on the carrier can be detected in real time. When the placement force reaches a predetermined target range, the driving device 22 can be controlled to stop driving the material picking head 27 to prevent damage to the chip or the carrier, or to prevent insufficient bonding force, resulting in the chip not being tightly attached.

[0051] In this embodiment, the pressure sensor 24 is a square sensor, two ends of which are respectively against the first mounting plate 261 and the connecting seat 23 , a gap is provided in the square sensor, and a strain gauge is provided in the gap.

[0052] In other embodiments, the pressure sensor 24 may also use a ceramic pressure sensor or a diffused silicon pressure sensor.

[0053] In order to guide the movement of the parallelism adjustment device 26 and facilitate the square sensor to accurately detect the force of the material head 27 placing the chip, a first sliding pair 25 is provided. The first sliding pair 25 is arranged on the side of the connecting seat 23, and the sliding direction of the first sliding pair 25 is arranged along the Y-axis direction. The first mounting plate 261 is connected to the connecting seat 23 through the first sliding pair 25, thereby constraining the first mounting plate 261 to move only along the Y-axis direction, that is, the parallelism adjustment device 26 only moves along the Y-axis direction. At this time, the force of the material head 27 placing the chip can be intuitively reflected on the square sensor, and the movement direction of the parallelism adjustment device 26 deviates from the Y-axis direction, which makes only one component of the force of the material head 27 placing the chip transmitted to the square sensor, thereby causing the detection distortion of the square sensor.

[0054] In this embodiment, when the square sensor is used to detect the force of the pick-up head 27 to place the wafer, the friction force of the first sliding pair, the gravity of the parallelism adjustment device 26 and the gravity of the pick-up head 27 need to be considered as influencing factors.

[0055] In this embodiment, the first sliding pair 25 is a linear guide rail, the slide rail of the linear guide rail is fixed on the connecting seat 23, and the slider of the linear guide rail is fixed on the first mounting plate 261.

[0056] In another embodiment, the first sliding pair 25 may also be a cross roller guide.

[0057] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the embodiments, and technicians in the relevant field can make various equivalent modifications or substitutions without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A material taking unit, characterized in that: It also includes a driving device, a parallelism adjusting device and a material taking head, wherein the parallelism adjusting device includes a first mounting plate and a second mounting plate, wherein the first mounting plate is arranged on the output end of the driving device, and the parallelism between the first mounting plate and the second mounting plate is adjustable, and the material taking head is fixed on the second mounting plate, and the driving device can drive the material taking head to perform linear reciprocating motion; The material taking unit also includes a fixing seat, the driving device is a voice coil motor, the voice coil motor includes a mounting frame, a coil and a magnet, the mounting frame is provided with a receiving groove, the coil is fixed in the receiving groove, and the magnet is fixed on the fixing seat; The material taking unit is provided with two or more mounting frames respectively belonging to the two or more voice coil motors and arranged in parallel on the fixing seat, and the magnets span the coils respectively belonging to the two or more voice coil motors; The coils are provided with two or more.

2. The material taking unit according to claim 1, characterized in that: A pressure sensor is also included, and the pressure sensor can detect the force of the material picking head to place the material on the carrier.

3. The material taking unit according to claim 2, characterized in that: The pressure sensor is arranged between the first mounting plate and an output end of the driving device.

4. The material taking unit according to claim 3, characterized in that: The first mounting plate is slidably connected to the output end of the driving device, and the sliding direction of the first mounting plate relative to the output end of the driving device is parallel to the direction in which the material taking head makes a linear reciprocating motion.

5. The material taking unit according to claim 1, characterized in that: The parallelism adjustment device also includes a ball, a first elastic element and a set screw, the ball is clamped between the first mounting plate and the second mounting plate, the second mounting plate can rotate around the ball, the first elastic element gives the second mounting plate an elastic force close to the first mounting plate, the set screw is threadedly connected to the first mounting plate, and one end of the set screw is abutted against the second mounting plate.

6. The material taking unit according to claim 5, characterized in that: The parallelism adjustment device also includes a screw, the first elastic element is a first spring, a through hole is provided on the first mounting plate, and after the screw passes through the through hole, it is threadedly connected to the second mounting plate, the first spring is sleeved on the screw, one end of the first spring is against a side of the first mounting plate away from the second mounting plate, and the other end of the first spring is against the screw.

7. A die bonding machine, characterized in that: The invention comprises a material taking unit as claimed in any one of claims 1 to 6.

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