Dispensing system with decoupled optical detection and dispensing device

Abstract

A system for dispensing an adhesive material in a semiconductor chip bonding process includes a mounting bracket and an optical detection device mounted on the mounting bracket for detecting a bonding position. A dispensing head is operative to dispense the adhesive material onto the bonding location detected by the optical detection device. A positioning mechanism coupled with the dispensing head is used for enabling the dispensing head to move relative to the optical detection device, so that the detection of the optical detection device and the dispensing of the dispensing head at different bonding positions are simultaneously carried out.

Description

Technical Field

[0001] The present invention generally relates to an automatic adhesive dispensing system for a semiconductor wafer bonding process, and more particularly, to a system for dispensing adhesive material in a semiconductor wafer bonding process and a method for manufacturing a semiconductor device using the system, wherein the system includes a decoupled optical detection and dispensing device, and the optical detection device is configured to detect the bonding position and bonding quality before dispensing the adhesive material. Background Art

[0002] As the size of dies or chips becomes smaller and smaller, a high-precision dispensing system is required to accurately dispense adhesive materials to the target bonding position or bonding pad in the semiconductor wafer bonding process. In order to improve the dispensing accuracy of the dispensing system, a camera is usually used to visually inspect the target bonding position, and then the dispensing head of the dispensing system is positioned to dispense the adhesive material to the target bonding position.

[0003] In a conventional dispensing system, the camera and the dispensing head are fixedly mounted on a positioning platform or mechanism, which is operated to move the camera and the dispensing head together along a preset movement direction. In this configuration, the camera and the dispensing head usually have to work at different times and cannot work at the same time, because the spacing distance between the two devices is likely to be different from the spacing distance between the respective bonding positions. Therefore, if the inspection and dispensing processes must be run at different times, it is difficult to improve the efficiency of the dispensing system. In addition, the positioning platform must be designed to be able to control the camera and the dispensing head at the same time. This will result in an increase in moving mass, thereby reducing the effective movement control capability and making the design of the positioning platform more complex and expensive. In addition, in the case where the camera and the dispensing head move simultaneously, the continuous movement of the camera and the dispensing head during positioning may cause more positioning errors in the image capture process, thereby affecting the accuracy of the dispensing system.

[0004] Meanwhile, in conventional dispensing systems, an integrated dispensing controller is typically used to regulate the discharge and dispensing of adhesive material in a syringe, which is fluidically connected to the dispensing controller via a pipe. The length of the pipe connecting the syringe and the dispensing controller may not allow the required dispensing pressure to be quickly reached in the syringe to discharge the adhesive material. This in turn affects the efficiency and accuracy of the dispensing process. In addition, in order to accurately control the amount of adhesive material discharged by the dispensing head during the dispensing process, it may be necessary to detect the contact force applied by the dispensing head during the dispensing process. However, in conventional dispensing system designs, it has been proven to be very challenging to detect small changes in the contact force of the dispensing head.

[0005] Therefore, it would be beneficial to provide a new dispensing system design that can solve at least one of the problems in the above-mentioned traditional dispensing systems. Summary of the invention

[0006] It is therefore an object of the present invention to provide an improved automated dispensing system having an optical detection system decoupled from a dispensing head, wherein the dispensing head and optical detection device can operate independently, thereby reducing the need for repeated repositioning of the dispensing system while enabling both devices to operate simultaneously on different bonding locations or bond pads.

[0007] According to a first aspect of the present invention, the present invention provides a system for dispensing adhesive material in a semiconductor chip bonding process. The dispensing system comprises: a mounting bracket; an optical detection device mounted on the mounting bracket for detecting bonding positions; a dispensing head, which is operated to dispense the adhesive material to the bonding positions detected by the optical detection device; and a positioning mechanism, which is coupled to the dispensing head and is operated to move the dispensing head relative to the optical detection device, so that the detection of the optical detection device and the dispensing of the dispensing head at different bonding positions are carried out simultaneously.

[0008] According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor device. The method comprises the steps of: detecting a first bonding position by an optical detection device mounted on a mounting bracket; when the optical detection device is aligned with a second bonding position, moving a dispensing head relative to the optical detection device by a positioning mechanism so that the dispensing head is aligned with the first bonding position; and dispensing adhesive material to the first bonding position by the dispensing head while detecting the second bonding position by the optical detection device.

[0009] The above and other features, aspects and advantages will become better understood with reference to the specification portion, appended claims and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the present invention will be described hereinafter by way of example only with reference to the accompanying drawings, in which:

[0011] Figure 1 is a schematic side view of a dispensing system according to one embodiment of the present invention;

[0012] Figure 2A The first embodiment of the present invention is shown. Figure 1 A schematic side view of the dispensing system shown when in use at different times T1 and T2;

[0013] Figure 2B The second embodiment of the present invention is shown. Figure 1 A schematic side view of the dispensing system shown in use at different times t1 to t4;

[0014] Figure 3Ais a perspective view of a dispensing system for dispensing adhesive material in a semiconductor wafer bonding process according to a preferred embodiment of the present invention; and Figure 3B yes Figure 3A Exploded view of the dispensing system shown.

[0015] In the drawings, the same reference numerals denote the same components. DETAILED DESCRIPTION

[0016] An embodiment of the present invention provides an automatic system for dispensing adhesive material in a semiconductor wafer bonding process. The automatic dispensing system includes a dispensing head and an optical detection device, which are configured to operate to work on different bonding locations simultaneously.

[0017] Figure 1 A schematic side view of a dispensing system 100 according to one embodiment of the present invention is shown. The dispensing system 100 includes a mounting bracket 110, a dispensing head (dispensing head) 120, an optical detection device 130, and a positioning mechanism 140.

[0018] Reference Figure 1 The optical detection device 130 is fixedly mounted on the mounting bracket 110 or coupled thereto for detecting the bonding position or bonding pad. The bonding position or bonding pad may be arranged on a substrate or on a lead frame, and the lead frame is placed on a bonding platform (not shown). The optical detection device 130 may include a camera or any other type of visual system.

[0019] The dispensing head 120 is movably coupled to the mounting bracket 110 via a positioning mechanism 140 so as to dispense adhesive material to the bonding locations after the optical inspection device 130 has inspected the bonding locations. The movement of the dispensing head 120 can be controlled by the positioning mechanism 140. The positioning mechanism 140 is movably mounted on the mounting bracket 110 and is used to position the dispensing head 120 during the dispensing process. The positioning mechanism 140 is operated to move the relative position of the dispensing head 120 and the optical inspection device 130 to adjust the distance between the two as needed, so that each device is aligned with different bonding locations at the same time, thereby achieving simultaneous dispensing and inspection operations.

[0020] Although in the present embodiment, the mounting bracket 110 supports the dispensing head 120, the optical detection device 130 and the positioning mechanism 140, it is understandable that in other embodiments, these devices can be installed on different supporting elements, frames or mounting brackets according to the specific requirements of the structural design of the dispensing system.

[0021] In this embodiment, the optical detection device 130 is fixedly mounted on the mounting bracket 110. In addition, the optical detection device 130 can also be detachably mounted on the mounting bracket 110 for easy replacement, or can be movably mounted on the mounting bracket 110 through an additional positioning mechanism, so as to adjust the relative distance between the optical detection device 130 and the dispensing head 120, thereby allowing the two devices to operate simultaneously.

[0022] Figure 2A A schematic side view of a dispensing system 100 according to a first embodiment of the present invention when in use at different times T1 and T2 is shown. The dispensing system 100 is used to dispense adhesive material to a plurality of bonding positions, wherein the positions are distributed on a substrate 101 placed on a movable bonding stage. During the dispensing process, the substrate 101 can move with the bonding stage. In the same row of bonding positions, the spacing between adjacent bonding positions is the same. Before starting the operation, the dispensing head 120 can be moved relative to the optical detection device 130 to adjust the distance between the two so that the two devices can work simultaneously on different bonding positions.

[0023] Reference Figure 2A , as the substrate 101 moves along the direction D (eg Figure 2A As shown by the arrow in the middle, at time T1, when the first bonding position 10A is located directly below the optical detection device 130 or aligned with the optical detection device 130, the optical detection device 130 can detect the first bonding position 10A. At this time, the dispensing head 120 is in an idle state. After detecting the first bonding position 10A, the substrate 101 continues to move along the direction D, so that the optical detection device 130 sequentially detects other bonding positions on the substrate 101. When the second bonding position 10B is aligned with the optical detection device 130 at time T2, the first bonding position 10A is located directly below the dispensing head 120, so while the optical detection device 130 detects the second bonding position 10B, the dispensing head 120 operates to dispense adhesive material onto the first bonding position 10A.

[0024] Unlike the dispensing system according to the prior art, the optical inspection device 130 and the dispensing head 120 do not need to move together because the positions of the optical inspection device 130 and the dispensing head 120 on the mounting bracket 110 are not fixed relative to each other. The positioning mechanism 140 can move the dispensing head 120 relative to the target bonding position and the optical inspection device 130 to align the dispensing head 120 with the target bonding position and to simultaneously operate the dispensing head 120 and the optical inspection device 130. This design of the dispensing system 100 further significantly reduces the moving mass controlled by the positioning mechanism 140 instead of the entire mounting bracket, effectively decoupling the movement of the dispensing head 120 and the optical inspection device 130. Therefore, this improvement greatly improves the efficiency and throughput of the dispensing system and reduces the operational requirements of the positioning mechanism 140.

[0025] exist Figure 2A In the first embodiment shown, when the distance between the dispensing head 120 and the optical detection device 130 is preset according to the spacing between two adjacent bonding positions on the substrate 101, since the bonding positions on the substrate 101 are regularly distributed, it is not necessary to move the dispensing head 120 relative to the optical detection device 130 during the dispensing process. That is, during the entire dispensing process, if the spacing distance between the devices has been correctly preset as the spacing distance between the bonding positions, the positioning mechanism 140 does not need to move the dispensing head 120 relative to the optical detection device 130. However, in other embodiments, if the bonding positions are not arranged at a regular spacing distance, or the sizes of the bonding positions are different, the positioning mechanism 140 may have to reposition the dispensing head 120 relative to the optical detection device 120 during the dispensing process, so that the dispensing head 120 and the optical detection device 130 can repeatedly align with different bonding positions.

[0026] Figure 2B Schematic side views of the dispensing system 100 according to the second embodiment of the present invention are shown when in use at different times t1 to t4. Figure 2B, when the substrate 101 moves along the direction D, the optical detection device 130 operates to sequentially detect the plurality of bonding positions 10a to 10d. Specifically, at time t1, the optical detection device 130 operates to detect the second bonding position 10b when the dispensing head 120 is idle. After completing the detection of the bonding position 10b, the substrate 101 is moved along the direction D until the third bonding position 10c is located directly below the optical detection device 130 at time t2. At the same time, the first bonding position 10a is located directly below or aligned with the dispensing head 120. Thereafter, while the optical detection device 130 detects the third bonding position 10c, the dispensing head 120 can dispense adhesive material onto the first bonding position 10a. After the operations of the dispensing head 120 and the optical detection device 130 are completed, the substrate 101 continues to be moved along the direction D so that the optical detection device 130 is aligned with the subsequent fourth bonding position 10d at time t3. At this time, the dispensing head 120 is not aligned with the second bonding position 10b because the distance d1 between the first bonding position 10a and the second bonding position 10b is inconsistent with the distance d2 between the third bonding position 10c and the fourth bonding position 10d. In order to correct this situation, the dispensing head 120 can be moved relative to the optical detection device 130 by the positioning mechanism 140 so that the dispensing head 120 is aligned with the second bonding position 10b. After alignment, the dispensing head 120 and the optical detection device 130 simultaneously detect and dispense the second bonding position 10b and the fourth bonding position 10d at time t4.

[0027] Figure 3A is a perspective view of a dispensing system 300 for dispensing adhesive material in a semiconductor wafer bonding process in accordance with a preferred embodiment of the present invention. Figure 3B yes Figure 3A An exploded view of the dispensing system 300 is shown. Figure 3A and Figure 3B The dispensing system 300 includes a mounting bracket 310 , a dispensing head 320 , an optical detection device 330 and a positioning mechanism 340 .

[0028] The optical inspection device 330 is fixedly mounted on the mounting bracket 310. When in use, the optical inspection device 330 is operated to detect a first bonding position that has been moved and positioned directly below the optical inspection device 330. The first bonding position may refer to any one of a plurality of bonding positions located on a substrate or a lead frame. In one example, the optical inspection device 330 may be operated to sequentially detect a plurality of bonding positions when the substrate or the lead frame is moved relative to the mounting bracket 310 by the bonding station. In addition, the optical inspection device 330 may also be used to detect the dispensing quality after the adhesive material is dispensed to the bonding position.

[0029] The dispensing head 320 includes a syringe 321 and a nozzle 322 coupled to the syringe 321. The dispensing head 320 is movably coupled to the mounting bracket 310, and the dispensing head 320 is driven to move by the positioning mechanism 340. More specifically, the dispensing head 320 is coupled to the positioning mechanism 340, which is movably mounted on the mounting bracket 310. When in use, the dispensing head 320 is operated to dispense or discharge the adhesive material in the syringe 321 to a second bonding position located directly below the dispensing head 320, which has been previously detected by the optical detection device 330. It is understood that the second bonding position can refer to any one of a plurality of bonding positions on the substrate or lead frame. In one example, the dispensing head 320 is operated to dispense the adhesive material to the plurality of bonding positions in sequence according to the incremental movement of the bonding stage during the dispensing process. At each fixed position of the substrate or lead frame, the optical detection device 330 and the dispensing head 320 can work at the first bonding position and the second bonding position respectively at the same time. The first and second bonding locations refer to different bonding locations on a substrate or a lead frame located on a bonding stage.

[0030] Reference Figure 3B The positioning mechanism 340 in this embodiment includes: a first axis actuation assembly 341 including a first axis linear motor 341a, a second axis actuation assembly 342 including a second axis linear motor 342a, and a third axis actuation assembly 343 including a third axis arc motor 343a. The first axis actuation assembly 341 is movably mounted on the mounting bracket 310 and is configured to actuate the syringe 321 to move along a first axis (including along a positive axis direction and a negative axis direction). In this embodiment, the first axis may be a Y axis, such as Figure 3A As shown. The movement along the Y axis can be movement along a plane parallel to the surface of the substrate or lead frame where the bonding position is located. The second axis actuating assembly 342 is movably mounted on the first axis actuating assembly 341 and is configured to actuate the injector 321 to move along a second axis. The second axis can be an X axis orthogonal to the Y axis. The movement along the X axis can also be movement along a plane parallel to the surface of the substrate or lead frame where the bonding position is located. In this embodiment, the first axis driving assembly 341 can be used to drive the dispensing head 320 to move relative to the optical detection device 330 to adjust the distance between the two. Therefore, the dispensing head 320 and the optical detection device 330 can be aligned with the first bonding position and the second bonding position at the same time, thereby achieving simultaneous operation of the two devices.

[0031] The third axis drive assembly 343 also includes a pivotable connection element 343b coupled to the arc motor 343a. The third axis can be a Z axis that is orthogonal to both the X axis and the Y axis. The third axis actuation assembly 343 is movably mounted on the second axis actuation assembly 342 and is mechanically connected to the syringe 321 through the pivotable connection element 343b. The third axis actuation assembly 343 can be used to position the syringe 321 at different heights relative to the surface of the substrate 101 where the bonding position is located. During operation, the third axis arc motor 343a drives the pivotable connection element 343b to rotate around the pivot point, thereby driving the syringe 321 to move vertically along the Z axis.

[0032] The dispensing system 300 may further include: a first detection device including a first axis encoder 351 attached to the first axis actuation assembly 341; a second detection device including a second axis encoder 352 attached to the second axis actuation assembly 342; and / or a third detection device including a third axis encoder 353 attached to the third axis actuation assembly 343. The first and second detection devices are operative to record the movement of the syringe 321 along the first and second axes, respectively. The third detection device is operative to record the rotational movement of the third axis arc motor 343a or the pivotable connection element 343bo of the third actuation assembly 343, for example, the rotation angle of the third axis arc motor 343a or the pivotable connection element 343b. The dispensing system 300 may further include: a processing unit configured to determine a change in the contact force between the nozzle 322 of the syringe 321 and the surface when dispensing the adhesive material based on the rotation angle measured by the third detection device and the current flowing through the third axis arc motor 343a during operation of the third axis arc motor 343a.

[0033] Compared to the linear motors used in conventional dispensing systems, the mechanical rigidity of the third axis drive assembly 343 is enhanced due to the use of the arc motor 343a and the integral pivotable connecting element 343b. In addition, since the syringe 321 is the main moving mass driven by the third axis actuation assembly 343, this can reduce the manufacturing cost of the dispensing system 300 and improve the performance and reliability of the third axis actuation assembly 343. In addition, the pivotal movement of the connecting element 343b used to actuate the syringe 321 for linear movement can be easily measured by the third axis encoder 353. In this way, small changes in the contact force applied by the nozzle 322 during the dispensing process can be accurately measured, so that the amount of adhesive material can be accurately measured based on the change in the contact force, improving the dispensing quality of the dispensing system 300.

[0034] Reference Figure 3A, the dispensing system 300 also includes a dispensing controller in fluid communication with the contents of the syringe 321. The dispensing controller includes a switch device 361 and a control module 362. The switch device 361 is detachably mounted on the mounting bracket 310 and is coupled to the contents of the syringe 321 through a first conduit 363, thereby controlling the airflow in fluid communication with the syringe 321 to generate a force to release the adhesive material from the syringe 321 and to dispense the adhesive material. The switch device 361 is fluidly connected to the control module 362 through a second conduit 364, so that the control module 362 is operated to generate a desired pressure in the syringe 321 to discharge the adhesive material from the syringe 321. The switch device 361 may include a solenoid valve.

[0035] The switch device 361 can be disposed at a location close to the connection point where the syringe 321 is attached to the first conduit 363, thereby reducing or minimizing the distance between the switch device 361 and the syringe 321. This in turn can shorten the length of the first conduit 363 connecting the switch device 361 and the syringe 321, thereby reducing the total volume of the first conduit 363 and the syringe 321. This arrangement helps to reduce the time required for the compressed air in the syringe 321 to be activated or released. Therefore, the total units per hour (UPH) of the dispensing system 300 is increased.

[0036] Although in the dispensing system 300 described, the optical detection device 330 is fixedly mounted on the mounting bracket 310, in other embodiments, it can be movably mounted on the mounting bracket 310 by an additional positioning mechanism. In this arrangement, the relative distance between the dispensing head 320 and the optical detection device 330 can be adjusted by moving the optical detection device 330 and / or the dispensing head 320 as needed. The optical detection device 330 is detachably mounted on the mounting bracket 310 or other fixed base element of the dispensing system 300, which is convenient for replacing the optical detection device 330 when necessary. The switch device 361 in the dispensing system 300 can also be fixedly or detachably mounted on other fixed structures of the dispensing system 300. In other embodiments, the configuration or arrangement of the positioning mechanism 340 may be different. For example, the second shaft actuation assembly 342 can be movably mounted on the mounting bracket 310, and accordingly, the first shaft actuation assembly 341 can be movably mounted on the second shaft actuation assembly 342, and the third shaft actuation assembly 343 can be movably mounted on the first shaft actuation assembly 341.

[0037] As can be understood from the above description, an embodiment of the present invention provides a dispensing system having a dispensing head and an optical detection device, which can work simultaneously on different bonding positions or bonding pads on a substrate or lead frame to improve the throughput of the dispensing system. Since the distance between the dispensing head and the optical detection device can be adjusted by moving the dispensing head relative to the optical detection device, the dispensing system can be used for dies of different sizes and / or irregularly arranged bonding pads on a substrate or lead frame. In addition, the dispensing controller is further divided into two components: a switch device and a control module. This division shortens the distance between the switch device and the syringe. Therefore, the speed of the process of introducing compressed air into the syringe can be accelerated. In addition, the use of an arc motor and a pivotable connecting element to drive the vertical movement of the syringe can not only improve the mechanical stiffness and mobility of the dispensing system, but also reduce the manufacturing cost of the dispensing system. This arrangement can also accurately detect slight changes in the contact force applied by the dispensing head, thereby controlling the amount of adhesive material discharged by the dispensing head based on the detected contact force changes, thereby improving the efficiency and accuracy of the dispensing system.

[0038] Although the present invention has been described in considerable detail with reference to certain embodiments, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

Claims

1. A system for dispensing adhesive material in a semiconductor wafer bonding process, comprising: Mounting bracket; an optical detection device mounted on the mounting bracket to detect the bonding position; a dispensing head operative to dispense said adhesive material onto said bonding locations inspected by said optical inspection device; as well as The positioning mechanism is coupled to the dispensing head and is operable to move the dispensing head relative to the optical detection device, so that the detection by the optical detection device and the dispensing by the dispensing head at different bonding positions are performed simultaneously.

2. The system according to claim 1, wherein: The optical detection device is fixedly mounted on the mounting bracket.

3. The system according to claim 1, wherein: The positioning mechanism is mounted on the mounting bracket for moving the dispensing head relative to the optical detection device.

4. The system according to claim 1, wherein: The bonding position includes a first bonding position and a second bonding position, and the positioning mechanism is operable to move the dispensing head relative to the optical detection device so that when the optical detection device is aligned with the second bonding position, the dispensing head is simultaneously aligned with the first bonding position that has been detected by the optical detection device.

5. The system according to claim 4, wherein: The dispensing head is operative to dispense the adhesive material onto the first bonding location simultaneously with the optical detection device detecting the second bonding location.

6. The system according to claim 1, wherein: The dispensing head includes a syringe, and the system further includes a switch device coupled to the syringe for controlling a gas flow in fluid communication with the syringe to generate a force to expel the adhesive material from the syringe and dispense the adhesive material.

7. The system according to claim 6, wherein: The switch device is fixedly mounted on the mounting bracket.

8. The system according to claim 7, further comprising: A first conduit is used to fluidically connect the syringe to a solenoid valve included in the switch device.

9. The system according to claim 8, further comprising: A second conduit is provided for fluidly connecting the switch device to a control module, the control module being operative to generate a desired pressure in the syringe to expel the adhesive material from the syringe.

10. The system according to claim 1, wherein: The positioning mechanism includes first, second and third actuating assemblies for positioning the dispensing head along a first axis, a second axis and a third axis, respectively, the first, second and third axes being orthogonal to each other.

11. The system according to claim 10, wherein: The third actuation assembly includes an arc motor configured to position the dispensing head at different heights relative to the bonding location along the third axis.

12. The system according to claim 11, wherein: The third actuating assembly further comprises a pivotable connecting element coupled to the arc motor, and the dispensing head is connected to the third actuating assembly via the pivotable connecting element.

13. The system according to claim 12, wherein: The first actuating assembly includes a first linear motor, which is configured to actuate the dispensing head to move along a first direction parallel to the surface where the bonding position is located; the second actuating assembly includes a second linear motor, which is configured to actuate the dispensing head to move along a second direction parallel to the surface where the bonding position is located, and the first and second directions are perpendicular to each other.

14. The system according to claim 10, wherein: The first actuating assembly is movably mounted on the mounting bracket, the second actuating assembly is movably mounted on the first actuating assembly, and the third actuating assembly is movably mounted on the second actuating assembly.

15. The system of claim 11, further comprising: A detection device is attached to the third actuation assembly for measuring a rotation angle of the third actuation assembly when positioning the dispensing head.

16. The system of claim 15, further comprising: A processing unit is used to determine the change of the contact force between the dispensing head and the surface when dispensing the adhesive material based on the rotation angle measured by the detection device and the current flowing through the arc motor when the arc motor is working.

17. The system of claim 1, wherein: The optical detection device is also operative to detect a dispensing quality of the adhesive material after dispensing the adhesive material to the bonding location.

18. A method for manufacturing a semiconductor device, comprising the steps of: detecting a first bonding position by an optical detection device mounted on the mounting bracket; When the optical detection device is aligned with the second bonding position, the dispensing head is moved relative to the optical detection device by using the positioning mechanism so that the dispensing head is aligned with the first bonding position; as well as Adhesive material is dispensed to the first bonding location by the dispensing head, while the second bonding location is detected by the optical detection device.

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