Assembly and method for engagement with an IC unit

Abstract

Assembly and method for engagement with an IC unit A picker assembly comprising: a shaft;

Description

Technical Field

[0001] The present invention relates to singulation of integrated circuit units, and more particularly to assemblies used to engage and transport individual units. In particular, the present invention relates to the adaptability of the picker assembly for adjusting the spacing between individual pickers within the assembly.

Background Art

[0002] When designing a machine for processing substrates and individual IC units, important factors such as minimization of waste, maintaining the number of units per hour (UPH), and suppressing downtime related to tool changes are all important design determinants.

[0003] Considering the adaptability of the machine, it is necessary to accommodate substrates with different spacings between IC units in order for the machine to be useful for various applications. For the machine, tool changes can be made for each application, but it would be more efficient if the machine could be relatively easily adapted to accommodate the spacing. In particular, the picker assembly used to transport singulated IC units between stations depends on the spacing of the units in order to engage them collectively. Therefore, it is considered useful if the spacing between pickers within the picker assembly can be adjusted to accommodate substrates with different spacings between IC units.

[0004] Several systems have been attempted to achieve this function. For example, one system uses a series of molded blocks between each picker in a picker array. A spring system is placed around the picker array, positioned to bias the pickers inward, to ensure the movement of the pickers within the array. If the springs apply a sufficiently large force, the pitch of the pickers can be changed by rotating the irregularly shaped blocks. However, to handle batch execution of integrated circuit (IC) substrates, it may be necessary to rapidly change the pitch of the pickers repeatedly. Given the mass of the picker array and intermediate blocks, there is an upper limit to the speed at which the springs can react without causing jitter or vibration. Furthermore, successive high-speed movements can lead to hysteresis effects, which can negatively affect the accuracy of pitch positioning.

[0005] As profit margins on integrated circuits, particularly memory, decline, there is increasing pressure to reduce processing costs, and therefore the need to accelerate production while maintaining quality. As a result, the cost of the infrastructure required to achieve these processes is equally burdened by the pressure to reduce costs while maintaining speed and quality. [Overview of the project] [Problems that the invention aims to solve]

[0006] In a first embodiment, the present invention provides a picker assembly comprising: a plurality of pickers in a relationship that allows for selective variation in spacing; a shaft; a plurality of internal positioning plates slidably engaged with the shaft and positioned between adjacent pickers, and coaxial with the shaft; a pair of end positioning plates slidably engaged with and coupled to the shaft and positioned outside the end pickers, and coaxial with the shaft; a pair of cams, each slidably engaged with and positioned at each end of the shaft and longitudinally coupled to the end positioning plates; and a pair of fixed cam followers, each rotatably engaged with the corresponding helical follower surface of the cam, wherein when the shaft rotates, the cams are biased by the pair of cam followers, and the rotation of the cams rotates the end and internal positioning plates, and the rotation of the shaft brings about a selective change in spacing such that the change in the thickness of the cam plates moves each picker along an axis parallel to the shaft. [Means for solving the problem]

[0007] In a second embodiment, the present invention provides a method in a picker assembly for selectively changing the spacing between pickers in the picker assembly, the method comprising a shaft having a plurality of coaxial ends and internal positioning plates, wherein the cam has a varying thickness, and the cam plate engages the shaft with the pickers, the steps of rotating the shaft and biasing the pickers using the ends and internal positioning plates, thereby resulting in a selective change in spacing by the rotation of the shaft, which moves each picker along an axis parallel to the shaft and changes the spacing between each picker.

[0008] Therefore, by providing a cam follower and cam mechanism, a more rigid response can be applied to changes in the picker's pitch, rather than using elastic or flexible members such as springs.

[0009] It would be convenient to further describe the present invention with reference to the accompanying drawings illustrating possible configurations of the invention. Other configurations of the invention are also possible, and therefore, the specificity of the accompanying drawings should not be understood to take precedence over the generality of the foregoing description of the invention. [Brief explanation of the drawing]

[0010] [Figure 1] This is an isometric view of a picker assembly having a pitch tracker according to one embodiment of the present invention. [Figure 2] Figure 1 is an isometric view of the picker assembly. [Figure 3] Figure 1 is an elevation view of the picker assembly. [Figure 4] Figure 1 is a detailed isometric view of the picker assembly. [Modes for carrying out the invention]

[0011] Prior art picker assemblies require a pitch tracker that is tuned by a spring system to provide a positive force to ensure that pitch adjustment is maintained. A biasing force that reacts to the spring force applied by the spring system is applied by various mechanisms.

[0012] However, the spring system is an inefficient means of maintaining the precise position of individual pickers. The picker assembly is subjected to the high processing speed of the IC unit. However, when the mass of the picker array moves against the spring system, the spring is inevitably subjected to jerk or jitter. As a result, there is a limit to the operating speed of picker assemblies using the spring system.

[0013] Furthermore, when a force is applied to a spring, there is an initial compression before the spring responds. This results in inaccurate positioning of the picker by the spring system, and thus hinders its ability to rapidly change the pitch. This is in contrast to the application of positioning force from a rigid configuration, such as that shown by the present invention, where no such initial compression exists and the response time is substantially instantaneous, as described below.

[0014] Figures 1-4 show an embodiment of the present invention that provides a significant improvement in pitch adjustment of a picker array. The picker assembly 1 includes a pitch tracker 5. The pitch tracker 5 includes an array 10 of pickers 15, each picker 15 including a vacuum nozzle 20 positioned to engage with an IC unit. The picker array 10 is mounted on a rotatable shaft 25, the shaft 25 having an actuator 35 positioned to rotate the shaft.

[0015] Multiple internal positioning plates 30 are arranged on the shaft 25. Each internal positioning plate 30 is positioned in the middle and in contact with the adjacent picker, while the end positioning plates are positioned outside the end pickers. The end and internal positioning plates 30, 37 are mounted on the shaft 25 as a sleeve. As shown in Figure 4, each end and internal positioning plate 30, 37 includes a periphery 57 in which the thickness changes uniformly in the circumferential direction of each positioning plate 30, 37. As the end and internal positioning plates rotate, the thickness changes at the ridge 57, allowing the ridge to push the picker outward or pull it inward.

[0016] At both ends of the shaft are cams 40 that are coupled to end positioning plates 37 and rotatably engage with cam followers 45. The cam followers 45 contact the cams 40 on a helical follower surface 50 via rollers that rotatably engage with the followers 45. As a result, the rollers roll along the cam surface as the cams 40 rotate.

[0017] As the shaft 25 rotates, the cam follower 45 biases the cam 40. As a result, the helical path on the follower surface reacts with the cam 40 to open and close the gap space of the internal positioning plate 30. Then, using the edge 57 of uniformly varying thickness, the internal positioning plate 30 adjusts the picker pitch to either a wider or narrower pitch as needed. It will be understood that the uniform variation in ridge thickness may be replaced by a step mechanism, where the size of the step corresponds to the preferred pitch spacing of the pickers.

[0018] In this way, the shaft is rotated to position the picker at the desired pitch, and as a result, the cam 40 rotates. By having a helical follower surface 50 instead of a spring system, fine adjustments are provided via the cam follower, which improves the speed of adjusting the pitch of the picker array without the delay or jitter caused by the spring.

[0019] Figure 3 shows a follower plate 65 to which a cam follower is mounted. The follower plate is mounted to the pitch tracker block via screws or bolts that fit into slots in the plate 65. The slots allow the follower plate to slide (70) when the mounting screws are loosened, which allows for fine adjustment of the cam follower and thus ensures a tight engagement between the cam follower and the cam.

Claims

1. Multiple pickers that are in a relationship where the interval can be selectively changed, The shaft and Multiple internal positioning plates are slidably engaged with the shaft, positioned between adjacent pickers, and coaxial with the shaft, A pair of end positioning plates are slidably engaged and coupled to the shaft, positioned on the outside of the end picker, and coaxial with the shaft, A pair of cams are arranged to be slidably engaged at each end of the shaft and longitudinally coupled to the end positioning plate, A pair of fixed cam followers, each rotatably engaged with the corresponding helical follower surface of the cam, It is equipped with, A picker assembly in which, when the shaft rotates, the cam is biased by the pair of cam followers, the rotation of the cam rotates the end and internal positioning plates, and a selective change in the spacing is brought about by the rotation of the shaft such that a change in the thickness of the cam plates moves each of the pickers along an axis parallel to the shaft.

2. The assembly according to claim 1, wherein the change in the thickness of the end plate and the internal positioning plate is continuous along the circumference of the end plate and the internal positioning plate.

3. The assembly according to claim 1, wherein the change in thickness is stepwise, and the stepwise thickness is a function of a predetermined interval of the picker.

4. The assembly according to claim 1, wherein the internal positioning plates are arranged to engage with adjacent pickers, and the internal positioning plates are arranged on the shaft such that the thickness of each internal positioning plate is the same at each point around the circumference of each plate.

5. A method in a picker assembly for selectively changing the spacing between pickers within the picker assembly, A shaft having multiple coaxial ends and internal positioning plates, wherein the cam has a varying thickness, and the cam plate rotates the shaft that engages with the picker, A step of biasing the picker using the end portion and the internal positioning plate. It includes, As a result, a method is provided in which a selective change in the spacing between the pickers is brought about by the rotation of the shaft, which moves each of the pickers along an axis parallel to the shaft and changes the spacing between the pickers.

Images