Automatic punch level adjustment in press systems

Abstract

To provide a mechanical press that can automatically adjust the press drive-in to improve the quality of processed products without having to stop the mechanical press during processing. [Solution] A press system for punching multiple leads of an electronic device includes a body casting to which a first die set is fixedly mounted, and a second die set which is driveable to move relative to the first die set between a standby level where the first and second die sets are at a preset separation distance and a punch level where the first and / or second die sets apply punching force to the leads of the electronic device. A fine adjustment motor operationally coupled to the body casting operates to adjust the position of the body casting so as to change the preset separation distance between the first and second die sets, thereby automatically changing the punch level for punching subsequent electronic devices using the first and second die sets.

Description

Technical Field

[0001] The present invention relates to a mechanical press for electronic devices, and more particularly to a mechanical press having an automatic adjustment function for improving the quality of processed electronic devices.

Background Art

[0002] Mechanical presses have conventionally been used in the semiconductor assembly and packaging industries to cut, bend, form, or separate electronic devices or components by punching. Conventional mechanical press manufacturers generally focus on moving the mechanical press with a regular and constant reciprocating motion.

[0003] To improve flexibility, some manufacturers incorporate an additional vision system to monitor the processed products for quality issues and stop the operation of the mechanical press if any defects are found. For example, if the forming angle or lead pitch of a processed electronic device is outside the specification limits, after stopping the mechanical press, the tooling parts are manually adjusted to avoid such defects from appearing in subsequent electronic devices being processed. When obvious defects are found in the packaged electronic devices, manufacturers have not considered fine-tuning the amount of press drive-in to adjust or improve the quality of the processed products, other than simply focusing on fixing the situation.

[0004] The drawback of the above approach is that production is only stopped if a defect is found during preventive maintenance or visual inspection. Furthermore, to maintain the quality of the processed products, problem tooling parts, such as those caused by wear and tear, must be manually adjusted or replaced.

[0005] It would be beneficial to design a mechanical press that avoids the aforementioned drawbacks of the prior art.

Prior Art Documents

[0006] [Patent Document 1] U.S. Patent No. 11,264,310 [Overview of the project] [Problems that the invention aims to solve]

[0007] The objective of this invention is to provide a mechanical press that can automatically adjust the press drive-in to improve the quality of processed products without having to stop the mechanical press during processing. [Means for solving the problem]

[0008] According to a first aspect of the present invention, a press system is provided for punching multiple leads of an electronic device, the press system comprising: a body casting to which a first die set is fixedly mounted; a second die set which is driveable to move relative to the first die set between a standby level where the first and second die sets are at a preset separation distance and a punch level where the first and / or second die sets apply punching force onto the leads of an electronic device; and a fine adjustment motor operationally coupled to the body casting, the fine adjustment motor operates to adjust the position of the body casting so as to change the preset separation distance between the first and second die sets, thereby automatically changing the punch level for punching subsequent electronic devices using the first and second die sets.

[0009] A second aspect of the present invention provides a method for manufacturing an electronic device by punching multiple leads of the electronic device in a press system, the method comprising: fixing and mounting a first die set to a body casting; driving a second die set to move relative to the first die set between a standby level where the first and second die sets are at a preset separation distance and a punch level where the first and / or second die sets apply punching force to the leads of the electronic device to punch the leads; adjusting the position of the body casting with a fine adjustment motor operationally coupled to the body casting to change the preset separation distance between the first and second die sets, thereby automatically changing the punch level to punch a subsequent electronic device using the first and second die sets; and punching a subsequent electronic device at the changed punch level.

[0010] It would be convenient hereafter to describe the present invention in more detail by referring to the accompanying drawings illustrating specific preferred embodiments of the invention. The specifics of the drawings and the related description should not be understood to supersede the generality of the broad identification of the invention as defined by the claims.

[0011] A specific example of the alignment system and method according to the present invention will now be described with reference to the attached drawings. [Brief explanation of the drawing]

[0012] [Figure 1] This is a side view of an electronic device in which leads are formed by a mechanical press. [Figure 2] This is an isometric view of a press system according to a preferred embodiment of the present invention, showing a feedback system for automatically adjusting the punch level of a mechanical press. [Figure 3] This is an illustrative flowchart showing how a press system can automatically adjust the punch level of a mechanical press. [Figure 4] This is a side view of a mechanical press showing how automatic punch level adjustment can be implemented according to a first embodiment of the mechanical press. [Figure 5] This is a side view of a mechanical press showing how automatic punch level adjustment can be implemented according to a second embodiment of the mechanical press. [Modes for carrying out the invention]

[0013] Figure 1 is a side view of an electronic device 100, in which its lead 102 is formed by punching the lead 102 during the manufacturing of the electronic device 100 using a mechanical press. The electronic device 100 is typically contained within a lead frame and is positioned between the upper die set 10A and the lower die set 10B of the mechanical press. Clamping components 12 of the upper and lower die sets 10A and 10B clamp portions of the lead 102 on both sides of the electronic device 100. A forming punch 14 adjacent to the clamping component 12 punches the end of the lead 102 down to the punch level 18 relative to the clamping component 12, so that the lead 102 is bent and formed into a Z shape.

[0014] The lead angle 16 of the lead 102 is determined by the depth to which the forming punch 14 presses against the lead 102 during punching. This lead angle 16 should be within a defined specification, which is generally determined by the punching depth or punch level 18. Due to repeated use, for example, wear and tear on the surface of the forming punch 14 from wear and tear on the mechanical press, the lead angle 16 may begin to change. Therefore, it would be beneficial if the punching depth or level could be automatically controlled to ensure that the lead angle 16 is maintained within the required specification without the need for manual intervention.

[0015] Figure 2 is an isometric view of a press system according to a preferred embodiment of the present invention, showing a feedback system for automatically adjusting the punch level 18 of the mechanical press 20. The press system typically includes the mechanical press 20, an image sensor such as a CCD camera 28, a fine-tuning motor controller 30, and a conveyor rail 24. The conveyor rail 24 is configured to transport the lead frame 26 (and the electronic devices 100 on it) bidirectionally from the position of the mechanical press 20 where the upper and lower die sets 10A, 10B are located, to the location of the CCD camera 28, and then to an off-loading position (not shown) where the lead frame 26 can be removed after processing. Each lead frame 26 typically includes a plurality of electronic devices 100 arranged in a matrix format, and these leads 102 need to be formed by the mechanical press 20 during processing.

[0016] The mechanical press 20 includes a main casting 22 positioned at the top of the mechanical press 20, which is supported by a plurality of columns 25 and mounted thereon using screws 23. The main casting 22 is slidably movable on the plurality of columns 25 to adjust its position. Both the main casting 22 and the lower die set 10B are driveable to move slidably along the plurality of columns 25.

[0017] In this embodiment, a first die set in the form of an upper die set 10A is fixedly mounted to the main body casting 22 and is held relatively stationary during the punching operation. On the other hand, a second die set in the form of a lower die set 10B is normally driven to move up and down relative to the upper die set 10A between a standby level, which represents a preset maximum separation distance between the upper and lower die sets 10A, 10B, and a punch level 18, to which punching force is applied on the leads 102 of the electronic device 100 by the upper and / or lower die sets 10A, 10B. During the punching operation, the lower die set 10B is configured to move from the standby level to bring the electronic device 100 of the lead frame 26 to the punch level 18 and into contact with the forming punch 14 in order to bend the leads 102 by punching, as described in relation to Figure 1.

[0018] After the lead 102 is bent and formed by the mechanical press 20, the conveyor rail 24 moves the lead frame 26 from the mechanical press 20 to a position below the CCD camera 28, where the lead 102 is inspected by the CCD camera 28. An image of the punched lead 102 is captured by the CCD camera 28 and transmitted to a fine-tuning motor controller 30, which is configured to determine whether the punch level 18 should be changed based on the result of punching the electronic device 100. In this example, the fine-tuning motor controller 30 inspects and optically determines whether the lead 102 is formed at a lead angle 16 within a predetermined specification. If it is determined that the lead angle 16 needs to be adjusted, the fine-tuning motor controller 30 can then provide a signal to adjust the position of the main casting 22 to the required extent so as to maintain the lead angle 16 within the required predetermined specification.

[0019] FIG. 3 is an exemplary flowchart showing how the press system can automatically adjust the punch level 18 of the mechanical press 20. After the lead frame 26 is formed by the mechanical press 20 and transported away from the mechanical press 20 (S32), an appearance inspection to check the quality of the leads 102 of the electronic device 100 is performed by the CCD camera 28 (S34). Next, the fine adjustment motor controller 30 determines whether the quality of the lead frame 26 is acceptable (S36).

[0020] If the quality of the lead frame 26 is not acceptable, the fine adjustment motor controller 30 will automatically adjust the mechanical press 20 to ensure that the punching depth or level of the upper die set 10A is appropriate for processing the next lead frame 26 (S38). If the quality of the lead frame 26 is acceptable, no adjustment is required and the lead frame 26 is transported to the next module such as an offloading module (S40).

[0021] FIG. 4 is a side view of the mechanical press 20 showing how automatic punch level adjustment can be implemented according to a first embodiment of the mechanical press 20. The mechanical press 20 has a mechanical press motor 42 that drives a press belt 44 connected to a press pulley to rotate the press pulley 46. Rotating the press pulley 46 in turn drives a crank 48 that functions to raise or lower a lower platen 50 on which the lower die set 10B is installed. When the lead frame 26 is disposed between the upper die set 10A and the lower die set 10B, the lower platen 50 raises the lower die set 10B toward the upper die set 10A while the upper die set 10A remains relatively stationary. The lower die set 10B will continue to rise until the forming punch 14 on the upper die set 10A fully bends the leads 102 on the electronic device 100.

[0022] In addition, the body casting 22 is configured to be adjustable along the column 25 by which it is supported. To achieve this, there is an extension arm 52 protruding from the body casting 22. The extension arm 52 is connected to a fine adjustment belt 54 driven by a fine adjustment motor 58 via a pulley 56, thus operatively coupling the fine adjustment motor 58 to the body casting 22. In this way, the fine adjustment motor 58 varies the preset maximum separation distance between the upper and lower die sets 10A, 10B associated with the standby level of the lower die set 10B, thereby adjusting the position of the body casting 22 to automatically vary the punch level 18 for punching a subsequent electronic device 100 using the upper and / or lower die sets 10A, 10B.

[0023] After the CCD camera 28 captures an image of the lead frame 26, the fine adjustment motor controller 30 processes the image to determine whether the leads 102 are formed within the required dimensional specifications. For example, if it is determined that the punch level 18 needs to be increased after a certain period of use, the fine adjustment motor controller 30 will send a signal to the fine adjustment motor 58 to operate the fine adjustment motor 58 to adjust the position of the body casting 22. If it is necessary to increase the punch level 18, the fine adjustment motor 58 will operate to rotate the belt in the clockwise direction in FIG. 4 to lower the extension arm 52 so that the body casting 22 and the upper die set 10A mounted thereon move closer to the lower die set 10B. As a result, the penetration of the forming punch 14 into the leads 102 with respect to the lower die set 10B will increase, thereby increasing the punch level 18.

[0024] Figure 5 is a side view of the mechanical press 20 showing how automatic punch level adjustment can be implemented according to a second embodiment of the mechanical press 20. In this embodiment, an extension arm 52 protruding from the main casting 22 is connected to a ball screw 60 instead of a fine adjustment belt 54. The ball screw 60 is driveable to rotate by a fine adjustment motor 62 (such as a stepper motor) to raise or lower the extension arm 52. As in the previous embodiment, in correspondence with raising or lowering the extension arm 52, the main casting 22 rises or falls along the column 25 on which it is supported.

[0025] In this embodiment, after the CCD camera 28 captures an image of the lead frame 26, the fine-tuning motor controller 30 processes the image to determine whether the lead 102 has been formed within the required specifications. If it is determined that the punch level 18 needs to be increased, the fine-tuning motor controller 30 sends a signal to the fine-tuning motor 62. If the punch level 18 needs to be increased, the fine-tuning motor 62 rotates the ball screw 60 to lower the extension arm 52 connected to the ball screw 60. Thus, the main casting 22 and the upper die set 10A mounted thereon move closer to the lower die set 10B. As a result, the penetration of the forming punch 14 into the lead 102 into the lower die set 10B increases, which will increase the punch level 18.

[0026] Apart from the electronic device 100 described in relation to Figure 1, a special lead frame, such as that described in Patent Document 1, can also be punched using embodiments of the present invention.

[0027] It will be obvious to those skilled in the art that, in addition to optical or visual inspection of the lead frame 26, data feedback can also be provided to the fine-tuning motor controller 30 by employing alternative means such as a fine-tuning motor controller 30 that measures the reaction force from the lead 102 of the electronic device 100 when the upper and / or lower die sets 10A, 10B are clamping the lead 102. Another approach is for the fine-tuning motor controller 30 to measure positional feedback relating to the relative positions of the upper and lower die sets 10A, 10B at the point where the upper and / or lower die sets 10A, 10B are clamping the lead 102 of the electronic device 100. Other measurement methods can also be employed. Based on such data feedback, the fine-tuning motor controller 30 can provide signals for adjusting the position of the body casting 22 and therefore the punch level 18.

[0028] It should be understood that the press system according to a preferred embodiment of the present invention can sustainably achieve automation in maintaining the quality of the processed lead frame 26 without the need for manual intervention. Therefore, throughput can be improved and the quality of the processed product can be continuously maintained.

[0029] The inventions described herein are subject to variations, modifications, and / or additions other than those specifically described, and it should be understood that the inventions include all such variations, modifications, and / or additions that fall within the spirit and scope of the above description. [Explanation of symbols]

[0030] 100 Electronic Devices 102 Reeds 10A Upper Die Set 10B Lower Die Set 12 fastening parts 14 Forming punch 16 Lead Angle 18 Punch Levels 20 Mechanical press 22 Main body casting 23 screws 24 Conveyor Rails 25 pillars 26 Lead Frame 28 CCD cameras 30 Fine-tuning motor controller 42 Mechanical press motor 44 Press Belt 46 Press Pulley 48 Crank 50 Platen 52 Extension Arms 54 Fine-tuning belt 56 Pulley 58 Fine-tuning motor 60 Ball screw 62 Fine-tuning motor

Claims

1. A press system for punching multiple leads of an electronic device, The main body casting to which the first die set is fixed and attached, A second die set, the second die set being driveable to move relative to the first die set between a standby level where the first and second die sets are at a preset separation distance and a punch level where the first and / or second die sets apply punching force to the leads of the electronic device; A fine adjustment motor is operationally coupled to the main body casting, and operates to change the preset separation distance between the first and second die sets, thereby adjusting the position of the main body casting to automatically change the punch level for punching subsequent electronic devices using the first and second die sets. A press system, including a press system.

2. The press system according to claim 1, further comprising a fine-tuning motor controller configured to determine whether the punch level should be changed based on the results of punching an electronic device.

3. The press system according to claim 2, wherein the fine adjustment motor controller operates to provide a signal to the fine adjustment motor to operate the fine adjustment motor to adjust the position of the main casting.

4. The press system according to claim 2, wherein the fine adjustment motor controller is configured to determine whether the punch level should be changed by measuring the reaction force from the leads of the electronic device when the first and / or second die sets are clamping the leads.

5. The press system according to claim 2, wherein the fine adjustment motor controller is configured to determine whether the punch level should be changed by measuring the relative positions of the first and second die sets at the point where the first and / or second die sets are clamping the leads of the electronic device.

6. The press system according to claim 2, further comprising an image sensor for capturing an image of the lead punched by the first and / or second die set for inspection.

7. The press system according to claim 6, further comprising conveyor rails for transporting the electronic device from the locations of the first and second die sets to the location of the image sensor.

8. The press system according to claim 6, wherein the fine adjustment motor controller is configured to determine whether the punch level should be changed by inspecting the image of the lead.

9. The press system according to claim 1, wherein while the first die set is relatively stationary, the second die set is driven by a press motor to move, so that the second die set moves from the standby level to the punch level to punch the leads of the electronic device.

10. The press system according to claim 1, wherein the main casting is mounted and supported on a plurality of columns, and both the main casting and the second die set are driveable to move along these columns to adjust the position of the main casting.

11. The press system according to claim 1, further comprising an extension arm protruding from the main casting, wherein the fine adjustment motor is coupled to the extension arm for adjusting the position of the main casting.

12. The press system according to claim 11, wherein the extension arm is connected via a pulley to a fine adjustment belt that can be driven by the fine adjustment motor.

13. The press system according to claim 11, wherein the extension arm is connected to a ball screw that is rotatable by the fine adjustment motor to adjust the position of the main body casting.

14. A method for manufacturing an electronic device by punching multiple leads of the electronic device in a press system, The first die set is fixed and attached to the main casting, The steps include driving a second die set to move relative to the first die set between a standby level where the first and second die sets are at a predetermined separation distance and a punch level where the first and / or second die sets apply punching force to the leads of an electronic device to punch the leads, A step of adjusting the position of the main body casting with a fine adjustment motor operatively coupled to the main body casting so as to change the preset separation distance between the first and second die sets, thereby automatically changing the punch level for punching subsequent electronic devices using the first and second die sets; The steps include punching the subsequent electronic device at the changed punch level, Methods that include...

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