The present invention relates to methods and apparatuses for precise marking and placement of an object including an integrated circuit unit.
Small objects such as integrated circuit (IC) and IC package are marked in different ways for inspection and identification. One of the popular ways for marking ICs is laser marking. During marking, the accuracy of the mark becomes critical due to constraint of the available area and increasing demand for characters to be marked. In many occasions where ICs require second marking, the area and location for second marking is even more constrained because of the presence of the first mark. Thus, precise and accurate marking positioning is very important in order to maintain the integrity of the mark with respect to the first mark.
An object may fail marking inspection in at least three ways. First is wrong marking. Second are cosmetic defects in the markings. And third is that the marked characters are offset or out-of-position from the desired location. This happens when the object is not properly positioned and at the same time the marking apparatus fails to correct the marking position.
The increasing demand for throughput and miniaturization of IC requires a new generation of handlers or handling systems being able to deliver high outputs at barely zero equipment assist. Therefore, there is an imperative need to have an apparatus that enables precise marking and placement. This invention satisfies this need by disclosing a precise marking and placement apparatus and method of using the same. Other advantages of this invention will be apparent with reference to the detailed description.
The present invention provides a precise marking apparatus for performing precise marking on an object and methods of using the same. The precise marking apparatus comprises an object input handler and an object output handler for handling the object; a transport system for transporting the object handlers during a marking process; a vision inspection unit for capturing and/or processing the image of the object; a marking system for marking the object; and a control unit for receiving information from and sending instructions to other components of the precise marking apparatus.
The present invention also provides a precise placement apparatus for precise marking and/or precise packaging an object and methods of using the same. The precise placement apparatus comprises an Input Stacker for storing and loading the object; a Main Track & Indexers for transporting the object; a Pick & Place (X, Y, θ Correction) for picking up the object and precisely placing the object for final packaging; an Inspection & Position Capture Camera for capturing the image of the object and optionally processing the captured image; an Output Stacker for unloading and outputting the precisely placed and optionally packaged object; and a control unit for receiving information from and giving instructions to other components of the precise placement apparatus.
The present invention further provides a precise marking and placement apparatus for performing precise marking on an object and precise placement of the object for final packaging and methods of using the same. The precise marking and placement apparatus comprises an object Input Handler for loading and holding the object; a Transport System for transporting the object handlers during a marking process; a pre-mark Vision Inspection Unit for capturing and/or processing the image of the object; a Marking System for marking the object; an object Output Handler for holding the marked object; a Pick & Place (X, Y, θ Correction) for picking up the object from the object output handler, carrying it over to the pre-placement Vision Inspection Unit and precisely placing the object for final packaging; an pre-placement Vision Inspection Unit for capturing the image of the object and optionally processing the captured image; an Output Stacker for unloading and outputting the precisely placed and optionally packaged object; and a Control Unit for receiving and processing information from the pre-mark Vision Inspection System and pre-placement Vision Inspection System and sending instructions to the components to execute precise marking and placement of an object to final packaging.
The objectives and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings.
Preferred embodiments according to the present invention will now be described with reference to the Figures accompanied herein, in which like reference numerals denote like elements.
The present invention may be understood more readily by reference to the following detailed description of certain embodiments of the invention.
Throughout this application, where publications are referenced, the disclosures of these publications are hereby incorporated by reference, in their entireties, into this application in order to more fully describe the state of art to which this invention pertains.
Current marking apparatus and process are confronted with two challenges. One is precision. Increasing information is marked onto an object. Another is marking dimension of an object. The object is becoming smaller and smaller. Thus the available space for marking is becoming smaller. This also demands higher precision. In addition, the automated inspection system demands precise packaging. With increased machine throughput and IC miniaturization, high-speed handlers will be more prone to pick & place errors resulting from equipment assist. The present invention provides solutions for the challenges.
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Prior to detailed description of each step, it is to be appreciated that the present invention needs not to be practiced following the exact sequences as shown in the flowchart of
Therefore, precise marking will be described first. Then precise placement and packaging will be discussed.
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The IC units may have different dimensions and configurations. The laser marking apparatus of the present invention may also be applied to mark any forms of IC units including singulated individual IC units and strip-formed IC units. While the discussion herein is focused on IC units as an illustration of the application of the present invention, it is to be appreciated that the method and apparatus disclosed herein in accordance with the principles of the present invention are applicable to any suitable applications and objects.
The IC units handlers 102 and 108 may be any available devices that are suitable for handling any IC units as required by each specific applications. In certain embodiments, the IC units input handler 102 comprises a stacking means for storing IC units and an input means for unloading IC units in a position so as to be carried to a predetermined location for marking. The stacking means may be a slot magazine for IC units in strip form or a stacked shipping tray for singulated IC units. For a stacked shipping tray, the input means may be stepper motor driven elevating type so that the stacked trays will be dropped from top to a working position. Thus, each tray will be processed at each time when the trays are elevated to the working position. In certain embodiments, a pneumatic cylinder actuated singulator tabs can be used to isolate one tray to be processed. For a slot magazine, the slot magazine may be parked at input and output stations. During the marking process, the strips are moved along the transporting system. In certain embodiments, a stepper motor driven kicker arm may be used to push one strip at one time to the Indexer 1″ so that the trip can be moved by the transporting system.
The IC units output handler 108 comprises a stacking means for storing the processed IC units, and an output means for loading the processed IC units into the stacking means. The stacking means may be similar or identical to the one employed in the IC units input handler 102. For example, the stacking means may be a slot magazine for IC units in strip form or a stacked shipping tray for singulated IC units. For a stacked shipping tray, the output means may be stepper motor driven elevating type so that each processed tray may be restacked in the stacked shipping tray. For a slot magazine, a stepper motor driven linear motion dragger may be used to load the processed IC strips to the offload slot magazine.
It is to be appreciated that any other means may be employed in this invention for storing the IC units and stacking/unstacking IC units so long as the means employed may function properly.
The transport system supports the transport of IC units from the input station parked by the IC units input handler 102 to the output station parked by the IC units output handler 108. In certain embodiments, the transport system comprises an input track 103 and an output track 107 along which the IC units can be transported from the input station to the processing positions to the output station. The transport system further comprises a transporting means not shown in
The vision inspection unit 104 comprises an image capture unit 104a and a vision PC 104b for processing any image captured by the image capture unit, as shown in
The image capture unit 104a includes a detection means and a light source. The IC units image which is an object of marking can be obtained by optically capturing the object with a camera or the like. The detection means to be used is not specifically limited as long as it is capable of converting the captured image of the object into an electric signal for output, so that it can be a charge-coupled device (CCD), a charge injection device, a photodiode array or a scanner. In one preferred embodiment, the detection means is a CCD camera. For example, the CCD camera is a progressive scan camera with a model number CV-M10BX from manufacturer JAI Coorporation. It will be apparent to those skilled in the art to utilize a different CCD camera.
In certain embodiments, an ordinary video camera is used as the camera, so that the captured image is outputted as an analogue video signal obtained by scanning a plurality of pixels. Accordingly, conversion of the analogue video signal into a digital signal represented in gray-scale (multi-valued image), conversion of the digital signal into a binary signal, conversion of the binary signal into a neighbor pixel state value, and calculation of the spot characteristics can be carried out in the vision PC 104b having a CPU, a ROM, a RAM, and an I/O port.
The light source is preferably a broad spectrum bulb that is configured to output light waves over a wide range of wavelengths. Preferably, the light source is optically coupled to an inspected IC unit. In a preferred embodiment, the light source is a LED lighting system, preferably a computerized LED lighting system. Various illumination methods are suitable for the present invention. The parameters that should be considered in choosing an illumination method include positions of the light source (e.g., front or back), illumination angle, effects of IC units surface, intensity of illumination, choice of lighting types, choice of diffuser, and optical alignment. In certain embodiments, the illumination method is preferably to be directional front lighting, with a suitable intensity level for achieving the best image acquisition results. The directional front lighting setup facilitates the design of IC units holder and the mounting of CCD vision camera for the inspection.
The marking system 105 may be any system that can maintain permanent marks on an IC unit so that any identification information can be incorporated into the permanent marks. The marking system 105 may be an ink printer or a laser marking device. In one preferred embodiment, the marking system 105 is the laser marking device that is preferably a Nd:YAG laser marking one, more preferably a Nd:YAG laser marking device with a Diode pump light source. In one specific embodiment, the parameters of the Nd:YAG laser marking device are about 50 watts for nominal power; about 133 mm for focal length; about 1064 nanometers for wavelength; and about 65 kHz for pulse frequency.
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Now described is a precise laser marking process as one preferred embodiment in accordance with the present invention in reference to
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Initially, the vision capture unit captures the image of each IC unit through its Field-of-View (FOV) as illustrated in
One IC unit has four sides designated as L1, L2, L3, and L4. The vision PC starts the outline regeneration process by identifying at least two points from each side as shown in
Next is the determination of the center of the regenerated IC outline. It can be done by computing the midpoints of the lines. The computed IC center is illustrated in
The Vision PC then transfers the data of each IC unit of a gang of IC units to the Handler PC/Controller. In certain embodiment, the gang of IC units may comprise a row of IC units.
So far the precise marking is done by pre-mark vision inspection. As discussed above, the precise marking for singulated IC units may also be reached by precise placement before the marking. This is the case when the steps 40 and 50 are done before step 30 of
Now for singulated IC units to be packaged, there is provided an apparatus for precise placement of IC units before they are packaged.
Referring to
The Pick & Place means 204 comprises at least one Smart Pick and Place system. In certain embodiments, the Pick & Place means 204 comprises two Smart Pick and Place systems that operate alternatively. Each Smart Pick and Place system comprises at least one pick-up module that picks up each IC unit from the input shipping tray 201 and places the picked IC unit in the output shipping tray 207. If the picked IC unit is rejected by the vision inspection (to be discussed later), the pick-up module will place the rejected IC units into the output tray 210 for rejected IC units. The pick-up module comprises at least one vacuum pick-up nozzle. In one preferred embodiment, the pick-up module comprises two vacuum pick-up nozzles that can transfer one IC unit at each motion. There are available of many conventional pick-up modules that can be employed in the present invention. The choices and arrangements of the pick-up modules are well known to those skilled in the art. Therefore, no more detailed discussion of the pick-up modules is needed.
While the precise placement apparatus shown in
The Smart Pick and Place System further comprises a driving module that operates the pick-up module. The driving module is able to adjust the pick-up module in X, Y, Z directions. More importantly, the driving module may operate to the theta precision. In preferred embodiments, the driving module is a motor including servomotor.
The Inspection & Position Capture Camera 205 is similar to the one in the laser marking apparatus as above described. In one preferred embodiment, the Inspection & Position Capture Camera 205 is located underneath the path along which the IC unit is picked-up from the input shipping tray and transferred to the output shipping tray.
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While the precise placement apparatus shown in
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Now described is a precise placement for final packaging as one preferred embodiment in accordance with the present invention in reference to
As discussed above, the precise marking and placement may be executed as an integral process. Therefore, the present invention provides a precise marking and placement apparatus for performing precise marking on an object and precise placement of the object for final packaging and methods of using the same. In one preferred embodiment, the precise marking and placement apparatus comprises an object Input Handler for loading and holding the object; a Transport System for transporting the object handlers during a marking process; a pre-mark Vision Inspection Unit for capturing and/or processing the image of the object; a Marking System for marking the object; an object Output Handler for holding the marked object; a Pick & Place (X, Y, θ Correction) for picking up the object from the object output handler, carrying it over to the pre-placement Vision Inspection Unit and precisely placing the object for final packaging; an pre-placement Vision Inspection Unit for capturing the image of the object and optionally processing the captured image; an Output Stacker for unloading and outputting the precisely placed and optionally packaged object; and a Control Unit for receiving and processing information from the pre-mark Vision Inspection System and pre-placement Vision Inspection System and sending instructions to the components to execute precise marking and placement of an object to final packaging.
The present invention also provides a precise marking and placement process for performing precise marking on an object and precise placement of the object for final packaging. The process comprises the steps of loading the object onto an input object handler; transporting the object loaded in the input object handler into a vision inspection position by using a transporting system; inspecting the object by a pre-mark vision inspection unit, wherein the images of the object is captured and optionally processed by the vision inspection unit, and wherein the information of the object is transferred to a control unit that is connected to a marking system; marking the object pursuant to the instructions from the control unit to the marking system; unloading the marked objects onto an object output handler; picking up the object from the Input Stacker and passing the object over a pre-placement Inspection & Position Capture Camera by a Pick & Place (X, Y, θ Correction); inspecting the picked up object by the pre-placement Inspection & Position Capture Camera, thereby the information of the images is transferred to a control unit; and placing the inspected object precisely into the Output Stacker pursuant to the instructions from the control unit; thereby the object is precisely packaged.
While the present invention has been described with reference to particular embodiments, it will be understood that the embodiments are illustrative and that the invention scope is not so limited. Alternative embodiments of the present invention will become apparent to those having ordinary skill in the art to which the present invention pertains. Such alternate embodiments are considered to be encompassed within the spirit and scope of the present invention. Accordingly, the scope of the present invention is described by the appended claims and is supported by the foregoing description.
This application is a continuation-in-part application of U.S. patent application Ser. No. 10/856,765 filed Jun. 1, 2004, which is hereby incorporated by reference.
Number | Date | Country | |
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Parent | 10856765 | Jun 2004 | US |
Child | 11074720 | Mar 2005 | US |