JP2005523424A - Shadow forming device - Google Patents

Abstract

【Task】
An apparatus (12) for accurately positioning a microelectronic chip (2) in a chip holding cavity (13) for visual inspection. The tip (2) has at least a front wall (5) and a pair of opposed side walls (6, 7) spaced apart. The front wall (5) meets the side walls (6, 7) and forms opposed first and second edges (8, 9) spaced apart. The cavity is formed with a cavity sidewall (24) formed in parallel with at least one of the sidewalls (6, 7) of the chip (2) and a recess (34) that generates a shadow projecting forward therefrom. A hollow side wall (24) with an indentation, the first leading edge (8) of the chip forms a shadow boundary that forms a contrast in gray that is objectively measurable between the shadow and the chip To do.

Description

  The present invention relates to visual inspection and testing of microelectronic chips. In particular, the present invention relates to an apparatus for conveniently placing the chip so as to be seated in a cavity in order to begin an accurate visual analysis of the surface of the chip.

  Due to the recent downsizing of microelectronic chips and the great demand for these chips, it is required to test the physical and electrical properties of the chips quickly, accurately and economically, and the more effective of the chips In order to perform a typical test, it is necessary to first remove visible cracked chips from the production line so that subsequent electrical tests are only performed on chips that are visually acceptable. Examples of such visible cracks include insulator delamination, metal termination cracks and smear cracks on the chip, and spills and unacceptable ripples. In order to test these physical characteristics, a visual inspection apparatus is used in the industry. These devices generally include a camera device for observing the chip, a software processing device for detecting and recording the cracks, and a bright light source for illuminating the chip.

  Conventional visual inspection devices have been unable to accurately and effectively observe the chip due to the high surface gloss value of the chip and surrounding materials. The specularity of a material describes the size and brightness of the specular highlight that it reflects. Smooth reflective objects have small and bright highlights. Coarse reflective objects have large and diffuse but still bright highlights. A rough or smooth object with little reflectivity has dim highlights. Conventional metal materials such as aluminum, stainless steel, and titanium, which are typically used to form a loading wheel for receiving the chip during the visual inspection process, are subject to normal wear and debris on the metal. Accumulation causes significant specular highlights. Although certain treatments and coatings can be used to reduce the sharp gloss of these surfaces, these remedies are in time and degrade over time. Replacing these metals with plastic-based materials or other similar materials is not effective because the weak physical properties inherent in plastic materials wear them out over time.

  The high degree of specularity around the exposed surface of the chip and the surrounding environment is electronic when the chip is placed in a chip holding cavity for a software program that initiates a visual test on the chip. Make it difficult to visualize accurately. The brightness and light reflection of the surrounding environment mix with that of the chip, making it difficult to visually distinguish the chip from the rest of the environment, especially under conditions of high speed processing, the chip staying in the cavity Time is in microseconds. For this reason, there is no reference point and the software program cannot start a visual inspection of the chip or starts the visual inspection at an incorrect reference point.

  The present invention provides an important dark, essentially black shadow located near at least a portion of the edge of the chip and provides contrast between the edge of the chip adjacent to the shadow and the shadow. The present invention relates to a device for producing a shadow to be given. A portion of the edge of the chip proximate to the shadow forms a contrast line that gives the inspection device a reference point for initiating its visual inspection. The present invention eliminates the problems associated with the conventional visual inspection method described above. In particular, the present invention provides a metallized, accurate having at least two oppositely spaced leading edges formed by respective association of a front wall and two oppositely spaced side walls. Useful for rectangular, parallelepiped microelectronic chips. This chip is of the type used throughout the computer industry today.

  The device according to the invention comprises a plurality of cavities, preferably arranged at the edge of the chip operating means, such as around the chip operating wheel for receiving the chip. The cavity is shaped and dimensioned to receive a single chip in an upright position, and temporarily holds the chip so that an inspection device can inspect and test the outer surface of the chip. The cavity may include at least one cavity side wall and may have a cavity back wall formed perpendicular to the cavity side wall to help retain the chip within the cavity. The hollow sidewall is adjacent to a portion of at least one of the sidewalls of the chip when the chip is properly seated.

  In another embodiment of the present invention, a part of the cavity side wall is formed in a recess including a first wall extending away from the cavity. The recess is disposed in proximity to the side wall of the chip. The indent reduces the amount of specularity and light reflection around the front edge of the chip and reduces interference so that the inspection device detects the edge of the chip.

  An observable depression is formed in at least one cavity side wall and the first wall. This dimple is deep enough to appear as a very dark, essentially black background, producing a contrast in gray that is objectively measurable between the dimple and the chip. . The chip is arranged in place in the cavity, at least a part of at least one leading edge of which forms a boundary, preferably a straight vertical black shadow or background, and for this purpose the leading edge of the chip And a clear line is formed between the pits and the depressions given a dark clear shape. The recess may be circular, oval, or a horizontal slot extending away from the cavity. The shape of the recess can be determined by various factors such as the size of the cavity holding the chip and the size of the chip.

  In another embodiment of the present invention, the recess further extends along the cavity side wall and along the cavity rear wall so as to form a shadow where it is eroded by the other leading edge of the chip. The resulting shadow forms a contrast in gray that is objectively measurable between the shadow and the chip. A clear line contrast is formed, where the other leading edge of the chip erodes the dark shadow of the cavity back wall depression.

  The depression is black under illumination conditions that contrast the gray level of the tip and the gray level of the operating wheel. In addition, the depression disposed in the vicinity of the chip causes the specularity of the surrounding environment. The contrast line indicates the location of the chip. Therefore, due to the outstanding contrast between the shadow of the depression and the chip, the inspection device can effectively and conveniently detect the edge of the chip to initiate a visual inspection of the chip. .

  During the inspection process, the chip is held in place by vacuum means for a long enough time to be tested by the inspection apparatus, which may include a charge coupled device, a software inspection unit, and an illumination source.

  Therefore, the main object of the present invention is a shadow generator that helps a software inspection device to accurately place the chip to initiate the visual inspection process. Other objects of the present invention can be manufactured to accommodate devices of all shapes, sizes and configurations, devices superior to temporary surface treatments or coatings, devices that are simple and economical to manufacture and maintain. Better due to the ability of the visual inspection device to quickly and accurately place the chip within the cavity, and the device, a device that is readily available to current visual inspection devices available in today's industry The equipment has a high production rate to produce the final product.

  These and other objects of the present invention will become more apparent upon reading the preferred embodiment and the accompanying drawings. The protection sought by the inventors is gathered from a fair read of the claims that complete this specification.

  Referring to the drawings, throughout the twelve figures, elements or limitations are identified by reference numerals, and similar elements or limitations are identified by similar numerals. 1 and 2 show a microelectronic chip 2 to which the present invention is directed, which has at least a front wall 5 and a pair of spaced apart side walls 6,7. A solid rectangular enclosed body 4 having a generally rectangular shape, the front wall 5 meeting each side wall 6, 7, respectively, with a first and second front edge 8 and second front edge spaced apart, respectively. 9 is formed. The chip 2 used in the present invention has a pair of ends 10 for connection to a circuit board, coated with metal and spaced apart from each other. Moreover, the chip | tip 2 may be a parallelepiped with an angle larger or smaller than 90 degree | times, and may have a different size. However, rectangular parallelepipeds are an industry standard and are products to which the present invention is essentially directed.

  As shown in FIGS. 3 and 8, the device 12 of the present invention is capable of chip operation, such as a chip operation wheel 16 for receiving inventory of the chip 2 so that the chip 2 can be arranged to be inspected and tested. It includes a cavity or pocket 13 formed in the means 14. The tip manipulating means 14 is similar to that shown in US Pat. No. 6,294,747 and includes a tip loading wheel 16, in particular a tip loading wheel having an external rim 18. The tip manipulating wheel 16 includes at least one, preferably a plurality of cavities 13 formed in an outer rim 18 for receiving the tips 2 and is adapted to receive a single tip 2 in an upright position within each cavity 13. Of shape and size.

  As shown in FIGS. 3, 7 a, 7 b and 7 c, the cavity 13 is juxtaposed adjacent to at least one portion of the side wall 6 of the chip 2 when the chip 2 is properly seated in the cavity 13. The boundary is limited by at least one cavity side wall 24 formed as described above. Further, the cavity 13 is bounded by a cavity back wall 26 that is preferably formed to be perpendicular to the cavity side wall 24. Another cavity side wall 28 spaced from the first side wall 24 is formed to aid the chip 2 disposed in the cavity 13. The cavity 13 has a bottom surface (not shown) on which the chip 2 rests. As shown in FIGS. 4 and 5, another embodiment of the present invention is applied to a portion of the side wall 6 of the chip 2 that is partially formed to reach the first wall 30 extending away from the cavity 13. An adjacent cavity sidewall 24 is shown. A recess 32 is formed where the first wall 30 extends away from the cavity 13. The recess 32 is arranged adjacent to the side wall 6 of the chip 2.

  As shown in FIGS. 4, 5, and 7, the width and depth are sufficient to project a black shadow from the side to the front of the cavity 13, and are objectively measured between the recess 34 and the chip 2. Recesses 34 are formed in the cavity sidewall 24 to create a contrast in grayness that is possible. The chip 2 is arranged at a predetermined position in the cavity 13, where at least a part of the first leading edge 8 forms a preferably straight and vertical boundary of the black shadow or background, for this purpose. A clear contrast line is formed between the second first leading edge 8 and the dark shaded depression 34. The height of the recess 34 is preferably set above the bottom wall and below the top wall of the tip end 10. The gray level of the shadow formed in the depression 34 is the gray level of the front wall 5 of the chip 2 up to 15 gray units (fifteen gray units) or at least 16 gray units on the standard gray scale of the Electronics Industry Association. Different. This grace kale is divided into 255 objectively different shades of gray ranging from pure white at one end to all black at the other end and is recognized in the color industry. The recess 34 is formed in the tip manipulation wheel 16 by cutting or drilling, and its depth depends on various factors such as the size and depth of the cavity 13 and the size of the tip 2. Furthermore, the recess 34 may consist of a circle (FIG. 7a), an oval (FIG. 7b) or a horizontal slot (FIG. 7c) extending away from the cavity 13 in the first wall 30. FIG. In yet another embodiment of the present invention, FIG. 9 shows that along the cavity side wall 24 to create a shadow in the depression 34 that is deprived of light by the second leading edge 9 of the chip 2 and the cavity back wall 26. A dimple 34 extending along is shown.

  As shown in FIG. 10, the device 12 includes holding means 40 for temporarily holding the chip 2 in the cavity 13 to allow inspection. The holding means 40 includes a vacuum source (not shown) and a vacuum transmission passage 42 extending from the vacuum source to the vacuum slot 44 and into the cavity 13. The vacuum serves to hold the chip 2 in the cavity 13 during inspection.

  In order to find the chip seated in the cavity 13, positioning means (not shown) are provided. The positioning means collects and focuses the image of the chip 2 and sends it to a nearby inspection device such as an image processing unit (not shown), a charge coupled device camera (not shown); A sufficient light source (not shown) for finding the edge 8 of the chip 2 where the edge 8 casts a dark shadow on the depression 34 may be included. The contrast line between the recess 34 and the chip 2 provides a reference point for the inspection device to find the chip 2 so that the inspection device can begin the test process.

  Although the invention has been described with reference to specific embodiments, those skilled in the art can make various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention. It is. All combinations of elements and steps that perform substantially the same action in substantially the same way to achieve substantially the same result are within the scope of the invention.

1 is a perspective view of a rectangular regular hexahedral microelectronic chip to which the present invention is directed; FIG. It is a front view of the chip | tip which shows the 1st front edge and 2nd front edge which are arrange | positioned by this invention. FIG. 5 is a perspective view of an exemplary cavity formed in an exemplary tip manipulating wheel showing a cavity sidewall in which a shadowing depression is formed that is observable in accordance with the teachings of the present invention. It is a perspective view of the other cavity which shows a cavity side wall, and the 1st wall which is a 1st wall and has the shadow formation hollow formed in this. FIG. 6 is a perspective view of yet another cavity showing a cavity side wall and a first wall formed with a horizontal slot extending into the wall. FIG. 2 is a perspective view of the chip shown in FIG. 1 seated in a cavity. FIG. 7 is a front view of a chip seated in the cavity shown in FIG. 6 showing a first leading edge that forms the boundary of the shadow generated by the circular depression. FIG. 7 is a front view of a chip seated in the cavity shown in FIG. 6 showing a first leading edge that forms the boundary of the shadow generated by the oval depression. FIG. 7 is a front view of a chip seated in the cavity shown in FIG. 6 showing a first leading edge that forms the boundary of a shadow generated by a depression formed in a horizontal slot. FIG. 4 is a perspective view of a tip manipulating wheel and a cut-out portion of the wheel showing the relationship between the depression, cavity, cavity side wall, and tip seated in the cavity. FIG. 5 is a front view of a chip seated in a cavity showing that a second edge erodes the shadow generated by a depression formed along the back wall of the cavity. 1 is a perspective view of a typical vacuum means.

Explanation of symbols

2 Microelectronic chip 5 Front wall 6, 7 Side wall 8, 9 First and second leading edge 12 Device 13 Cavity 14 Chip operating means 24, 28 Cavity side wall 26 Cavity rear wall 30 First wall 32 Recess 34 Recess

Claims (32)

The front wall is associated with each side wall so as to form at least a front wall and a pair of oppositely spaced side walls, the first and second front edges being spaced apart from each other. An apparatus for accurately positioning a microelectronic chip having a front wall and a pair of opposing side walls in a chip holding cavity for visual inspection,
A cavity sidewall formed to be adjacent in parallel with at least one sidewall of the chip;
The hollow side wall has a depression formed in the hollow side wall to cause a shadow to project forward from the depression, and the first front edge of the chip is objective between the shadow and the chip. An apparatus for forming the shadow boundary so as to form a contrast at a gray level that is measurable.   The apparatus of claim 1, wherein a first leading edge of the tip forms a straight boundary of the shadow.   The apparatus of claim 1, wherein a first leading edge of the tip forms a vertical boundary of the shadow.   In addition, it includes vacuum holding means for temporarily holding the chip in the cavity, the vacuum holding means for the vacuum source and for the chip to assist in holding the chip in the cavity. And a vacuum transmission path from the vacuum source to the cavity for providing a vacuum.   The apparatus of claim 1, wherein the shaded shade grayness differs from the front grayness of the chip by up to 15 gray units in an industrial grayness scale of 255 units.   The apparatus of claim 1, wherein the shaded shade grayness differs from the front grayness of the chip by at least 16 gray units in an industrial grayness scale of 255 units.   The apparatus of claim 1, wherein the depression is circular.   The apparatus of claim 1, wherein the depression is oval.   The apparatus of claim 1, wherein the indentation is a horizontal slot.   The apparatus of claim 1, wherein the cavity is bounded by a cavity back wall.   The depression extends along the cavity side wall and the cavity rear wall so as to form a shadow here eroded by the second leading edge of the chip, and the shadow formed in the cavity rear wall depression is The apparatus of claim 10, wherein a contrast that is objectively measurable is formed between the shadow and the chip. The front wall is associated with each side wall so as to form at least a front wall and a pair of oppositely spaced side walls, the first and second front edges being spaced apart from each other. An apparatus for accurately positioning a microelectronic chip having a front wall and a pair of side walls in a chip holding cavity for visual inspection,
A cavity sidewall formed adjacent to and parallel to at least a portion of at least one side wall of the chip, extending away from the cavity and positioned proximate to the sidewall of the chip and the first leading edge; A cavity side wall partially formed in the first wall forming the recess,
The hollow side wall and the first wall are depressions formed therein, and have a depression that causes a shadow to project forward from the depression, and the first front edge of the chip has the shadow and the first wall. An apparatus for forming the shadow boundary so as to form a contrast in gray level that is objectively measurable with the chip.   The apparatus of claim 12, wherein the first leading edge of the tip forms a straight boundary of the shadow.   The apparatus of claim 12, wherein the first edge of the tip forms a vertical and straight boundary of the shadow.   Furthermore, it includes vacuum holding means for temporarily holding the chip in the cavity, the vacuum holding means for the vacuum source and the chip to assist in holding the chip in the cavity. And a vacuum transmission path from the vacuum source to the cavity for providing a vacuum.   13. The apparatus of claim 12, wherein the shaded shade grayness differs from the front grayness of the chip by up to 15 gray units in an industrial grayness scale of 255 units.   The apparatus of claim 12, wherein the shaded shade grayness differs from the front grayness of the chip by at least 16 gray units in an industrial grayness scale of 255 units.   The apparatus of claim 12, wherein the recess is circular.   The apparatus of claim 12, wherein the depression is oval.   The apparatus of claim 12, wherein the indentation comprises a horizontal slot.   The apparatus of claim 12, wherein the cavity is bounded by a cavity back wall.   The depression extends along the cavity side wall and the cavity rear wall to form a shadow here eroded by the second leading edge of the chip, and the shadow formed in the cavity rear wall depression is The apparatus according to claim 12, wherein an objective moderate contrast is formed between the shadow and the chip. A method of determining a position of a microelectronic chip having adjacent chip front walls and chip sidewalls having grayness characteristics and forming a leading edge within a cavity having cavity side walls, comprising:
The chip side wall is proximate to the cavity side wall, and the cavity side wall is proximate to a second portion of the chip side wall, and has a depression for forming a depression gray degree characteristic, and the depression gray degree characteristic is the chip. Receiving the chip in the cavity so as to be reasonably different from the gray characteristics of the front wall or the chip sidewall, and between the recess and the chip front wall or the chip sidewall to determine the position of the chip Using differences in the grayness characteristics of the method.   24. The method of claim 23, wherein a leading edge of the tip forms a straight boundary with the depression and provides a reference for optical inspection.   24. The method of claim 23, further comprising providing a vacuum to hold the tip within the cavity.   24. The method of claim 23, wherein the grayness characteristics of the recess and the front wall of the chip differ by at least 16 gray units on an industrial 255 unit gray scale.   24. The method of claim 23, wherein the grayness characteristics of the recess and the front wall of the chip differ by up to 15 gray units on an industrial 255 unit gray scale.   24. The method of claim 23, wherein the depression has a circular, oval or slot shape.   The cavity includes a cavity back wall adjacent to the cavity side wall and a second cavity side wall, the cavity back wall and / or the second cavity side wall being a second chip side wall, a chip back wall, or a chip front 24. The method of claim 23, comprising other depressions having a grayness characteristic that is reasonably different from the grayness characteristic of the wall.   24. The method of claim 23, comprising inspecting the chip for visible scratches while the chip is held in the cavity.   24. The method of claim 23, wherein the depression reduces specularity around the area of the chip that is subjected to optical inspection.   31. The method of claim 30, wherein the dent increases the amount of optical inspection information or reduces the error rate.

Images