JP2018134759A - Semiconductor chip, light-emitting device head, image formation apparatus and light-emitting device head manufacturing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance traceability.SOLUTION: An LED chip 44 which is provided on an LED head 23 of an image formation apparatus 1 is provided with a shot map 67 expressing a regional shot area 51B on a semiconductor wafer 50 and a chip address 66 expressing the position in the shot area, at the stage of the manufacture on the basis of the semiconductor wafer 50. With this, an operator can identify the position of the LED chip 44 on the semiconductor wafer 50 at the manufacture when visually recognizes it using a microscope or the like even after the LED chip is divided from the semiconductor wafer 50 after the manufacture and mounted on a printed wiring board 42.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a semiconductor chip, a light emitting element head, an image forming apparatus, and a light emitting element head manufacturing system, and is suitable for application to, for example, an electrophotographic printer (hereinafter simply referred to as a printer).

  As a conventional printer, an electrostatic latent image is formed by irradiating light onto the surface of a photosensitive drum from a light emitting element head equipped with a light emitting element such as an LED (Light Emitting Diode) chip, and further to the electrostatic latent image. An apparatus that prints an image by developing a toner image by attaching toner is widely used.

  Among these, the LED chip is manufactured from a semiconductor wafer made of silicon or the like, for example, by a manufacturing process similar to a general semiconductor chip. In this manufacturing process, for example, after various processes such as exposure processing and etching processing are sequentially performed on the surface of the semiconductor wafer, various elements and circuit patterns corresponding to a plurality of LED chips are collectively formed. Then, each LED chip is divided by dicing.

  In such an LED chip manufacturing process, for example, inspection is performed in the state of a semiconductor wafer, and after confirming whether there is a manufacturing defect for each LED chip, only a non-defective LED chip may be mounted on the light emitting element head. Conceivable.

  Therefore, for example, the inspection result of a semiconductor chip such as an LED chip is stored in a computer or the like in advance in association with a position on a semiconductor wafer (hereinafter referred to as a wafer position), and is read out to be a non-defective product. A device in which only a certain semiconductor chip is mounted on a semiconductor product has been proposed (see, for example, Patent Document 1).

  In this case, for example, a unique serial number may be assigned to each semiconductor product, and the serial number and each semiconductor chip wafer position may be associated with each other and registered in a database or the like. As a result, even if the semiconductor chip is found to be defective after the manufacture of the semiconductor product, the wafer position of the semiconductor chip can be checked based on the serial number.

JP2003-37121A (FIG. 3 etc.)

  By the way, when a semiconductor chip is a defective product, it is desirable to reduce the proportion of defective products and increase the proportion of non-defective products by pursuing and improving the cause of defective products, that is, to increase the yield. In particular, the semiconductor chip is exposed in the state of a semiconductor wafer. For this reason, if the occurrence rate of defective products is high at a specific position on the semiconductor wafer, it can be estimated that the cause of the occurrence of defects in the semiconductor chip was the exposure process, and the solution can be further eliminated.

  However, if a defect of the semiconductor chip is found in the inspection of the semiconductor product after the semiconductor chip is mounted on the semiconductor product, an operator or the like can know the wafer position of the semiconductor chip by using the serial number of the semiconductor product. It is necessary to perform a database search process or the like based on the above, and it takes time and effort. In addition, when the semiconductor chip is replaced by an operator and the semiconductor chip removed from the semiconductor product is mixed with other semiconductor chips, the correct wafer position of the semiconductor chip cannot be known. .

  In other words, in the method of registering the wafer position of a semiconductor chip in a database or the like, it is necessary to perform a search or the like in order to know the wafer position later, and there is a possibility that the correct wafer position cannot be known due to mixing of semiconductor chips or the like. Therefore, there is a problem that the traceability of the semiconductor chip is poor.

  The present invention has been made in consideration of the above points, and intends to propose a semiconductor chip, a light emitting element head, an image forming apparatus, and a light emitting element head manufacturing system capable of improving traceability.

  In order to solve this problem, in the semiconductor chip of the present invention, a plurality of semiconductor chips are manufactured from a semiconductor wafer, and an electronic circuit and position information representing individual positions on the semiconductor wafer are provided.

  In the light emitting element head of the present invention, a substrate and a plurality of the semiconductor chips attached to the substrate are provided, and the electronic circuit of the semiconductor chip has a light emitting element that emits light.

  Further, in the image forming apparatus of the present invention, the above-described light emitting element head is provided.

  Further, the light emitting element head manufacturing system of the present invention is a light emitting element head manufacturing system for manufacturing the above-described light emitting element head, wherein a mounting portion for mounting a semiconductor chip at a predetermined position of the substrate and a semiconductor chip mounted on the substrate A storage unit for storing the position and the position on the semiconductor wafer at the time of manufacturing the semiconductor chip in association with each other is provided.

  Since the present invention provides position information on a semiconductor chip, the position on the semiconductor wafer at the time of manufacturing the semiconductor chip can be determined by referring to the position information even after the semiconductor chip is mounted on a substrate or the like. It can be easily and accurately grasped. Thus, according to the present invention, when a defect occurs in a semiconductor chip, the correlation with the position on the semiconductor wafer when the semiconductor chip is manufactured can be easily estimated.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor chip which can improve traceability, a light emitting element head, an image forming apparatus, and a light emitting element head manufacturing system are realizable.

1 is a schematic diagram illustrating an overall configuration of an image forming apparatus. It is a basic diagram which shows the structure of an image forming unit. It is a basic diagram which shows the structure of a LED head. It is a basic diagram which shows arrangement | positioning of the shot area | region in a semiconductor wafer. It is a basic diagram which shows arrangement | positioning and chip address of the LED chip in a shot area | region. It is a basic diagram which shows the position of the chip address in a LED chip, and a shot map. It is a basic diagram which shows manufacture of a LED chip. It is a basic diagram which shows the structure of a 1st photomask. It is a basic diagram which shows the structure of a 2nd photomask and a slit mask. It is a basic diagram which shows the whole structure of a LED head manufacturing system. It is a basic diagram which shows the structure of a management apparatus. It is a basic diagram which shows the structure of a chip database. It is a basic diagram which shows manufacture of the LED chip by other embodiment. It is a basic diagram which shows the structure of the photomask by other embodiment.

  Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

[1. Configuration of image forming apparatus]
As shown in FIG. 1, an image forming apparatus 1 according to the present embodiment is configured as an electrophotographic printer. For example, a desired color image is formed on a sheet P having a size such as A3 size or A4 size. Is to be printed.

  In the image forming apparatus 1, various components are arranged inside a printer housing 2 formed in a substantially box shape. In the following description, the right end portion in FIG. 1 is defined as the front surface of the image forming apparatus 1, and the vertical direction, the horizontal direction, and the front-rear direction when viewed from the front are defined and described.

  The image forming apparatus 1 is configured to perform overall control by the control unit 3. The control unit 3 is connected to a host device (not shown) such as a personal computer by wireless or wired via a communication processing unit (not shown). When image data representing a color image to be printed is given from the host device and the printing of the color image is instructed, the control unit 3 executes a printing process for forming a print image on the surface of the paper P.

  At the bottom of the printer housing 2, a paper storage cassette 4 that stores the paper P and a paper feed that separates and feeds the paper P stored in a state of being stacked in the paper storage cassette 4 one by one. Part 5 is provided. The paper feeding unit 5 is located above the front end of the paper storage cassette 4 and advances the paper P along the conveyance path W indicated by the alternate long and short dash line. In addition to a plurality of rollers such as a hopping roller 6 provided above the front end of the sheet storage cassette 4 with the central axis directed in the left-right direction, and a registration roller 7 and a pinch roller 8 facing each other, A guide or the like for guiding the paper P is provided.

  The paper feeding unit 5 rotates the hopping roller 6 and the like under the control of the control unit 3 to separate and take in the paper P stored in the paper storage cassette 4 one by one, and feed the taken paper P into the transport path W. , And then proceed so as to be folded back at a position that is substantially in the middle of the top and bottom in the vicinity of the front end in the printer casing 2.

  After passing through the paper supply unit 5, the paper P is conveyed from the front side to the rear side along the conveyance path W by the middle conveyance unit 10 formed so as to greatly traverse the inside of the printer housing 2 from the front side to the rear side. Is done. Four image forming units 11C, 11M, 11Y, and 11K are sequentially arranged from the rear side to the front side above the middle conveyance unit 10, that is, above the center of the printer housing 2.

  The image forming units 11C, 11M, 11Y, and 11K correspond to cyan (C), magenta (M), yellow (Y), and black (K) colors, respectively. The image forming units 11C, 11M, 11Y, and 11K (hereinafter collectively referred to as the image forming unit 11) are different only in color and are configured in the same manner. Further, transfer rollers 13C, 13M, 13Y, and 13K are arranged at positions sandwiching the conveyance path W below the image forming units 11C, 11M, 11Y, and 11K, respectively.

  As shown in FIG. 2, the image forming unit 11 includes an image forming unit 21, a toner cartridge 22, and an LED (Light Emitting Diode) head 23. The toner cartridge 22 contains toner as a developer, is disposed above the image forming unit 21, and is attached above the image forming unit 21. The toner cartridge 22 supplies the stored toner to the toner storage unit 31 of the image forming unit 21.

  As shown in FIG. 3, the LED head 23 as a light emitting element head is configured around a plate-like substrate 41 that is long in the left-right direction and thin in the front-rear direction. The printed circuit board 42 and the rod lens array 43 are attached to the front side of the board 41.

  The printed wiring board 42 is configured in a plate shape shorter than the board 41 in the left-right direction and the up-down direction, and a predetermined circuit pattern is formed. A plurality of LED chips 44 are attached to the front side of the printed wiring board 42 in a state of being aligned along the left-right direction, for example, 26 pieces. The printed wiring board 42 has a number for uniquely identifying each location (hereinafter referred to as a chip mounting location) where the LED chip 44 is to be mounted (hereinafter referred to as a chip position number). ) Are sequentially assigned from the left side to the right side, for example.

  Incidentally, the printed wiring board 42 is assigned a board number that is a unique number one by one at the time of manufacture, and a board label 42L that is a piece of paper on which the board number is printed is attached to a flat portion. In the board label 42L, the board number is represented by numerals and characters, and also represented by a bar code, a two-dimensional code, and the like. Therefore, the printed wiring board 42 can easily and accurately read the board number from the board label 42L by using a bar code reader or the like.

  The LED chip 44 is formed in a rectangular parallelepiped shape that is long in the left-right direction and short in the up-down direction and the front-rear direction. For example, 192 LED elements are arranged along the left-right direction on the front side. The LED chip 44 is manufactured by appropriately performing an exposure process, an etching process, or the like on a semiconductor wafer, as in a general semiconductor element (details will be described later).

  The rod lens array 43 is formed in a rectangular parallelepiped shape that is long in the left-right direction, and a large number of minute cylindrical lenses (refractive index distribution type lenses) having a central axis along the vertical direction are arranged in the left-right direction. Yes. Incidentally, in addition to the printed wiring board 42 and the rod lens array 43 described above, other components such as a protective plate for protecting each component mounted on the printed wiring board 42 are attached to the LED head 23. (Indicated by broken lines in the figure).

  In addition to the toner storage unit 31, the image forming unit 21 includes a supply roller 32, a developing roller 33, a developing blade 34, a photosensitive drum 35, and a charging roller 36. In addition, the image forming unit 21 rotates the supply roller 32, the developing roller 33, and the charging roller 36 in the direction of the arrow R2 (counterclockwise in the figure) by being supplied with a driving force from a motor (not shown), and the photosensitive member. The drum 35 is rotated in the direction of arrow R1 (clockwise in the figure).

  A predetermined bias voltage is applied to the supply roller 32, and the toner in the toner container 31 is attached to the peripheral side surface, and the toner is attached to the peripheral side surface of the developing roller 33 by rotating. The developing roller 33 is also applied with a predetermined bias voltage, and after the excess toner is removed from the peripheral side surface by the developing blade 34, the peripheral side surface is brought into contact with the peripheral side surface of the photosensitive drum 35.

  On the other hand, the charging roller 36 contacts the photoconductor drum 35 in a state where a predetermined bias voltage is applied, thereby uniformly charging the peripheral side surface of the photoconductor drum 35. The LED head 23 exposes the photosensitive drum 35 by emitting light at predetermined time intervals with a light emission pattern based on image data supplied from the control unit 3 (FIG. 1). As a result, an electrostatic latent image is formed on the peripheral side surface of the photosensitive drum 35 in the vicinity of the upper end.

  Subsequently, the photosensitive drum 35 is rotated in the direction of the arrow R <b> 1 to bring the portion where the electrostatic latent image is formed into contact with the developing roller 33. As a result, toner adheres to the peripheral side surface of the photosensitive drum 35 based on the electrostatic latent image, and the toner image based on the image data is developed.

  The transfer roller 13 is positioned below the photosensitive drum 35, and the vicinity of the upper end of the peripheral side surface thereof is in contact with the vicinity of the lower end of the photosensitive drum 35 on the conveyance path W. The transfer roller 13 is applied with a predetermined bias voltage, supplied with driving force from a motor (not shown), and rotated in the direction of arrow R2. Therefore, the transfer roller 13 can transfer the toner image developed on the peripheral side surface of the photosensitive drum 35 to the paper P when the paper P is being transported along the transport path W.

  In this way, the image forming units 11K, 11Y, 11M, and 11C sequentially transfer and superimpose toner images of respective colors onto the conveyed paper P.

  A fixing unit 15 is provided near the rear end of the middle conveyance unit 10 (FIG. 1). The fixing unit 15 includes a heating roller 16 and a pressure roller 17. The heating roller 16 is formed in a cylindrical shape whose central axis is directed in the left-right direction, and a heater is provided therein. The pressure roller 17 is formed in the same cylindrical shape as the heating roller 16 and presses the upper surface against the lower surface of the heating roller 16 with a predetermined pressing force.

  The fixing unit 15 heats the heating roller 16 and rotates the heating roller 16 and the pressure roller 17 in predetermined directions based on the control of the control unit 3. As a result, the fixing unit 15 applies heat and pressure to the paper P delivered from the image forming unit 11, that is, the paper P on which the toner images of four colors are superimposed, and further fixes the toner to the rear and upward. hand over.

  A paper discharge unit 18 is disposed above the fixing unit 15. The paper discharge unit 18 includes a combination of a plurality of discharge rollers, a guide for guiding paper, and the like. The paper discharge unit 18 rotates each discharge roller appropriately according to the control of the control unit 3, thereby conveying the paper P delivered from the fixing unit 15 rearward and upward and then folding it back forward. The sheet is discharged to a discharge tray 2T formed on the upper surface.

  As described above, when executing the printing process, the image forming apparatus 1 forms toner images by causing the LED heads 23 (FIG. 2) to emit light in the image forming units 11 of the respective colors, and sequentially forms them on the paper P. It is designed to transcribe.

[2. Arrangement of LED chip and configuration of LED chip on semiconductor wafer]
Next, the position of the LED chip 44 on the semiconductor wafer will be described. As shown in FIG. 4, the semiconductor wafer 50 is made of, for example, single crystal silicon, and is formed in a disk shape having a diameter of about 200 [mm] and a thickness of about 0.725 [mm].

  In the semiconductor wafer 50, a plurality of shot areas 51 are set by dividing the surface of the board into a lattice shape along, for example, the vertical direction and the horizontal direction. Specifically, although eight shot regions 51 are arranged in each of the vertical direction and the horizontal direction on the semiconductor wafer 50, a portion that protrudes greatly from the surface of the semiconductor wafer 50 is omitted, so that a total of 60 shot areas 51 are provided. The shot area 51 is provided.

  As will be described later, the semiconductor wafer 50 is exposed to a predetermined pattern by an exposure process, and further subjected to a predetermined mask process, an etching process, etc., thereby forming an electronic circuit with various elements and wiring patterns. In particular, the semiconductor wafer 50 is subjected to the exposure process for each shot region 51 instead of being exposed at the same time due to the restriction of the lens that collects the light for exposure in the exposure process. It has become.

  As shown in FIG. 5, for example, 70 LED chips 44 in the vertical direction and 2 in the horizontal direction, that is, a total of 140 LED chips 44 are arranged in an orderly manner in each shot area 51. In other words, in the semiconductor wafer 50, when an exposure process is performed in each shot region 51, patterns of elements, wirings, and the like constituting the 140 LED chips 44 are simultaneously exposed.

  For convenience of explanation, hereinafter, the shot area 51 in which an arbitrary LED chip 44 is arranged at the time of manufacture is also referred to as an associated shot area 51B of the LED chip 44. Each shot area 51 is assigned a shot number for uniquely specifying in the semiconductor wafer 50. The shot numbers are assigned consecutive numbers such as “1”, “2”,..., “60”, for example, from the upper left to the right, with appropriate line feeds.

  In the shot area 51, a chip address for uniquely identifying each position is assigned to each LED chip 44 position. This chip address is a continuous 3-digit integer from “001” to “140”. Therefore, in each shot area 51, if the chip address of the LED chip 44 is known, the position of the LED chip 44 can be specified.

  Incidentally, in the semiconductor wafer 50 (FIG. 4), even within the shot region 51, the LED chip 44 cannot be normally formed at a portion protruding from the surface of the semiconductor wafer 50 or a portion near the outer periphery. For this reason, in the semiconductor wafer 50, as indicated by hatching in FIG. 4, the LED chip 44 is disposed only in a part of each shot region 51 in the vicinity of the outer periphery.

  As shown in FIG. 6A, the LED chip 44 has a plurality of LED elements 61 on the surface of the chip main body 60 along the longitudinal direction (that is, the left-right direction in the LED head 23 (FIG. 3)) at predetermined intervals. And a plurality of electrode pads 62 are arranged at sufficient distances along the left-right direction at locations away from the LED element 61 in the lateral direction. For example, after the LED chip 44 is mounted on the printed wiring board 42 (FIG. 3), the electrode pads 62 are electrically connected to electrode pads (not shown) provided on the printed wiring board 42. One end of a bonding wire (not shown) is welded.

  Further, on the surface of the chip body 60, a chip address area 63 and a shot map area 64 are formed at portions where various elements, wiring patterns, etc. are not formed and one electrode pad 62 is sandwiched from the left and right directions. Each is formed. Each of the chip address area 63 and the shot map area 64 has a vertical length equal to or longer than that of the electrode pad 62, and a horizontal length equal to or longer than that of the electrode pad 62.

  In the chip address area 63 and the shot map area 64, a chip address 66 and a shot map 67 are written, respectively, as shown in FIG. 6B in which a part of FIG. 6A is enlarged.

  As described above, the chip address 66 is assigned to the position of each LED chip 44 in the shot area 51 (FIG. 5), and is represented by a three-digit number. For this reason, the LED chip 44 can make the operator recognize the number of the chip address 66 when the chip address area 63 is visually observed by a worker using a microscope or the like after manufacture, for example. It is possible to immediately grasp the position in the shot area 51 when the chip 44 is manufactured. For convenience of explanation, the chip address 66 is also referred to as chip position information below.

  The shot map 67 represents the arrangement of each shot region 51 on the semiconductor wafer 50 (FIG. 4), specifically, a square combination of the mutual positional relationship, as if the position of each shot region 51 Is configured as a map representing Further, in the shot map 67, the portion representing the assigned shot area 51 </ b> B of the LED chip 44 is different from the other shot areas 51. Specifically, in the shot map 67, each shot region 51 is represented by a square having the same size (hereinafter referred to as a shot mark M), and the assigned shot region 51B is a square that is slightly larger than the others (hereinafter referred to as this). Is called a belonging shot mark MB).

  For this reason, for example, when the shot map area 64 is visually observed by an operator using a microscope or the like after manufacturing, the LED chip 44 can cause the operator to visually recognize the shot map 67, thereby It is possible to intuitively grasp the position of the belonging shot area 51B. For convenience of explanation, hereinafter, the shot map 67 is also referred to as shot position information.

  That is, the LED chip 44 allows the operator or the like to visually recognize the shot map 67 and the chip address 66, whereby the position of the associated shot area 51 </ b> B in the semiconductor wafer 50 at the time of manufacture and the LED chip 44 in the associated shot area 51 </ b> B. Can be recognized. In other words, the LED chip 44 can promptly recognize the individual position of the LED chip 44 on the semiconductor wafer 50 at the time of manufacture by using the shot map 67 and the chip address 66.

[3. LED chip manufacturing]
Next, an LED chip manufacturing process for manufacturing a large number of LED chips 44 (FIG. 6) from the semiconductor wafer 50 (FIG. 4) will be described. The semiconductor wafer 50 has a structure in which a plurality of thin film layers such as a conductive layer and an insulating layer are sequentially stacked on the upper side thereof.

  First, as shown in a schematic side view of FIG. 7A, the semiconductor wafer 50 is a metal made of a material having high conductivity such as copper on the upper side of a substrate 71 made of, for example, silicon single crystal by sputtering or the like. A film 72 is formed. Next, as shown in FIG. 7B, the semiconductor wafer 50 has a SiN (silicon nitride) film 73 formed on the metal film 72.

  Next, as shown in FIG. 7C, a part of the SiN film 73 is removed from the semiconductor wafer 50 by using a photolithography technique, an etching technique, or the like, and a portion corresponding to an LED element, a wiring, an electrode, or the like. Is left behind.

  At this time, the semiconductor wafer 50 is first subjected to exposure processing using a first photomask 81 as shown in FIG. This first photomask 81 corresponds to the entire range of one shot region 51 (FIG. 5). For each of a total of 140 LED chips 44 arranged in the shot region 51, elements, wiring, All mask patterns for forming electrodes and the like are formed.

  In the first photomask 81, a number representing a chip address 66 is written in each chip address area 63 of each LED chip 44 (FIGS. 6A and 6B). The chip address 66 is a number corresponding to the position of each LED chip 44 in the shot area 51 as shown in FIG. 8B in which a part of FIG. 8A is enlarged.

  Further, on the first photomask 81, a part of the shot map 67 is drawn in each shot map region 64 in each LED chip 44 (FIGS. 6A and 6B). In the shot map area 64, as shown in an enlarged view in FIG. 8C, all the shot areas 51 constituting the shot map 67 are drawn as equivalent squares, that is, as simple shot marks M. . In other words, the assigned shot mark MB (large square) indicating the position of the assigned shot area 51B is not drawn in the shot map area 64.

  For this reason, the semiconductor wafer 50 is exposed to each shot region 51 using the first photomask 81, so that elements corresponding to 140 LED chips 44 in each shot region 51, wiring, electrodes, etc. A pattern can be formed. In addition to this, the semiconductor wafer 50 can form numbers of chip addresses 66 corresponding to the respective positions in the chip address areas 63 of the LED chips 44 in each shot area 51, and in all the shot map areas 64 A part of the shot map 67 can be formed, which is a figure in which the shot region 51 is represented by only the shot mark M. In other words, the same pattern is formed by the first photomask 81 in all the shot regions 51 in the semiconductor wafer 50.

  Next, as shown in FIG. 7D, a part of the SiN film 73 is further removed from the semiconductor wafer 50 by using a photolithography technique, an etching technique, or the like. At this time, the semiconductor wafer 50 is exposed using a second photomask 82 as shown in FIG. 9A and a slit mask 83 as shown in FIG. 9C.

  9B, the second photomask 82 corresponds to the entire range in one shot region 51 (FIG. 5) in the vertical direction in the figure, and has 70 pieces. 70 mask patterns respectively corresponding to the respective shot map areas 64 in the LED chip 44 are aligned. Further, in the second photomask 82, 60 types of mask patterns composed only of assigned shot marks MB, which correspond to the positions of the respective shot regions 51 on the semiconductor wafer 50, are arranged in the order of shot numbers in the horizontal direction of the figure. Has been. That is, on the second photomask 82, mask patterns corresponding to the shot map regions 64 are arranged in a grid pattern, and each mask pattern is all the same along the vertical direction of the figure, while Each one is different along the direction.

  The slit mask 83 is slightly longer than the shot area 51 in the vertical direction in the figure, and is approximately twice as long as the shot area 51 in the horizontal direction in the figure. The slit mask 83 is almost entirely a light-shielding portion that shields light, while light is allowed to pass through an elongated slit (gap) SL along the vertical direction at substantially the center in the horizontal direction. The length of the slit SL in the horizontal direction is slightly wider than one mask pattern in the second photomask 82.

  In the slit mask 83, the slit SL is arranged in accordance with any mask pattern row along the vertical direction in the second photomask 82, so that only the mask pattern for one vertical row in the second photomask 82 is used. Light can pass through.

  In the semiconductor wafer 50, in each shot region 51, a mask pattern corresponding to the position of the shot region 51 in the second photomask 82 is matched with the shot map region 64, and the slit SL in the slit mask 83 is also in the shot map region 64. An exposure process is performed in a state of being arranged so as to match, and an etching process or the like is further performed.

  As a result, in the semiconductor wafer 50, as shown in FIG. 6B, in the shot map area 64 of each LED chip 44 in each shot area 51, the assigned shot mark MB (that is, large size) is aligned with the position of the shot area 51. ), And the pattern of the shot map 67 can be completed.

  Incidentally, in the semiconductor wafer 50, the shot pattern 67 appropriately representing the position of each shot region 51 can be completed by switching the mask pattern sequence used in the second photomask 82 for each shot region 51. .

  Thereafter, the semiconductor wafer 50 is subjected to predetermined etching processing, ion implantation processing, and the like, thereby completing elements, circuits, electrodes, and the like. Further, the semiconductor wafer 50 is determined whether it is a non-defective product or a defective product by performing a predetermined inspection process on each LED chip 44, and the result is stored in a predetermined management device (described later). Thereafter, each LED chip 44 is divided by a dicing process using a predetermined blade.

  As described above, the semiconductor wafer 50 is subjected to exposure processing for each shot region 51 to produce a plurality of LED chips 44. At this time, in addition to elements, wirings, electrodes, and the like, chip addresses different from each other in the shot region 51 are manufactured. 66 is written, and a different shot map 67 is formed for each shot area 51.

  Incidentally, a unique wafer number is assigned to each semiconductor wafer 50, and a wafer number mark 50L (FIG. 4) representing the wafer number is engraved in the vicinity of the outer periphery by laser marking or the like. The wafer number mark 50L is represented by a bar code, a two-dimensional code, or the like in addition to the wafer number represented by numerals and characters, as with the substrate label 42L of the printed wiring board 42 (FIG. 3). Therefore, in the semiconductor wafer 50, the wafer number can be easily and accurately read from the wafer number mark 50L by using a bar code reader or the like.

[4. Production of LED head]
Next, the LED head manufacturing process which manufactures the LED head 23 using the LED chip 44 manufactured through each process mentioned above is demonstrated. The LED head 23 is manufactured by the LED head manufacturing system 100 shown in FIG.

  An LED head manufacturing system 100 as a light emitting element head manufacturing system includes a management device 101, a die bonder 102, and a head assembly device 103, a transport device that transports LED chips 44, components, and the like being manufactured between the devices. It is comprised by the container (not shown) etc. which accommodate various components. Among them, the management device 101 is configured in substantially the same manner as a general computer device, and as shown in a schematic block diagram in FIG. 11, a control unit 111, a storage unit 112, a communication unit 113, a display unit 114, and An operation unit 115 is provided.

  The control unit 111 has a CPU (Central Processing Unit) (not shown) inside, and performs various processes by reading out various programs from the storage unit 112 and executing them appropriately. The storage unit 112 includes a nonvolatile ROM (Read Only Memory), a hard disk drive, a flash memory, and the like, and a volatile RAM (Random Access Memory), and stores various programs and various data. .

  In the storage unit 112, a chip database DB1 in which information related to the LED chip 44 is stored is constructed. As shown in FIG. 12, the chip database DB1 includes manufacturing information indicating the position on the manufactured semiconductor wafer 50, the wafer number of the semiconductor wafer 50, and the like, and the mounted printed wiring board 42 ( 3), the mounting information indicating the mounting position, the board number, and the like is stored in association with each other. The chip database DB1 also stores information indicating whether each LED chip 44 is a good product or a defective product.

  The communication unit 113 is connected to the die bonder 102 and the head assembly apparatus 103, and performs various communication processes between them. The communication unit 113 is also connected to an inspection device (not shown) that inspects the LED chip 44 manufactured based on the semiconductor wafer 50. Therefore, when the management apparatus 101 acquires the inspection result of each LED chip 44 from the inspection apparatus via the communication unit 113, the management apparatus 101 stores it in the chip database DB1 of the storage unit 112. At this time, in the chip database DB1, for example, contents indicating that the inspection result is defective are stored in association with the wafer number, shot number, and chip address of the LED chip 44 whose inspection result is defective.

  The die bonder 102 includes a control unit 121 that performs overall control, a chip mounting unit 122, a wafer number reading unit 123, a chip supply unit 124, a substrate mounting unit 125, a substrate number reading unit 126, a substrate transport unit 127, and the like. A chip mounting portion 128 and the like are provided.

  Like the control unit 111 of the management apparatus 101, the control unit 121 has a CPU (not shown) inside, and controls each unit by reading various programs from a storage unit (not shown) and executing them appropriately. Perform the process.

  In the chip mounting portion 122, a plurality of LED chips 44 are placed on a predetermined tray or the like while maintaining the arrangement when manufactured on the semiconductor wafer 50, and adjusted to a predetermined position. Placed. Further, on the chip mounting portion 122, the outer peripheral portion on which the wafer number mark 50 </ b> L is engraved of the semiconductor wafer 50 is also mounted.

  The wafer number reading unit 123 is configured in the same manner as a so-called bar code reader, reads the wafer number from the wafer number mark 50 </ b> L stamped on the semiconductor wafer 50, and supplies this to the control unit 121. Thereby, the control unit 121 can know the wafer number of the LED chip 44 mounted on the chip mounting unit 122.

  The chip supply unit 124 can transport the tray on which the LED chip 44 is placed. Specifically, the chip supply unit 124 conveys the tray on which the LED chip 44 is placed between a chip container (not shown) in which a plurality of trays are accommodated and the chip placement unit 122, The LED chips 44 can be supplied from the chip container to the chip mounting unit 122 in units of 50 semiconductor wafers.

  The printed wiring board 42 is placed on the board placing portion 125 at a predetermined position. The board number reading unit 126 is configured in the same manner as the wafer number reading unit 123, reads the board number from the board label 42 </ b> L attached to the printed wiring board 42, and supplies the board number to the control unit 121.

  The substrate transport unit 127 includes a substrate adsorption unit that adsorbs the printed wiring board 42 and a substrate moving unit that moves the substrate adsorption unit in the vertical direction, the horizontal direction, the front-rear direction, and the like. Based on the control of the control unit 121, the substrate moving unit is configured such that the substrate adsorption unit has a predetermined position in a substrate container (not shown) in which a plurality of printed wiring boards 42 are arranged side by side, a predetermined position in the substrate platform 125, or The head assembly apparatus 103 can be moved to a predetermined position or the like.

  The chip mounting unit 128 includes a suction head that sucks or opens the LED chip 44 and a chip moving unit that moves the suction head in the vertical direction, the horizontal direction, the front-rear direction, and the like. The chip moving unit can move the suction head to a predetermined position on the chip mounting unit 122, a predetermined position on the substrate mounting unit 125, or the like based on the control of the control unit 121.

  The die bonder 102 starts a mounting process for mounting the LED chip 44 on the printed wiring board 42 when a predetermined operation is received by an operator or the like via an operation unit (not shown). Specifically, the control unit 121 of the die bonder 102 first controls the chip supply unit 124 to tray the plurality of LED chips 44 manufactured from one semiconductor wafer 50 from the chip container to the chip mounting unit 122. Are transported and placed. Subsequently, the control unit 121 causes the wafer number reading unit 123 to read the wafer number mark 50 </ b> L of the semiconductor wafer 50 and stores the read wafer number in the storage unit 112 (FIG. 11) of the management apparatus 101.

  Further, the control unit 121 controls the substrate transport unit 127 to take out and transport one printed wiring board 42 from the substrate container, and place it on the substrate platform 125. Subsequently, the control unit 121 causes the board number reading unit 126 to read the board label 42 </ b> L of the printed wiring board 42, and stores the read board number in the storage unit 112 of the management apparatus 101. Further, the control unit 121 applies a predetermined adhesive to each chip mounting location on the surface of the printed wiring board 42, that is, each location where the LED chip 44 is to be mounted, by an adhesive application unit (not shown).

  Then, the control unit 121 causes the chip mounting unit 128 to take out one LED chip 44 from the chip mounting unit 122 and to mount it on the printed wiring board 42 in cooperation with the control unit 111 of the management apparatus 101. Repeat in order.

  Specifically, the control unit 121 refers to the chip database DB1 provided in the storage unit 112 of the management apparatus 101, and among the chip mounting positions on the printed wiring board 42, the LED chip 44 is not mounted (hereinafter referred to as this). Confirm that the target chip mounting location remains. In addition, the control unit 121 selects one LED chip 44 that remains in the chip mounting unit 122 and is a non-defective product. At this time, the control unit 121 specifies the position of the LED chip 44 in the chip mounting unit 122 by the shot number and the chip address. In addition, the control unit 121 identifies the position of the target chip mounting location on the printed wiring board 42 by the chip position number.

  Subsequently, the control unit 121 moves the suction head of the chip mounting unit 128 to the position of the LED chip 44 in the chip mounting unit 122 and sucks it, and moves it to the target chip mounting location of the printed wiring board 42, After the LED chip 44 is bonded, the suction by the suction head is released.

  Furthermore, the control part 121 records the information regarding each LED chip 44 mounted at this time in chip database DB1, respectively. Specifically, in the chip database DB1, as the manufacturing information of the LED chip 44, in addition to the wafer number of the semiconductor wafer 50, the position on the chip mounting unit 122, that is, the shot number of each shot area 51 and the chip address are included. Recorded in combination. In the chip database DB1, a combination of the board number of the printed wiring board 42 and the chip position number on the printed wiring board 42 is recorded as mounting information of the LED chip 44.

  When the control unit 121 finishes mounting all (for example, 26) LED chips 44 on one printed wiring board 42, the printed circuit board 42 is transferred to the head assembly apparatus 103 by the board transfer unit 127. At the same time, a new printed circuit board 42 is taken out from the substrate container, and is transported to the substrate platform 125 and placed thereon.

  In this manner, the die bonder 102 sequentially mounts a plurality of LED chips 44 on each printed wiring board 42 and records information on each LED chip 44 in the chip database DB1.

  The head assembly apparatus 103 completes the LED head 23 by attaching various components such as the rod lens array 43 (FIG. 3) to the printed wiring board 42 on which the LED chip 44 is mounted.

[5. Effect]
In the above configuration, the LED chip 44 provided in the LED head 23 (FIG. 3) of the image forming apparatus 1 according to the present embodiment has the shot map 67 and the chip address 66 at the stage of being manufactured based on the semiconductor wafer 50. Formed (FIG. 6). For this reason, even after the LED chip 44 is manufactured and divided from the semiconductor wafer 50 and further mounted on the printed wiring board 42, the semiconductor wafer at the time of manufacture can be obtained by allowing an operator to visually observe it through a microscope or the like. The position on 50 can be specified.

  As a result, for example, when the LED chip 44 is mounted on the printed circuit board 42 and then replaced due to a failure or the like, the LED chip 44 may be mixed with other LED chips 44 due to operator inconvenience or the like. However, each LED chip 44 can be identified based on the shot map 67 and the chip address 66.

  In addition, when the LED chip 44 is manufactured, a shot map 67 and a chip address 66 are formed by processes such as exposure processing and etching processing similar to those of various elements, wirings, electrodes, and the like (FIGS. 7 and 8). ). For this reason, the LED chip 44 can be formed simultaneously with various elements by an etching process or the like simply by providing a shot map 67 and a chip address 66 on the mask pattern in advance in the manufacturing process as compared with the conventional one. There is no need to increase the number of steps as in the case of increasing the number of layers.

  In particular, for the LED chip 44, the chip address 66 may be provided in advance with a mask pattern for forming various elements, wirings, electrodes, etc. with respect to the chip address 66, and it is necessary to increase the number of processes compared to the conventional case. There is no. Further, the LED chip 44 prepares mask patterns (FIG. 9) of the assigned shot marks MB corresponding to the respective positions of the shot map 51 with respect to the shot map 67, and matches the position of the shot map area 64. An exposure process or the like may be performed, and only a few steps such as an exposure process may be added as compared with the conventional process.

  Further, the LED chip 44 represents the chip address 66 by a number assigned in the shot area 51, and the shot map 67 represented the position of each shot area 51 in the semiconductor wafer 50 by a schematic map (FIG. 6). Therefore, the LED chip 44 can directly understand the contents of the chip address area 63 and the shot map area 64 when the operator looks at the chip address area 63 and the shot map area 64 using a microscope or the like. Without being performed, the position on the semiconductor wafer 50 at the time of manufacture can be immediately recognized.

  In addition, the LED chip 44 has a chip address area 63 and a shot map area 64 disposed at positions where one electrode pad 62 is sandwiched from the left and right directions (FIG. 8). For this reason, the LED chip 44 can simultaneously accommodate the chip address 66 and the shot map 67 within the field of view even when the operator relatively increases the magnification of the microscope and the field of view is narrow. The detailed position on the semiconductor wafer 50 at the time can be easily grasped. In other words, the LED chip 44 can increase the magnification of the microscope in a state where the chip address 66 and the shot map 67 are simultaneously within the range of the visual field. It is possible to avoid the misreading of the map 67 and to visually recognize it accurately.

  Further, in the LED head manufacturing system 100 (FIG. 10), when the LED chip 44 is mounted on the printed wiring board 42, the wafer number, shot number, and chip address of the manufactured semiconductor wafer 50 and the mounted printed wiring board 42. The substrate number and the chip position number in FIG. 3 are associated with each other and recorded in the chip database DB1 (FIG. 11). Therefore, in the LED head manufacturing system 100, even after the LED chip 44 is mounted on the printed wiring board 42, even if the chip address 66 or the like cannot be visually recognized due to adhesion of foreign matter or the like, the board number and the chip are based on the chip database DB1. From the position number, the wafer number, shot number, and chip address of the LED chip 44 can be searched.

  Further, in the LED head manufacturing system 100, by performing statistical processing such as tabulation processing on the chip database DB1, it is possible to find a place where the degree of occurrence of defects on the semiconductor wafer 50 is high and to identify the cause. It becomes possible. For example, in the LED head manufacturing system 100, when the defective rate is high in the LED chip 44 manufactured in each shot region 51 and the chip address is “019”, the chip in the first photomask 81 (FIG. 8). There is a high possibility that a foreign substance is attached to the position of the address “019”, and by removing this, the occurrence of a defect can be prevented.

  According to the above configuration, the LED chip 44 provided in the LED head 23 of the image forming apparatus 1 according to the present embodiment has the associated shot region 51 </ b> B on the semiconductor wafer 50 at the stage of being manufactured based on the semiconductor wafer 50. A shot map 67 to be represented and a chip address 66 to represent a position in the shot area are provided. As a result, the LED chip 44 is divided from the semiconductor wafer 50 after manufacturing and is further mounted on the printed wiring board 42, and when viewed by the operator through a microscope or the like, the semiconductor wafer at the time of manufacturing The position on 50 can be specified.

[6. Other Embodiments]
In the embodiment described above, a chip address consisting of a three-digit number is assigned to each LED chip 44 in the shot area 51, and the chip address 66 is represented as a number in the chip address area 63 of each LED chip 44. The case was described (FIG. 6). However, the present invention is not limited to this. For example, as in the shot map 67, the position in the shot area 51 may be represented by a map or the like. In short, it is only necessary that when the operator looks at the chip address area 63 of the LED chip 44 using a microscope or the like, the position in the shot area 51 at the time of manufacturing the LED chip 44 can be surely grasped.

  In the above-described embodiment, the case where the map-like shot map 67 that schematically represents the position of each shot region 51 in the semiconductor wafer 50 is provided in the shot map region 64 has been described (FIG. 6). However, the present invention is not limited to this, and for example, the shot number may be represented as a number in the shot map area 64, or each shot area 51 may be represented by coordinates combining a horizontal order and a vertical order. In short, when the operator looks at the shot map area 64 of the LED chip 44 using a microscope or the like, the position of the assigned shot area 51B on the semiconductor wafer 50 at the time of manufacturing the LED chip 44 can be accurately grasped. good.

  Further, in the above-described embodiment, a case has been described in which each shot mark M is formed by a portion obtained by removing a part of the SiN film 73 when the shot map 67 is formed on the semiconductor wafer 50 (FIG. 7). However, the present invention is not limited to this. For example, as shown in FIG. 13 corresponding to FIG. 7C, each shot mark M may be formed by a portion where a part of the SiN film 73 is left. In short, it is only necessary that the operator can visually recognize the shot map 67 by making the structure different between each shot mark M portion and the surrounding portion. The same applies to the chip address 66.

  Further, in the above-described embodiment, when the shot map 67 is formed on the semiconductor wafer 50, the shot mark M is first created using the first photomask 81 (FIG. 8), and then the second photomask 82. And 83 (FIG. 9), the case where the assigned shot mark MB is added has been described. However, the present invention is not limited to this. For example, the shot map 67 is omitted from the first photomask 81, and the entire portion of the shot map 67 is added to the photomask 182 instead of the second photomask 82, as shown in FIG. That is, mask patterns for all shot marks M and associated shot marks MB may be formed. In this case, the assigned shot mark MB does not need to be larger than the shot mark M, and the assigned shot mark MB may have a shape different from that of the shot mark M, such as a triangle or a diamond.

  Further, in the above-described embodiment, the case where the chip address 66 is represented in the chip address area 63 by a number that can be read visually by the operator has been described. However, the present invention is not limited to this. For example, although it is difficult for an operator to visually understand, such as a one-dimensional bar code or a two-dimensional code, the contents are obtained by performing a predetermined analysis process on an image captured by the imaging device. The chip address may be expressed by a technique that can decipher. Or you may display with the number etc. which an operator can understand visually. The same applies to the shot map area 64.

  Further, in the above-described embodiment, the case where each shot region 51 is substantially square has been described (FIG. 4). However, the present invention is not limited to this, and each shot region 51 may have various other shapes such as a rectangle. Further, the semiconductor wafer 50 may be provided with shot regions 51 having an arbitrary number of 59 or less or 61 or more.

  Further, in the embodiment described above, a plurality of shot areas 51 are provided on the semiconductor wafer 50 (FIG. 4), and when the exposure process is performed for each shot area 51, the semiconductor wafer 50 is referred to by the chip address 66 and the shot map 67. The case where the position of each LED chip 44 on 50 is represented was described. However, the present invention is not limited to this. For example, when the exposure process is performed on the entire surface of the semiconductor wafer 50 at a time, the positions of the LED chips 44 on the semiconductor wafer 50 are assigned consecutive numbers to all the LED chips 44. It may be expressed by various methods such as assignment or assignment of coordinates with the vertical and horizontal directions as axes. In short, it is only necessary that the position on the semiconductor wafer 50 at the time of manufacture can be grasped when the operator visually observes the content displayed on the LED chip 44.

  Further, in the above-described embodiment, the case where the chip address area 63 and the shot map area 64 are respectively arranged at the positions sandwiching one electrode pad 62 from the left and right directions has been described (FIG. 6). However, the present invention is not limited to this, and for example, the chip address area 63 and the shot map area 64 may be arranged at locations separated from each other or at locations adjacent to each other. Alternatively, the chip address 66 and the shot map 67 may be arranged in a single area without particularly dividing the chip address area 63 and the shot map area 64.

  Furthermore, in the above-described embodiment, the case where the chip address 66 indicating the position in the shot area 51 and the shot map 67 indicating the position of the assigned shot area 51B in the semiconductor wafer 50 are provided in the LED chip 44 has been described. However, the present invention is not limited to this. For example, only one of the chip address 66 and the shot map 67 may be provided. Alternatively, in addition to the chip address 66 and the shot map 67, characters or numbers representing the wafer number of the semiconductor wafer 50 may be formed on each LED chip 44.

  Further, in the above-described embodiment, the chip address 66 and the shot map 67 are formed on the SiN film 73 which is the same layer in the semiconductor wafer 50 (FIG. 7), and both are formed on the metal film 72 by an etching process or the like thereafter. The case of forming, that is, the case of forming both in the same layer has been described. However, the present invention is not limited to this. For example, when a plurality of wiring layers are formed at the time of manufacturing the LED chip 44, the chip address 66 and the shot map 67 may be formed in different layers. Further, the chip address 66 and the shot map 67 may be formed in a layer different from various elements and wirings. Further, in this case, at least a part of the chip address 66 and the shot map 67 may be arranged at a position overlapping with various elements and wirings. In any case, the visibility can be improved by forming the chip address 66 and the shot map 67 in the later steps as much as possible, that is, in the upper layer as much as possible.

  Further, in the above-described embodiment, the chip address is utilized by using an exposure process or an etching process for forming various elements, wirings, etc. when manufacturing the LED chip 44 based on the semiconductor wafer 50 (FIG. 7). 66 and the shot map 67 are formed. However, the present invention is not limited to this, and the chip address 66 and the shot map 67 may be formed on the surface of each LED chip 44 by various known methods such as laser marking and printing technology.

  Further, in the embodiment described above, in the LED head manufacturing system 100 (FIG. 10), the printed wiring is stored in the chip database DB1 (FIGS. 11 and 12) constructed in the storage unit 112 (FIG. 11) of the management apparatus 101. The case where information regarding each LED chip 44 mounted on the substrate 42 is sequentially stored has been described. However, the present invention is not limited to this. For example, information regarding each LED chip 44 mounted on the printed wiring board 42 may not be stored in the chip database DB1.

  Further, in the above-described embodiment, the case where the present invention is applied to the LED chip 44 provided in the LED head 23 of the image forming apparatus 1 has been described. However, the present invention is not limited to this, and may be applied to various semiconductor chips such as various transistors and various integrated circuits.

  Furthermore, the present invention is not limited to the above-described embodiments and other embodiments. That is, the scope of the present invention extends to embodiments in which some or all of the above-described embodiments and other embodiments described above are arbitrarily combined, and embodiments in which some are extracted. It is.

  Further, in the above-described embodiment, the case where the LED chip 44 as the semiconductor chip is configured by the LED element 61 and the electrode pad 62 as the electronic circuit, the chip address 66 as the position information, and the shot map 67 has been described. However, the present invention is not limited to this, and a semiconductor chip may be configured by electronic circuits having various other configurations and position information.

  The present invention can be used with, for example, an LED chip provided in an LED head mounted on an electrophotographic printer.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 11 ... Image forming unit, 23 ... LED head, 41 ... Board, 42 ... Printed wiring board, 42L ... Board label, 44 ... LED chip, 50 ... Semiconductor wafer, 50L: Wafer number mark, 51: Shot area, 51B: Affiliated shot area, 61: LED element, 62: Electrode pad, 63: Chip address area, 64: Shot map area, 66: Chip Address, 67 ... Shot map, 100 ... LED head manufacturing system, 101 ... Management device, 102 ... Die bonder, 111 ... Control unit, 112 ... Storage unit, 121 ... Control unit, 122 ... Mounted on chip Placement unit, 123 ... Wafer number reading unit, 124 ... Chip supply unit, 125 ... Substrate placement unit, 126 ... Substrate number reading unit, 127 ... Base Transport unit, 128 ...... chip mounting portion, DB1 ...... chip database, M ...... shot mark, MB ...... belongs shot mark.

Claims (10)

A plurality of semiconductor chips manufactured from a semiconductor wafer,
Electronic circuit,
A semiconductor chip comprising: position information representing individual positions on the semiconductor wafer. The electronic circuit is formed by being exposed for each of a plurality of set shot areas on the semiconductor wafer,
The semiconductor chip according to claim 1, wherein the position information includes shot position information representing a position of the shot region on the semiconductor wafer. The semiconductor chip according to claim 2, wherein the shot position information represents a position on the semiconductor wafer by a map. A plurality of the electronic circuits are formed in the shot region,
The semiconductor chip according to claim 2, wherein the position information includes chip position information representing a position of the electronic circuit in the shot area. The semiconductor chip according to claim 4, wherein the chip position information is formed at a location that does not overlap with the shot position information. The semiconductor chip according to claim 1, wherein the position information is formed at a location that does not overlap the electronic circuit. The electronic circuit has a plurality of thin film layers laminated,
The semiconductor chip according to claim 1, wherein the position information is formed in the same layer as at least a part of the plurality of thin film layers constituting the electronic circuit. A substrate,
A plurality of the semiconductor chips are attached to the substrate, and the semiconductor chip according to any one of claims 1 to 7,
The light emitting element head, wherein the electronic circuit of the semiconductor chip has a light emitting element that emits light. An image forming apparatus comprising the light emitting element head according to claim 8. A light-emitting element head manufacturing system for manufacturing the light-emitting element head according to claim 8,
A mounting portion for mounting the semiconductor chip at a predetermined position of the substrate;
A light emitting element head manufacturing system comprising: a storage unit that stores a position where the semiconductor chip is mounted on the substrate and a position on the semiconductor wafer at the time of manufacturing the semiconductor chip in association with each other.

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