JP2010078574A - Automatic tester of sheet metal surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic tester of a sheet metal surface which enables testing of various defective items in final inspection of lead frames simultaneously in real time under highest reliability. <P>SOLUTION: The automatic tester of sheet metal products includes: various types of lighting means for irradiating illumination rays on sheet metal products; a plurality of imaging means for imaging the sheet metal products; a carrying means for transferring the sheet metal products in one direction at constant speed; a supply part for supplying the sheet metal products one by one on the carrying means; an inspecting part which uses the image data obtained by imaging of the sheet metal products with a plurality of imaging means to detect any defect contained in the sheet metal products and then determine quality of them; a removal part for sorting and removing any sheet metal product with its quality level determined by the inspecting part depending on the determination; and a control part for controlling operation of the entire tester. Each imaging means picks up images those sheet metal products reaching the imaging position of each imaging means, while synchronizing with the carrying means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic inspection apparatus for inspecting a wiring pattern defect, a plating defect, a positional misalignment defect, a width defect and the like using image data on both sides of a plate-like metal obtained by a plurality of imaging means.

Some plate-shaped metal products are partially plated and taped. For example, a lead frame which is a base material of a semiconductor package corresponds to this. Hereinafter, this lead frame will be described as an example.
Currently, semiconductor packages using lead frames are required to have strict quality assurance for lead frames as base materials due to the expansion of applications. Generally, iron nickel alloy (42 materials), copper alloy, etc. are used as the base material of the lead frame, and the manufacturing method is a stamping method in which metal is mechanically punched using an ultra-precision mold, and the metal is corroded chemically. There is an etching method for forming a pattern.

  In recent years, the packaging technology in the semiconductor technology field is becoming narrower with higher integration and higher functionality of semiconductor devices, and lead frames used in these packages are also becoming more multi-pin and narrower. . In addition, with the increase in the speed of semiconductor elements, the use of metal materials having high electrical conductivity is increasing year by year.

  Conventionally, the inner lead of the lead frame is designed to extend so as to spread radially with the center of the die pad as a reference. In a semiconductor device using a lead frame, an IC chip is fixed to a die pad, and an electrode pad of the IC chip and a bonding portion at the tip of the inner lead are electrically connected by wire bonding or the like. As IC chips become more multifunctional, the number of electrode pads increases, and with the miniaturization of IC chips, the spacing between electrode pads is becoming narrower. Along with this, the number of lead portions of the lead frame to be connected to the electrode pads is increased, the number of leads is increased, and the pitch between leads and the lead width are various.

The patterned lead frame is subjected to silver plating at a predetermined position such as the inner lead tip. This plating part is used as a bonding part.
Leads with a narrow pitch and lead width between the leads are weak in strength, and the lead is deformed even by a slight external force. This has led to the manufacture of lead frames with protective tape applied to prevent contact between the inner leads and the suspension leads that support the die pad and the inner leads, electrical shorts, deformation of the inner leads, etc. .
Further, after the down-press process, there is also a process in which a tip cut process for cutting the tip of the inner lead is performed.

FIG. 1 shows an outline of the lead frame 10. FIG. 1A shows the lead frame 10 when observed from the front surface side, and FIG. 1B shows the lead frame when observed from the back surface side.
A lead frame 10 manufactured by an etching method or the like has a die pad 1, an inner lead 2, an outer lead 3, a dam bar 4, and a frame portion 5, and a portion where no wiring pattern is formed is defined as a space portion 9. Thereafter, plating 6 is applied to the inner lead 2 in order to reduce the connection resistance between the semiconductor element and the bonding portion. Further, a protective tape 7 is attached to prevent contact between the inner leads and the suspension leads supporting the die pad and the inner leads, electrical short circuit, and deformation of the inner leads. In consideration of the fact that the protective tape 7 is an insulator, polyimide tape is used. Further, a step is formed on the suspension lead 8 by down-pressing, taking into consideration the loading of semiconductor elements on the die pad 1, the inner lead tip cutting for removing the conduction at the tip of the inner lead 2 is performed, and the lead frame is completed. Note that the actual lead frame is in a state in which the above-described wiring patterns are multifaceted.

  As described above, the defect items in the lead frame final inspection include pattern defects (open / short / foreign matter, etc.), lead deformation, tape defects (existence / position misalignment / width defect, etc.), plating defects (existence / non-attachment / attachment). Discrimination of products using automatic inspection machines is indispensable. However, it is difficult to inspect all defects with a single inspection machine. Recently, the demand for inspection on tapes and plating has increased further, and the quality of partial plating applied to bonding parts that connect with IC chips is increasing. Is particularly important, and for example, Patent Document 1 has been proposed as a method of imaging a plating portion with a CCD camera or the like and inspecting the plating state using image processing.

  Although it is possible to obtain the difference in contrast between the plate-like metal surface and the plated portion by the technique of Patent Document 1, strictly speaking, the plating state including the side tapered portion of the wiring pattern having a three-dimensional shape is good. An inspection method for judging badness is desirable, and an imaging and inspection method capable of clearly contrast-separating the metal surface and the plated portion, and simultaneously performing the quality of the metal surface as well as the plated portion is desirable. In addition, when microscopic observations are made on the surface of a metal plate or plated surface, there are rolling flaws and irregularities caused by the metal material manufacturing method, and minute brightness and darkness due to these irregularities occurs on the image, depending on the threshold setting in image processing, overdetection It becomes an element, and stable automatic judgment is difficult.

  Therefore, as a method for clearly separating the contrast between the metal surface and the plated portion, a means for imaging the surface of the substrate at an imaging angle of 0 ° to 10 °, and reflection between the metal material of the non-plated portion and the plated material of the plated portion A method for inspecting the surface of a metal substrate using a light source unit having a wavelength range in which the difference in intensity is maximum and an irradiation unit that emits indirect light having a solid angle of 2π has been proposed. Thus, simultaneous imaging and inspection of the plated portion and the non-plated portion can be performed in one optical system, and an inexpensive apparatus can be realized as compared with individual imaging and inspection of the plated portion and the non-plated portion.

  Recently, however, it has been found that the surface state and composition of the plated part change due to slight fluctuations in manufacturing conditions, and the inspection by contrast separation from the metal surface is rarely stabilized. It is also true that there are varieties with different finishes of plating, such as semi-gloss and matte, depending on the presence or absence of the glossy material in the manufacturing process. Therefore, we are further investigating an imaging method suitable for inspecting defects on the surface of the plated metal pattern with high accuracy regardless of slight variations in plating manufacturing conditions. In addition, the defective items in the lead frame final inspection include tape defects, down press defects, misalignment defects, width defects, and the like. In fact, there is a demand for an inspection apparatus that can perform all these inspections. is there.

JP 2000-171402 A

  The present invention has been made in view of the above-described circumstances, and includes defective items in lead frame final inspection, pattern defects (open system / short system / foreign matter, etc.), lead deformation, tape defects (existence / position misalignment / Provided is an inspection apparatus capable of simultaneously inspecting whether there is a width defect, etc., plating defect (existence / non-attachment / adhesion / position misalignment / width defect, etc.), downpress presence / absence at high reliability in real time. The purpose is that.

In order to solve this problem, in claim 1, a plate-shaped metal product inspection apparatus,
A first illuminating unit that irradiates one surface of the plate-shaped metal product with indirect illumination light; a first imaging unit that images a surface illuminated by the first illuminating unit of the plate-shaped metal product;
Second illumination means for irradiating one surface of the plate-shaped metal product with indirect illumination light and direct illumination light; and second imaging means for imaging the surface illuminated by the second illumination means of the plate-shaped metal product;
Third imaging means for imaging from the other surface side the third illumination means for irradiating one surface of the plate-shaped metal product with diffused illumination light and the region illuminated by the third illumination means for the plate-shaped metal product. Means,
4th illumination means which irradiates only the indirect illumination light, or indirect illumination light and direct illumination light to the surface on the opposite side to the said 1st illumination means illuminated of the said plate-shaped metal product, and said plate shape Fourth imaging means for imaging the surface illuminated by the fourth illumination means of the metal product;
Conveying means for moving the plate-shaped metal product in one direction at a constant speed;
A supply unit for supplying the plate-shaped metal products one by one on the conveying means;
Using the image data obtained by imaging the plate-shaped metal product by the plurality of imaging means, an inspection unit that detects a defect existing in the plate-shaped metal product and determines pass / fail,
A discharge unit that sorts and discharges the plate-like metal product determined by the inspection unit according to the quality, and
A control unit for controlling the operation of the entire inspection apparatus,
A plate-like metal surface inspection apparatus characterized in that the first to fourth imaging means perform imaging of a plate-like metal product that has reached the imaging position of each imaging means while synchronizing with the conveying means. It is.

  Thus, by performing image processing specialized for each defect detection using image data obtained by the imaging means most suitable for each defective item, it is possible to simultaneously inspect the surface of the sheet metal product with high accuracy. It becomes possible.

  According to a second aspect of the present invention, the plate-shaped metal surface inspection apparatus according to the first aspect is characterized in that the plate-shaped metal product is a lead frame.

Moreover, in Claim 3 of this invention, The plate-shaped metal surface inspection apparatus of Claim 1 which has a discharge part which sorts the said plate-shaped metal product as a non-defective product, a defective product, and a verification product by an inspection result,
Storage means for storing defect information such as defect coordinates, defect type and defect image of the verified product;
Detailed observation means for referring to the defect information of the verify product in detail and observing a defective portion;
Network means for mutually connecting the plate-shaped metal surface inspection apparatus, the storage means and the detailed observation means, and exchanging the defect information;
It is set as the plate-shaped metal surface inspection system characterized by providing.

  Thereby, the verified product of the plate-like metal product can be efficiently reconfirmed by visual observation, and it becomes easy to further classify products with minor defects as good products. Further, by raising the results of automatic inspection and verification inspection as quality information to the higher-level core system, it can be used for process improvement such as improvement of the non-defective product rate.

  According to claim 4 of the present invention, the plate-like metal surface inspection system according to claim 3, wherein the plate-like metal product is a lead frame.

  The present invention is an inspection apparatus that simultaneously inspects wiring pattern defects, plating defects, misalignment defects, width defects, and the like using image signal data obtained by a plurality of imaging means as described above, and each defect is appropriately imaged. Since automatic detection can be performed using signal data and image processing, it is possible to provide an inspection apparatus with excellent defect detection sensitivity. As a result, it is possible to cope with the miniaturization and mass production of the plate-like metal product accompanying the increase in density and function of the semiconductor device.

  Embodiments of a plate-like metal surface inspection apparatus according to the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram showing an embodiment of the plate-shaped metal surface inspection apparatus according to the first aspect of the present invention.

  The plate-shaped metal surface inspection apparatus of the present invention includes a supply unit 20 that supplies a plate-shaped metal product (lead frame) 10 to an imaging inspection unit, and a transport unit 60 that moves the plate-shaped metal product 10 in one direction at a constant speed. A plurality of imaging means 30 for imaging the surface state of the plate-shaped metal product that has reached the inspection position in synchronization with the conveying means, and an image signal obtained by imaging the plate-shaped metal surface by the plurality of imaging means An inspection unit 70 that detects and automatically determines each defective portion existing on the surface of the plate-like metal using data, a discharge unit 50 that discriminates the quality of the plate-like metal product 10 determined by the inspection unit 70, and each stage drive And a control unit 80 for controlling various sensors.

  The supply unit 20 includes a magazine for storing the lead frame 10 with an interleaf and a mount, a suction pad for vacuum-adsorbing the lead frame, a sensor for identifying and detecting the lead frame, the interleaf, and the mount, and a lead frame in the magazine And a transfer head for picking up the paper and transferring it to the inspection section transporting means, and a recovery head for vacuum-sucking the interleaf and mount in the magazine with a suction pad and recovering them in the interleaf / mountboard recovery section. Then, the lead frame picked up by the transfer head is transferred to the inspection stage, and the lead frame transferred to the inspection stage removes dust and the like by the ionizer and the air blower 40, and proceeds to imaging and inspection operations. . The supply unit 20 can be picked up not only from a magazine, but also from a dedicated hard case specified by the product type or customer.

  The inspection stage on which the lead frame is placed and fixed is moved to the imaging area in one direction at a constant speed by the conveying means 60. At this time, the movement amount of the inspection stage attached to the conveying means, that is, the movement amount of the plate metal product is increased. A signal for each unit distance is obtained from a unit that accurately measures, and the signal is divided and distributed, and this signal is sent to the inspection unit, thereby performing scanning imaging so as not to be affected by the speed variation of the inspection stage.

  The transport means 60 is a linear reciprocating motion and control means having a pair of transport portions arranged in parallel at a predetermined interval, and a substrate on which one or more substrates 10 can be placed. A flap portion 13, a flap control portion, and a stopper portion 14 for limiting the drive range of the flap portion 13, which are arranged on the gap side between the placement portion 11 and the pair of transport portions, and on which one or more substrates can be placed. A tube actuator using a flexible tube 12 as a flap driving means is utilized to carry the substrate with an accuracy commensurate with the required inspection accuracy (FIG. 3).

  The imaging means 30 is equipped with four types of a front reflection plating head 31, a front reflection raw material head 32, a front transmission head 33, and a back reflection head 34. The surface reflection plating head 31 obtains image signal data for inspecting the plating state of the lead frame surface, and the surface reflection raw material head 32 is image signal data for inspecting the raw material state (material) of the lead frame surface. The front transmission head 33 obtains image signal data focusing on the defects across the wiring pattern and the gap when observed from the lead frame surface, and the back reflection head 34 is image signal data for inspecting the state of the lead frame back surface. Is to get.

  The illumination means of the front reflection raw material head 32 and the back reflection head 34 uses dome illumination that emits indirect light. A wiring pattern formed by an etching method or the like has a curved side taper portion due to the directionality of corrosion progress. When the illumination means is coaxially reflected, light is reflected on the surface of the wiring pattern, and the accuracy of revealing the defect generated between the wiring patterns and in the side taper portion is lowered.

  On the other hand, the dome illumination can irradiate many inspected components including the coaxial direction by irradiating the object to be inspected with a solid angle of 2π. For dome lighting, a light exit is formed on the inner surface of the dome and light is irradiated directly from the direction of the solid angle 2π to the object to be inspected, and a light exit is formed on the inner surface of the dome and reflected on the inner surface of the dome. There is a type that irradiates the object to be inspected, but either type may be used as long as the same effect can be produced.

  In addition, aiming to reduce the influence of shading as much as possible, the plate metal product has a dome inner diameter of 2 W or more with respect to the plate metal product width W, and the entire plate metal product is imaged by one imaging. As the light source, a metal halide light source, a halogen light source, or the like is selected and used in consideration of the amount of light necessary for imaging.

  The imaging means of the front reflection raw material head 32 and the back reflection head 33 captures a linear region of the plate-like metal surface 10 at a predetermined position orthogonal to the conveyance direction of the plate-like metal product 10, and the entire plate-like metal surface. Image signal data is obtained. The elevation angle θ of the imaging means indicates the angle formed by the vertical direction of the plate-shaped metal product and the optical axis, and the elevation angle θ is preferably around 5 °. The reason why the elevation angle θ is not 0 ° is that fine irregularities such as rolling flaws on the surface of the plate-like metal are reduced at the time of imaging to aim at prevention of erroneous detection and overdetection. And it is necessary to form the opening for imaging at the upper part of the dome illumination that irradiates the indirect light at a predetermined position according to the elevation angle θ.

  The illumination means of the surface reflection plating head 31 includes both a dome illumination 36 that irradiates indirect light and a direct illumination 35 that directly irradiates light (FIG. 4). The dome illumination 36 is effective for plating inspection in a state in which the surface of the plated portion is highly flat, that is, a surface state that can be expressed as gloss or semi-gloss, and has the largest difference in reflection intensity depending on the plate-like metal material and the plating material to be used. The plate-shaped metal material and the plating material are optically separated by utilizing the wavelength range of 400 nm to 600 nm.

  The direct illumination 35 uses the same wavelength region, and is effective for plating inspection in a state where the flatness of the plated portion surface is low, that is, a state where it can be expressed as matte. By direct light irradiation in an irradiation range of 20 to 60 °, , High contrast extraction of the plating part. Note that indirect light irradiation and direct light irradiation are not used at the same time, and an image to be obtained is obtained by the user appropriately selecting according to plating manufacturing conditions. The camera can be selected from a line camera, an area camera, monochrome, and color according to the application. In this example, the line camera is used.

  FIG. 5A is a schematic diagram showing the outline of the inner lead 2, the plating part 6, and the space part 9, and FIG. 5B shows a profile on the line L1 in FIG. As described above, the luminance information is separated in each of the inner lead 12, the plating 16, and the space portion 19, and the separation from the plating portion and the portion to be plated becomes possible on the image, and the image processing can be independently developed.

  A feature of this embodiment is that the back side has illumination means and imaging means similar to the front side. For example, the back side of the lead frame is not plated, but the lead frame Since there is a possibility that plating wraparound (adhesion) may occur, similar illumination means and imaging means are made to face the inspection stage in order to perform this defect inspection. In the case where the plating inspection on the back side is not performed, it is not necessary to mount a means for optically separating the plate-like metal material and the plating material. Further, the inspection of the presence or absence of the down press of the lead frame can be performed by detecting a down press mark called a tool mark generated on the suspension lead 8, and this tool mark is also generated on the surface of the suspension lead on the back side. The press presence / absence inspection may be performed by either the front surface reflection inspection or the back surface reflection inspection.

  The imaging means of the front transmission head 33 guides light from a halogen light source or a metal halide light source to a line-shaped light guide, and the line-shaped light guide is provided with a cylindrical lens or a diffusing plate so that uniform diffused light is emitted from the back surface of the plate-shaped metal. Light that is transmitted toward the surface is irradiated, and the image is obtained by the imaging means 33 for transmission imaging inspection.

  The inspection unit 70 / control unit 80 controls the conveying means and various sensors, and uses the image signal data obtained by photographing the plate-like metal surface to extract defective portions existing on the plate-like metal surface. . FIG. 6 is a flowchart showing the overall operation relating to the image processing / defect determination means. An image signal is obtained by synchronizing with the conveying means for moving the plate-shaped metal product in one direction at a constant speed and the conveying means for moving the plate-shaped metal product in one direction at a constant speed.

  This image signal data is sent to the control / image processing means, and information on each part of the metal surface and the plating part is extracted from this image signal data (step S2). Further, defect detection / determination processing is executed using the extracted information (step S3). This defect detection / determination process is executed for all the wiring patterns, plating, tapes, etc. formed on the lead frame, and thereafter the entire operation is completed (step S4, YES).

  For example, for the image signal data obtained by the front reflection plating head 31, the front reflection raw material head 32, the front transmission head 33, and the back reflection head 34, defect distribution and an appropriate processing method are set as shown in Table 1. Then, defect detection / determination processing (step S3) is performed.

  In order to detect each defect in the master data by preliminarily holding a reference image as master data in each of the front reflection plating head 31, the front reflection raw material head 32, the front transmission head 33, and the back reflection head 34. Defective detection is performed by setting the parameters.

  First, processing related to the plating section will be described. The binarization process that extracts only the plating part is performed on the master data, and further, the expansion and contraction process on the binary image is performed as many times as necessary (the number of steps) to suppress the rattling of the edge part. After that, this image is newly used as plating master data. Then, after performing a position correction process using a reference position set in advance between the master data and the captured image, by performing a division matching process after appropriately setting the matching area 130 in the plating portion, Detection of plating residue, no plating, and non-plating (FIG. 7).

  Next, the plating area deviation detection is performed as follows. The distance between the center of the lead frame island 1 and the plating end in the four directions on the master image is determined in advance. Using this distance as a reference value, the same processing is performed on the captured image every time, and the obtained island 1 center, the distance between the plating ends, and the reference value of the master image are compared. (FIG. 8A).

  Note that the plating is not necessarily applied from the tip of the inner lead, but there are some that are applied in the middle of the inner lead. In that case, the distance between the inner plating end, the outer plating end, and the island center is obtained in each direction, and the plating area deviation is detected by comparison with the reference value (FIG. 8B).

  There is another method (FIG. 8C). I want to determine whether the plating ends on the island side and tie bar side are within the intersection range. Therefore, in the Y direction, the island side plating end reference MIy = (MSy + MSy ′) / 2 and the tie bar side plating end reference MOy = (MEy + MEy ′) / 2 are obtained. Similarly, the plating end reference MIx and MOx are calculated for the X direction. Then, compare the reference value with the measured value for the island side and tie bar side plating end reference, and | MI-MS |, | MI-MS '|, | MO-ME |, | MO-ME' | If this value is within the set tolerance, it is determined that the product is non-defective and the tolerance is not acceptable. The tolerance (threshold value) may be common to eight locations or may be individual.

  In addition, plating adhesion refers to a defect in which plating is attached to a portion that should not be attached, and whether or not there is a luminance value portion that is equal to or higher than the binarization level for the plating area in order to detect this failure. (FIG. 9).

  Next, processing related to the metal part to be plated will be described. Performs binarization processing to extract only the part to be plated from the master data, and further performs expansion / contraction processing for the binary image as many times as necessary (the number of steps) to suppress rattling of the edge portion. Then, this image is newly used as master data for the metal part to be plated. Then, after performing position correction processing using a reference position set in advance between the master data and the captured image, the matching area 130 is appropriately set with the metal portion, and then division matching processing is performed.・ Pits, shorts, protrusions, open, foreign matter between leads, dirt / discoloration / scratches, lead deformation, dents are detected (FIG. 10).

  In addition, the lead width defect and gap defect of the inner lead part are obtained by finding the edge of the lead at a predetermined measurement pitch between the preset measurement start line 140 and end line 150, and the amount of change in the distance between the lead edges and the gap edge is changed. If there is more than a certain threshold, it is determined that there is a defect. In the case of a lead with a tip cut, a lead tip serving as a reference is obtained in advance, and if the lead tip position is deviated by more than a predetermined position (X, Y), the tip position deviation is It can also be determined that it has occurred (FIG. 11).

  Next, processing related to the protective tape 7 will be described. As for the case where the presence or absence of the tape 7 that should originally be is inspected, first, the measurement start line 140 and the end line 150 are set in advance so as to cross a predetermined position of the tape 7. The lead edge is obtained from the binarization level of the lead from the measurement start line 140, and the luminance value is scanned toward the measurement end line 150 on the lead space center line. If the luminance level (black level low gradation) of the tape portion does not continuously exist between the measurement start line 140 and the end line 150, it is determined that there is no tape (FIG. 12).

  Next, regarding the tape misalignment, the island center is obtained in advance, and the measurement start line 140 and the end line 150 are set so as to straddle the tape 7. The lead edge is obtained from the binarization level of the lead from the measurement start line 140, and the luminance value is scanned toward the measurement end line 150 on the lead space center line. After the presence of the tape is confirmed at the brightness level (black level low gradation) of the tape portion, the tape center is obtained from the distance between the tape edges, and the distance from the island center is obtained as a reference value. The same processing is performed on the captured image every time, and the distance between the obtained island center and the tape center coordinates is compared with the reference value of the master image. (FIG. 13A).

  There is still another method (FIG. 13B). I want to determine if the tape center is within the intersection. Therefore, the tape center reference TCy = (Ty + Ty ′) / 2 is obtained in the Y direction. Similarly, the center reference TCx is calculated for the X direction. Then, the comparison between the reference value and the measured value, | TC−T |, | TC−T ′ | is performed in the XY2 direction. If this value is within the set tolerance, it is determined that the product is non-defective and the outside of the tolerance is defective. The tolerance (threshold value) may be common to four locations or may be individual.

  The tape width defect is obtained from the master image using the distance between the tape edges as a reference value in advance in the same manner as the above-described method for determining the tape position deviation, and the reference value and the distance between the tape edges obtained from the captured image are obtained each time. By comparison, it is determined that a tape width defect has occurred if the threshold is equal to or greater than a certain threshold (FIG. 13C).

  By the way, by using an illumination means that includes light in the wavelength range (for example, 600 nm or more) in which the amount of light transmitted through the polyimide tape is large at the illumination wavelength, the transmitted light through the tape portion increases, so that a defect exists under the protective tape. Can also be inspected (FIG. 13D). In general, the pattern under the tape cannot be inspected with a fully processed lead frame, and in order to carry out the inspection, it is indispensable to carry out the inspection before the tape is applied. However, it is possible to detect defects such as chips or pits under the tape by using light in a long wavelength region and making the tape pass through. Also, for the tape position deviation and tape width defect inspection, the processing using the same method as described above can be performed by detecting the tape edge.

  Finally, the down press presence / absence processing will be described. This process is determined based on the presence or absence of a tool mark on the suspension lead 8. Specifically, the center of the island is obtained in advance, a measurement line is set in the tool mark part on the suspension lead, and the brightness level (black level low gradation) of the tool mark exists continuously in this measurement line. If the black level does not exist continuously, it is determined that there is no down press (FIG. 14).

  It is desirable to perform each measurement process regarding the defect of the plating width and position, the defect of the tape width and position, and the presence / absence of the down press described above in each of the vertical, horizontal, and diagonal directions.

  The plate-like metal product that has been judged pass / fail by the inspection unit using the image signal data obtained by each imaging means in this manner is discriminated by the discharge unit 50. Discharge parts are classified into non-defective, defective and verified products. The verify product refers to a product that has been detected as defective but whose defect size and variation in luminance of the detection unit are difficult to determine as a defective product. It is considered to include so-called remedies.

  The discharge unit 50 is a non-defective product, a defective product, a verified product magazine, a magazine containing the interleaving paper and the mount, and a suction pad for vacuum-sucking the lead frame, with the lead frame determined to pass or fail stored between Sensors for identifying and detecting lead frames, interleaving sheets, and mounts, transfer heads that pick up the lead frames from the inspection stage and transfer them to the magazine, and vacuum sucking with an adsorbing pad from the interleaving sheets and mounting magazines, interleaving / mounting sheets Is provided with a transfer head for transferring to the magazine. Further, the discharge unit 50 can be delivered directly to a dedicated hard case specified not only by a magazine but also by product type or customer.

  With the above operations, pattern inspection (open / short / foreign matter, etc.), lead deformation, tape failure (existence / position misalignment / width failure, etc.), plating failure (existence / non-attachment / attachment / Inspection of presence / absence of misalignment / width down) and down press is performed at the same time and with high reliability in real time.

Further, defect information such as defect coordinates, defect type and defect image detected in the work determined as the verified product is converted into data during automatic inspection, and this data is stored in the data server 100 on the network via the hub 90, The same data is used for verification work by the microscope 110 by displaying the reference data on the verification device 120 (FIG. 15). Note that the inspection apparatus and the verification apparatus are not necessarily 1: 1, and n: m can be used because the verification data is stored using a data server on the network.
Furthermore, by raising the results of automatic inspection and verification inspection as quality information to the higher-level core system, it is possible to make use for process improvement such as improvement of the non-defective product rate.

(A) Schematic diagram showing the shape of the lead frame surface (b) Schematic diagram showing the shape of the back surface of the lead frame 1 is a schematic configuration diagram showing the main configuration of an inspection apparatus according to a first embodiment of the present invention. Schematic diagram of tube actuator use Schematic diagram showing the illumination form of the surface reflective plating head (A) State explanatory diagram near inner lead plating (b) Explanatory diagram showing line profile on line L1 in (a) Flow chart showing overall schematic operation of defect inspection apparatus Plating matching outline explanatory diagram (A) Outline of measurement of plating misalignment during lead tip plating (b) Outline of explanation of misalignment measurement during lead intermediate plating (c) Outline of misalignment measurement using plating reference average value Overview of plating labeling Plating part division matching outline explanatory diagram Lead measurement outline explanatory diagram Outline of tape measurement process (without tape) (A) Outline of tape measurement process (tape misalignment) (b) Outline of tape deviation measurement using average tape reference position (c) Outline of tape measurement process (bad tape width) (d) Defect inspection under tape Outline illustration Down press measurement process (no down press) overview Verification screen overview

Explanation of symbols

10 ... Plate metal products (lead frame)
DESCRIPTION OF SYMBOLS 1 ... Island or die pad 2 ... Inner lead 3 ... Outer lead 4 ... Dam bar 5 ... Frame part 6 ... Plating 7 ... Protective tape 8 ... Hanging lead 9 ... · Space portion 20 ··· Supply portion 30 ··· Imaging means 31 ··· Imaging means: front reflective plating head 32 ··· Imaging means: front reflective raw material head 33 ··· Imaging means: front transmission head 34 · .. Imaging means: Back reflection head 40... Ionizer and blower 50... Discharge unit 60... Conveying means 70 .. Inspection unit 80. 110 ... (substance) microscope 120 ... verify device 130 ... division matching area 140 ... measurement start line 150 ... measurement end line

Claims (4)

An inspection apparatus for plate-shaped metal products,
A first illuminating unit that irradiates one surface of the plate-shaped metal product with indirect illumination light; a first imaging unit that images a surface illuminated by the first illuminating unit of the plate-shaped metal product;
Second illumination means for irradiating one surface of the plate-shaped metal product with indirect illumination light and direct illumination light; and second imaging means for imaging the surface illuminated by the second illumination means of the plate-shaped metal product;
Third imaging means for imaging from the other surface side the third illumination means for irradiating one surface of the plate-shaped metal product with diffused illumination light and the region illuminated by the third illumination means for the plate-shaped metal product. Means,
Fourth illumination means for irradiating only the indirect illumination light or the indirect illumination light and the direct illumination light onto the surface of the plate-shaped metal product opposite to the surface illuminated by the first illumination means, and the plate Fourth imaging means for imaging the surface illuminated by the fourth illumination means of the metal product,
Conveying means for moving the plate-shaped metal product in one direction at a constant speed;
A supply unit for supplying the plate-shaped metal products one by one on the conveying means;
Using the image data obtained by imaging the plate-shaped metal product by the plurality of imaging means, an inspection unit that detects a defect existing in the plate-shaped metal product and determines pass / fail,
A discharge unit that sorts and discharges the plate-like metal product determined by the inspection unit according to the quality, and
A control unit for controlling the operation of the entire inspection apparatus,
The plate-shaped metal surface inspection apparatus characterized in that the first to fourth imaging units perform imaging of a plate-shaped metal product that has reached the imaging position of each imaging unit while synchronizing with the transport unit. 2. The plate metal surface inspection apparatus according to claim 1, wherein the plate metal product is a lead frame. The plate-shaped metal surface inspection device according to claim 1, further comprising: a discharge unit that sorts the plate-shaped metal product as a non-defective product, a defective product, and a verified product according to an inspection result;
Storage means for storing defect information such as defect coordinates, defect type and defect image of the verified product;
Detailed observation means for referring to the defect information of the verify product in detail and observing a defective portion;
Network means for mutually connecting the plate-shaped metal surface inspection apparatus, the storage means and the detailed observation means, and exchanging the defect information;
A plate-shaped metal surface inspection system comprising: 4. The plate metal surface inspection system according to claim 3, wherein the plate metal product is a lead frame.

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