JP2010171112A - Lead inspection method for ic lead frame, and apparatus of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead inspection method for an IC lead frame and an apparatus of the same capable of easily inspecting the distance between adjacent lead frontend parts with accuracy. <P>SOLUTION: On an image of an IC lead frame having an island and a plurality of leads, arranged radially around the island, and which is formed so that a shape along a frontend of the lead is polygonal, each side of the polygon along the frontend of the lead is calculated. A reference line obtained by moving each side from a position along the frontend of the lead to a predetermined position in parallel is calculated; a first cross point consisting of a cross point of a first corner which is one corner among the opposed corners of adjacent leads and the reference line is calculated; a detected line consisting of a plurality of lines passing the first cross point and a second corner which is the other corner among the opposed corners is calculated; and a straight-line distance between the first cross point and the second corner on the reference line and on the detected line is calculated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a lead inspection method and apparatus for an IC lead frame, and more particularly to a method and apparatus for inspecting the interval between inner lead tips.

The IC lead frame has an island on which an IC chip is mounted as an inner lead portion, and a plurality of leads that are electrically connected to the IC chip by a gold wire or the like. The distance between these leads is narrow, and the distance between the lead tips is particularly narrow. In addition, a bonding region where a gold wire or the like for electrically connecting the IC chip and the lead is crimped is disposed at the tip of the lead.

Therefore, since the tool for crimping the gold wire to the bonding region in the bonding process touches the lead tip, the lead tip is likely to move. In this case, for example, even if a slight bend occurs at the tip of the lead, adjacent leads are likely to come into contact with each other, and the leads may be short-circuited. With the recent increase in functionality of ICs and miniaturization of IC packages, the distance between leads is becoming increasingly narrow, and the risk of this short circuit is increasing.

Therefore, in the IC packaging process, for example, before the bonding process, the lead tip part is inspected, for example, whether the lead tip part is bent or not. Conventionally, these inspections were performed by visual inspection by workers. However, according to the visual inspection, there is a problem that the work efficiency is deteriorated because the skill of the worker is required, and especially the judgment results such as the proximity of the leads are caused by the variation of the worker. There was a problem that there was a possibility that it could not be obtained.

Therefore, various proposals have been made to solve such problems.
For example, there is a method of acquiring an image of the lead tip and measuring the minimum distance between the lead tips based on this image (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 3-93249

According to Patent Document 1, (1) a step of detecting the contour of the lead tip by a camera, (2) a step of obtaining a dividing line N1 for dividing the detected contour in the length direction of the lead, and (3) Next, a step of obtaining a dividing line N2 for dividing the dividing line of adjacent leads, and (4) a lead on both sides of the dividing line N2 from the dividing line N2 obtained in the step (3). A step of obtaining the distance to the contour of the tip end portion La at a pitch, and (5) a step of obtaining a minimum value of the sum of the distances on both sides in each pitch, and a minimum of the lead tip end portion of the lead frame. An interval measurement method is disclosed.

However, according to Patent Document 1, a dividing line N1 that divides the width of the leading end of the lead into substantially equal parts is obtained, and a dividing line N2 that divides the dividing lines N1 and N1 of adjacent leads into two equal parts is obtained. Including a method of obtaining (see FIG. 2 and FIG. 3 of Patent Document 1). However, most of the IC lead frames corresponding to the recent minimization of the lead interval are by etching, and from a flat, substantially elliptical lead tip portion by conventional press (see FIGS. 2 to 4 of Patent Document 1). Also, the lead tip has a narrow width and the tip has a sharp shape with no straight line.

Therefore, according to Patent Document 1, a dividing line N1 that divides the width of the leading end portion of the lead thinly formed by etching or the like into two equal parts is obtained, and further, between the adjacent dividing lines N1 and N1 is divided into two equal parts. There has been a problem that the operation of obtaining the dividing line N2 to be divided becomes difficult and complicated, and the accuracy of the obtained minimum interval may be lowered.
In addition, for all the leads, the work for obtaining the dividing line N1 and the dividing line N2 described above is complicated and there is a problem that it may take a long time.

Therefore, the present invention has been made in view of the above-described conventional problems, and the object of the present invention is to provide an IC lead frame having a lead tip portion whose width is reduced by etching or the like. An object of the present invention is to provide an IC lead frame lead inspection method and apparatus capable of accurately and easily inspecting the interval between adjacent lead tips.

  According to the first aspect of the present invention, there is provided a frame, a quadrangular island in plan view, which is disposed substantially at the center of the frame, and on which an IC chip is mounted, and extends from the four corners of the island to the frame. A suspension lead connected to the frame part, and a plurality of leads provided radially at the periphery of the island and having a bonding region at the tip part for wiring between the electrodes of the IC chip. An IC lead frame lead inspection method for inspecting a lead tip interval of an IC lead frame formed in a polygonal shape along a tip, and acquiring an IC lead frame image including the island and the plurality of leads And a second step of obtaining each side of the polygon along the tip of the lead on the IC lead frame image, A third step of obtaining a reference straight line obtained by translating the side from a position along the tip of the lead to substantially the bonding region, and one side of opposing sides of adjacent leads. A fourth step for obtaining a first intersection formed by an intersection of the first side and the reference straight line; and a second side that passes through the first intersection and is the other side of the opposing sides. A fifth step of obtaining a detection straight line comprising a plurality of straight lines passing through the side; and a sixth step of obtaining a straight line distance between the first intersection and the second side on the reference straight line and the detection straight line. A lead inspection method for an IC lead frame, comprising: a step of obtaining a shortest distance consisting of a minimum value among the plurality of linear distances, and comparing the shortest distance with predetermined value data. is there.

According to a second aspect of the present invention, in the lead inspection method for an IC lead frame according to the first aspect, the fifth step is a step of rotating the reference straight line by a predetermined angle clockwise around the first intersection. And a step of rotating the reference straight line by a predetermined angle counterclockwise about the first intersection.

According to a third aspect of the present invention, in the lead inspection method for an IC lead frame according to the first aspect, the fifth step passes through the first intersection, and the reference straight line and the second side edge The method includes a step of obtaining straight lines that respectively pass through a plurality of neighboring pixels located in the vertical vicinity of a pixel that includes a second intersection formed by the intersection.

According to a fourth aspect of the present invention, there is provided a frame portion, an island having a rectangular shape in plan view that is disposed substantially at the center of the frame portion and mounting an IC chip, and extending from the four corners of the island to the frame portion. A suspension lead connected to the frame part, and a plurality of leads provided radially at the periphery of the island and having a bonding region at the tip part for wiring between the electrodes of the IC chip. An IC lead frame lead inspection apparatus for inspecting a lead tip interval of an IC lead frame formed in a polygonal shape along a tip, an irradiation unit for irradiating the IC lead frame with light, and the IC An image capturing unit that captures an image of a lead frame and acquires the image data, a processing unit that processes the image data, and an image of the IC lead frame are displayed. And an input unit that inputs position data on the image displayed on the display unit to the processing unit, receives the position data from the input unit, and receives the position data on the IC lead frame image. And a side setting means for setting each side of the polygon along the tip of the lead, and a reference straight line formed by translating each side from a position along the tip of the lead to the bonding region. And a first intersection detection means for detecting a first intersection formed by an intersection of the first side that is one of the opposing sides of the adjacent leads and the reference straight line. And a detection line setting means for setting a detection line consisting of a plurality of straight lines passing through the first intersection and passing through the second side which is the other side among the opposing sides, and the reference line Above and on the detection line A linear distance acquisition means for calculating a linear distance between the first intersection and the second side, and a shortest distance consisting of a minimum value among the plurality of linear distances acquired by the linear distance acquisition means. A lead inspection apparatus for an IC lead frame, comprising: shortest distance acquisition / comparison means for comparing the shortest distance with predetermined value data.

According to the present invention, the frame, the island having a rectangular shape in plan view that is disposed at the approximate center of the frame and mounting the IC chip, and the island extending from the four corners of the island to the frame are provided with the island. A suspension lead connected to the frame portion, and a plurality of leads disposed radially around the island and having a bonding region for wiring between the electrodes of the IC chip at the tip portion, and the tip of the lead An IC lead frame lead inspection method for inspecting a lead tip interval of an IC lead frame formed in a polygonal shape along the shape of the IC lead frame, wherein an IC lead frame image including the island and the plurality of leads is acquired. A first step, a second step for obtaining each side of the polygon along the tip of the lead on the IC lead frame image, A third step of obtaining a reference straight line obtained by translating the recording side from a position along the tip of the lead to the bonding region, and one of the opposing sides of the adjacent leads. A fourth step for obtaining a first intersection formed by an intersection of the first side and the reference straight line; and a second side that passes through the first intersection and is the other side of the opposing sides. A fifth step of obtaining a detection straight line comprising a plurality of straight lines passing through the side; and a sixth step of obtaining a straight line distance between the first intersection and the second side on the reference straight line and the detection straight line. And a seventh step of obtaining a shortest distance consisting of a minimum value among the plurality of straight line distances and comparing the shortest distance with predetermined value data. Etch by finding the shortest distance between the side and the second side IC lead frame lead inspection method capable of accurately inspecting the interval between adjacent lead tip portions even with an IC lead frame having a lead tip portion in which the width of the lead tip portion is narrowed by the Can provide.

The fifth step includes a step of rotating the reference straight line by a predetermined angle clockwise about the first intersection, and a predetermined counterclockwise rotation of the reference straight line about the first intersection. Therefore, by adjusting the predetermined angle, it is possible to reliably and efficiently obtain the detection straight line passing through the adjacent lead tips with the first intersection as the center. .

Further, the fifth step includes a plurality of pixels that pass through the first intersection point and that are located in the vicinity of the vertical direction of the pixel including the second intersection point that is an intersection point of the reference straight line and the second side. Since the configuration includes a step of obtaining straight lines that pass through neighboring pixels, a detection straight line that passes through the lead tip centered on the first intersection is selected by selecting a predetermined pixel from a plurality of neighboring pixels. It can be determined reliably and easily.

Further, the frame, an island having a rectangular shape in plan view, which is disposed substantially at the center of the frame, and on which the IC chip is mounted, are extended from the four corners of the island to the frame, and the island is connected to the frame. And a plurality of leads having a bonding region arranged radially around the island and having wiring between the tip of the IC chip and the electrode of the IC chip, and a shape along the tip of the lead A lead inspection device for an IC lead frame for inspecting the interval between lead tips of an IC lead frame formed in a polygonal shape, wherein an irradiation unit for irradiating light to the IC lead frame, and an image of the IC lead frame An imaging unit that captures and acquires image data, a processing unit that processes the image data, and a display unit that displays an image of the IC lead frame An input unit that inputs position data on the image displayed on the display unit to the processing unit, receives position data from the input unit, and receives the lead data on the IC lead frame image. Side setting means for setting each side of the polygon along the tip, and a reference straight line setting for setting a reference straight line obtained by translating each side from a position along the tip of the lead to the bonding region. A first intersection detection means for detecting a first intersection formed by an intersection of a first side that is one of the opposing sides of adjacent leads and the reference straight line; and Detection line setting means for setting a detection straight line comprising a plurality of straight lines passing through the intersection of one and passing through the second side which is the other side among the opposite sides; and on the reference straight line and the detection Said first on a straight line A linear distance acquisition means for obtaining a linear distance between a point and the second side, a shortest distance consisting of a minimum value among the plurality of linear distances obtained by the linear distance acquisition means, and the shortest distance And the shortest distance acquisition / comparison means for comparing the predetermined value data with each other, the width of the lead tip is narrowed by etching or the like by obtaining the shortest distance between the first intersection and the second side. It is possible to provide an IC lead frame lead inspection device capable of accurately inspecting the interval between adjacent lead tip portions even with an IC lead frame having lead tip portions formed. In addition, since the operator only needs to input the position data on the image of the IC lead frame to the processing unit via the input unit, the burden on the operator is reduced and the distance between the tips of adjacent leads is reduced. It is possible to provide a lead inspection apparatus for an IC lead frame that can be easily inspected.

It is a plane explanatory view of an IC lead frame in this embodiment. It is an enlarged plan view for explaining a lead tip of an IC lead frame in the present embodiment. It is a schematic block diagram of the IC lead frame inspection apparatus of this embodiment. 2 shows a planar image of an IC lead frame in the present embodiment. It is explanatory drawing of the lead inspection method of the IC lead frame of this embodiment. (Example 1) It is explanatory drawing of the lead inspection method of the IC lead frame of this embodiment. (Example 2) It is explanatory drawing for supplementing the effect of the lead inspection method of the IC lead frame concerning this embodiment.

Hereinafter, embodiments of the present invention will be described.
The lead inspection apparatus for an IC lead frame according to the present embodiment includes a frame, a quadrangular island in a plan view that is disposed substantially at the center of the frame and on which an IC chip is mounted, and the four corners of the island. Suspended leads that extend and connect the island to the frame portion, and a plurality of leads that are arranged radially around the island and have a bonding region at the tip portion for wiring between the electrodes of the IC chip. Moreover, it is a lead inspection device for an IC lead frame that inspects the interval between the lead tips of the IC lead frame formed in a polygonal shape along the tip of the lead, and irradiates the IC lead frame with light. An irradiation unit; an imaging unit that captures an image of the IC lead frame and acquires the image data; a processing unit that processes the image data; A display unit that displays an image of an IC lead frame; and an input unit that inputs position data on the image displayed on the display unit to the processing unit, and receives position data from the input unit. Side setting means for setting each side of the polygon along the tip of the lead on the IC lead frame image, and each of the sides is translated from a position along the tip of the lead to the bonding region. A reference straight line setting means for setting a reference straight line, and a first intersection formed by an intersection of the reference straight line and the first side which is one of the opposing sides of the adjacent leads. And a detection straight line that sets a detection straight line that includes a plurality of straight lines that pass through the first intersection and pass through the second side that is the other side of the opposing side. Setting means and previous A straight line distance obtaining unit for obtaining a straight line distance between the first intersection and the second side on a reference straight line and the detection straight line, and a minimum of the plurality of straight line distances obtained by the straight line distance obtaining unit And a shortest distance acquisition / comparison means for comparing the shortest distance with predetermined value data.

Hereinafter, an example of a preferred embodiment of the present invention will be described with reference to the drawings.
First, an example of the IC lead frame 10 inspected in the present embodiment will be described with reference to FIGS.
FIG. 1 is an explanatory plan view illustrating an IC lead frame 10 according to the present embodiment. FIG. 2 is an enlarged plan view for explaining the leading end of the IC lead frame 10. FIG. 4 shows an image 17 of the IC lead frame 10 displayed on the display unit 60 described later.

As shown in FIG. 1, the IC lead frame 10 includes, for example, a rectangular frame portion 12 having a side of about 3 cm to 5 cm and an IC chip (not shown) disposed substantially at the center of the frame portion 12. A rectangular island 14 to be mounted in plan view, suspension leads 16a, 16b, 16c, and 16d that extend from the four corners of the island 14 to the frame portion 12 and connect the island 14 to the frame portion 12, and radially around the island 14 And a plurality of leads 18 arranged on the surface. The IC lead frame 10 of this embodiment is formed by etching a Cu material, for example.

As shown in FIG. 2, each lead 18 is formed of a long thin plate having a tip 29 formed in a substantially V shape with a thin thin plate having a width of about 80 μm to 200 μm, for example. And as shown in FIG. 2, the bonding area | region 20 is provided in the front-end | tip part 24. As shown in FIG. The bonding region 20 is a region to which one end of, for example, a gold wire (not shown) as a wiring is crimped when wiring is performed between the electrodes of the IC chip. In the present embodiment, the center 23 of the bonding region 20 is disposed at a position of, for example, approximately 0.5 mm from the tip of the lead.

In the IC lead frame 10 of the present embodiment, the above-described leads 18 are radially arranged with the approximate center of the island 14 as the center, as shown in FIG. Moreover, the shape 13 along the tip 29 of the lead 18 is formed in a polygonal shape as shown in FIGS. Specifically, as shown in FIG. 4, the shape 13 along the tip 29 of the lead 18 is a tip of a lead (for example, the tip of the lead) disposed at a position facing and spaced apart from the approximate center of each side of the island 14. H) and each of the suspension leads 16a, 16b, 16c, 16d has a substantially regular octagonal shape having apexes in the vicinity of the island 14.
In other words, the shape of the tip of the lead that faces each side of the island 14 is substantially “<” shaped with the tip of the lead arranged at a position facing the center of each side of the island 14 being spaced apart. (See FIG. 4).
The shape along the tip 29 of the lead 18 is not limited to the substantially regular octagonal shape in the present embodiment. For example, the shape of each of the suspension leads 16 a, 16 b, 16 c, and 16 d has a substantially rectangular shape or a shape having apexes near the island 14. It may be hexagonal.
Further, as described above, since the leads 18 are arranged radially around the center of the island 14, the longitudinal directions of adjacent leads are parallel as the number of leads increases due to the increase in the number of pins. (See FIG. 2).
As shown in FIG. 2, for example, a plating region 22 is provided at the tip portion 24 of the IC lead frame 10 in order to increase the pressure bonding strength with the gold wire. 1 and 4, the tie bar is omitted.

Next, the lead inspection apparatus 50 for an IC lead frame according to the present embodiment will be described with reference to FIG. FIG. 3 is a schematic configuration diagram showing a lead inspection apparatus 50 for an IC lead frame according to the present embodiment.
As shown in FIG. 3, an IC lead frame lead inspection apparatus 50 according to this embodiment includes an irradiation unit 52, an imaging unit 56, a processing unit 57, a display unit 60, an input unit 64, a stage 54, and the like. Prepare.
First, the irradiation part 52 consists of an illuminating device provided with an LED lamp, for example, and irradiates light upward as shown in FIG.
Next, the imaging unit 56 includes a digital camera including a CCD, for example, and is disposed above the irradiation unit 52 as shown in FIG.
Next, the stage 54 is a stage that supports the IC lead frame 10 with the surface of the IC lead frame 10 being substantially horizontal. The stage 54 is composed of, for example, an XY stage that is movable in the horizontal direction, and includes a through hole (not shown) through which light from the irradiation unit 52 passes. And the stage 54 is arrange | positioned between the irradiation part 52 and the imaging part 56, as shown in FIG.

The irradiation unit 52 irradiates the surface of the IC lead frame 10 with light in a substantially orthogonal direction from below the IC lead frame 10 toward the IC lead frame 10. On the other hand, the imaging unit 56 receives the light from the irradiation unit 52 that has passed between the leads of the IC lead frame 10, captures an image of the IC lead frame 10, and acquires the image data. At that time, the positional relationship among the irradiation unit 52, the imaging unit 56, and the IC lead frame 10 is configured to form a silhouette image of the IC lead frame 10 on the imaging unit 56. That is, the imaging unit 56 is configured to acquire a substantially planar image of the IC lead frame 10. Then, the imaging unit 56 transmits the image data to the processing unit 57 described later.

Next, as shown in FIG. 3, the processing unit 57 includes a CPU 58 that executes processing of image data and the like, and a storage unit 59 such as a memory or a hard disk that stores image data, predetermined value data that will be described later, and the like. Process the image data. The CPU 58 executes processing by a program stored in a ROM (not shown) or the like, and serves as an edge setting unit, a reference line setting unit, a first intersection detection unit, a detection line setting unit, and a linear distance acquisition / comparison unit, which will be described later. Function.

Next, as shown in FIG. 3, the display unit 60 is composed of, for example, a monitor device, and displays the image 17 and the like of the IC lead frame 10 in accordance with an instruction from the CPU 58 (see FIG. 4).
Next, the input unit 64 includes a mouse 62 and a keyboard 63, for example, as shown in FIG. The mouse 62 instructs the CPU 58 of the position on the image displayed on the display unit 60. Specifically, the display unit 60 displays a pointer (not shown) corresponding to the position on the image. The pointer moves on the image while interlocking with the movement of the mouse 62, and the position data including the coordinates of the pointer is input to the processing unit 57 by clicking the mouse 62. .

Next, a first embodiment of the lead inspection method for the IC lead frame 10 by the lead inspection apparatus 50 for the IC lead frame will be described mainly with reference to FIGS. FIG. 4A is an explanatory diagram mainly for the second step, and FIG. 4B is an explanatory diagram mainly for the third step. FIG. 5 is an enlarged explanatory view for explaining a lead inspection method for an IC lead frame according to a first example of the present embodiment.

First, in a first step, an IC lead frame image including the island 14 and the plurality of leads 18 is acquired via the imaging unit 56, and the image 17 is displayed on the display unit 60 (see FIG. 4). At that time, the CPU 58 functions as an image display unit, receives the image data from the imaging unit 56, and causes the display unit 60 to display the image 17 of the IC lead frame 10.

Next, in the second step, each side of a substantially regular octagon that is a polygon along the tip 29 of the lead 18 is obtained on the IC lead frame image 17.
For example, a plurality of leads arranged opposite to a predetermined side 34 of the island 14 will be described. As shown in FIG. 4A, the lead H adjacent to the central portion of the side 34 and the lead adjacent to the suspension lead 16a. A straight line HI that connects the tip I of the two is obtained. A straight line obtained by extending the straight line HI up to the suspension lead 16a thus obtained constitutes one side 30a (see FIG. 4A) having a substantially regular octagon.
Next, as shown in FIG. 4A, a straight line HJ that connects the above-described lead tip H and the lead tip J of the lead adjacent to the suspension lead 16b is obtained. A straight line obtained by extending the straight line HJ to the suspension lead 16b constitutes a side 30b continuous with the side 30a having a substantially regular octagon. The remaining sides 31a, 31b, 32a, 32b, 33a, and 33b shown in FIG. 4A can be obtained by the same procedure as described above.
In addition, when the polygon along the tip of the lead 18 is, for example, a substantially quadrilateral having vertices in the vicinity of the island 14 of each suspension lead 16a, 16b, 16c, 16d, each side of the substantially square is each side of the island 14. It becomes a straight line substantially parallel to.

At that time, the CPU 58 functions as side setting means for receiving position data from the mouse 62 as an input unit and setting each side of a substantially regular octagon along the tip of the lead on the IC lead frame 10 image.
Specifically, when the operator moves the mouse 62 and clicks on the IC lead frame image 17 with the pointer substantially positioned at the lead tip H described above, the coordinate data of the lead tip H is processed as position data. 57. Next, when the mouse 62 is moved and the pointer is substantially positioned at the above-described lead tip I and clicked, the position data of the lead tip I is input to the processing unit 57. In this way, the CPU 58 that has received the position data from the mouse 62 as the input unit stores the straight line data obtained by extending the straight line HI up to the suspension lead 16a in the storage unit 59 as the data of one side 30a of the substantially regular octagon. The process to memorize is executed.
By repeating this step for each side constituting the substantially regular octagon, each of the substantially regular octagonal sides 30a, 30b, 31a, 31b, 32a, 32b, 33a, 33b along the tip of the lead 18 can be set.

Next, in the third step, the sides (30a, 30b, 31a, 31b, 32a, 32b, 33a, 33b) obtained as described above are moved from the position along the tip of the lead to the bonding region. A reference straight line obtained by translation is obtained.
For example, as shown in FIGS. 4 and 5, the side 30 a is translated approximately 0.5 mm toward the frame portion 12 in a direction substantially orthogonal to the side 30 a, for example. The straight line after the movement is set as the reference straight line 35a. As described above, since the center 23 of the bonding region 20 is located approximately 0.5 mm from the lead tip, the side 30a is translated from the position along the lead tip to the bonding region. The reference straight line 35a can be obtained. Thus, by obtaining the reference straight line 35a passing through the bonding region 20, the accuracy of the inspection of the lead interval in the vicinity of the bonding region can be increased.
The direction in which the side 30a is translated is not limited to the direction of the present embodiment. For example, the side 30a may be translated along the longitudinal direction of the lead near the center of the plurality of leads corresponding to the side 30a.

By the same method as described above, as shown in FIG. 4B, reference straight lines 35b, 36a, 36b, 37a formed by translating the other sides 30b, 31a, 31b, 32a, 32b, 33a, 33b, respectively. , 37b, 38a, 38b. In FIG. 4B, the reference straight line 35b corresponds to the side 30b, the reference straight line 36a corresponds to the side 31a, the reference straight line 36b corresponds to the side 31b, the reference straight line 37a corresponds to the side 32a, The straight line 37b corresponds to the side 32b, the reference straight line 38a corresponds to the side 33a, and the reference straight line 38b corresponds to the side 33b.

At that time, the CPU 58 serves as a reference straight line setting means for setting a plurality of reference straight lines 35a... 38b obtained by translating each side 30a... 33b from a position along the tip of the lead to the bonding region. Function.
For example, the CPU 58 moves the side 30a in a direction substantially perpendicular to the side 30a and translates the side 30a by about 0.5 mm toward the frame portion 12, and uses the straight line data after the movement as a result. The process which memorize | stores in the memory | storage part 59 as data of the reference | standard straight line 35a is performed.
And CPU58 performs the same process with respect to edge 30b, 31a, 31b, 32a, 32b, 33a, 33b, respectively.

Next, in a fourth step, a first intersection point that is an intersection point of the first side that is one of the opposing sides of the adjacent leads and the reference line is obtained.
Taking one reference straight line 35a as an example, as shown in FIG. 5, the first side 19 which is one of the opposing sides of the adjacent leads 21 and 21 'and the reference straight line 35a. The intersection point is obtained, and the intersection point is set as the first intersection point A.

At that time, the CPU 58 functions as a first intersection detection unit that detects a first intersection that is an intersection of the first side that is one of the opposing sides of the adjacent leads and the reference straight line. To do. To explain using the above-described example, the CPU 58 calculates the first side 19 that is one of the opposing sides of the adjacent leads 21 and 21 ′ and the data of the reference straight line 35 a. The coordinate data of one intersection A is detected and stored in the storage unit 59 as the position data of the first intersection A.

Next, in the fifth step, a plurality of straight lines that pass through the first intersection A and pass through the second side that is the other side among the opposing sides of the adjacent leads 21 and 21 ′. A detection straight line consisting of In this embodiment, the fifth step includes a step of rotating the reference straight line around the first intersection at a predetermined angle Θ in the clockwise direction, and a predetermined step in the counterclockwise direction around the first intersection. And rotating at an angle Θ.
For example, as shown in FIG. 5, a straight line 40 obtained by rotating the reference straight line 35a around the first intersection A in the clockwise direction, for example, at an angle of about 1 degree, as shown in FIG. Let's say i. Next, a straight line 39 obtained by rotating the reference straight line 35a around the first intersection A in the counterclockwise direction, for example, at an angle of about 1 degree is defined as a detection straight line B. In this way, detection is made of a plurality of straight lines that pass through the first intersection A and pass through the second side 25 that is the other side of the opposing sides of the adjacent leads 21 and 21 ′. The straight lines A and B are obtained.

At that time, the CPU 58 sets a detection straight line setting means for setting a detection straight line composed of a plurality of straight lines passing through the first intersection A and passing through the second side 25 which is the other side among the opposing sides. Function as.
Taking the above-described reference straight line 35a as an example, as shown in FIG. 5, the CPU 58 sets the reference straight line 35a on the image of the IC lead frame 10 in the clockwise direction about the first intersection A, for example, approximately once. A process of rotating at an angle and storing the data of the straight line 40 obtained by the rotation in the storage unit 59 as the data of the detected straight line A is executed. Next, the CPU 58 rotates the reference straight line 35a about the first intersection A in the counterclockwise direction at an angle of about 1 degree, and the data of the straight line 39 obtained by the rotation is stored as data of the detection straight line B. The process stored in 59 is executed.

Next, in a sixth step, a linear distance between the first intersection A and the second side 25 is determined on the reference straight line and the detection straight line.
The above described adjacent leads 21 and 21 ′ will be described as an example. As shown in FIG. 5, a second intersection B that is an intersection of the reference straight line 35a and the second side 25 is obtained, and the first intersection A And a linear distance AB between the second intersection B and the second intersection B. Next, a third intersection C, which is an intersection between the detection straight line A and the second side 25, is obtained, and a linear distance AC between the first intersection A and the third intersection C is obtained. Next, a fourth intersection D, which is an intersection between the detected straight line B and the second side 25, is obtained, and a linear distance AD between the first intersection A and the fourth intersection D is obtained.

At this time, the CPU 58 functions as a linear distance acquisition unit that calculates a linear distance between the first intersection and the second side on the reference straight line and the detection straight line.
Explaining in the above example, the CPU 58 obtains the coordinate data of the second intersection B that is the intersection of the reference straight line 35a and the second side 25, and the linear distance between the first intersection A and the second intersection B. Obtain AB data. And the process which memorize | stores the data of the linear distance AB in the memory | storage part 59 is performed. Next, the CPU 58 obtains the coordinate data of the third intersection C, which is the intersection of the detected straight line A and the second side 25, and obtains the data of the straight line distance AC between the first intersection A and the third intersection C. Ask. And the process which memorize | stores the data of the linear distance AC in the memory | storage part 59 is performed. Next, the CPU 58 obtains the coordinate data of the fourth intersection D, which is the intersection of the detected straight line B and the second side 25, and obtains the data of the linear distance AD between the first intersection A and the fourth intersection D. Ask. And the process which memorize | stores the data of the linear distance AD in the memory | storage part 59 is performed.

Next, in a seventh step, a shortest distance consisting of a minimum value among the plurality of straight line distances is obtained, and the shortest distance is compared with predetermined value data.
For example, the adjacent leads 21 and 21 ′ described above will be described. For example, the shortest distance L is defined as the shortest distance L among the straight distance AB, the straight distance AC, and the straight distance AD. For example, the size of the standard T and the shortest distance L between adjacent leads 21 and 21 ′ lead tips is compared. When the shortest distance L is smaller than the standard T, the IC lead frame 10 can be determined as a defective product.

At that time, the CPU 58 obtains the shortest distance consisting of the minimum value among the plurality of straight line distances acquired by the straight line distance acquisition means, and functions as the shortest distance acquisition comparison means for comparing the shortest distance with predetermined value data. To do.
Explaining in the above example, the CPU 58 reads the data of the straight line distance AB, the data of the straight line distance AC, and the data of the straight line distance AD from the storage unit 59 and, for example, the straight line distance AC having the minimum value among these data. Is obtained as data of the shortest distance L, and a process of comparing the size of the data of the standard T and the data of the shortest distance L, which are stored in the storage unit 59 in advance as predetermined value data, is executed. For example, when the shortest distance L is smaller than the standard T, the CPU 58 may determine that the IC lead frame 10 is defective.

Then, the fourth to seventh steps are repeated for all adjacent leads of the IC lead frame 10 to complete the inspection of one IC lead frame 10.

In this embodiment, the detection straight line consists of two straight lines, a detection straight line A and a detection straight line B. In addition to these detection straight lines A and B, two more detection straight lines are added to obtain four detection straight lines. The structure to do may be sufficient. For example, a straight line obtained by rotating the reference straight line 35a around the first intersection A in the clockwise direction, for example, at an angle of about 2 degrees is set as the third detection straight line, and the reference straight line 35a is set at the first intersection A as the center. For example, a straight line obtained by rotating counterclockwise at an angle of, for example, approximately 2 degrees is set as the fourth detection straight line.
Thus, by increasing the detection straight line, the shortest interval between adjacent lead tips over a wider range of the second side 25 can be obtained, and the accuracy of inspection is further increased.

Next, a second embodiment of the lead inspection method for the IC lead frame 10 using the lead inspection apparatus 50 for the IC lead frame will be described mainly with reference to FIG.
FIG. 6 is an enlarged explanatory view for explaining a lead inspection method for an IC lead frame according to a second example of the present embodiment. In FIG. 6, the same members or the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. In FIG. 6, each square represents one pixel constituting the image of the IC lead frame 10.

The difference between the first embodiment and the second embodiment is that the fifth step passes through the first intersection point and includes a second intersection point including the intersection point of the reference straight line and the second side. This is a point comprising a step of obtaining a plurality of straight lines respectively passing through a plurality of neighboring pixels located in the vicinity in the vertical direction.
The above-described adjacent leads 21 and 21 'will be described as an example. First, as shown in FIG. 6, a second intersection B formed by the intersection of the reference straight line 35a and the second side 25 is obtained. Next, a straight line 41 passing through the first intersection 43 A and passing through the first pixel 43 adjacent above the pixel 45 including the second intersection B is obtained, and this straight line 41 is set as a detection straight line e. Next, a straight line 42 passing through the first intersection A and passing through the second pixel 44 adjacent below the pixel 45 including the second intersection B is obtained, and this straight line 42 is set as a detection straight line.
In this way, detection is made of a plurality of straight lines that pass through the first intersection A and pass through the second side 25 that is the other side of the opposing sides of the adjacent leads 21 and 21 ′. It seeks a straight line.
In FIG. 6, a symbol M indicates an intersection between the detection straight line E and the second side 25. The symbol N indicates the intersection between the detection straight line F and the second side 25.

In this embodiment, the detection straight line is composed of two straight lines that are a detection straight line and a detection straight line e. In addition to these detection straight lines, e, two additional detection straight lines are added to obtain four detection straight lines. The structure to do may be sufficient. For example, a straight line passing through the first pixel 43 while passing through the first intersection A and passing through a pixel adjacent to the first pixel 43 is defined as a fifth detection line, and passing through the first intersection A and below the second pixel 44. The straight line passing through the pixels adjacent to is the sixth detection straight line, and there are four detection straight lines. As described above, a plurality of neighboring pixels located in the vertical vicinity of a pixel including the second intersection B formed by the intersection of the reference straight line 35a and the second side 25 are selected, and a detection straight line passing through these pixels is selected. You may ask for.

Here, with reference to FIG. 1, FIG. 4, and FIG. 7, the effects of the lead inspection method for the IC lead frame 10 and the lead inspection apparatus 50 for the IC lead frame according to the present embodiment will be supplemented.
FIG. 7A is an enlarged view showing the tip of the lead that faces the vicinity of the center of one side 34 of the island 14 among the plurality of leads of the IC lead frame 10. FIG. 7B is an enlarged view showing the leading end portion of the lead arranged in the vicinity of the suspension lead 16a among the plurality of leads of the IC lead frame 10 and arranged in the vicinity of the suspension lead 16a.

As shown in FIGS. 1 and 4, the leads 18 of the IC lead frame 10 are arranged radially around the island 14 around the center of the island 14. Therefore, as shown in FIG. 7A, for the leads facing the vicinity of the center of one side 34 of the island 14, the reference straight line 35a described above is substantially orthogonal to the longitudinal direction of these leads. On the other hand, as shown in FIG. 7B, as the suspension lead 16a is approached, the angle at which the reference straight line 35a and the longitudinal direction of the lead intersect tends to deviate from 90 degrees.
Therefore, for the leads facing the vicinity of the center of the side 34, as shown in FIG. 7A, the shortest distances a, b, c, d between the tips of adjacent leads on a substantially reference straight line 35a are obtained. be able to. However, as it approaches the suspension lead 16a, the shortest distances e, f, g between the tips of adjacent leads cannot be obtained on the reference straight line 35a.
Therefore, by setting not only the reference straight line but also the above-described detection straight line, and determining the shortest distance between adjacent lead tips on the detection straight line, it is possible to accurately inspect the distance between adjacent lead tips. It can be done.

Further, according to the lead inspection method for the IC lead frame 10 and the lead inspection device 50 for the IC lead frame of the present embodiment, for example, the inspection of the distance between the suspension lead 16a and the adjacent lead can be performed in the same procedure as described above. It becomes.
In the description so far, one IC lead frame 10 has been described. However, even if the IC lead frame 10 is a matrix-like IC lead frame in which, for example, m rows × n columns are arranged in a matrix, the stage 54 is used. The lead inspection can be performed on a plurality of IC lead frames by placing the stage 54 and moving the stage 54 in the XY directions.

According to the embodiments described so far, even in the case of an IC lead frame having a lead tip portion whose width is narrowed by etching or the like, the interval between adjacent lead tip portions can be accurately and easily set. An IC lead frame lead inspection method and apparatus capable of being inspected can be provided.

As described above, some of the embodiments of the present invention have been described in detail with reference to the drawings. However, these are merely examples, and the present invention is variously modified and improved based on the knowledge of those skilled in the art. Can be implemented.

10 IC lead frame 12 Frame portion 13 Shape along lead tip 14 Island 16 Suspended lead 18 Lead 19 First side 20 Bonding area 21, 21 ′ Adjacent lead 24 Tip portion 25 Second side 29 Lead tip 30a to 33b Sides 35a to 38b Reference straight lines 43, 44, 45 Pixel 50 IC lead frame lead inspection device 52 Irradiation unit 56 Imaging unit 57 Processing unit 60 Display unit 64 Input unit A First intersection point B Second intersection point AB, AC, AD Straight line distance Θ Angle b, b, e, f Detection straight line

Claims (4)

A frame portion, a quadrangular island in plan view that is disposed at substantially the center of the frame portion and on which an IC chip is mounted, and a suspension that extends from each of the four corners of the island to the frame portion and connects the island to the frame portion The lead has a plurality of leads arranged radially around the island and having a bonding region for wiring between the electrodes of the IC chip at the tip, and the shape along the tip of the lead is polygonal. An IC lead frame lead inspection method for inspecting a lead tip interval of an IC lead frame formed in a shape,
A first step of acquiring an IC lead frame image including the island and the plurality of leads;
A second step of determining each side of the polygon along the tip of the lead on the IC lead frame image;
A third step of obtaining a reference straight line obtained by translating each of the sides from a position along the tip of the lead to substantially the bonding region;
A fourth step of obtaining a first intersection consisting of an intersection of a first side which is one side of adjacent sides of adjacent leads and the reference line;
A fifth step of obtaining a detection straight line comprising a plurality of straight lines passing through the first intersection and passing through the second side which is the other side among the opposing sides;
A sixth step of obtaining a linear distance between the first intersection and the second side on the reference straight line and the detection straight line;
A lead inspection method for an IC lead frame, comprising: a seventh step of obtaining a shortest distance consisting of a minimum value among the plurality of linear distances and comparing the shortest distance with predetermined value data. The fifth step includes a step of rotating the reference straight line by a predetermined angle clockwise about the first intersection, and a reference angle rotating the reference straight line by a predetermined angle counterclockwise about the first intersection. The lead inspection method for an IC lead frame according to claim 1, further comprising: The fifth step includes a plurality of neighboring pixels that pass through the first intersection and are located in the vicinity of a pixel in the vertical direction including a second intersection that is an intersection of the reference straight line and the second side. 2. The lead inspection method for an IC lead frame according to claim 1, further comprising a step of obtaining straight lines respectively passing through the IC lead frame. A frame portion, a quadrangular island in plan view that is disposed at substantially the center of the frame portion and on which an IC chip is mounted, and a suspension that extends from each of the four corners of the island to the frame portion and connects the island to the frame portion The lead has a plurality of leads arranged radially around the island and having a bonding region for wiring between the electrodes of the IC chip at the tip, and the shape along the tip of the lead is polygonal. An IC lead frame lead inspection device for inspecting the interval between lead tips of an IC lead frame formed into a shape,
An irradiation unit for irradiating light to the IC lead frame;
An image capturing unit that captures an image of the IC lead frame and acquires the image data;
A processing unit for processing the image data;
A display unit for displaying an image of the IC lead frame;
An input unit for inputting position data on an image displayed on the display unit to the processing unit;
Side setting means for receiving position data from the input unit and setting each side of a polygon along the tip of the lead on the IC lead frame image;
A reference straight line setting means for setting a reference straight line obtained by translating each of the sides from a position along the tip of the lead to substantially the bonding region;
First intersection detection means for detecting a first intersection consisting of an intersection of a first side that is one of the opposing sides of adjacent leads and the reference straight line;
A detection line setting means for setting a detection line composed of a plurality of straight lines passing through the first intersection and passing through the second side which is the other side among the opposing sides;
Linear distance acquisition means for calculating a linear distance between the first intersection and the second side on the reference straight line and the detection straight line;
It includes a shortest distance acquisition / comparison unit that obtains a shortest distance including a minimum value among the plurality of straight line distances acquired by the linear distance acquisition unit and compares the shortest distance with predetermined value data. IC lead frame lead inspection device.

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