JPH05347499A - Detecting method for position of flat tip end portion of lead of electronic component - Google Patents

Abstract

PURPOSE:To correctly mount a chip on a board by vacuum-attracting a chip roughly corrected in its positional displacement on a nozzle of a transfer head, and transferring the same upward a laser apparatus, and further detecting the position of a lead and a tip end flat portion with laser light. CONSTITUTION:Position of a chip carried onto a rough correction device B is roughly corrected by a Y table 21 and an X table 24. Then, the chip is sucked in a vacuum with a vacuum suction nozzle 8 of a transfer head 7, and is transferred upward of a laser light apparatus C. A lead L of the chip is irradiated with laser light from a light emission part 5 of the laser light apparatus C and reflected light is received with an optical detection part 6 to detect the position of the lead L. On the basis of the detected position, the laser light is irradiated in the direction of the lead L to detect the position of a flat part La of the tip end of the lead L, which is in turn registered in a memory of a computer. The operation is executed for all leads. Hereby, the chip is accurately mounted on the board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the position of a flat end portion of a lead of an electronic component, and more specifically, to accurately detect the position of a flat portion of the lead end to be soldered by landing on an electrode of a substrate. The present invention relates to a method for detecting the position of a flat end portion of a lead of an electronic component.

[0002]

2. Description of the Related Art An electronic component mounting apparatus for mounting electronic components with leads (hereinafter referred to as "chips") such as QFP and SOP on a substrate is a chip mounted on a tray or a tape unit provided in a chip supply device. Is vacuum-sucked to the nozzle of the transfer head to be picked up, the transfer head is moved above the substrate, and the nozzle is lowered there to mount the chip on the substrate.

In this case, since it is necessary to mount the chip on the substrate by accurately matching the lead of the chip with the electrode of the substrate, the lead is observed by the camera before mounting the chip on the substrate. The position was being detected.

However, since the camera does not always have sufficient resolution, it is difficult to accurately detect the position of the lead, and the camera can detect plane information such as the displacement of the lead in the XYθ directions. There is a problem in that height information such as the floating of can not be detected.

Therefore, the present applicant first provided a chip mounting means for solving such a problem (Japanese Patent Laid-Open No. 3-126300). As shown in FIG. 1 to FIG. 3 of the publication, this one mounts a chip P (reference numeral is incorporated in the publication) on XY tables 21 and 24, and a lead L of the chip P has a key shape. By pressing the position regulating member 43, the positional deviation of the chip P in the XYθ directions is roughly corrected, and then the chip P is vacuum-sucked and picked up by the nozzle 8 of the transfer head 7, and the chip P is laser-scanned. The position of the lead is detected by moving the device C upward and irradiating the lead L with laser light from the light emitting unit 5 and receiving the reflected light by the light receiving unit 6. Since this conventional means measures the lead L with a laser beam, the XYθ of the lead is measured.
Not only the positional deviation in the direction (that is, the plane information) but also the presence or absence of the floating (that is, the height information) can be detected with high accuracy, and the positional deviation of the chip P on the XY tables 21 and 24 can be roughly corrected. The laser light lead L
It is possible to improve the accuracy of the hit.

[0006]

By the way, the lead is soldered by landing the flat portion of the tip on the electrode of the substrate. Therefore, when the lead is inspected by the laser device, this flat portion is particularly used. It is important to accurately detect positions such as position deviation, vertical floating, and horizontal bending.

Therefore, the present invention is based on the above-mentioned Japanese Patent Laid-Open No. 3-1263.
It is an object of the present invention to provide a method capable of accurately detecting the position, float, etc. of the flat portion of the lead tip by using the roughness correction means for an electronic component and the laser device as disclosed in Japanese Patent Publication No. 00.

[0008]

To this end, the present invention first teaches the position of the flat portion of the lead tip as follows. That is, after correcting the positional deviation of the chip with the rough correction device, this chip is vacuum-sucked to the nozzle of the transfer head and transferred to the upper part of the laser device, and the laser device irradiates the lead with laser light to adjust the position of the lead. To detect. Then, based on the detected position, laser light is emitted in the length direction of the lead to detect the position of the flat portion at the tip of the lead, and position data of the detected flat portion is registered in the memory of the computer. After performing the teaching of the position of the flat portion in this way, the flat portion of the lead mounted on the substrate is irradiated with the laser beam of the laser device based on the position data of the flat portion obtained by the teaching. The position of the flat part is detected.

[0009]

According to the above structure, the laser light of the laser device can be surely hit on the flat portion of the tip of the lead mounted on the electrode of the substrate, and the positional deviation, floating, etc. of the flat portion can be accurately detected.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view of an electronic component mounting apparatus, and FIG. 2 is a plan view of a roughness correction apparatus. This structure has the same structure as that described in the above-mentioned Japanese Patent Laid-Open No. 3-126300, and a brief description will be given below.

The present apparatus comprises a chip supply section A, a roughness correction apparatus B, a laser apparatus C as a fine measuring apparatus, and a positioning section D for the substrate 1. A tray 2 is provided in the chip supply section A, and a chip P having leads such as QFP is stored in the pocket thereof. Besides the tray 2, a tape unit or the like is frequently used as the chip supply unit.

Prior to the precise measurement of the lead by the laser device C, the roughening correction device B ensures that the lead is accurately measured by the laser device C.
The position deviation of the chip P is roughly corrected so that the chip P enters the measurement area, and its detailed structure will be described later. 3 is
It is a sub-transfer head that is driven by the moving table 20 and moves in the XY directions, vacuum picks up the chip P of the chip supply unit A to the nozzle 4, picks it up, and transfers and mounts it on the rough correction device B.

The laser device C is arranged in the transfer path of the chip P from the roughness correction device B to the positioning portion D. The upper surface of the laser device C is notched in a V shape, and the laser emitting portion 5 and the light receiving portion 6 are provided on the inclined surface (see also FIG. 3). Reference numeral 7 denotes a transfer head, which is driven by a moving table 19 to move in the XY directions, and vacuum picks up a chip P for which rough correction has been completed in the rough correction device B to the nozzle 8 to pick it up. Transfer to the upper part, where X
By moving in the Y direction, the laser light emitted from the laser emitting portion 5 is emitted in the direction traversing the leads L protruding from each side of the chip P, and the reflected light is received.
By receiving the light, the positional deviation, floating, presence or absence of the lead L is precisely measured.

The positioning portion D is provided with clamp members 9 and 9 for clamping and fixing the substrate 1 from both sides. Three
Reference numeral 1 denotes an electrode formed on the substrate 1, and the lead L is mounted on this electrode 31. 10 is a positioning portion D for the substrate 1
It is a conveyor that carries in and out. Next, a detailed structure of the roughening correction device B will be described.

In FIGS. 1 and 2, reference numeral 11 is a base plate, on the upper surface of which a cylinder 12 is arranged, and on the other side thereof, a Y-direction rail 13 is arranged. Reference numeral 14 is a rotary arm provided on the cylinder 12 so as to be horizontally rotatable around a hinge 15, 16 is a roll attached to the tip of the rotary arm, and 17 and 18 are air tubes. Tube 17,
When air is taken in and out from 18, the rotating arm 14 rotates about the hinge portion 15 in the horizontal directions N1 and N2.

In FIGS. 1 and 3, reference numeral 21 is a slider 2
2 is a Y table slidably arranged on the Y direction rail 13 via 23, 23 is an X direction rail provided on the Y table 21, and 24 is a slider 25 and slides on the X direction rail 23. It is an X table movably arranged. X
The table 24 is biased toward the cylinder 12 by the coil spring material 26 (FIG. 1).

A bracket 27 is attached to the side surface of the Y table 21 and extends above the cylinder 12. A long hole 28 is formed in the bracket 27, and the roll 16 is fitted in the long hole 28. Therefore, when the rotating arm 14 horizontally rotates and the roll 16 rotates in the N1 direction as described above, the Y table 21 slides in the Y1 direction along the Y-direction rail 13 and when the roll 16 rotates in the N2 direction. , Y table 21
Slides in the Y2 direction.

Reference numeral 31 is a bracket provided on the rear edge of the base plate 11, and the pin 32 has a substantially L-shaped lever 3
3 is horizontally rotatably attached to the shaft, and rolls 34 and 35 are attached to the tip of the lever 33. 36 is a coil spring material for urging the lever 33, and 49 is a stopper. In FIG. 3, a cutout portion 37 is formed at the tip corner portion of the Y table 21, and the roll 34 presses against the cutout portion 37 as described later. Also X table 24
A side plate 38 is attached to the side surface of the roll 3
5 presses against this side plate 38. 1 and 2,
Reference numeral 39 is a small hole opened in the X table 24, and 40 is a suction tube connected to the X table 24. The suction force of the suction tube sucks the chip P on the X table 24 without rattling.

In FIG. 1, reference numerals 41 and 42 denote columns which are erected on the base material 11, and a key-shaped position restricting member 43 is provided on the upper part thereof. This position regulating member 43
The X-direction pressing portion 44 and the Y-direction pressing portion 45 are provided immediately above the X table 24 and on the inner surface orthogonal to the X table 24. Reference numeral 30 denotes a defective chip dump box provided below the moving path of the transfer head 7. FIG. 4 is a block diagram of an electric circuit. Data obtained by the laser device C is stored in a memory 51, and necessary calculation is performed by a calculation unit 52 such as a CPU based on the data stored in the memory 51. Done. This device has the above-mentioned configuration,
Next, the entire operation will be described.

A chip P having a good shape is selected as a master chip, and teaching described below is performed. First, the chip P is vacuum-sucked to the nozzle 4 of the sub-transfer head 3,
Place on the X table 24. Next, when the roll 16 swings, the Y table 21 moves in the Y direction, and when the roll 35 swings, the X table 24 moves in the X direction, and the tip portion of the lead L moves to the position regulating member 43. It is pressed against the pressing portions 44 and 45, and the positional deviation in the XYθ directions is roughly corrected. By thus roughly correcting the positional deviation of the lead L, it is possible to reliably hit the lead L with the laser light emitted from the laser device C. Such an operation is the same as that described in Japanese Patent Laid-Open No. 3-126300.

Next, the transfer head 7 vacuum-sucks the chip P on the X-table 24 to the nozzle 8 and picks it up, and transfers it above the laser device C. Next, the process of detecting the flat end portion of the lead L will be described with reference to FIGS.

In FIG. 5, WA is the lateral dimension of the chip P, W
B is vertical. The horizontal dimension WA and the vertical dimension WB are known from catalog values and the like, and are registered in advance in the memory 51 of the computer as known data. However, the actual chip P
The horizontal dimension Wa and the vertical dimension Wb are slightly different from the catalog values of the horizontal dimension WA and the vertical dimension WB due to a molding error and deformation of the lead L after molding. The actual horizontal dimension Wa and vertical dimension Wb are measured.

Next, a first start point S1 is set at a quarter point of WB, laser light is repeatedly scanned and irradiated in the direction of arrow N1 at a small pitch t from this point, and the reflected light is received. The light is received by the unit 6 and the lateral dimensions W1, W2, W3 ... In each scanning are measured. Then, the longest lateral dimension (for example, W2) is extracted from the measured lateral dimensions W1, W2, W3 .... Similarly, other 1 /
Laser light is emitted from the start points S2, S3, S4 of No. 4 in the directions of the arrows N2, N3, N4 to extract the longest horizontal dimension and vertical dimension of each. The longest horizontal and vertical dimensions extracted in FIG. 5 are underlined.
The measurement of the horizontal dimension and the vertical dimension and the extraction of the longest horizontal dimension and the vertical dimension can be easily performed by the well-known processing means of the computer.

In this embodiment, the lateral dimension is W as shown in FIG.
2 and W4 are extracted, and W1 and W2 are extracted in the vertical dimension. Therefore, next, the average value of these values is obtained as follows.

Horizontal average value Wa = (W2 + W4) × 1/2 Vertical average value Wb = (W1 + W2) × 1/2 The horizontal dimension Wa and the vertical dimension Wb thus obtained are the master chips P. Are the actual horizontal and vertical dimensions, and the dimensions are, as described above, the horizontal dimension WA and vertical dimension WA such as the catalog values.
Is slightly different from.

Next, with reference to FIG. 6, a method of detecting an end lead (a lead at the most end of the leads extending outward from each side of the molded body M of the chip P) will be described.

According to the process described with reference to FIG. 5, the actual outer dimensions (horizontal dimension Wa, vertical dimension Wb) of this chip P are obtained.
Based on the result, the first start point S1 is set at a point that is considered to be outside the lead L extending from the lower side of the molded body M of the chip P, and the arrow N1 is set from here.
Scanning irradiation with laser light to the right as shown in
The presence or absence of the lead L is detected. If the lead L is not detected, the second start point S is set at a point inside by the pitch t.
2 is set, and scanning with laser light is performed in the same manner.
Further, if the lead L is not detected by this, the third start point S3 is set further inside and the laser beam is similarly scanned. In this embodiment, the laser beam hits the lead L during the third scanning, and the end leads L1 and L5 at both ends are detected. As shown in the figure, the arrows N2,
By performing the same optical scanning in the N3 and N4 directions, the end leads L1 and L5 on each side are detected.

After the positions of the end leads L1 and L5 on each side of the molded body M are determined in this manner, next, as shown in FIG. 7, the end leads (for example, the lower side of the molded body M in FIG. 6). The length d of the lower surface of the flat portion La at the tip of the lead L1 and the point A that bisects this length d are radiated by irradiating the laser light in the length direction of the end lead L1) at the left end portion. The coordinates (X1, Y1) are calculated. By repeating such an operation for all the other end leads L1 and L5, the flat portions L of all the end leads L1 and L5 can be obtained.
Coordinates (X2, Y2) to (X8, Y) of the bisection points B to H of a
8) is obtained (see FIG. 8).

Next, as shown in FIG. 8, A and B, C and D,
The number of the leads L on each side (in the present embodiment, by scanning and irradiating laser light along the lines passing through E and F and G and H so as to cross each lead L (see arrows N1 to N4)). (5 for all), each pitch T of each lead L, and further the coordinates of the center of each lead L in the width direction. FIG. 9 shows an output waveform of the light-receiving unit 6 in this case. The output is large in the portion where the laser light is reflected by the lead L, and the center of the lead L in the width direction is measured from the position of the intermediate point Q. The coordinates are known.

If the number of leads L is detected in this way,
The type of chip P can be confirmed from the number of leads L, and the position of lead L and the presence or absence of bending can be detected by determining the pitch T of lead L and the coordinates of the center in the width direction. Incidentally, in FIG. 8, when the lead L has a horizontal bend, as shown by the chain line on the right side of the mold body M, the pitch T is distorted and the center coordinate of the lead L in the width direction also changes. , The bend of the lead L can be detected. Furthermore, for example, A and B, C and D, E and F, G
The center coordinates (X0, Y0) of the chip P can be detected by finding the intersection of the lines K1 and K2 that bisects and H. Although the teaching by the master chip P is completed as described above, the data obtained by the teaching is registered in the memory 51 and used as mounting data of the chip P described below.

The chip P is mounted on the substrate 1 as follows. In FIG. 1, the sub transfer head 3 adsorbs the chip P of the tray 2 onto the nozzle 4 and picks it up,
It is mounted on the table 24. Next, the X table 24 and the Y table 21 are moved in the XY directions to move the position regulating member 43.
The pressing portions 44 and 45 of the chip P are pressed against the tips of the leads L of the chip P to roughly correct the positional deviation of the chip P.

Next, the transfer head 7 arrives above the chip P, and the chip P is adsorbed and picked up by the nozzle 8. In this case, since the center coordinates (X0, Y0) of the chip P are known by the process shown in FIG.
The nozzle P can be landed on this center (X0, Y0) to pick up the chip P.

Next, the transfer head 7 transfers the chip P to above the laser device C, and as shown in FIG. 10, the laser beam is directed to the flat portion La1 by the same method as that described with reference to FIG. Scanning irradiation in the length direction, flat part L
A center A1 which is a bisector of the length d1 of a1 is obtained. This operation may be performed appropriately instead of every time. In this case, in the above teaching, since the center A of the flat portion La of the lead L has already been obtained by using the master chip P, it is possible to reliably hit the flat portion La1 with the laser light to obtain the center A1. ..

In this way, all end leads L1, L
When the positions of the centers A1 to H1 (see FIG. 11) of 5 are obtained, the points A1 to H1 are set in the same manner as the case described in FIG.
Laser light is cross-irradiated in a direction passing through (see arrows N1 to N4), and positional deviation, floating, bending, etc. of all the leads L are detected.

The defective chip P in which the lead L is floated or bent is transferred to the dump box 30,
Therefore, the vacuum suction state of the nozzle 8 is released and the nozzle 8 is discarded. Further, the non-defective chip P is mounted on the substrate 1 after correcting the positional deviation in the XYθ directions. The displacement in the XY direction is corrected by correcting the movement amount of the transfer head 7 in the XY direction, and the displacement in the θ direction is rotated by the motor (not shown) about the axis of the nozzle 8. To correct it. By correcting the positional deviation in the XYθ directions in this manner, the lead L can be accurately matched with the electrode 31 of the substrate 1 and mounted.

If the data such as the horizontal dimension Wa, the vertical dimension Wb, and the pitch T found in the above teaching are different from the data found by the actual mounting work of the chip P, the actual chip P data is obtained. Is preferably registered in the memory 51 in place of teaching data. By doing so, the reliability of the data can be improved. Further, the reliability may be improved by registering the coordinate values of the bisected points A to H of the flat portion La of a large number of chips and the average value of the data such as the horizontal dimension Wa and the vertical dimension Wb to further improve the reliability. The correction may be performed by means using a camera instead of the rough correction device B, and various modes are possible.

[0037]

According to the present invention, the position of the flat portion of the tip of the lead of the chip can be accurately detected, the flat portion can be accurately aligned with the electrode of the substrate, and the chip can be mounted on the substrate. It is possible to reliably detect a defective chip having a floating or bending.

[Brief description of drawings]

FIG. 1 is a perspective view of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a roughness correction device according to an embodiment of the present invention.

FIG. 3 is a front view of a roughness correction device and a laser device according to an embodiment of the present invention.

FIG. 4 is a block diagram of an electric circuit according to an embodiment of the present invention.

FIG. 5 is a plan view of a chip during optical scanning according to an embodiment of the present invention.

FIG. 6 is a plan view of a chip during optical scanning according to an embodiment of the present invention.

FIG. 7 is a side view of a chip during optical scanning according to an embodiment of the present invention.

FIG. 8 is a plan view of a chip during optical scanning according to an embodiment of the present invention.

FIG. 9 is an output waveform diagram of the light receiving section of the laser device according to the embodiment of the present invention.

FIG. 10 is a side view of a chip during optical scanning according to an embodiment of the present invention.

FIG. 11 is a plan view of a chip during optical scanning according to an embodiment of the present invention.

[Explanation of symbols]

 A chip supply part B rough correction device C laser device P electronic component L lead La flat part 5 light emitting part 6 light receiving part 7 transfer head 8 nozzle

Claims (1)

[Claims] 1. A process of roughly correcting a positional deviation of an electronic component by a rough correction device, and the rough-corrected electronic component is vacuum-sucked and picked up by a nozzle of a transfer head, and the electronic component is moved upward of a laser device. A process of transferring, a process of irradiating a lead of an electronic component with a laser beam emitted from a light emitting portion of a laser device, and receiving a reflected light thereof in a light receiving portion of the laser device, thereby detecting a position of the lead, Based on the position of the lead detected by the process, the process of irradiating the laser beam in the length direction of the lead to detect the position of the flat part of the lead tip, and the position data of the flat part detected by the process The process of registering in the memory of the computer and the teaching process of the position of the flat part of the lead tip are configured from and mounted on the substrate based on the position data. That the laser light is irradiated for electronic components of the laser device in the flat portion of the lead, the position detecting method of the leading end flat portion of the electronic component leads, characterized in that to detect the position of the flat portion.