JP2004146841A - Paste coater and paste coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paste coater and paste coating method which can improve the application efficiency and ensure the quality of application. <P>SOLUTION: In a paste application method, which draws and applies paste 7 on the application area 6a of a lead frame by an application nozzle, the discharge port of the nozzle is shifted by a nonstop drawing action on a shifting cause which leads to the application finish point from an application starting point, via first nozzle transition points P1 (A, B, C, and D) set near each corner of the application area 6a and second nozzle transition points P2 (A, B, C, and D) set inside the application area 6a in the order, so that it is shaped with the shifting course leading to the next corner from one corner comes inward of the application area 6a. This can prevent nonconformities such as drop in application efficiency caused by the intermission of discharge, the unevenness in quantity of application, the defects of application form, etc. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a paste application apparatus and a paste application method for applying a bonding paste to an application area set on an application target such as a substrate.

ダ イ In die bonding for bonding a chip to a substrate such as a lead frame, a bonding paste is applied to the surface of the substrate. As one of the paste application methods, drawing application is used in which a required application is performed in an application area on a substrate surface by moving an application nozzle while discharging a paste from an application nozzle by a dispenser. In this method, a moving path of a coating nozzle from a coating start point to a coating end point is set in a coating area set according to a chip shape. This movement path has various shapes according to the application pattern. For example, for a rectangular application area, a cross shape in which the application nozzle is moved in an X-shape, or an asterisk shape in which a cross is further superimposed on this cross shape, etc. Is used.

However, the drawing application by the conventional paste application apparatus has various problems as follows. First, the above-mentioned cross shape or asterisk shape is composed of a combination of a plurality of line segments, and conventionally, the application nozzle is raised and lowered each time each line segment is drawn, and the discharge of the paste from the dispenser is intermittently performed every time this lifting operation is performed. I was For intermittent paste ejection, it is necessary to set a response time until the dispenser actually performs the intermittent operation after the intermittent command, or a stabilization time until the state after the response is stabilized. For this reason, the frequency of intermittent ejection increases as the number of line segments constituting the pattern increases, so that the proportion of time during which the dispenser only performs the intermittent operation but does not actually perform the application increases, thereby lowering the overall application efficiency. The result was.

(4) Frequent intermittent ejection causes inconveniences such as a variation in the application amount and a defective application shape due to a thread stringing phenomenon of the paste in which a small amount of paste droops from the ejection port even after the ejection is stopped. Furthermore, since the application is performed by combining a large number of line segments, the application line is overlapped at the central portion of the application area, and the application height of the paste is increased. As a result, the discharge is caused by the paste adhering to the lower end of the application nozzle. There was also a problem of causing defects. As described above, the conventional paste coating method has problems that the coating efficiency is low and it is difficult to ensure the coating quality.

Therefore, an object of the present invention is to provide a paste coating apparatus and a paste coating method that can improve coating efficiency and ensure coating quality.

The paste application device according to claim 1, wherein the paste is applied from a discharge port of a coating nozzle to apply the paste to an application area set on a surface of an object to be coated. A paste discharging means for discharging the paste, a moving means for moving the discharge port relatively to the object to be coated, and setting the application start point, the application end point of the paste application and the vicinity of each corner position of the application area. Storage means for storing the position of the nozzle passing point to be performed, and a stroke which does not intersect the movement trajectory of the application nozzle from the application start point to the application end point via the nozzle passage point. Control means for controlling the moving means so as to be performed by a drawing operation, wherein the movement trajectory of the discharge port is located between the nozzle passing points of adjacent corners. In a shape to enter the center of the most coating area, and the paste is made to satisfy a region surrounded by said movement locus.

The paste application device according to claim 2 is the paste application device according to claim 1, wherein the application start point and / or the application end point is set to a center point of the application area.

According to a third aspect of the present invention, in the paste application apparatus according to the first aspect, the application start point and the application end point are set near a center point of the application area.

According to a fourth aspect of the present invention, in the paste application apparatus according to the first aspect, the application start point and the application end point are set to the same point near a center point of the application area.

The paste application method according to claim 5, wherein the paste is applied from an ejection port of an application nozzle to apply the paste into an application area set on a surface of an application object, wherein the application nozzle discharges the paste. The outlet is moved by a one-stroke operation that does not intersect the movement locus of the application nozzle from the application start point to the application end point via the nozzle passing point set near each corner of the application area. Thereby, in the step of drawing and applying the paste, the moving path from the nozzle passing point at one corner to the nozzle passing point at the next corner enters the inside of the application area with respect to a straight line connecting the two nozzle passing points. The paste was formed into a shape, and the paste filled an area surrounded by the movement trajectory.

According to a sixth aspect of the present invention, there is provided the paste applying method according to the fifth aspect, wherein the application start point and / or the application end point are set to a center point of the application area.

According to a seventh aspect of the present invention, there is provided the paste application method according to the fifth aspect, wherein the application start point and the application end point are set near a center point of the application area.

According to an eighth aspect of the present invention, in the paste application method according to the fifth aspect, the application start point and the application end point are set to the same point near a center point of the application area.

According to a ninth aspect of the present invention, there is provided the paste applying method according to any one of the fifth to eighth aspects, wherein a paste is additionally applied to a central portion of the application area in addition to the drawing application.

According to the present invention, a single stroke of the movement from the application start point to the application end point after following a movement path of entering the inside of the application area via the nozzle passage point set near the corner position of the application area is drawn. By performing the operation, it is possible to prevent problems such as a decrease in application efficiency due to intermittent ejection, a variation in application amount, and a defective application shape.

Preferably, the positions of the application start point and the application end point are appropriately set with respect to the center point of the application area, so that the paste can be prevented from adhering to the nozzle tip. Furthermore, the total application amount can be adjusted by additionally applying the paste to the center of the application area separately from the drawing application.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a control system of the die bonding apparatus, FIG. 3 is an explanatory view of the paste application pattern, and FIG. FIG. 5 is an explanatory diagram of the paste application sequence, and FIG. 5 is an explanatory diagram of the drawing pattern.

First, the structure of the die bonding apparatus will be described with reference to FIG. In FIG. 1, a wafer sheet 2 is held by a chip supply unit 1 by a holding table (not shown). A large number of chips 3 as semiconductor elements are adhered to the wafer sheet 2. A transport path 5 is provided on the side of the chip supply unit 1. The transport path 5 transports the lead frame 6 and positions the lead frame 6 at the paste application position and the bonding position. A bonding head 4 is provided above the chip supply unit 1, and the bonding head 4 is moved horizontally and vertically by a moving mechanism (not shown).

ペ ー ス ト A paste application unit 9 is provided on the side of the transport path 5. The paste application unit 9 is configured by mounting a syringe 15 of a dispenser having an application nozzle 15a on a moving table 10. The moving table 10 is configured by stacking an X-axis table 12 on a Y-axis table 11 and vertically connecting a Z-axis table 14 via an L-shaped bracket 13 thereon. The Y-axis table 11, the X-axis table 12, and the Z-axis table 14 include a Y-axis motor 11a, an X-axis motor 12a, and a Z-axis motor 14a, respectively.

By driving the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a, the syringe 15 moves on the lead frame 6 in the horizontal and vertical directions. A paste 7 for adhering the chip 3 to the lead frame 6 is stored inside the syringe 15, and a valve 15 b (see FIG. 2) that opens and closes the application nozzle 15 a while applying air pressure to the syringe 15 is opened. By doing so, the paste is discharged from the discharge port of the application nozzle 15a.

The chip bonding portion 6a of the upper surface of the lead frame 6 where the chip 3 is bonded is an application area 6a to which the paste is applied. The discharge port of the application nozzle 15a is located in the application area 6a, and the paste is discharged from the application nozzle 15a. The paste 7 is applied in an X-shaped application pattern in the application area 6a set on the surface of the lead frame 6, which is the object to be applied, by moving the application nozzle 15a while moving. The air pressure applying means for applying air pressure to the syringe 15, the application nozzle 15a and the syringe 15 is a paste discharging means, and the moving table 10 is a moving means for moving the discharge port of the coating nozzle 15a.

After the paste is applied, the lead frame 6 is sent to the bonding position 8 on the transport path 5 and positioned. Then, the chip 3 picked up from the chip supply unit 1 is bonded by the nozzle 4a of the bonding head 4 onto the paste 7 applied in the application area 6a.

Next, a control system of the die bonding apparatus will be described with reference to FIG. 2, air supplied from an air source 20 is supplied into the syringe 15 via a regulator 21. The regulator 21 is capable of remotely controlling a set pressure, and by controlling the regulator 21 by the control unit 28, the pressure of the air supplied to the syringe 15 is adjusted, and the discharge amount of the paste discharged from the application nozzle 15a Can be controlled. The valve drive unit 22 drives a valve 15b that opens and closes the application nozzle 15a. By controlling the valve drive unit 22 by the control unit 28, the discharge of the paste from the application nozzle 15a can be interrupted. The pressure set by the regulator 21 may not be controlled by the control unit 28, but may be set manually to obtain a required discharge amount.

The X-axis motor drive unit 23, the Y-axis motor drive unit 24, and the Z-axis motor drive unit 25 drive the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a of the moving table 10, respectively. The operation of the moving table 10 is controlled by controlling the X-axis motor drive unit 23, the Y-axis motor drive unit 24, and the Z-axis motor drive unit 25 by the control unit 28 as control means.

The storage unit 26 stores data on the coating operation of the coating nozzle 15a, that is, data such as the coating start point and coating end point set in the coating area, the position of the nozzle passing point during the coating operation, and the like. Data such as a moving speed pattern and a paste discharge amount is stored. That is, the storage unit 26 serves as a storage unit. The movement operation of the application nozzle 15a driven by the movement table 10 by the control unit 28 based on the data stored in the storage unit 26, and the paste from the nozzle 15a of the syringe 15 By controlling the discharge operation, the paste can be applied in a predetermined drawing pattern in the application area 6a. The bonding head driving unit 27 drives the bonding head 4 under the control of the control unit 28.

Next, the above-described drawing pattern and nozzle passing points for obtaining the drawing pattern will be described with reference to FIG. An application area 6a indicated by a square frame in FIG. 3 indicates a range in which the paste is applied before the chip 3 is mounted. A point C is a center point (area center of gravity) of the application area 6a, and the center point C is set as a coating start point and a coating end point by the nozzle 15a in this drawing pattern.
In the application area 6a, a passing point through which the nozzle 15a passes is set other than the application start point and the application end point in the drawing application. First nozzle passing points P1A, P1B, P1C and P1D are set near the four corner positions of the application area 6a. Second nozzle passing points P2A, P2B, P2C and P2D are set inside the first nozzle passing points P1A, P1B, P1C and P1D in the application area 6c. The data of these nozzle passing points is stored in the storage unit 26.

This bonding apparatus is configured as described above, and the operation of the bonding apparatus will be described below. In FIG. 1, a lead frame 6 is transported on a transport path 5 and positioned below a paste application section 9. Next, the moving table 10 is driven to position the application nozzle 15a of the syringe 15 on the application area 6a of the lead frame 6, and the drawing application is performed. In performing drawing application, the movement locus of the nozzle is determined according to the following basic rules.

(1) The start and end of application are set to either the center of the application area or the passing point of the second nozzle.
(2) When moving from the first nozzle passing point to the next first nozzle passing point, the vehicle passes at least once over the second nozzle passing point.
(3) As a rule, each nozzle passes only once.
(4) The movement trajectories of the nozzles do not intersect.

例外 As exceptions to (3), there are a case where the application end point is set at the center of the application area and a case where the application start point and the application end point are set to the same second nozzle passage point. In the former case, one second nozzle passing point where the nozzle passes twice occurs, and in the latter case, the nozzle does not pass over the second nozzle passing points set as the application start point and the application end point. .

Next, an example of drawing application will be described. First, the application nozzle 15a is moved to the center point C shown in FIG. 3 so that the lower end of the nozzle 15a from the application surface has a predetermined height suitable for application. Then, while maintaining this height, the discharge of the paste 7 is started, and the application nozzle 15a is moved along a predetermined path. First, the application nozzle 15a reaches the second nozzle passing point P2A from the center point C, and then moves outward toward the first nozzle passing point P1A. Then, it inverts inward at the first nozzle passing point P1A, passes through the second nozzle passing point P2B from the first nozzle passing point P1A, and reaches the first nozzle passing point P1B near the corner again. That is, the moving path of the application nozzle 15a from the nozzle passing point of one corner to the nozzle passing point of the next corner is applied to a straight line connecting the two nozzle passing points (first nozzle passing points P1A and P1B). It is shaped so as to enter the inside of the area 6a, and further into the center of the application area 6a at the midpoint between the two adjacent nozzle passing points (first nozzle passing points P1A and P1B). ing.

Thereafter, the application nozzle 15a follows the same movement path, and again passes through the second nozzle passing point P2C, the first nozzle passing point P1C, the second nozzle passing point P2D, and the first nozzle passing point P1D. The process returns to the second nozzle passing point P2A. After that, when the center point C as the application end point is reached, the discharge of the paste from the nozzle 15a is finished, the application nozzle 15 is raised, and the drawing application to one application area 6a is completed. That is, in this drawing application, the application nozzle 15a is moved down to the center point C, which is the application start point, and returns to the center point C, which is the application end point, via a predetermined movement path. Is moving in a one-stroke operation without interrupting application. In this drawing application, the paste discharged from the discharge port of the application nozzle 15a fills an area surrounded by the movement locus of the discharge port of the application nozzle 15a.

In the present embodiment, the coating start point and the coating end point are set at the center point C of the coating area 6a, but the coating start point and the coating end point are set at various positions as shown in FIG. You may. That is, in FIG. 4A, both the application start point Ps and the application end point Pe are set at the center point C, and in FIG. 4B, the application start point Ps is at the center point and the application end point Pe is at the center. In FIG. 3C, the coating end point Pe is set to a center point, and the coating start point Ps is set to a point near the center point C by an offset amount d2. That is, in (A), (B), and (C), the application start point Ps and / or the application end point Pe are set to the center point C.

FIG. 4D shows an example in which both the application start point Ps and the application end point Pe are set near the center point C by offset amounts d3 and d4, respectively. 2) shows an example in which both the application start point Ps and the application end point Pe are set to the same point near the center point C and separated by the offset amount d5.

位置 By setting the positions of the application start point Ps and the application end point Pe in various patterns as described above, the following problems which have conventionally occurred in the drawing application can be prevented. In other words, depending on the drawing pattern, the movement path of the application nozzle 15a may overlap the center point of the application area, and the paste may be applied in the same range in an overlapping manner. Height becomes too large. As a result, problems such as nozzle clogging due to the paste adhering to the lower end of the application nozzle 15a are likely to occur. In such a case, it is possible to prevent the paste from being intensively applied to a specific range by selecting appropriate settings of the application start point and the application end point from the various patterns in FIG.

FIG. 5 shows an example of a drawing pattern other than the X-shape shown in the above embodiment. In FIG. 5, (a) is an asterisk shape, which is a pattern in which a cross shape is overlapped with an X-shape to increase the application amount at the center. In the figure, P3A to P3D are the first nozzle passage points, and P4A to P4L are the second nozzle passage points. (B) is a snow-mark shape, in which the application amount at the center is further increased compared to the asterisk shape. In the drawing, P5A to P5D are first nozzle passing points, and P6A to P6Z, P6a, and P6b are second nozzle passing points. The snow-mark shape is effective when bonding a large chip, that is, when the application area is large. (C) is a double Y shape used when the application area is rectangular, and (d) is a pattern in which the application amount at the center of the double Y shape is increased. In the figure, P7A to P7D are the first nozzle passing points, and P8A to P8G are the second nozzle passing points.

As shown in the appended nozzle path pattern, both patterns perform drawing application in one stroke without interrupting drawing by the application nozzle. The application nozzle moves from the nozzle passing point of one corner to the nozzle of the next corner. The moving route to the passing point has a shape that enters the inside of the application area with respect to a straight line connecting the nozzle passing points of the two corners. In any of the patterns, the paste discharged from the discharge port of the application nozzle 15a fills a region surrounded by the movement locus of the discharge port of the application nozzle 15a.

効果 By using such a pattern of drawing application, the following effects can be obtained. First, since it is a single stroke, there is no need to perform a nozzle elevating operation for moving to the next coating line, and the nozzle can be moved at a high speed. Further, since the paste is continuously discharged, no loss time such as a response time and a stabilization time required when the discharge is intermittently occurs. Furthermore, there is no variation in the application amount caused by the intermittent ejection, and no problem in the application shape due to stringing of the paste from the nozzle tip. As described above, according to the above-described application pattern, the application efficiency can be improved, and the paste application with stable application quality can be performed.

In the present embodiment, an example is shown in which paste application by drawing application is performed only during movement from the application start point to the application end point, but before the application nozzle 15a starts moving or after the movement ends. Alternatively, the paste may be additionally applied to the center of the application area separately from the drawing application. As a result, even in the case where the entire coating amount cannot be ensured only by the drawing coating, the total coating amount can be adjusted by performing the stable ejection while the coating nozzle is stationary, and the high accuracy can be achieved. Application amount management can be realized.

The paste application apparatus and the paste application method according to the present invention provide an application end point after tracing a moving path that enters the inside of the application area through a nozzle passing point set near the corner position of the application area from the application start point. Is moved by a one-stroke drawing operation, so that problems such as a decrease in application efficiency due to intermittent ejection, a variation in application amount, and a defective application shape can be prevented.
Also, preferably, the positions of the application start point and the application end point are appropriately set with respect to the center point of the application area, so that it is possible to prevent the paste from adhering to the nozzle tip, and furthermore, the drawing application Separately, the paste is additionally applied to the center of the application area, so that the total application amount can be adjusted, and it is useful as a paste application device and a paste application method for bonding chips to a substrate. It is.

1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of a control system of a die bonding apparatus according to an embodiment of the present invention. Explanatory drawing of the paste application pattern of one Embodiment of this invention Explanatory drawing of the paste application sequence of one embodiment of the present invention Explanatory drawing of the drawing pattern of one Embodiment of this invention

Explanation of reference numerals

6 Lead frame 6a Application area 7 Paste 10 Moving table 15 Syringe 15a Application nozzle 22 Valve drive unit 26 Storage unit 28 Control unit C Center point P1A, P1B, P1C, P1D First nozzle passage point P2A, P2B, P2C, P2D Nozzle passing point 2 Ps coating start point Pe coating end point

Claims (9)

What is claimed is: 1. A paste application device configured to apply a paste to an application area set on a surface of an application object by ejecting a paste from an ejection port of an application nozzle, comprising: a paste ejection unit configured to eject the paste from the ejection port; A moving means for moving an exit relatively to the object to be coated, and a coating start point, a coating end point of the paste coating, and a position of a nozzle passing point set near each corner of the coating area are stored. The storage means, and the movement means so that the discharge port moves from the application start point to the application end point via the nozzle passing point by a one-stroke drawing operation that does not intersect the movement locus of the application nozzle. Control means for controlling the discharge port so that the movement trajectory of the discharge port is located at the center of the coating area at the intermediate point between the nozzle passing points of adjacent corners. It becomes free shape, and paste application device and satisfies the region where the paste is surrounded by the moving track. The paste application apparatus according to claim 1, wherein the application start point and / or the application end point are set at a center point of the application area. The paste application apparatus according to claim 1, wherein the application start point and the application end point are set near a center point of the application area. The paste application apparatus according to claim 1, wherein the application start point and the application end point are set to the same point near a center point of the application area. A paste coating method of discharging a paste from a discharge port of a coating nozzle and applying a paste to a coating area set on a surface of an application target, wherein the discharge port of the coating nozzle is moved from a coating start point to a position in the coating area. In the step of drawing and applying the paste by moving the movement path to a coating end point through a nozzle passing point set near each corner position by a single-stroke drawing operation that does not intersect the movement locus of the coating nozzle, A moving path from a nozzle passing point at one corner to a nozzle passing point at the next corner has a shape that enters the inside of the application area with respect to a straight line connecting the two nozzle passing points, and the paste moves along the moving locus. A paste application method characterized by filling a region enclosed by a circle. The paste application method according to claim 5, wherein the application start point and / or the application end point are set at a center point of the application area. The paste application method according to claim 5, wherein the application start point and the application end point are set near a center point of the application area. The paste application method according to claim 5, wherein the application start point and the application end point are set to the same point near a center point of the application area. 9. The paste application method according to claim 5, wherein a paste is additionally applied to the center of the application area separately from the drawing application.

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