JP2000286275A - Paste coater, and paste coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the application efficiency and ensure quality of application. 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 5a 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.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste application method for applying a bonding paste in an application area set on an application object such as a substrate.

[0002]

2. Description of the Related Art 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 the cross shape, etc. Is used.

[0003]

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 formed 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, and a stabilization time until the state after the response is stabilized. For this reason, as the number of line segments constituting the pattern increases, the frequency of intermittent ejection increases, and therefore, the proportion of time during which the dispenser only performs the intermittent operation but does not actually perform the application increases, thereby reducing the overall application efficiency. The result was.

[0004] In addition, frequent repetition of intermittent discharge causes problems such as a variation in the amount of application and a defect in the application shape due to a stringing phenomenon of the paste in which a small amount of paste droops from the discharge port even after the discharge 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, and as a result, the paste is attached 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 secure the coating quality.

Accordingly, an object of the present invention is to provide a paste coating apparatus and a paste coating method capable of improving coating efficiency and ensuring coating quality.

[0006]

According to a first aspect of the present invention, there is provided a paste coating apparatus for discharging a paste from a discharge port of a coating nozzle to apply the paste to a coating area set on a surface of an object to be coated. A paste discharging means for discharging paste from the discharge port, a moving means for moving the discharge port relative to the application target, a coating start point of the paste coating, a coating end point and Storage means for storing a position of a nozzle passing point set in the vicinity of each corner position of the application area; and a stroke of movement from the application start point to the application end point via the nozzle passing point from the application start point. Control means for controlling the moving means so as to be performed by a drawing operation.

According to a second aspect of the present invention, there is provided the paste application apparatus according to the first aspect, wherein the paste enters the center of the application area at an intermediate point between the nozzle passing points at adjacent corners.

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

According to a fifth 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. I have.

The paste application method according to claim 6, wherein the paste is applied from a discharge port of an application nozzle to apply the paste into an application area set on the surface of an object to be applied. Drawing and applying the paste by moving the discharge path of the nozzle from the application start point to the application end point through the nozzle passing point set near each corner position of the application area by a single stroke operation In the step of performing, the moving path from the nozzle passing point at one corner to the 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. .

A paste application method according to a seventh aspect is the paste application method according to the sixth aspect, wherein the application start point and / or the application end point are set at a center point of the application area.

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

According to a ninth aspect of the present invention, in the paste application method according to the sixth aspect, the application start point and the application end point are set to the same point near a center point of the application area. I have.

A paste application method according to a tenth aspect is the paste application method according to any one of the sixth to ninth aspects, wherein a paste is additionally applied to the center of the application area in addition to the drawing application. I did it.

According to the present invention, the movement from the coating start point to the coating end point after following a moving path that enters the inside of the coating area through the nozzle passage point set near the corner position of the coating area. Is performed by a one-stroke drawing 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, thereby preventing the paste from adhering to the nozzle tip. Furthermore, the total application amount can be adjusted by additionally applying a paste to the center of the application area separately from the drawing application.

[0018]

Embodiments of the present invention will now 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 attached to the wafer sheet 2. A transport path 5 is provided on the side of the chip supply unit 1, and 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).

A paste application section 9 is provided on the side of the transport path 5. The paste application unit 9 includes a moving table 10
Syringe 1 of dispenser provided with application nozzle 15a
5 is mounted. The moving table 10 is Y
The X-axis table 12 is stacked on the axis table 11, and the Z-axis table 1 is further placed thereon via the L-shaped bracket 13.
4 in the vertical direction. The Y-axis table 11, the X-axis table 12, and the Z-axis table 14 are respectively a Y-axis motor 11a, an X-axis motor 12a, and a Z-axis motor 1.
4a.

The syringe 15 is driven by driving the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a.
Moves horizontally and vertically on the lead frame 6. 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.

A chip bonding portion 6a on the upper surface of the lead frame 6 to which the chip 3 is bonded is an application area 6a to which the paste is applied, and a coating nozzle 15a
Is positioned within the application area 6a, and the application nozzle 1
By moving the application nozzle 15a while discharging the paste from 5a, 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. Syringe 1
5. The air pressure applying means for applying air pressure to 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 application of the paste, the lead frame 6 is sent to the bonding position 8 on the transport path 5 and positioned. Then, the paste 7 applied in the application area 6a
The chip 3 picked up from the chip supply unit 1 is bonded thereon by the nozzle 4a of the bonding head 4.

Next, a control system of the die bonding apparatus will be described with reference to FIG. In FIG. 2, the air source 20
Is supplied through the regulator 21 into the syringe 15. The regulator 21 can remotely control the set pressure.
By controlling with 8, 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 driving unit 22 is a valve 15 that opens and closes the application nozzle 15a.
Drive b. By controlling the valve driving unit 22 by the control unit 28, the discharge of the paste from the application nozzle 15a can be interrupted. Note that the set pressure of 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 are connected to the X-axis motor 12a, the Y-axis motor 11a and the Z-axis motor 11a of the moving table 10, respectively.
The shaft motor 14a is driven. Control unit 28 as control means
X-axis motor drive unit 23, Y-axis motor drive unit 24
By controlling the Z-axis motor drive unit 25, the operation of the moving table 10 is controlled.

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 of the nozzle 15 and a discharge amount of the paste are stored. That is, the storage unit 26 is a storage unit.
The application nozzle 15a driven to the moving table 10 by the control unit 28 based on the data stored in the storage unit 26
Of the application area 6a by controlling the movement operation of the paste and the discharge operation of the paste from the nozzle 15a of the syringe 15.
The paste can be applied in a predetermined drawing pattern. The bonding head driving unit 27 drives the bonding head 4 under the control of the control unit 28.

Next, the drawing pattern and the nozzle passing point for obtaining the drawing pattern will be described with reference to FIG. Application area 6 indicated by a square frame in FIG.
“a” indicates a range in which the paste is applied before the chip 3 is mounted. Point C is the center point (area center of gravity point) of the application area 6a, and this center point C is set as the application start point and the application end point by the nozzle 15a in this drawing pattern.

In the coating area 6a, a passing point through which the nozzle 15a passes is set in addition to the coating start point and the coating end point in the drawing coating. The first nozzle passing points P1A and P1 are located near the four corner positions of the coating area 6a.
B, P1C and P1D are set. Inside the first nozzle passing points P1A, P1B, P1C, and P1D in the application area 6c, the second nozzle passing points P2A, P
2B, P2C and P2D are set. 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 the drawing application, the movement locus of the nozzle is determined according to the following basic rules.

(1) The start of coating and the end of coating are set to either the center of the coating area or the passing point of the second nozzle.

(2) From the first nozzle passing point, the next first nozzle
When moving to the nozzle passing point of at least one time,
Pass over the second nozzle passage point.

(3) In principle, each nozzle passes only once.

(4) The movement trajectories of the nozzles do not intersect.

The exception to (3) is when the coating end point is set at the center of the coating area and when the coating start point and coating end point are set to the same second nozzle passage point. There is. 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 passage point P1A, passes from the first nozzle passage point P1A, passes through the second nozzle passage point P2B, and reaches the first nozzle passage point P1B near the corner again. That is, the application nozzle 15a is 1
The moving path from the nozzle passing point at one corner to the nozzle passing point at the next corner is directed toward the inside of the application area 6a with respect to a straight line connecting the two nozzle passing points (first nozzle passing points P1A and P1B). The first nozzle passing point (the first nozzle passing points P1A and P1B) is located at the center of the application area 6a at the middle point between the two adjacent nozzle passing points (first nozzle passing points P1A and P1B).

Thereafter, the application nozzle 15a follows a similar movement path, passing 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. And the second nozzle passing point P2
Return to A. Then, after reaching the center point C as the application end point, the paste discharge from the nozzle 15a is ended, the application nozzle 15 is raised, and one application area 6
The drawing application for a is completed. That is, in this drawing application, the application nozzle 15a is lowered 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.
“a” moves in a one-stroke operation without interrupting the application.

In this embodiment, the coating start point and the coating end point are set at the center point C of the coating area 6a. However, the coating start point and the coating end point are set to various positions as shown in FIG. May be set. That is, FIG.
In FIG. 7, both the application start point Ps and the application end point Pe are set to the center point C. In FIG.
s is set at the center point, and the coating end point Pe is set near the center point C by an offset amount d1. In (c), the coating end point Pe is at the center point, and the coating start point Ps is offset from the center point C. It is set near by 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.

In FIG. 4D, the coating start point Ps
In the example shown in FIG. 5E, both the application end point Pe and the application end point Pe are set near the center point C by offset amounts d3 and d4, respectively. Shows an example in which the same point is set near the center point C and separated by an offset amount d5.

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, by appropriately setting the application start point and the application end point from the various patterns shown in FIG. 4, it is possible to prevent the paste from being applied intensively to a specific range.

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 passing points, P4A to P4P.
4L is the second nozzle passage point. (B) is a snow-mark shape, in which the amount of application at the center is further increased than in the asterisk shape. In the figure, 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 large chips, 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 passage points, and P8A to P8G.
Is the second nozzle passage point.

As shown in the appended nozzle path pattern, each of the patterns performs the drawing application in one stroke without interrupting the drawing by the application nozzle, and the application nozzle moves from the nozzle passing point of one corner to the next. The movement path to the nozzle passage point of the corner is shaped to enter the inside of the application area with respect to a straight line connecting the nozzle passage points of the two corners.

By using such a pattern for drawing application, the following effects can be obtained. First, since it is a one-stroke drawing, there is no need to perform a nozzle elevating operation for moving to the next application 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 application pattern, it is possible to improve the application efficiency and perform paste application with stable application quality.

In the present embodiment, an example is shown in which paste application by drawing application is performed only during the movement from the application start point to the application end point, but before or before the application nozzle 15a starts moving. After the completion, 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, it is possible to stably perform the discharge while the coating nozzle is stationary and to adjust the total coating amount, thereby achieving high accuracy. Application amount management can be realized.

[0044]

According to the present invention, the application end point is traced after moving along a moving path extending from the application start point to the inside of the application area through the nozzle passage point set near the corner position of the application area. Since the movement is performed by a one-stroke drawing 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. 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. Separately, the paste is additionally applied to the center of the application area, so that the total application amount can be adjusted.

[Brief description of 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 according to the embodiment of the present invention;

FIG. 3 is an explanatory diagram of a paste application pattern according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a paste application sequence according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a drawing pattern according to the embodiment of the present invention;

[Explanation of symbols]

 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

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seichi Sato 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Nobuyuki Suedo 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.F-term (reference) 4D075 AC07 AC92 AC93 DA06 DB14 DC22 EA35 4F041 AA06 BA05 BA22 BA34 BA57 5F047 BB11 BB16 FA21

Claims (10)

[Claims] 1. A paste application apparatus for applying 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, wherein the paste is ejected from the ejection port. Means, a moving means for moving the discharge port relatively to the object to be applied, and a nozzle passing point set near the application start point, the application end point, and each corner position of the application area of the paste application. Storage means for storing the position of the nozzle, and control means for controlling the movement means so that the ejection port moves from the application start point to the application end point via the nozzle passage point by a single stroke operation. And a paste application device. 2. The paste coating apparatus according to claim 1, wherein the movement trajectory of the discharge port enters the center of the coating area at an intermediate point between the nozzle passing points of adjacent corners. 3. 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. 4. The paste coating apparatus according to claim 1, wherein said coating start point and said coating end point are set near a center point of said coating area. 5. The paste application apparatus according to claim 1, wherein the application start point and the application end point are set at the same point near a center point of the application area. 6. A paste coating method for discharging a paste from a discharge port of a coating nozzle to apply the paste into a coating area set on a surface of an object to be coated. In the step of drawing and applying the paste by moving the moving path from the nozzle to a coating end point through a nozzle passing point set near each corner position of the coating area by a single stroke drawing operation, A paste application method, wherein a moving path from a nozzle passing point to a nozzle passing point at a next corner has a shape that enters inside the application area with respect to a straight line connecting the two nozzle passing points. 7. The paste application method according to claim 6, wherein the application start point and / or the application end point are set at a center point of the application area. 8. The paste application method according to claim 6, wherein the application start point and the application end point are set near a center point of the application area. 9. The paste application method according to claim 6, wherein the application start point and the application end point are set at the same point near a center point of the application area. 10. The paste application method according to claim 6, wherein a paste is additionally applied to the center of the application area in addition to the drawing application.