JP3507033B2 - Paste coating machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste applicator for applying a paste onto a substrate such as a printed circuit board, and more particularly to measuring a distance (vertical distance) between a nozzle and a substrate with a distance sensor (measuring means). However, the present invention relates to a paste applicator that adjusts the distance between the nozzle and the substrate (that is, the nozzle height) to a desired value based on the measurement data of the distance sensor even if the substrate has a warp.

[0002]

2. Description of the Related Art In order to mount (fix) electronic devices such as semiconductor devices and resistors and capacitors on a substrate to realize a desired electronic circuit, for example, solder is supplied from a nozzle provided at the tip of a solder paste container. While discharging the paste, the nozzle is moved up and down, front and back, left and right with respect to the surface of the board (board surface) to apply the solder paste to predetermined wiring pad positions on the board surface one by one. Machine is being used.

However, in the conventional paste applicator, every time the nozzle is moved to a predetermined wiring pad position on the substrate, the distance between the nozzle and the substrate surface is measured by a distance sensor,
The paste is ejected from the nozzle after adjusting the distance between the nozzle and the substrate surface based on the measurement data.Therefore, as the number of places to apply the solder paste increases, the time required to measure this distance increases and the productivity increases. There was a problem of lowering.

In order to solve such a problem, Japanese Patent Laid-Open No.
In Japanese Patent No. 5654, the distance between the nozzle and the substrate surface is measured by a distance sensor at two different positions (measurement positions) on the substrate surface, and the paste is applied from the measurement result and the distance between these measurement positions. It has been proposed to obtain the inclination of the substrate surface and adjust the distance between the nozzle and the substrate surface based on this inclination.

[0005]

However, in such a known technique, in order to accurately adjust the distance between the nozzle and the substrate surface at the position where the paste is applied, the paste is placed on the straight line connecting the two measurement positions. It is necessary that there be a wiring pad to be coated with, and as the number of coating pads increases, the time required to measure the distance between the nozzle and the substrate surface increases, and there is a problem that productivity decreases. .

An object of the present invention is to solve such a problem, and even if there are many places where solder paste is applied, the time required for measuring the distance between the nozzle and the substrate surface does not increase, and the nozzle is attached to the substrate surface. An object of the present invention is to provide a paste applicator capable of maintaining a desired height and applying a paste with high productivity.

[0007]

In order to achieve the above object, the present invention is to eject paste from the nozzle while changing the relative positional relationship between the substrate mounted on the table and the nozzle. In a paste applicator for applying and drawing a desired paste pattern on a substrate, a measuring means for measuring a vertical distance from a preset reference surface to the paste application surface of the substrate, and the paste application surface do not intersect each other 2
Two common straight lines are set, and the common straight line is calculated from the vertical distances at two different measurement positions on the common straight line on the paste application surface measured by the measuring means and the distance between the two measurement positions. By determining the inclination of the paste-coated surface along the line, and using the inclination, the
A first calculation means for obtaining a vertical distance from the reference surface to the paste application surface at an arbitrary position between two measurement positions, and an arbitrary position not existing on the two common straight lines on the paste application surface are set. And a third common straight line that intersects with the two common straight lines is set, and the second common straight line and the third common straight line are set.
On the basis of the vertical distances obtained by the first calculating means at the respective intersections with the common straight line, the tilt degree of the paste coating surface along the third common straight line is obtained, and the tilt degree is used. Thus, the second calculation means for obtaining the vertical distance from the reference surface to the paste application surface at an arbitrary position on the third common straight line, and the second calculation means obtained by the first and second calculation means And a means for setting the height of the nozzle with respect to the paste application surface at an arbitrary position on the paste application surface according to the vertical distance, and discharging the paste from the nozzle to apply the paste to the paste application surface. It is a thing.

As a result, the time required to measure the vertical distance (gap value) from the reference surface to the paste application surface can be reduced regardless of the number of locations where the paste is applied.
Productivity is improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of a paste applicator according to the present invention, in which 1 is a nozzle and 2 is a nozzle.
Is a paste container (syringe), 3 is an optical rangefinder (measuring means), 4 is a Z-axis table, 5 is an X-axis table, and 6 is Y.
Axis table, 7 is substrate, 7a is substrate surface (paste application surface), 8 is θ-axis table, 9 is mount, 10 is Z-axis table support, 11a is image recognition camera, 11b is mirror of image recognition camera 11a. A cylinder, 12 is a nozzle support, 13 is a suction table for the substrate 7, 14 is a control device, 15a to 15d are servomotors, 16 is a monitor, and 17 is a keyboard.

In FIG. 1, an X-axis table 5 is fixed on a pedestal portion 9, and a Y-axis table 6 movable in the X-axis direction is mounted on the X-axis table 5. A movable θ-axis table 8 is mounted on the Y-axis table 6, and a suction table 13 is fixed on the θ-axis table 8. A substrate 7 such as a printed circuit board is mounted on the suction table 13.
However, for example, it is adsorbed so that each side thereof is parallel to the X and Y axis directions.

The substrate 7 mounted on the suction table 13 can be moved in the X and Y axis directions by the control drive of the controller 14. That is, the servomotor 15b is controlled by the control device 14
When driven by, the X-axis table 5 moves in the X-axis direction, the substrate 7 moves in the X-axis direction, and the servo motor 15c
When is driven, the Y-axis table 6 moves in the Y-axis direction and the substrate 7 moves in the Y-axis direction. Therefore, when the control device 14 moves the X-axis table 5 and the Y-axis table 6 respectively by arbitrary distances, the substrate 7 moves by an arbitrary distance in an arbitrary direction within a plane parallel to the mount 9. Become. In addition, the θ-axis table 8 is a servo motor 15d shown in FIG.
By this, it is possible to rotate about the center position in the θ-axis direction.

A Z-axis table support section 10 is installed on the pedestal section 9, and the Z-axis table support section 10 is installed in the Z-axis direction (vertical direction).
A movable Z-axis table 4 is attached. The Z-axis table 4 is mounted with the nozzle 1, the paste storage cylinder 2, and the optical distance meter 3. The control device 14 also controls and drives the Z-axis table 4 in the Z-axis direction (vertical direction).
Done by. That is, when the servo motor 15a is driven by the controller 14, the Z-axis table 4 moves in the Z-axis direction, and the nozzle 1, the paste storage cylinder 2, and the optical distance meter 3 move in the Z-axis direction accordingly. To do.

The nozzle 1 is provided at the tip of the paste storage cylinder 2, but the nozzle 1 and the lower end of the paste storage cylinder 2 are slightly separated by a nozzle support 12 having a connecting portion.

The optical distance meter 3 measures the vertical distance (spacing) between the paste discharge port, which is the tip (lower end) of the nozzle 1, and the upper surface of the substrate 7 (that is, the substrate surface 7a) in a non-contact and triangulation manner. It is measured by the method.

That is, as shown in FIG. 2, the optical rangefinder 3
Is cut in a triangular shape, and two slopes facing the cut portion are formed. A light emitting element is provided on one of these slopes, and a light receiving element is provided on the other. The nozzle support 12 is attached to the tip of the paste storage cylinder 2 and extends below the cut portion of the optical distance meter 3, and the nozzle 1 is attached to the lower surface of the tip.

The light receiving element provided in the cut portion of the optical distance meter 3 has a substrate surface 7a, as indicated by a chain line.
(FIG. 1) The lower position of the upper nozzle 1 is illuminated and the light reflected from it is received. When the distance between the paste discharge port at the tip of the nozzle 1 and the substrate surface 7a is the correct distance,
The positional relationship between the nozzle 1 and the optical distance meter 3 and the arrangement of the light emitting element and the light receiving element in the optical distance meter 3 are set so that the light from the light receiving element irradiates the substrate surface 7a directly below the nozzle 1. Has been done. Therefore, when the distance between the paste ejection port of the nozzle 1 and the substrate surface 7a (that is, the nozzle height) changes, the light irradiation position of the light emitting element is changed to the nozzle 1 on the substrate surface 7a.
Will be displaced from the position directly below, and as a result, the light receiving state of the light receiving element will change. Thereby, the distance between the paste ejection port of the nozzle 1 and the substrate surface 7a can be measured.

Due to variations in the mounting accuracy of the paste storage cylinder 2, nozzle support 12 and nozzle 1, the nozzle 1
The position of may differ before and after the replacement. However, as shown in FIG. 2, when the application point S is within an allowable range (ΔX, ΔY) of a preset size centered on the light irradiation position, the nozzle 1 is normally attached. And However, ΔX is the width of the allowable range in the X-axis direction, and ΔY is the width in the Y-axis direction.

Returning to FIG. 1, the control device 14 controls the servomotors 15a, 15b, 15c and the servomotor 15d for the θ-axis table 8 according to the data supplied from the optical rangefinder 3 and the image recognition camera 11a. (See FIG. 3). In addition, the encoders provided in these servo motors feed back data on the drive status of each motor to the control device 14.

In such a configuration, the rectangular substrate 7
When is placed on the suction table 13, the suction table 13 holds the substrate 7 by vacuum suction. Then, by rotating the θ-axis table 8, the position of each side of the substrate 7 is set so as to be parallel to each of the X and Y axes. Thereafter, the servo motor 15a is driven and controlled based on the measurement result of the optical distance meter 3, so that the Z-axis table 4 moves downward, and the nozzle 1 is changed to the paste discharge port from above the substrate surface 7a. It is lowered until the distance to the substrate surface 7a reaches a specified distance.

After that, the paste supplied from the paste container 2 through the nozzle support 12 is discharged from the paste discharge port of the nozzle 1, and together with this, the servo motor 1
The X-axis table 5 and the Y-axis table 6 are appropriately moved by drive control of 5b and 15c, whereby a paste pattern having a desired shape is applied and drawn on the substrate surface 7a. The paste pattern to be formed can be converted by the distance in the X and Y axis directions. Therefore, when desired data is input from the keyboard 17, the controller 14 converts the data into the number of pulses given to the servomotors 15b and 15c and outputs a command, whereby the paste application operation is automatically performed. .

FIG. 3 is a block diagram showing an example of the configuration of the control device 14 in FIG. 1, in which 14a is a microcomputer, 14b is a motor controller, 14ca is a Z-axis driver, 14cb is an X-axis driver, and 14cc is a Y-axis. A driver, 14 cd is a θ-axis driver, 14 d is an image processing device, 14 e is an external interface, 15 d is a servo motor for the θ-axis table 8 in FIG. 1, E is an encoder, 18 is a measurement result (distance) of the optical rangefinder 3. Is an AD converter for converting the data into digital data, and the portions corresponding to those in FIG.

In the figure, the control unit 14 has a ROM storing a processing program and an R storing various data.
AM, a microcomputer 14a having a built-in CPU for calculating various data, and servo motors 15a
˜15d motor controller 14b, servomotors 15a to 15d drivers 14ca to 14cd, an image processing device 14d that processes an image read by the image recognition camera 11a, an image processing device 14d, and a keyboard 17.
And an external interface 14e to which the A / D converter 18 is connected.

Data input from the keyboard 17, various data such as data measured by the optical distance meter 3, various data generated by the processing of the microcomputer 14a, and the like are stored in the RAM incorporated in the microcomputer 14a. Stored in.

FIG. 4 is a front view showing a specific example of the substrate 7 mounted and fixed on the suction table 13 in FIG.

In the figure, a region D is formed on the substrate surface 7a.
It is assumed that one semiconductor element (QFP) is mounted on each of 1 to D4. A thin strip-shaped wiring pad P is provided around each of these regions D1 to D4 (hereinafter, referred to as a mounting position).
Rows of n (however, n = 1, 2, 3, ...) Are provided, and leads extending in all directions from a semiconductor element (not shown) are fixed to these wiring pads Pn by soldering. Here, for each of the mounting positions D1 to D4, there are two pad rows in which ten wiring pads are arranged in the horizontal direction and six pad rows in which six wiring pads are arranged in the vertical direction. The four pad rows are provided around the two mounting positions. Therefore, a total of 32 array pads are provided around each of these mounting positions. Solder paste is discharged from the nozzle 1 (FIG. 1) and applied to all of these wiring pads Pn, one at a time.

The optical range finder 3 (FIG. 1) does not measure the entire gap (gap) between the nozzle 1 (FIG. 1) and each wiring pad Pn, but two pads in the lateral direction of the mounting position Dl. In the row, the array pad P1 having the smallest central X-axis coordinate value and the smallest central Y-axis coordinate value is set as the first measurement position (this is also referred to as measurement position P1), and 2 in the lateral direction of the mounting position D2. Of the two pad rows, the array pad P2 having the largest central X-axis coordinate value and the smallest central Y-axis coordinate value is the second measurement position (also referred to as the measurement position P2), and the mounting position D3 in the lateral direction. The array pad P3 having the smallest central X-axis coordinate value and the largest central Y-axis coordinate value of the two pad rows of is set as the third measurement position (also referred to as measurement position P3) and Of the two columns in the horizontal direction, the center X-axis coordinate value is the maximum And the arrangement pads P4 center Y-axis coordinate value is maximized fourth measurement position (this measurement position P4
Also, based on the measurement results (nozzle heights H1 to H4) at the measurement positions Pl to P4, respectively, the size of the distance (distance or gap value) from the nozzles 1 to all the wiring pads on the substrate surface 7a. ), And apply a desired amount of solder paste to all the wiring pads.

Incidentally, the measurement positions Pl to P4 on the array pad
May be set in advance by the operator or may be automatically set in the program.

Next, the overall operation of the paste applicator shown in FIG. 1, that is, the size of the gap (gap value) between the nozzle 1 and all the wiring pads on the substrate surface 7a is determined,
The process of applying a desired amount of solder paste to all the wiring pads will be described with reference to FIG.

In FIG. 5, first of all, when starting the operation, the power is turned on (S (step) 1), and then an initialization process of data necessary for paste application is performed (S).
2).

In this initial setting processing S2, it is designated whether or not the measurement positions Pl to P4 on the array pad shown in FIG. 4 are automatically set, or the measurement positions Pl to P4 when manually input. Data such as the desired height of the nozzle 1, the length of coating on each wiring pad, and the number of substrates 7 of the same shape to be coated are input from the keyboard 17 (FIG. 1). Further, the origin return of the moving members such as the Z-axis table 4, the X-axis table 5, the Y-axis table 6, and the θ-axis table 8 is performed as an initial setting.

After the initial setting process, the substrate 7 is held on the suction table 13
It is mounted on (FIG. 1) (S3). Then, the gap value measurement process is performed for each of the measurement positions Pl to P4 on the array pad (S4).

Here, this gap value measurement processing (S4)
Will be described in detail with reference to FIGS. 4, 6 and 7.

FIG. 6 is a straight line T12 parallel to the X coordinate axis set so as to pass (connect) the measurement positions Pl and P2 in FIG.
It is a cross-sectional view taken along (hereinafter referred to as X direction gap value correction straight line T12), and the portions corresponding to FIG.
12 and further, the X-direction gap value correction straight line T1
A method of obtaining the gap value at an arbitrary position on 2 will be described. It should be noted that BH indicates a surface having a reference height (reference surface) set when the noise height is measured by the optical distance meter 3.

As shown in FIG. 4, the X coordinate value X1 and the Y coordinate value Y1 of the measurement position Pl have already been set as the positions to which the paste is to be applied.
Positions are set to the measured values P1 of 1, 1 and the measured position P1
The distance (gap value) H1 from the reference surface BH to the pad on the substrate surface 7a at
4a (FIG. 3) of RAM. Similarly, the optical distance meter 3 is moved to the measurement position P2 (X2, Y2), and the distance (gap value) H2 from the reference surface BH to the pad on the substrate surface 7a is measured there, and the microcomputer 1
4a of RAM. Further, regarding the measurement positions P3 and P4 of the mounting positions D3 and D4, a straight line T3 parallel to the X coordinate axis set so as to pass (tie) the measurement positions P3 and P4.
4 (hereinafter, referred to as X direction gap value correction straight line T34) is the same, and the distances (gap values) H3 and H4 from the reference surface BH to the pad on the substrate surface 7a are measured in the same manner, and Store in RAM.

It should be noted that the measurement positions P3 and P4 are passed (connected).
The X-direction gap value correction straight line T34 thus set is also shown in FIG. 4, but the illustration of the measurement situation on this straight line is omitted.

The X-direction gap value correction lines T12 and T34 in FIG. 4 are the microcomputer 14a.
In (1), it is drawn (set) virtually in parallel for measurement, and here it is parallel to the X coordinate axis.

Here, the X-direction gap value correction straight line T1
2, T34 is parallel to the X coordinate axis, so the Y coordinate value Y
Since 1 and Y2 are equal to Y1 = Y2, once the measurement position of the optical range finder 3 is set to the measurement position P1, the optical range finder 3 is moved horizontally with respect to the substrate 7 to obtain the measurement position P2. Can be set to. The same applies to the measurement positions P3 and P4.

As described above, the distances H1 to H1 from the reference surface BH to the pads on the substrate surface 7a at the measurement positions P1 to P4.
When H4 is obtained, the substrate surface 7 between the measurement positions Pl and P2
Inclination of a in the X-axis direction (inclination per unit length) ∠H1
2, and the inclination degree (inclination per unit length) ∠H34 of the substrate surface 7a between the measurement positions P3 and P4 is calculated by the following equation: ∠H12 = (H2-H1) / (X2-X1 ) (1) ∠H34 = (H4-H3) / (X4-X3) (2)

Further, an arbitrary position P between the measured values P1 and P2 on the X direction gap value correction straight line T12 parallel to the X coordinate axis.
The X coordinate value of 12n is X12n, and the X coordinate value of an arbitrary position P34m between the measured values P3 and P4 on the X direction gap value correction straight line T34 which is also parallel to the X coordinate axis is X34.
m, the distance H12 from the reference surface BH to the pad on the substrate surface 7a at these arbitrary positions P12n and P34m.
n and H34m are expressed by the above equations (1) and (2) by the following equations (3) and (4): H12n = ∠H12 * (X12n-X1) + Hl (3) H34n = ∠H34 * (X34m -X3) + H3 (4). However, in the case of the inclination shown in FIG. 6, ∠H12 <0 ∠H34 <0.

The reason why the straight lines T12 and T34 are called X-direction gap value correction straight lines is that these straight lines T12 and T34 are used.
Distance (gap value) H12n at an arbitrary position above,
H34n can be calculated by the above formulas (3) and (4) without measurement.
This is because it can be obtained at.

Next, the X-direction gap value correction straight line T12,
A method of obtaining the distance (gap value) Hn at the position Pn of the arbitrary wiring pad on the substrate surface 7a not existing on T34 will be described below. However, the position Pn of this pad
Is known, its X coordinate value is Xn, and Y coordinate value is Yn.
And

It passes through an arbitrary position Pn in FIG. 4 and intersects with the X direction gap value correction straight lines T12 and T34 (in FIG. 4,
A straight line (which is hereinafter referred to as a Y-direction gap value correction straight line) T13 that is parallel to the Y-coordinate axis that is orthogonal (is similar to the X-direction gap value correction straight lines T12 and T34) is virtually set by the microcomputer 14a (FIG. 3). To do. The intersections of the Y-axis direction gap value correction straight line T13 and the X direction gap value correction straight lines T12 and T34 are respectively P12n,
P34n.

Since these intersections P12n and P34n are present on the X-direction gap value correction straight lines T12 and T34, the Y coordinate values Y12n and Y34n are respectively Y1 and Y1.
It is Y3. In addition, the Y axis direction gap value correction straight line T13
Passes through the above position Pn, the intersections P12n and P34n
The X coordinate values X12n and X34n of are both Xn.

FIG. 7 is a sectional view taken along the Y-axis direction gap value correction line T13 in FIG. 4, and the portions corresponding to FIG. 4 are denoted by the same reference numerals. A method of obtaining the distance (gap value) Hn from the reference plane BH to the pad at the position Pn of the arbitrary pad will be described.

In FIG. 7, the gap value H12 at the intersection points P12n and P34n is calculated by the above equations (3) and (4).
Since n and H34n are obtained, the inclination ∠T of the Y-axis direction gap value correction straight line T13 can be obtained by ∠T = (H34n-H12n) / (Y34n-Y12n) (5).

By using this equation (5), the gap value Hn at the position Pn of the arbitrary pad on the Y-axis direction gap value correction straight line T13 is Yn since the Y coordinate of this position Yn is Hn = ∠T * (Yn−Y12n) + H12n (6)

In this way, the above equations (1) to (6)
By using the formula, the gap value Hn at any position to which another paste should be applied can be simply measured only by measuring the gap value at four pad positions (for example, measurement positions Pl to P4) on the substrate surface 7a. It can be calculated by simple calculation.

The gap value thus calculated is hereinafter referred to as a correction gap value Hn. The position data (Xn, Y) of an arbitrary position Pn for obtaining the correction gap value Hn.
n) is already input and stored in the RAM of the microcomputer 14a in the initial setting process (S2) of FIG. 5, the position data (Xn, Yn) is associated with the correction gap value Hn. Store in RAM.

When the substrate surface 7a is not inclined and the surface 7a of the substrate 7 placed on the suction table 13 (FIG. 1) is horizontal, the above equations (1), (2) and (5) are used. The gradients ∠H12, ∠H34, and ∠T obtained by are all zero. Therefore, the gap values of all the wiring pads Pn are given by Hl, and the calculated value and the actual state match.

When all the correction gap values are associated with the position data and stored in the RAM, the process goes to the paste application process (S6) shown in FIG.

That is, in FIG. 5, in the paste coating process (S6), the position data of the pad position to be coated input in the initial setting process (S2) and the measurement position Pl obtained in the gap measuring process (S4) are calculated. Based on the gap values H1 to H4 at P4 and the corrected gap value Hn at the arbitrary pad position Pn obtained in the gap correction process (S5),
The solder paste is sequentially applied to the pad position on the substrate 7 where the application is desired, that is, on the wiring pad.

When the application of the solder paste on all the wiring pads is completed, the adsorption of the substrate 7 on the adsorption table 13 is released, the applied substrate 7 is discharged, and the substrate input by the initial setting is released. The number of sheets is reduced by one (S7). Then, based on the number of substrates, it is judged whether there is a substrate 7 to be coated yet (S8), and if there is a substrate 7 to be coated, a new substrate 7
On the other hand, the process returns to the substrate mounting process (S3) and the above processes (S3 to S7) are repeated. When the paste process for all the substrates 7 is completed and there is no substrate to be applied, all the processes are completed (S8).

In the above embodiment, the gap value correction straight lines T12, T34, T13 in FIG. 4 are parallel to the X coordinate axis and the Y coordinate axis, but they do not necessarily have to be parallel.
However, in this case, the denominator value of the first term on the right-hand side of each of the gradient equations shown in the above equations (1), (2), and (5) represents the actual distance between the two positions. In addition, these gap value correction lines T12, T34, T13
Since the arbitrary position on the above is different in the X coordinate value and the Y coordinate value, respectively, according to the above equation (3),
The values used in (4) and (6) are also different.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment as illustrated below.

That is, when the substrate 7 is relatively large and undulations are expected to exist on the substrate surface 7a, this substrate 7
Is divided into several blocks (regions), and the above series of processes may be sequentially executed for each division. At this time, the wiring pad positions for measuring the gap value by the optical distance meter 3 are set at four positions for each block, and the above process is performed for each region.

Further, as described above, when the substrate 7 is divided into a plurality of blocks, when there is a measurement position approaching the optical distance meter 3 between adjacent blocks, one of the approaching blocks is approached. It is also possible to combine the measurement result of the measurement position with the other measurement position close to it and omit the measurement of the other, thereby further reducing the number of measurements,
The coating accuracy can be maintained.

Further, as the measurement position of the gap value,
Substrate 7 to be used when aligning substrate 7 with a paste coating machine or mounting electronic components with a downstream component mounting machine.
You may make it use the alignment mark provided in. In this case, each measurement position is slightly deviated from the position where the pattern is actually applied, that is, the substantially central portion of the wiring pad, but if it is deviated to this extent, the application accuracy is not affected at all.

Further, if the alignment accuracy of the board 7 is not good, or if the accuracy of the board 7 itself is not good, a combination of those whose measurement positions are not on the wiring pad surface and which are out of the wiring pads is obtained. In some cases, the measurement is performed on the surface of the insulating material of the peripheral substrate 7 or the resist portion, and at such a location, the light receiving sensitivity of the light receiving element of the optical distance meter 3 is lowered, and the measurement state is on the wiring pad surface. Is different from the measured light receiving sensitivity. Therefore, the upper limit value or the lower limit value is set for the measurement data or the correction gap value, and if the measured value or the correction gap value is out of the range, an abnormality detection process such as an abnormal measurement is performed to perform alignment, measurement, and gap correction. It is possible to prevent defective coatings by executing the above procedure again.

Further, the measurement position may be the surface of the insulating material or the resist portion on the substrate near the application position, instead of the wiring pad to be applied. However, in this case, since there is a step due to the pad at the measurement position, it is advisable to obtain a correction amount due to the step and take this correction amount into account when correcting the gap.

Further, in FIG. 4, the X-direction gap value correction straight lines T12 and T34 are two parallel lines, and the Y-axis direction gap value correction straight line T13 is orthogonal to these X-direction gap value correction straight lines T12 and T34. However, this applies to the arrangement of the mounting positions D1 to D4, and since each position data is a scalar quantity, these straight lines do not have to be parallel or orthogonal. In order to improve accuracy, the measurement positions should be separated unless the substrate is undulating.

[0061]

As described above, according to the present invention,
Even if there are many places to apply the solder paste, the nozzle can be maintained at a desired height with respect to the substrate surface without increasing the time required to measure the gap value, while maintaining good productivity. The paste can be applied accurately.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a paste applicator according to the present invention.

FIG. 2 is a perspective view showing an arrangement relationship between a paste storage cylinder, a nozzle, and a distance meter in the embodiment shown in FIG.

FIG. 3 is a block diagram showing an electric system of a control device in the embodiment shown in FIG.

FIG. 4 is a plan view showing a specific example of a printed circuit board to which a paste is applied in the embodiment shown in FIG.

FIG. 5 is a flowchart showing a specific example of the operation of the embodiment shown in FIG.

FIG. 6 is a diagram illustrating a situation in which a gap value is measured on the substrate shown in FIG.

FIG. 7 is a diagram illustrating a situation in which the gap value is corrected on the substrate shown in FIG.

[Explanation of symbols]

1 nozzle 2 Paste storage cylinder 3 Optical rangefinder 4 Z-axis table 5 X-axis table 96 Y-axis table 7 substrate 7a substrate surface 8 θ-axis table 14 Control device 14a Microcomputer

Front page continued (72) Inventor Akio Igarashi 5-2 Koyodai, Ryugasaki, Ibaraki Hitachi Techno Engineering Co., Ltd. Ryugasaki Plant (72) Yutaka Igarashi 5-2 Koyodai, Ryugasaki, Ibaraki Hitachi Techno Engineering Co., Ltd. Company Ryugasaki Factory (56) Reference JP 10-5654 (JP, A) JP 3-91998 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B05C 5/00 G01B 21/16 H05K 3/34

Claims (4)

(57) [Claims] 1. A paste applicator for ejecting paste from the nozzle to apply and draw a desired paste pattern on the substrate while changing the relative positional relationship between the substrate placed on a table and the nozzle. measuring means for measuring the vertical distance from the reference plane to the paste applied surface of the substrate, to set the first, second common line does not intersect with each other in the paste coated surface, the first, second common each s linear husband, and a distance between the same said common has been the vertical distance and the two measurement positions measured by said measuring means at two measurement positions different in on a straight line in the paste applied surface, said common linear First computing means for obtaining the vertical distance at an arbitrary position between the two measurement positions on the same common straight line by obtaining the inclination of the paste application surface along , The The first paste applied surface through the arbitrary position that is not present in the second common straight line, and set the third common line together intersecting the said first and second common lines, said first , No.
Based on the vertical distances obtained by the first computing means at the respective intersections of the second common line and the third common line, the inclination degree of the paste application surface along the third common line Seeking
According to the second calculation means for calculating the vertical distance at an arbitrary position on the third common straight line by using the inclination, and the vertical distances calculated by the first and second calculation means. hand,
First in the paste applied surface, the second and third common linear
A means for setting the height of the nozzle with respect to the paste application surface at an arbitrary position above, and discharging the paste from the nozzle to apply the paste to the paste application surface. 2. The first and second common straight lines are parallel straight lines to each other, and the third common straight line is orthogonal to the first and second common straight lines according to claim 1.
A paste applicator characterized by a straight line . 3. The paste application surface according to claim 1, wherein the paste application surface is divided into a plurality of blocks, and the first and second arithmetic means include the vertical distance at an arbitrary position of the paste application surface for each block. A paste applicator characterized by seeking. 4. The adjoining block according to claim 3, wherein the first computing unit shares the vertical distance at the measurement positions separated by each other on the paste application surface measured by the measurement unit. And paste applicator.