JPH07304155A - Retaining device for squeegee device - Google Patents

Abstract

PURPOSE:To retain the parallelism of the bottom face of a squeegee device with printing medium or the upper face of a mask by controlling two motors installed on a retainer operating respectively and independently to support, lift and lower the squeegee device. CONSTITUTION:Distance measuring devices 3L and 3R are mounted on an outer side wall of a squeegee device 1. An air cylinder 6 exclusively for supporting the squeegee device 1 is mounted on a central section of the squeegee device through a retainer 4, and motors exclusively for lifting and lowering are directly connected with retainer tools 4L and 4R on left and right ends. A supersonic receiving and transmitting device is adopted as a distance measuring device, and an operation control device for controlling the operation of respective motors based on signals from distance measuring devices 3L and 3R is provided. As the squeegee device 1, a device consisting only of a squeegee blade and its supporting tools is included in the category and used.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device for depositing a solder paste at a predetermined position before mounting an electronic component on an electronic circuit board, and more particularly to holding a squeegee device.

2. Description of the Related Art Among printing apparatuses used for screen printing or mask printing (hereinafter abbreviated as printing) on an electronic circuit board, squeegee apparatuses are classified into the following two types. One is a plate-shaped rectangular squeegee blade made of a hard plastic material such as polyurethane resin, which has been known for a long time. The second one, which appeared in the technical field several years ago, forms a housing structure whose top, bottom, left and right, front and back do not directly contact the outside air. Therefore, in other words, the former can be said to be a squeegee device having a non-housing structure. The blade used in the former device has a strip shape made of an extremely thin steel plate having a thickness of about 0.1 mm to at most 0.2 mm.
A sheet is provided at the bottom of the squeegee device called the housing structure. Concept of housing structure and squeegee device of the structure that has been used up to now and also used below
The meaning and structure are the same as or similar to those found in the literature (Japanese Patent Application No. 5-3922).

The above-mentioned conventional holding device for a squeegee device is also characterized in each case. That is, in the first case of the preceding paragraph, as shown in FIG. 6, reference numeral B is a squeegee blade, 11 is a kind of holding rod capable of holding the blade, and reference numeral J is an engaging member of both. Represents B through the engaging tool
Is capable of smoothly inclining to the left and right, and the subscripts L, R, and C mean left, right, and center, respectively (hereinafter the same). Reference numeral 12 represents a support rod which can be connected to the holding rod to suspend and support them. 13 The type of screw coupling through the 11 _c and the groove, by raising or lowering it, the pressure of the print medium of the B (screen or mask, etc.) (hereinafter, printing pressure abbreviated) may adjust the It is a thing. 1
Reference numeral 4 denotes a support base or a support rod capable of suspending and supporting B to 11 through 11 _c , and 15 (A) is an air cylinder, which is a whole of B to 13 through 11 _c when compressed air comes in and out. Can be moved up and down with respect to the print medium surface. However, illustrations of the pipes for venting air in and out, the vents, and the like are omitted. In the second case of the preceding paragraph, the document (Japanese Patent Application 5-153
064), since the weight of the squeegee device of the housing structure is considerably heavier than that of the former, a set of supports dedicated to the left and right ends of the device are provided for exclusive use. The self-weight of the device is canceled by the air cylinder, and the device is moved up and down by the air cylinder dedicated to lifting and lowering attached to the central part of the device.

[Problems to be Solved by the Invention] In the first case of the conventional example, when the width of the squeegee blade (B) is relatively small, the blade and the printing medium, especially the upper surface of the screen in the gap type screen printing are separated. Contact (hereinafter,
It is unlikely that the parallelism between the bottom surface of the blade and the screen surface will be a problem when the contact surface is abbreviated. That is, if the parallelism is lost and either the left or right edge comes into contact with the surface first, indentation or "scratch" is generated on the screen surface because the load weight on the screen surface is relatively small, or the blade tip. This is because it is unlikely to occur because the hardness of the part is not great. However, when the blade becomes large, an indentation or "scratch" may occur due to the increase in the weight to be loaded. Further, even if the blade is softly contacted with the gap type screen surface by 15 (A), the adjustment by 13 is the only way to increase the parallelism including the adjustment of the printing pressure described in the previous section. It is very troublesome. In the second case of the conventional example, the situation is more serious. That is, not only the blade but also the entire squeegee device of the housing structure tries to come into contact, so the load weight is obviously larger than the first one, and even if the width of the squeegee device is small, indentation or "scratch" occurs at the time of contact. Is easily generated on the screen, for example. Further, even if a soft contact surface can be obtained, it is very difficult to increase the parallelism including adjusting the printing pressure.

The present invention has been made in view of the above problems, and provides a holding device for a squeegee device which solves the above problems by a configuration common to each of the above-mentioned two broadly divided conventional examples. is there.

[Means for Solving the Problems] In order to solve the above problems, a holding device for a squeegee device according to the present invention (hereinafter, abbreviated as a holding device), first, the left and right end portions in the width direction of the squeegee device. A motor as a power unit capable of supporting and elevating the squeegee device is coupled to the holder attached to the squeegee, and the outer side wall in the width direction of the squeegee device is not directly contacted with the print medium. Further, a distance measuring means capable of measuring the distance to the medium surface is provided.

Next, in the holding device according to the present invention, in addition to the preceding paragraph, an air cylinder dedicated for supporting the device is attached to the central part of the squeegee device through a holding tool, and instead is directly connected to the holding tools at the left and right ends. The motor is exclusively for lifting.

Subsequently, in the holding device according to the present invention, air cylinders dedicated to raising and lowering are attached to the holding tools at the left and right ends in place of the motors in the preceding paragraph.

An ultrasonic wave transmitting / receiving device is commonly used as the distance measuring means, and an operation control device capable of controlling the operation of each of the motors based on a signal from the device is provided. The squeegee device referred to in this section also includes a squeegee blade and a support for the squeegee blade. The same applies below unless otherwise specified.

[Operation] In the holding device according to the present invention, the operation of the motors provided in the holders attached to the left and right ends of the squeegee device in the width direction is independently and cooperatively supported to lift and lower the squeegee device. By controlling so that the bottom surface of the squeegee device can be brought into contact with the upper surface while maintaining high parallelism with the screen or the mask upper surface as a print medium.

Next, in the holding device according to the present invention, an air cylinder dedicated to support is attached to the central portion of the squeegee device, and motors dedicated to raising and lowering are attached to the left and right end portions of the device in the width direction, whereby the above squeegee is attached. The bottom surface of the device can keep the parallelism with the upper surface of the printing medium such as a screen smoother and can come into contact with the upper surface.

Next, in the holding device according to the present invention, not only as a power device dedicated to supporting the central portion of the squeegee device, but also as a power device dedicated to lifting and lowering provided on the holders at the left and right ends of the device in the width direction. Also, by using an air cylinder, the bottom surface of the squeegee device can be in contact with the upper surface of the print medium while maintaining the parallelism with the upper surface.

Incidentally, in common with the above three means, the squeegee device is equipped with a distance measuring device capable of measuring the distance from the portion to the upper surface of the printing medium on the left and right outer side wall parts, and signals from the left and right devices are provided. Based on the result of calculating the difference between the left and right distances based on the result and providing an operation control device capable of individually controlling the power devices for left and right lifting, the parallelism with the bottom surface of the squeegee device in each of the above means is maintained sufficiently high. Then, the surface may come into contact with the upper surface.

[Embodiment] Hereinafter, the gist of the present invention will be described based on an embodiment with reference to the drawings. 1 and 2
FIG. 2 is a longitudinal sectional view of the essential parts for explaining the mechanism of the first and second embodiments of the holding device according to the present invention, in which common to both figures is 1 is a squeegee device and 2 is an outer wall of the device. The holding means for holding the distance measuring means or its holding portion attached to the above, 3 for holding the distance measuring element under the holding portion for measuring the distance to the upper surface (S) of the print medium, and 4 for holding 1 Respectively. The subscripts L and R of 4 mean left and right (hereinafter the same). Reference numeral 5 represents a support base or a column that can suspend and support the above-mentioned holder, and 6 represents an air cylinder that mechanically connects with 5 and holds 1 exclusively for supporting. P represents the printing direction perpendicular to the paper surface. However, 4 is a kind of concept diagram common to both figures, and its concrete configuration is shown in FIGS. 3 and 4, respectively.

That is, in the case of FIG. 1, the function of supporting and elevating 1 is achieved by the motor represented by M in FIG. 3 as a power unit. 4 (M) in FIG. 3 conceptually symbolizes this. 7 is a rotary shaft or rod having a thread groove, 8 is a transmission means for transmitting the power of the motor M to 7, D is a connecting plate which is a free universal connecting plate, and J is 1 It is a non-universal engaging tool that connects the and D, but has a structure that smoothly moves with respect to the left and right inclination of 1 and does not transmit 1 to the above D and does not transmit the motion. F (4), which also means a cylindrical body that freely surrounds 7 and D, means that 4 (M) is directly connected to the printing apparatus or the same support base 5 as described above. Although 7 also moves up and down in response to the ascending / descending movement of 1 with respect to S, M in the figure does not hinder that movement, and it is of course possible to provide it at a position not directly above 7 by the constitution of 8. .

FIG. 4 corresponds to the second and third cases according to the present invention and is a conceptual diagram of a type of air cylinder.
A and A'represent the compressed air in and out and the pipes for that,
Reference numeral 4 (A) is a holder 1 compared with 4 (M) in FIG. 3, V is a kind of valve, and other symbols are the same as those already described. Since 6 in FIG. 2 is an air cylinder dedicated to support for canceling the own weight of 1 in order to make the movement of 1 smoother, the compressed air inlet / outlet pipe may be only A ′ in FIG. Is unnecessary. Of course, it goes without saying that the "escape" outlet for air in the cylinder is provided at the top. In the second embodiment, 6 is an air cylinder and 4 is a motor, and the third embodiment is 6
Not only that, 4 also uses an air cylinder. In this case, in order to bring 1 closer to S, the compressed air is put in A to escape it from A ', and when it rises or rises from S, the opposite operation may be performed.

FIG. 5 is a block diagram of an operation control device which is indispensable in common to each embodiment of the holding device according to the present invention. Reference numeral 9 in the same figure receives the signals from the left and right distance measuring devices 3 _L and 3 _R to compare and calculate the left and right distances to the upper surface of the print medium,
It means a kind of central signal processing device (hereinafter abbreviated as CPU) capable of sending operation command signals to the electronic circuits 10 _L and 10 _R for operating the left and right holders based on the result.
Reference numeral 10 denotes a motor drive circuit when the holder 4 is a motor, and an air valve opening / closing motor drive circuit for sending compressed air when the holder 4 is an air linder. Similarly, the arrow from 10 means that electric signals for rotating the motor and opening / closing the valve of the air cylinder are sent to the motor and the air valve.

With the structure and mechanism shown in FIGS. 1 to 5, the holding device of the squeegee device according to the present invention can be brought into contact with the upper surface of the print medium while keeping the bottom surface of the squeegee device parallel. This will be described using mathematical expressions. 1 and 2
The relationship between the distances or the gaps represented by the respective symbols commonly shown in FIG. That is, H _L = H _I + d _L (1), H _R = H _r + d _R (2) The difference in distance (H ₁ −H _r ) which is a problem in the present invention is _{expressed by the} formulas (1) and (2). from _{H l -H r = Δh = ΔH} -Δd (3) However, in the _{(3), ΔH = H L} -H R, Δd = d L
A -d _R. As can be easily understood from the equation (3), the parallelism is determined by the magnitude relationship between ΔH and Δd obtained from the measured value. For this purpose, it is necessary to know Δd. This is known by the following procedure.

On the upper surface of the main surface of the machine platen, a certain thickness or more (for example,
The same size metal gauge 1 over the number of mm), along the width direction of the squeegee device, placed one by pair, measuring the H _L, H _R to surface contact the right and left end portions of the device lowermost surface on the gauge surface To do. At this time, the right and left exchange the same size gauge, an average of several measurements each H _{L (1),} expressed as H R ₍₂₎ is expressed as follows. That is, H _L (1) = G _L + d _L (4), H _R (1) = G _R + d _R (5) H _L (2) = G _R + d _L (6), H _R (2), G _L + d _R (7) G is the dimension of the gauge and is expressed by the following equation using the true value and the error. That is, G _L = G _L0 + ΔG _L (8), G _R = G _R0 + ΔG _R (9) By the assumption, G _L0 = G _R0 , and _therefore (4) to
From _{(9), H L (1} ) -H R (1) = ΔG L -ΔG R + Δd (10) H L (2) -H R (2) = ΔG R -ΔG L + Δd (11) (10) , (11), Δd = [{H _L (1) + H _L (2)}-{H _R (1) + H _R (2)}] × 1/2 (12), and from only the measured value, ( That is, it is possible to know Δd in the equation (3).

Now, based on the equation (3), the above item [007
To increase the reliability when performing the comparison calculation described in 1]), it is necessary to know the measurement accuracy and the measurement limit. For this purpose, it is sufficient to use the fact that the following kind of identity holds from the expressions (4) to (7). That is, by knowing the difference between the _{H L (1) + H R} (1) = H L (2) + H R (2) (13) (13) of the type of both sides value, ranging in retention device according to the present invention You can know the accuracy and its limits. Thus, the operations of the motors and the air cylinders provided on the left and right holders of the squeegee device may be controlled so that Δh in the expression (3) is made as zero as possible. Specific examples of the distance measuring means or device will be described below.

The distance measuring device common to each of the above embodiments is as follows:
A combination of a pair of ultrasonic wave transmitting / receiving elements and a circuit for driving / detecting them may be adopted. In the holding device according to the present invention, the parallelism can be adjusted at a distance of 1 to several cm from the lowest surface of the squeegee device to the upper surface of the printing medium in order to prevent the detection sensitivity from decreasing and to increase the holding operation speed. The pulse width by electronic technology is at most nsec.
This is because there is no choice but to use ultrasonic waves for non-contact distance measurement. The ultrasonic transmission / reception elements may be combined for both transmission and reception or for both transmission and reception.

Gap type screen printing is most suitable as a printing example to which each of the above embodiments of the present invention should be applied, but of course, it can be applied to contact type screen printing and mask printing. Is. Furthermore,
In combination with the squeegee device to be held, the first embodiment is applicable to both housing type and non-housing type, but the second is applied to the housing type and the third is applied to the non-housing type. It is desirable to do. In addition to the above embodiments, various configurations and structures are possible without departing from the scope of the present invention, and the present invention is not particularly limited to the drawings of the above embodiments.

[Effects of the Invention] As can be easily understood from the above description, the present invention has the following effects in holding the squeegee device which is the main part of the printing device.

Instead of moving the squeegee device up and down with respect to the upper surface of the print medium at the center in the width direction, a pair of holders are provided at the left and right ends in the width direction to perform the lifting operation. By performing the configuration independently and in cooperation with each other, the parallelism between the bottom surface of the squeegee device and the upper surface of the print medium can be maintained regardless of whether the squeegee device is a housing type or a non-housing type. It can be held sufficiently high so that both sides are in contact with each other.

Further, when carrying out the holding or raising / lowering operation of the preceding paragraph, the deviation of the parallelism is detected by a distance measuring device combined with ultrasonic wave transmitting / receiving elements attached to the left and right ends of the squeegee device in the width direction, By correcting the above deviation by the CPU, a sufficiently high parallelism is maintained and the above-described contact surface is formed, and as a result, the upper surface of the print medium is not damaged.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part configuration showing an embodiment of a holding device.

FIG. 2 is a vertical cross-sectional view of the essential parts showing an embodiment of a holding device.

FIG. 3 is a longitudinal cross-sectional view of a main part configuration of a holding device having a motor as a power unit.

FIG. 4 is a vertical cross-sectional view of the main configuration of a holding device that uses an air cylinder as a power unit.

FIG. 5 is a block diagram showing an example of operation control of a holding device.

FIG. 6 is a vertical cross-sectional view of the main configuration of a conventional holding device.

[Explanation of symbols]

1 Squeegee device (squeegee blade) 2 Distance measuring means holding unit 3 Distance measuring device (distance measuring element) 4 Holder 5 Support stand (support) 6 Air cylinder for support 7 Rotating shaft (rod) 8 Power transmission device 9 Central signal processing Device (CPU) 10 Motor drive circuit (air valve opening / closing circuit) P Printing direction S Print medium upper surface H, d Distance J Engagement tool (joint) M Motor D Coupling plate F Fixed support tool A Air cylinder a, a 'Compressed air V valve (valve plate)

Claims (3)

[Claims] 1. A holder that can hold the device, one set each being attached to each end of the squeegee device at the uppermost end and in the width direction perpendicular to the printing direction, and the holder is suspended and supported. Support base or support, and a motor as a power unit capable of moving the squeegee device up and down via the holder,
A transmission means capable of transmitting the power of the motor to the holder, an ultrasonic wave transmitting / receiving device as distance measuring means attached to the left and right outer wall portions in the width direction of the squeegee device, and a signal from the distance measuring means. A squeegee device having an operation control device capable of controlling the operation of the motor based on the squeegee device, wherein the upper surface of the screen or the mask as a print medium and the bottom surface of the squeegee device can be in parallel contact with each other during printing. Holding device 2. A holder as an exclusive means for supporting the squeegee device, which comprises an air cylinder attached to the uppermost part of the squeegee device and at the center in the width direction perpendicular to the printing direction, and also to the squeegee device. A holder as a means for raising and lowering the device, which is attached to each of the left and right ends of the uppermost portion in the width direction, a support base or a column for suspending and supporting the holders, and a holder for raising and lowering A motor as a power device capable of raising and lowering the squeegee device via a tool, a transmission means capable of transmitting the power of the motor to the pair of left and right holders, and the outermost left and right ends of the squeegee device in the width direction. An ultrasonic wave transmitting / receiving device as a distance measuring means attached to each section, and an operation control device capable of controlling the operation of the motor based on a signal from the distance measuring means, Occasionally, a holding device for a squeegee device configured such that a screen or a mask upper surface as a print medium and a bottom surface of the squeegee device can be in parallel contact with each other. 3. A holding device for a squeegee device according to claim 2, wherein the power device dedicated to raising and lowering the squeegee device comprises an air cylinder.