JPH11254641A - Printing device and method for printing paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing device and method for a printing paste wherein variations in viscosity of a solder paste can be sensed on real time. SOLUTION: A pressure sensing member 30, wherein a pressure sensor is embedded in a pressure sensing slope inclined upward in a printing direction, is moved in a non-contact manner with respect to the surface 3a of a mask 3 to sense the pressure of a solder paste 7 produced between the pressure sensing slope and the surface 3a. And the viscosity of the solder paste is determined at a control device 81 based on the sensed pressure. Thus variations in the viscosity of the solder paste can be sensed on real time and printing conditions can be changed properly so that the quality of printing can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a printing paste, for example, cream solder, on a surface of a circuit board to be printed.
The present invention relates to a printing paste printing apparatus and a printing method for applying.

[0002]

2. Description of the Related Art Conventionally, cream solder is mainly used for soldering electronic components such as chip components on a printed circuit board in the manufacture of an electronic circuit board, and the cream solder is printed and applied in a desired pattern. For this purpose, a cream solder printing machine is used. Conventional cream solder printing machine 100
FIG. 1 shows an example of a squeegee head mounted on a tower.
The structure shown in FIG. Normally, in the printing operation, the squeegee head 102 moves alternately from left to right and from right to left in FIG. 14 for each printed circuit board 5. At this time, in the rightward printing from left to right, the rightward printing is performed. The directional squeegee 101a is used for directional printing, and the leftward squeegee 101b is used for leftward printing. The printed circuit board 5 by such a conventional cream solder printer 100 is used.
The operation of printing cream solder on the substrate will be described with reference to FIGS. 14 and 15, reference numeral 3 denotes a mask on which an opening 4 having a desired pattern is formed, 5 denotes a printed board, 6 denotes a land on which cream solder 7 is printed, and 8 denotes a solder resist. The desired pattern of the mask 3 refers to a pattern in which the openings 4 are formed corresponding to the lands 6 on the printed circuit board 5.

[0003] First, when performing the above-described rightward printing, the printed board 5 is positioned on the mask 3 so that the openings 4 and the lands 6 coincide with each other, and the leftward printing squeegee 101b is raised. In this state, the rightward printing squeegee 101a is lowered to bring the squeegee tip 103 into contact with the surface 3a of the mask 3 at an appropriate printing pressure. In this state,
By moving the rightward printing squeegee 101a linearly along the rightward direction, the cream solder 7 previously provided on the surface 3a of the mask 3 is filled in the opening 4 of the mask 3. After the rightward printing squeegee 101a moves to the right end of the mask 3, the printing operation is completed by separating the printed circuit board 5 from the mask 3. Also, when performing the above leftward printing,
Similarly to the above-described rightward printing, the printed circuit board 5 is
Then, while the rightward printing squeegee 101a is being raised, the leftward printing squeegee 101b is lowered to bring the squeegee tip 103 into contact. The subsequent operation is the same as the above-described rightward printing. As described above, these operations are alternately repeated for each of the printed circuit boards 5, so that the cream solder 7 is continuously printed and applied onto the lands 6 of each of the printed circuit boards 5 via the mask 3.

On the other hand, the cream solder 7 is a paste-like substance obtained by mixing a solder powder with a high-viscosity flux. Therefore, the types of the cream solder 7 are innumerable depending on the type of the flux and the type of the solder powder or the combination of the mixing ratio thereof, and the flow characteristics thereof are also various. The flow characteristics of the cream solder 7 are generally represented by viscosity, but are often qualitatively expressed. When the viscosity is low, it is called a soft cream solder, and when the viscosity is high, Called hard cream solder. For example, in the case of the cream solder 7 having a low viscosity, since the fluidity is good, the cream solder 7, especially the flux, is filled in the minute gap between the back surface of the mask 3 and the printed board 5 when filling the opening 4. The flux and the cream solder 7 tend to bleed out as a result of printing on the printed circuit board 5, and so-called printing bleeding and printing defects such as bridges are likely to occur. On the other hand, in the case of the cream solder 7 having a high viscosity, since the fluidity is poor, the cream solder 7 is difficult to be filled in the opening 4, and printing failure such as unfilling or blurred print is likely to occur. As described above, since the printing quality is greatly affected by the flow characteristics, that is, the viscosity, of the cream solder 7, in the conventional cream solder printing process, the inspection result report of the cream solder 7 attached by the maker when the cream solder 7 is purchased. At present, the viscosity of the cream solder 7 is controlled by referring to the described viscosity or measuring the viscosity of the cream solder 7 by a viscometer before printing.

[0005]

However, a cream solder printing apparatus in an actual circuit board production process performs continuous printing for a long time from the viewpoint of productivity. Therefore, the cream solder 7 on the surface 3a of the mask 3 is constantly stressed because squeezing is repeatedly performed in the left and right printing directions. In addition, since the amount of the cream solder 7 on the surface 3a is gradually reduced by the continuous printing, new cream solder 7 is replenished every predetermined time. In addition, during continuous printing for a long time, the ambient temperature around the cream solder printing apparatus also changes. Due to such conditions, the viscosity of the cream solder 7 on the surface 3a changes each time, and also changes with the aging of the cream solder 7 itself. Therefore, in the conventional viscosity management using the viscosity value based on the inspection report at the time of purchase or the value measured by a viscometer before printing, the cream solder 7 on the surface 3a of the mask 3 during the printing process is not used. However, there is a problem that printing failure occurs due to a change in viscosity of the cream solder 7 during continuous printing. The present invention has been made to solve such a problem, and provides a printing paste printing apparatus and a printing method that can prevent the occurrence of printing failure due to a change in viscosity of a printing paste such as cream solder. The purpose is to:

[0006]

According to a first aspect of the present invention, there is provided a printing paste printing apparatus, wherein a squeegee moves in a printing direction on a surface of a printing mask having an opening formed therein, so that a printing paste on the surface is formed. A printing paste printing apparatus that prints and applies the circuit board surface located on the back surface of the printing mask through the opening, and the tip is in a non-contact state with a gap to the surface during printing. A pressure detecting member that is disposed and moves in the same direction as the squeegee, and has a pressure detector for detecting the pressure generated in the print paste by the movement and determining the viscosity of the print paste during printing by the squeegee. And, based on the viscosity of the printing paste obtained based on the pressure measured by the pressure detector, at least the moving speed of the squeegee,
A control device for controlling any one of an angle formed by the squeegee and the surface, a pressing force of the squeegee, and a temperature of the print paste is provided.

[0007] In a printing paste printing method according to a second aspect of the present invention, the printing paste on the surface is printed through an opening formed in the printing mask by squeezing the surface of the printing mask. A printing paste printing method for printing and applying on a circuit board surface located on a back surface of a printing mask, wherein a pressure generated in the applied printing paste is detected to measure a viscosity of the printing paste during printing. It is characterized by.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printing paste printing apparatus and a printing method according to one embodiment of the present invention will be described below with reference to the drawings. The printing method is executed by the printing paste printing apparatus. In each of the drawings, components that perform the same or similar functions have the same reference characters allotted, and description thereof will not be repeated. In this specification, cream solder, which is a paste solder obtained by mixing powder solder with high-viscosity flux, is taken as an example of the printing paste. Therefore, in the present embodiment, a cream solder printing device is taken as an example of the print paste printing device, and a cream solder printing method is taken as an example of the print paste printing method.

The cream solder printing apparatus 1001 has substantially the same configuration as that of a conventional cream solder printing apparatus.
As shown in FIG. 7, a substrate loading device 55 for loading the substrate 5 on which printing is performed into the cream solder printing device 1001, an X, Y, θ position correcting device for the loaded substrate 5, a mask 3 and a substrate 5 after printing. Stage 60 having a plate separating device for separating a plate from a substrate, a substrate support device 61 for supporting the substrate 5, and a recognition camera 62 for correcting a substrate position for obtaining information for positioning the mask 3 and the substrate 5. , The squeegee head 10, a driving device 76 for driving the squeegee head 10, and a control device 81 for controlling the operation of the cream solder printing apparatus 1001. In addition, among the above-described components, the remaining components other than the squeegee head 10 and the control device 81 having the characteristic structure in the present embodiment are the same as the conventional cream solder printing device,
Hereinafter, the squeegee head 10 and the control device 81 will be mainly described. The cream solder printing apparatus 1
001 is a type in which the squeegee moves in both the left and right printing directions described above.

FIG. 1 schematically shows the periphery of a squeegee head 10 in a cream solder printing apparatus 1001 according to this embodiment. The squeegee head 10 has a rightward printing squeegee 14a used at the time of rightward printing and a leftward printing squeegee 14b used at the time of leftward printing, similarly to the conventional squeegee head shown in FIG. Pressure detector 35 for measuring the pressure for determining the viscosity of cream solder 7 during printing of cream solder 7
The pressure detecting member 30 having First, the printing squeegees 14a and 14b will be described. Each of the printing squeegees 14a and 14b for filling the opening 4 of the mask 3 with the cream solder 7 during printing is a printing squeegee attached to the base plate 17 of the squeegee head 10 constituting the cream solder printing apparatus 51, respectively. The upper and lower driving devices 15 and 16 are attached to the distal ends of the output shafts 13a and 13b, respectively, and can be moved up and down between the standby position 18 and the squeezing position 19 by the upper and lower driving devices 15 and 16. The base plate 17 is moved in the left and right printing directions by a driving device 76 whose operation is controlled by a control device 81. FIG. 1 shows a state in which rightward printing is being performed, and thus a state in which the rightward printing squeegee 14a has been lowered to the squeezing position 19 and the leftward printing squeegee 14b has been raised to the standby position 18. ing. When the rightward printing squeegee 14a or the leftward printing squeegee 14b is located at the squeezing position 19, the tip portions 20a and 20b of each squeegee apply an appropriate pressure to the mask 3.
Surface 3a of the mask 3 in such a state as to be applied to the surface 3a of the
a, and the filling operation of the cream solder 7 into the opening 4 of the mask 3 is performed. Each of the driving device 76 and the vertical driving devices 15 and 16 is connected to the cream solder printing device 5.
1 is connected to a control device 81 which controls the operation of the first control device.

The pressure detecting member 30 is attached to a tip of an output shaft 32 of a driving device 31 for the pressure detecting member attached to the base plate 17. The pressure detecting member 30 includes:
As shown in detail in FIG. 2, the opposing surface facing the surface 3a of the mask 3 is a wedge-shaped inclined surface 34 for pressure detection which is inclined upward from the tip 33 of the pressure detecting member 30 in the printing direction. In the present embodiment, the pressure detecting surface 35a of the pressure detector 35 is
A pressure detector 35 is buried in the front end 33 so as to be flush with the surface. Such a pressure detector 35 is
In the present embodiment, as shown in FIG.
Is provided substantially at the center in the width W direction. still,
The arrangement position and number of the pressure detecting members 30 in the width W direction are not limited to those described above. As shown in FIG. 3, such a pressure detecting member 30 is provided outside the region of the substrate 5 on which the cream solder 7 is printed, that is, the non-opening region 91 on the mask 3 where the opening 4 is not formed. And the width W is long enough to squeeze a part of the non-opening area 91.
The cream solder 7 exists even in the non-opening portion 91. Further, the pressure detector 35 is connected to the control device 81, and the control device 81 performs the operation based on the pressure information (“p” described below) of the cream solder 7 supplied from the pressure detector 35.
The viscosity of the cream solder 7 during printing is determined.

The driving device 31 is connected to the control device 81, and when the pressure is measured under the control of the control device 81, as shown in FIG.
The pressure detecting member 30 is arranged so as to form a gap H2 having the dimension h2 between the tip 33 and the tip 33 of the pressure detecting member. During the pressure measurement, the dimension h2 of the gap H2 does not change. When the pressure detecting member 30 is arranged with the gap H2 as described above, the side surface 36 of the pressure detecting member 30 on the printing direction side.
The dimension of the gap H1 between the intersection line 37 between the pressure sensing slope 34 and the surface 3a is h1. Also, the gap H1
The distance between the gap and the gap H2 is L.

The reason why the pressure of the cream solder 7 during printing can be detected by the pressure detecting member 30 will be described.
In the state shown in FIG. 1, when the pressure detecting member 30 is moved rightward as indicated by the arrow, the cream solder 7 moves from the above-described gap H1 to the pressure detecting slope 34 of the pressure detecting member 30. It flows in and flows out of the gap H2. This phenomenon can be explained by considering the flow of material into the narrow wedge-shaped gap. That is, a model as shown in FIG. 5 is considered. This model is a generally well-known model used in the description of fluid lubrication in bearings and the like.
It is similar to the form from the gap H2 of 0 to the gap H1.
In FIG. 5, the size of the gap on the inlet side of the fluid between the wall body 301 and the reference surface 302 is h ₁ , the size of the gap on the outlet side is h ₂ , the interval between the inlet gap and the outlet gap is L, x
Is the size of the gap between the wall 301 and the reference surface 302 at a distance of h, the moving speed of the wall 301 is v, and the viscosity of the fluid is η.
It is well known that the pressure p generated at the position of the distance x by the flow of the fluid is expressed by the following equation. p = (6ηvL / (h ₁ ² −h ₂ ² )) · ((h ₁ −h) (h−h ₂ ) / h ² ) (1) Here, the cream solder 7 in the above formula (1) is used. Viscosity η
And the dimension h of the gap H1, which is a condition other than the printing speed v
1, the pressure detecting member 30 so that the conditions of the dimension h2 of the gap H2 and the distance L between the gap H1 and the gap H2 are kept constant.
Is arranged, the above equation (1) is transformed into the equation (2). p = A ₁ ηv (However, A ₁ is a _{constant) (A 1 = (6L /} (h 1 2 -h 2 2)) · ((h 1 -h) (h-h 2) / h 2) ... ( 2) Therefore, the viscosity η of the cream solder 7 can be represented by the pressure p generated at the cream solder 7 by the pressure detecting member 30 and the printing speed v as shown in the following equation (3): η = A ₂ (P / v) (where A ₂ is a constant, A ₂ = 1 / A ₁ ) (3)

As described above, the viscosity of the cream solder 7 during printing can be measured by detecting the pressure of the cream solder 7 by the pressure detector 35. The reason why the pressure detecting member 30 is arranged corresponding to the non-opening portion 91 will be described. If the pressure detecting member 30 is arranged in a region where the opening 4 is formed, the cream solder 7 may fill the opening 4 due to the pressure generated by the pressure detecting member 30. In this case, In this case, the filling is performed twice by the pressure detecting member 30 and the printing squeegee 14a, and the filling state differs between the opening 4 through which the pressure detecting member 30 has passed and the opening 4 not passing through. Because. or,
In the area of the circuit board 5, that is, in the area where the opening 4 is formed, the dimension h2 of the gap H2 at the tip 33, which is a position near the arrangement of the pressure detector 35, changes depending on the presence or absence of the opening 4. Therefore, in the area where the opening 4 is formed, the cream solder 7 detected by the pressure detector 35 is used.
Is fluctuated, and the required viscosity of the cream solder 7 changes. For these reasons, the pressure detecting member 30 is arranged corresponding to the non-opening portion 91.

The installation position of the pressure detecting member 30 is not limited to the position shown in FIG. 3, and as shown in FIG. 6, for example, adjacent to the printing squeegee 14a in the longitudinal direction of the printing squeegee 14a. 7 or a cream solder printing apparatus 1002 shown in FIG. 8 which is a side view of FIG.
The pressure detecting member 30 may be directly attached to the end in the longitudinal direction of “a”. Such a cream solder printing apparatus 1
In 002, for example, when the printing squeegee 14a performs filling and scraping, that is, when the tip 20a contacts the surface 3a of the mask 3, the tip 33 of the pressure detecting member 30 is set.
So that the gap dimension between the surface and the surface 3a becomes the above h2,
A pressure detecting member 30 is attached to the printing squeegee 14a. Further, since the pressure detecting member 30 is directly attached to the printing squeegee 14a in this manner, the cream solder printing apparatus 1002 does not include the driving device 31 for driving the pressure detecting member 30.

Since the pressure detecting slope 34 is inclined upward in the printing direction as described above, the cream solder 7 is gradually compressed along the pressure detecting slope 34 during printing, and Exhausted from H2. Therefore, the pressure of the cream solder 7 passing through the pressure detecting member 30 becomes the largest in the vicinity of the tip as shown by a graph 92 in FIG. 12, and the pressure change due to the viscosity of the cream solder 7 is the largest. Becomes Therefore, the position of the pressure detector 35 is preferably in the vicinity of the tip 33 as in the present embodiment, but is not limited to the tip 33 portion. However, the above graph 92
Since the pressure of the cream solder 7 drops sharply by moving away from the tip 33 by a distance of １ ／ to の of the length of the pressure detecting slope 34 as shown in FIG. It is preferable to be within the range up to the position at a distance of 1/4 to 1/3.

FIG. 1 shows the state of the pressure detecting member 30 in rightward printing. However, when performing leftward printing in the cream solder printing apparatus 1001, the pressure detecting member 30 is in the state shown in FIG. Become. That is, since the pressure detecting slope 34 needs to be inclined upward in the printing direction as described above, the pressure detecting member 30 is arranged to be rotated by 180 degrees about the output shaft 32 by the driving device 31. . Further, as a type in which the rotation operation of the pressure detecting member 30 is omitted, a cream solder printing apparatus 1003 shown in FIG. 10 can be configured. The cream solder printing apparatus 1003 has a pressure detection member 40 having a cross section of a ship bottom instead of the above-described pressure detection member 30, and raises and lowers the pressure detection member 40 instead of the above-described driving device 31. It has a driving device 41. Pressure detecting member 40
Is a pressure detecting member 3 shown in FIG. 2 as shown in FIG.
0 is symmetrically arranged, and a pressure detector 35-1 is installed in the vicinity of the front end 43 on the pressure detecting slope 42 where the cream solder 7 is compressed during the rightward printing. A pressure detector 35-2 is installed on the slope 44 for pressure detection in which the cream solder 7 is compressed during the above-described leftward printing. Further, the driving device 41 arranges the pressure detecting member 40 such that the front end 43 forms a gap H2 having a dimension h2 with respect to the surface 3a of the mask 3 as in the case of the pressure detecting member 30. By providing such a pressure detecting member 40, the pressure of the cream solder 7 is detected by the pressure detector 35-1 during the rightward printing, and by the pressure detector 35-2 during the leftward printing. The pressure of the cream solder 7 is detected. The detected pressure is sent from the pressure detector 35-1 to the control device 81 in the right direction printing and from the pressure detector 35-2 in the left direction printing.

The operation of the cream solder printing apparatus 1001 configured as described above will be described below.
The operation of loading the substrate 5, the operation of aligning the mask 3 with the substrate 5, and the operation of printing with the printing squeegees 14a and 14b are the same as those of the conventional cream solder printing apparatus. The description is omitted, and here, the operation related to the pressure detecting member 30 will be mainly described. The operation of the cream solder printing apparatus 1001 is controlled by the control device 81. The case where the rightward printing is performed by the printing squeegee 14a will be described as an example. The drive device 31 operates under the control of the control device 81,
The pressure detecting member 30 is arranged so that the tip 33 of the pressure detecting member 30 forms a gap H2 having a dimension h2 with respect to the surface 3a of the mask 3. In addition, since rightward printing is performed, the pressure detecting slope 34 of the pressure detecting member 30 is arranged by the driving device 31 so as to be inclined upward to the right. In such a state, the squeegee head 10 is moved rightward at a predetermined speed by the driving device 76 that drives the squeegee head 10. Therefore, the pressure detecting member 30 also moves rightward as the printing squeegee 14a moves rightward. Therefore, the cream solder 7 placed on the surface 3a of the mask 3
Of the above, those existing corresponding to the substrate 5 are filled into the openings 4 of the mask 3 by the printing squeegee 14a. Also, of the cream solder 7 placed on the surface 3a of the mask 3, the cream solder 7 existing in the non-opening area 91 flows from the gap H1 of the pressure detecting member 30 to the gap H2 side, and the gap H2 Pass through. At this time, the cream solder 7 sandwiched between the pressure detection slope 34 of the pressure detection member 30 and the surface 3a of the mask 3 is detected by a pressure detector 35 installed near the tip 33 of the pressure detection member 30. Is detected by the pressure detector 35, and the pressure information is sent to the control device 81 in real time.

In the present embodiment, the control device 81 obtains the viscosity of the cream solder 7 during printing based on the pressure information by substituting the supplied pressure information into the above equation (3). When the viscosity of the cream solder 7 is lower than the predetermined viscosity suitable for printing based on the obtained viscosity, the control device 81 increases the operating speed of the driving device 76 and reduces the moving speed of the squeegee head 10, for example. The printing squeegee 1 is driven by driving the up-down drive device 15 to increase the speed, to increase the angle α between the printing squeegee 14a and the surface 3a.
4a performs at least one operation of pressing the surface 3a, that is, lowering the printing pressure, lowering the temperature of the cream solder 7, and changing the printing conditions such as the printing speed and the squeegee filling angle, or The viscosity of the cream solder 7 is adjusted to a viscosity suitable for the printing. As a specific method for lowering the temperature of the cream solder 7, for example, lowering the ambient temperature of the cream solder printing apparatus 1001 can be considered. On the other hand, when the determined viscosity is higher than the predetermined viscosity suitable for the printing, the control device 81 decreases the operating speed of the driving device 76 and the moving speed of the squeegee head 10, for example, At least one operation of reducing the squeegee angle α, driving the vertical drive device 15 to increase the printing pressure, and increasing the temperature of the cream solder 7 is performed to change the printing conditions, or The viscosity of 7 is adjusted to a viscosity suitable for the printing.

The control device 81 determines the viscosity of the cream solder 7 during printing based on the pressure information as follows.
The method is not limited to the method of directly substituting the measured pressure information into the above equation (3). In addition, for example, a so-called table in which the cream solder viscosity for the pressure information is calculated and listed in advance may be used. A graph showing the relationship between the pressure information and the cream solder viscosity can be used, or various known methods can be used.

After the printing in the right direction is performed as described above and the printing squeegee 14a moves to the right end, the printing squeegee 14a is arranged at the standby position 18 and the printing squeegee 1
4b is arranged at the squeezing position 19, and the driving device 31 is operated to move the pressure detecting member 30 to the left so that the pressure detecting slope 34 is inclined upward toward the left.
Invert 0 degrees. The pressure detecting member 30 detects the pressure of the cream solder 7 while performing the printing operation in the same manner as in the above-described rightward printing, and the control device 81 obtains the viscosity of the cream solder 7 during printing.

As described above, in the present embodiment, the pressure detector 3
5, the viscosity of the cream solder 7 on the surface 3a of the mask 3 is changed by the squeezing on the surface 3a of the mask 3 even when the viscosity of the cream solder 7 on the surface 3a of the mask 3 changes due to continuous printing for a long time. Is obtained in real time, the change can be captured in real time. Therefore, according to the change in the viscosity of the cream solder 7, the printing conditions can be changed,
In addition, since the pressure changes due to the consumption of the cream solder 7, the cream solder 7 can be replenished at an appropriate time. Therefore, occurrence of printing failure can be prevented.

The viscosity measurement of the cream solder 7 may be performed in real time as described above, or may be performed for each substrate 5 or for a predetermined number of printed sheets. In the present embodiment, the pressure detecting slope 34 of the pressure detecting member 30 is used.
Is a flat surface, but is not limited to this. For example, a curved surface that is convex toward the surface 3a of the mask 3 may be used.
In other words, the pressure detecting slope 3 moves in the printing direction.
4 in the gap between the surface 3a of the mask 3 and the dimension h1 are larger than the dimension h2, that is, h
_1> as long as it has a relationship of h ₂ shape of the pressure detecting the slope 34 is not limited. Further, the tip 33 of the pressure detecting member 30 may be sharp as shown, or may have a plane parallel to the surface 3a over an appropriate length along the printing direction.

In this embodiment, the pressure detector 35 is provided on the pressure detecting slope 34 so as to directly detect the pressure of the cream solder 7. This is, for example, the pressure detecting member 3
Even in the case where the area of the pressure detecting slope 34 is changed by replacing 0, it is advantageous in that the information and the like obtained by the use up to that point can be diverted as long as the pressure detector 35 itself is not changed. However, the present invention is not limited to this mode. That is, a place where the pressure of the cream solder 7 can be detected, for example, the pressure detecting member 30 and the driving device 31
A sensor such as a load cell may be attached to a portion connected to the output shaft 32, and the pressure of the cream solder 7 generated on the entire surface of the pressure detecting slope 34 may be detected from the sensor.

The cream solder printing apparatus 1001
Is a type that moves in both the left and right printing directions,
Although both the printing squeegees 14a and 14b are provided, the cream solder printing apparatus may be of a type that moves to only one of them, and in that case, the printing squeegee 14a or the printing squeegee 14b corresponding to the moving direction is provided. Provided.

[0026]

As described in detail above, according to the printing paste printing apparatus of the first aspect and the printing paste printing method of the second aspect of the present invention, a pressure detecting member and a control device are provided.
Since the viscosity of the printing paste during the squeezing is directly measured by the pressure detecting member, the printing conditions can be changed in a timely and appropriate manner according to the change in the viscosity of the printing paste. Therefore, it is possible to prevent the occurrence of printing failure due to a change in the viscosity of the printing paste.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a structure of a squeegee head of a cream solder printing apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a pressure detecting member shown in FIG. 1;

FIG. 3 is a view showing an arrangement position of a pressure detecting member shown in FIG. 1;

FIG. 4 is a perspective view of the pressure detecting member shown in FIG.

FIG. 5 is a view showing a model for obtaining a filling pressure of cream solder by the pressure detecting member shown in FIG. 1;

FIG. 6 is a view showing a modification of the arrangement position of the pressure detecting member shown in FIG.

FIG. 7 is a view showing another modification of the arrangement position of the pressure detecting member shown in FIG.

8 is a side view of FIG. 7 when a pressure detecting member is arranged as shown in FIG.

FIG. 9 is a diagram illustrating a state in which leftward printing is performed by the pressure detecting member illustrated in FIG. 1;

FIG. 10 is a view showing a modification of the pressure detecting member shown in FIG. 1;

FIG. 11 is a perspective view of the cream solder printing apparatus shown in FIG. 1;

12 is a diagram showing a pressure distribution of cream solder obtained by the pressure detecting member shown in FIG.

FIG. 13 is a diagram showing the arrangement position and gap size of the pressure detector in the pressure detecting member shown in FIG.

FIG. 14 is a view showing a squeegee head in a conventional cream solder printing apparatus.

FIG. 15 is a view showing a state of the cream solder when the cream squeegee is filled into the opening of the mask by the printing squeegee shown in FIG. 14;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cream solder printing apparatus, 3 ... Printing mask, 3a ...
Surface, 5: circuit board, 7: cream solder, 14a, 14
b: printing squeegee, 30: pressure detecting member, 31: driving device, 33: tip, 34: pressure detecting slope, 35: pressure detector, 81: control device, 1001, 1002: cream solder printing device.

Claims (7)

[Claims] A printing mask (3) having an opening formed therein.
When the squeegees (14a, 14b) move in the printing direction on the front surface (3a), the printing paste (7) on the front surface is printed through the opening on the circuit board surface located on the back surface of the printing mask. A tip (33) arranged in a non-contact state with a gap (H2) away from the surface during printing, and moves in the same direction as the squeegee, and A pressure detector (3) for detecting the pressure generated in the printing paste and determining the viscosity during printing of the printing paste by the squeegee.
5) a pressure detecting member (30) having at least a moving speed of the squeegee and an angle between the squeegee and the surface based on the viscosity of the printing paste obtained based on the pressure measured by the pressure detector. And a controller (81) for controlling any one of the pressing force of the squeegee and the temperature of the printing paste. 2. The printing paste printing apparatus according to claim 1, wherein the pressure detecting member is arranged at a position corresponding to a non-opening area where the opening is not formed in the printing mask. 3. The printing paste printing apparatus according to claim 1, wherein the pressure detecting member is disposed in front of the squeegee in the printing direction. 4. A pressure detecting slope (34) which is inclined upward from the front end in the printing direction on a surface of the pressure detecting member facing the surface of the mask. 4. The printing paste printing apparatus according to claim 1, wherein a container is provided on the pressure detecting slope. 5. The printing paste printing apparatus according to claim 4, wherein the pressure detector is buried near the tip of the slope. 6. The printing mask (3) by squeezing the surface (3a) of the printing mask (3) to pass the printing paste (7) on the surface through the opening formed in the printing mask (3). A print paste printing method for printing and applying on a circuit board surface located on a back surface of the print paste, wherein a pressure generated in the applied print paste is detected to measure a viscosity of the print paste during printing. Printing paste printing method to do. 7. Based on the measured viscosity of the printing paste, at least the speed of the squeegee, the angle between the squeegee performing the squeezing and the surface, the pressure of filling the printing paste into the opening, and The print paste printing method according to claim 6, wherein one of the temperatures of the print paste is controlled.