JP4013861B2 - Screen printing apparatus and screen printing method - Google Patents

Description

  The present invention relates to a screen printing apparatus and a screen printing method for printing a paste such as cream solder or a conductive paste on a small electronic component held on a carrier.

In the electronic component manufacturing field, screen printing is widely used as a method for printing paste such as cream solder or conductive paste on a substrate. This screen printing is performed not only on a mounting board on which electronic components are mounted, but also on small pieces of electronic components such as a crystal oscillator held on a carrier. As a carrier for holding such small electronic components, the electronic components are held by suction by sucking the suction holes provided at the component holding positions in order to prevent the electronic components from being displaced and held in a stable state. The thing of the structure to perform is known (for example, refer patent document 1).
JP 2002-33372 A

  When such a carrier that holds and holds electronic components is applied to a screen printing apparatus, the following problems may occur. A rectangular electronic component such as a crystal oscillator is accommodated in a recess provided in the carrier, and in the printing position, the electronic component is placed in the recess by vacuum suction of a suction hole provided in communication with the recess. Adsorption is held.

  However, in a carrier having such a configuration, not all of the small electronic components are held in a normal posture in each recess, and some electronic components are partially removed from the recess due to vibration or impact during carrier transportation. In some cases, it may be overhanging. When the carrier reaches the printing position in this state, there is a problem that the lower surface of the screen mask is pressed against the protruding electronic component and is damaged. Such a protruding state of the electronic component is not visually confirmed when the carrier enters the lower surface side of the screen mask, and there has been a demand for a method that can reliably detect the presence or absence of the protruding electronic component. It was.

  Therefore, an object of the present invention is to provide a screen printing apparatus and a screen printing method that can reliably detect the presence or absence of an electronic component protruding from a recess in a carrier.

In the screen printing apparatus of the present invention, a mask plate provided with a pattern hole is brought into contact with a small electronic component held in a recess of a carrier, and paste is supplied onto the mask plate to slide a squeegee. A screen printing apparatus for printing a paste on the electronic component through the pattern hole, wherein the positioning unit is disposed below the mask plate, and the carrier is provided on the positioning unit and receives the carrier. The electronic component is sucked and held in the concave portion by vacuum suction from a suction hole communicating with the concave portion, and the electronic component is carried into the component holding portion together with the carrier from the component holding portion. Component conveying means for unloading the electronic component together with the carrier, and the electronic component partially protruding from the recess. Component holding abnormality detecting means for detecting a component holding abnormality held in an abnormal state, wherein the component holding abnormality detecting means is provided for the carrier that is received by the component holding portion and holds the electronic component in the recess. In the normal state where all electronic components are normally held in the recesses, the entire carrier is covered in a sealed state, and in contact with the protruding electronic component in the abnormal state, the component is stopped and held. An inspection jig through which air flows in from a gap between the upper surface of the part, a vacuum degree detecting means for detecting a vacuum degree in the substrate holding part vacuumed by the vacuum suction means, and based on the vacuum degree detection result Determination means for determining the normal state / abnormal state.

In the screen printing method of the present invention, a mask plate provided with a pattern hole is brought into contact with a small electronic component held in a recess of a carrier, and paste is supplied onto the mask plate to slide a squeegee. A screen printing method for printing a paste on the electronic component through the pattern hole, wherein the electronic component is held on the carrier by a component holding portion provided in a positioning portion disposed below the mask plate A component holding step of receiving and holding the electronic component, a printing step of executing screen printing in a state where the electronic component is sucked and held, and bringing the electronic component into the component holding portion together with the carrier and from the component holding portion. In the component conveying step of unloading the electronic component together with the carrier, and in an abnormal state where the electronic component partially protrudes from the recess. A component holding abnormality detecting step for detecting a held component holding abnormality, and in the component holding abnormality detecting step, the carrier in a state of being held by the component holding portion and holding the electronic component in the recess, Covers the entire carrier in a sealed state in a normal state in which all electronic components are normally held in the recesses, and stops in contact with the protruding electronic component in the abnormal state and between the upper surface of the component holding unit An inspection jig into which air flows in from the gap is approached, and the degree of vacuum in the substrate holding part vacuumed by the vacuum suction means is detected by the vacuum degree detection means, and the normal state is determined based on the detection result of the degree of vacuum・ Determine the abnormal state.

  According to the present invention, in a normal state in which all the electronic components are normally held in the recesses, the entire carrier is covered in a sealed state, and the electronic components protrude in an abnormal state where the electronic components partially protrude from the recesses. The inspection jig that comes into contact with it is brought close to it, and the degree of vacuum in the substrate holding part that is vacuumed by the vacuum suction means is detected by the vacuum degree detection means, and the normal state / abnormal state is determined based on the detection result of the vacuum degree. By doing so, it is possible to reliably detect whether or not the electronic component protrudes from the recess in the carrier.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the screen printing apparatus according to an embodiment of the present invention, and FIG. 3 is a screen printing apparatus according to an embodiment of the present invention. FIG. 4 and FIG. 5 are cross-sectional views of a carrier and a receiving part of a screen printing apparatus according to an embodiment of the present invention. FIG. 6 is a flowchart of the screen printing method according to the embodiment of the present invention. 7 is an operation explanatory diagram of the component holding abnormality detection process in the screen printing method according to the embodiment of the present invention.

First, the structure of the screen printing apparatus will be described with reference to FIGS. In FIG. 1, the screen printing apparatus is configured by disposing a positioning unit 1 below a screen printing unit 11. The positioning unit 1 is configured by stacking a Y-axis table 2, an X-axis table 3, and a θ-axis table 4, and further placing a Z-axis table 5 thereon. The on Z-axis table 5 is disposed is below accepted part 6. Lower receiving only 6 receives under the electronic component 9 carrier 8 which holds the pieces, such as printed crystal oscillator. The carrier 8 is held in the horizontal position by sandwiching both ends thereof by the clamper 7.

Electronic component 9 is carried by the carrying conveyor 17 in a state of being accommodated in the recess 8a of the carrier 8, are to be passed to the print conveyer 18 mounted on the lower accept part 6. Then, the printed carrier 8 is carried out by the carry-out conveyor 19. Input conveyor 17, the print conveyer 18 and discharge conveyor 19 constitute the component carrying means for carrying out the crotch accept part 6 carries the electronic component 9 together with the carrier 8 on the lower accept part 6 an electronic component 9 together with a carrier 8 .

  A screen printing unit 11 is disposed above the positioning unit 1. The screen printing unit 11 includes a mask plate 12 extended on a holder frame. A squeegee unit 13 is disposed on the mask plate 12, and the squeegee unit 13 is moved in the Y direction by a moving means (not shown). The plate 14 of the squeegee unit 13 is provided with a squeegee lifting mechanism 15 that moves the squeegee 16 up and down.

  In a state where the electronic component 9 held by the carrier 8 is in contact with the lower surface of the mask plate 12, a cream solder as a paste is supplied onto the mask plate 12 and the squeegee 16 is slid to form a pattern hole (not shown). The cream solder is printed on the connection electrodes (not shown) of each electronic component 9 via.

  A camera 20 is provided above the mask plate 12. As shown in FIG. 3, the camera 20 is horizontally moved in the XY directions by the X-axis table 21 and the Y-axis table 22. The camera 20 images the recognition mark provided on the carrier 8. And the position of each recognition mark is detected based on the image data obtained by imaging. Based on the position detection result, the wafer 9 and the mask plate 12 are aligned.

  In FIG. 2, a jig lifting mechanism 23 is disposed on the right side of the screen printing unit 11. The jig lifting mechanism 23 has a configuration in which an inspection jig 26 for detecting a component holding abnormality mounted on the lower surface of the holding head 25 is held up and down by the lifting mechanism 24 so as to hold the electronic component 9. With the carrier 8 moving below the jig lifting mechanism 23, the holding head 25 is lowered with respect to the carrier 8 so that a component holding abnormality described later can be determined.

Referring now to FIG. 4, it will be described carrier 8 and Shita受only part 6. The carrier 8 is a rectangular plate-like member, and a plurality of concave portions 8a are provided on the upper surface of the carrier 8, and small electronic components 9 such as a crystal resonator are accommodated in the concave portion 8a. The bottom of the recess 8a is provided with a suction hole 8b, the upper surface of the lower accept part 6, the suction hole 6a is provided so as to correspond to the arrangement of the suction holes 8b.

In the state in which the carrier 8 is mounted on the lower accept part 6, the suction hole 8b communicates with the suction hole 6a provided on the upper surface of the lower accept part 6. The inner space 6b of the lower accept part 6 is connected to a vacuum suction means 27 such as a vacuum blower, by driving the vacuum suction means 27, vacuum from the suction hole 8b through the inner space 6b, the suction hole 6a The electronic component 9 can be sucked and held on the bottom of the concave portion 8a by suction.

  A vacuum degree detection means 28 such as a vacuum sensor is connected to the internal space 6b, and the detection result of the vacuum degree detection means 28 is sent to the control unit 29 of the screen printing apparatus. The control unit 29 determines whether or not the electronic component 9 is normally held in the recess 8a based on the vacuum degree detection result of the internal space 6b, that is, whether or not there is a component holding abnormality.

  Here, the determination of the presence or absence of the above-described component holding abnormality will be described. In the determination of the component holding state by detecting the degree of vacuum for the carrier 8 that holds a large number of electronic components 9, the component size greatly affects the determination accuracy, and the smaller the component, the lower the determination accuracy. That is, when the size of the suction holes for sucking electronic components becomes finer corresponding to the size of the electronic components, the fluctuation of the vacuum suction state from one suction hole has a small effect on the overall degree of vacuum, and therefore the normal state and It becomes difficult to set a threshold value for distinguishing between abnormal states.

That is, even when the electronic components 9 are normally accommodated in all the recesses 8a, some vacuum leaks exist in a steady state in each recess 8a. For this reason, even if the fluctuation of the leak amount due to the electronic component 9 protruding from the recess 8a in one recess 8a occurs, the ratio of the change to the leak amount in the steady state is small, and the normal value and the abnormal value are clearly shown. This is because it becomes difficult to separate.

  In order to solve the difficulty in setting the threshold value, in the present embodiment, in detecting the degree of vacuum for detecting a component holding abnormality, an inspection jig 26 as shown in FIG. In this state, the degree of vacuum is detected. On the lower surface side of the inspection jig 26, a recess having a depth dimension d slightly larger than the height from the lower surface of the carrier 8 to the upper surface of the electronic component 9 in a state where the electronic component 9 is accommodated in each recess 8 a in a normal posture. 26a is formed.

  When the inspection jig 26 is lowered and lowered and pressed against the lower receiving portion 6, the carrier 8 holding the electronic component 9 is positioned in a substantially sealed state from the outside in the recess 26a. In this state, the degree of vacuum is detected by vacuuming the interior space 6a. In this suction state, the entire carrier 8 is in a sealed state, so that almost no vacuum leak from the suction hole 8b occurs. The degree of vacuum is higher than when vacuum suction is performed in an open state.

  FIG. 5A shows a state of component holding abnormality. In this state, when the inspection jig 26 is lowered with respect to the lower receiving portion 6, the inspection jig 26 comes into contact with the electronic component 9 protruding from the recess 8a, and the lower end portion of the inspection jig 26 is received by the lower receiving portion. Stop without contacting the upper surface of the part 6. That is, the concave portion 26 a does not become a sealed space, and even if the internal space 6 b of the lower receiving portion 6 is vacuum-sucked, the concave portion 26 a enters the concave portion 26 a from the gap between the lower end portion of the inspection jig 26 and the upper surface of the lower receiving portion 6. Air flows in. For this reason, the degree of vacuum in the internal space 6b shows a clear difference in degree of vacuum as compared with the normal state shown in FIG.

  That is, the inspection jig 26 configured as described above is approached from above with respect to the carrier 8 that is received by the lower receiving portion 6 and holds the electronic component 9 in the concave portion 8a, and all the electronic components 9 are in the concave portion 8a. In the normal state where the carrier 8 is normally held, the entire carrier 8 is covered in a sealed state, and the electronic component 9 comes into contact with the protruding electronic component 9 and stops in an abnormal state where the electronic component 9 partially protrudes from the recess 8a.

  Therefore, by setting a threshold value between the degree of vacuum in the state shown in FIG. 4 and the degree of vacuum in the state shown in FIG. 5B, the component holding abnormality can be detected stably. The vacuum suction means 27, the vacuum degree detection means 28, the control unit 29, and the inspection jig 26 detect a component holding abnormality in which the electronic component 9 is held in an abnormal state in which the electronic component 9 partially protrudes from the recess 8a. It is a detection means.

  This screen printing apparatus is configured as described above, and the screen printing method will be described below with reference to FIGS. In this screen printing method, a mask plate 12 provided with a pattern hole is brought into contact with a small electronic component 9 held by a plate-like carrier 8, and paste is supplied onto the mask plate 12 to slide a squeegee. By moving, the paste is printed on the electronic component through the pattern hole.

In FIG. 6, first, the carrier 8 holding the electronic component 9 is carried into the positioning portion 1 as shown in FIG. 7A (ST1). Next, the lower receiving portion 6 provided in the positioning portion 1 is raised, the vacuum suction means 27 is turned on (ST2), and the electronic component 9 held by the carrier 8 is received and held by suction. Next, the carrier 8 is moved below the jig lifting mechanism 23 (ST3), and then the inspection jig 26 is lowered with respect to the carrier 8 on the lower receiving portion 6 as shown in FIG. ST4) With the upper surface of the lower receiving part 6 sealed, the degree of vacuum of the lower receiving part 6 is detected (ST5).

  Here, the detection result of the degree-of-vacuum detection means 28 is determined by the control unit 29, and it is determined whether or not the degree of vacuum is equal to or greater than a specified value that is a threshold value for separating normality from abnormality (ST6). Here, if the degree of vacuum is equal to or less than the specified value, it is determined as the component holding abnormality shown in FIG. 5B, and the machine is stopped and notified to that effect (ST7). If the degree of vacuum is equal to or greater than the specified value in (ST6), it is determined that the component holding state is the normal state shown in FIG. 4B, and the process proceeds to the next step.

  That is, the inspection jig 26 is raised (ST8), and the carrier 8 is moved to a printing position below the screen printing unit 11 (ST9). Next, a printing operation for printing the cream solder on the electronic component 9 is performed (ST10). That is, the Z-axis table 5 is driven to bring the electronic component 9 together with the carrier 8 into contact with the lower surface of the mask plate 12 to which the cream solder 27 is supplied, and the squeegee 16 is slid in the Y direction on the upper surface of the mask plate 12. .

As a result, cream solder is filled in the pattern holes of the mask plate 12, and then the electronic component 9 is lowered together with the carrier 8 and separated from the mask plate 12, thereby completing the printing of the cream solder on the electronic component 9. And if completing the screen printing, receiving unit 6 is lowered down vacuum suction is released by the lower accept part 6 (ST11), then carries out the carrier 8 (ST12), terminates the printing operation for one cycle To do.

That is, a screen printing method described above, the substrate for attracting and holding the electronic component 9 held by the carrier 8 on the lower accept part 6 provided in the positioning portion 1 arranged below the mask plate 12 to receive the lower a holding step, a printing step for executing a screen printing the electronic component 9 while holding adsorbed carrier electronic component 9 from the crotch accept parts 6 carried on the lower accept part 6 an electronic component 9 together with a carrier 8 9 In addition, a board transporting process for unloading and a component holding abnormality detecting process for detecting a component holding abnormality in which the electronic component 9 is held in an abnormal state partially protruding from the recess 8a are included.

  In the component holding abnormality detecting step, the inspection jig 26 is brought close to the carrier 8 that is received by the lower receiving portion 6 and holds the electronic component 9 in the recess 8 a, and is vacuumed by the vacuum suction means 27. The degree of vacuum in the sucked lower receiving portion 6 is detected by the degree of vacuum detection means 28, and the normal state / abnormal state of component holding is determined based on the result of the degree of vacuum detection.

  As a result, even if it is difficult to detect abnormalities in the component holding state by detecting the degree of vacuum normally for small electronic components such as crystal units, the component holding abnormality that protrudes from the concave portion of the carrier Can be detected with high accuracy, and problems such as breakage of the screen mask due to the carrier being carried into the printing position in an abnormal state can be prevented.

  The screen printing apparatus and the screen printing method of the present invention can reliably detect the presence or absence of an electronic component popping out of the recess in the carrier, and the screen mask is broken by the carrier being brought into the printing position in an abnormal state. This is effective in the field of screen printing in which pastes such as cream solder and conductive paste are printed on small-sized electronic components held on a carrier.

1 is a front view of a screen printing apparatus according to an embodiment of the present invention. The side view of the screen printing apparatus of one embodiment of this invention The top view of the screen printing apparatus of one embodiment of this invention Sectional drawing of the carrier of the screen printing apparatus of one embodiment of this invention, and a receiving part Sectional drawing of the carrier of the screen printing apparatus of one embodiment of this invention, and a receiving part Flow diagram of a screen printing method according to an embodiment of the present invention Operation explanatory diagram of component holding abnormality detection processing in the screen printing method of one embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate positioning part 6 Bottom receiving part 8 Carrier 8a Recessed part 9 Electronic component 11 Screen printing part 12 Mask plate 13 Squeegee unit 23 Jig raising / lowering mechanism 26 Inspection jig 27 Vacuum suction means 28 Vacuum degree detection means 29 Control part

Claims (2)

The mask plate provided with the pattern hole is brought into contact with a small electronic component held in the concave portion of the carrier, the paste is supplied onto the mask plate, and the squeegee is slid to pass through the pattern hole. A screen printing apparatus for printing a paste on an electronic component, wherein a vacuum is formed from a positioning portion disposed below the mask plate, and a suction hole provided in the positioning portion for receiving the carrier and communicating with the recess. A component holding unit that sucks and holds the electronic component in the recess by vacuum suction by a suction unit, and the electronic component is carried into the component holding unit together with the carrier, and the electronic component is carried out from the component holding unit together with the carrier. And the electronic component is held in an abnormal state in which the electronic component partially protrudes from the recess. A component holding abnormality detecting means for detecting an article holding abnormality, the component holding abnormality detecting means approaching from above the carrier that is received by the component holding portion and holds the electronic component in the recess, In a normal state where the electronic component is normally held in the recess, the entire carrier is covered in a hermetically sealed state, and in contact with the protruding electronic component in the abnormal state, the gap is between the upper surface of the component holding unit. An inspection jig through which air flows from, a vacuum degree detecting means for detecting the degree of vacuum in the substrate holding part vacuumed by the vacuum suction means, and the normal state / abnormal state based on the degree of vacuum detection result. A screen printing apparatus comprising: a determination unit for determining. The mask plate provided with the pattern hole is brought into contact with a small electronic component held in the concave portion of the carrier, the paste is supplied onto the mask plate, and the squeegee is slid to pass through the pattern hole. A screen printing method for printing a paste on an electronic component, wherein the electronic component held by the carrier is received and sucked and held by a component holding portion provided in a positioning portion disposed below the mask plate. A component holding step, a printing step in which screen printing is performed in a state where the electronic component is sucked and held, and a component that carries the electronic component into the component holding portion together with the carrier and carries the electronic component from the component holding portion together with the carrier. Detecting a component holding abnormality in which the electronic component is held in an abnormal state where the electronic component partially protrudes from the recess. In the component holding abnormality detection step, all the electronic components are normal in the recesses with respect to the carrier received by the component holding unit and holding the electronic components in the recesses. For the inspection in which the entire carrier is covered in a sealed state in a normal state held in the air and stopped in contact with the protruding electronic component in the abnormal state and air flows in from a gap between the upper surface of the component holding part The degree of vacuum in the substrate holding part vacuumed by the vacuum suction means is detected by a vacuum degree detection means, and the normal state / abnormal state is determined based on the detection result of the vacuum degree. Screen printing method.

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