KR100327232B1 - Squeegee Device of Screen Printer_ - Google Patents

Abstract

A plurality of second squeegees are arranged side by side on the same surface of the single plate-shaped first squeegee so as not to interfere with the COB mounting parts, thereby increasing adhesion to the surroundings of the COB mounting parts when solder paste is applied. Disclosed is a screen printer squeegee device which improves reliability of component mounting by uniform application of solder paste.

Description

Squeegee Device of Screen Printer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squeegee device of a screen printer which applies a bonding material such as solder paste to mount a small electronic component such as a semiconductor chip on an electronic circuit wiring printed on a printed circuit board, and more particularly, a general mounting component and a COB. The present invention relates to a squeegee device of a screen printer for applying a bonding material to a printed circuit board mounted in a state where a chip-on-board mounting component is mixed.

The printed circuit board, which is embedded as a main component of electrical and electronic equipment, is formed with electronic circuit wiring in which a conductive layer such as a copper film (Cu Film) is printed in a predetermined pattern. The component is mounted to be electrically connected. As a method for mounting such a small electronic component on a printed circuit board, screen printing is mainly used.

The above screen printing method is to solder a small electronic component such as a semiconductor chip to a printed circuit board by using solder paste or cream solder as a bonding material, and is printed through a squeegee device of the screen printer. The solder paste is evenly applied to the electronic circuit wiring printed on the circuit board, the conductor lead of the electronic component is seated thereon, and the solder paste is cured. The conductor lead of the electronic component is soldered and bonded to the electronic circuit wiring of the printed circuit board. Is connected.

On the other hand, in order to meet the recent trend of miniaturization of electrical and electronic equipment, electronic component manufacturers directly cut bare chip devices having electronic circuits formed on silicon wafers without a normal packaging process and directly skip the printed circuit board. There is an increasing tendency to sell flip chip devices manufactured to be mounted to set makers.

A mounting component that is directly bonded to and electrically connected to an electrode pad formed on an electronic circuit wiring of a printed circuit board, such as the flip chip, is referred to as a chip on board (COB) mounting component. , Mounted on a printed circuit board in a state where the conductor lead is mixed with a general surface mount component which is supported to be mounted on the lead frame and is electrically connected to the electrode pad formed on the electronic circuit wiring of the printed circuit board in a resin molded package state. It is common to be.

In the case of a so-called COB mixed printed circuit board mounted such that the above-described COB-type mounting parts and general mounting parts are mixed, solder to electrode pads formed on the electronic circuit wiring of the printed circuit board to mount each type of electronic component. Various problems occur in the screen printing process of applying a bonding material such as paste. Therefore, one type of either a general surface mount component or a COB type mounting component is mounted first, and the other type is mounted later. In this selective mounting process, when a general surface mount component is first mounted on a printed circuit board rather than a COB type component, a reflow machine can be completed to solder the general surface mount component before the COB type component is mounted. The printed circuit board is passed through the reflow machine. At this time, since an oxide film is formed by applying a thermal stress to a pad formed on the electronic circuit wiring of the printed circuit board to which the COB-type mounting component is bonded, this oxide film prevents the connection of the COB-type mounting component. There is a problem that has a fatal effect on the reliability.

In order to improve the connection reliability of COB-type mounting parts by excluding these problems, when COB-type mounting parts are mounted on a printed circuit board before general surface mounting parts, FIGS. 1 and FIG. As shown in FIG. 2, the squeegee device 100 of the screen printer is pre-mounted on the printed circuit board 10 in the process of applying the solder paste S to the electrode pad formed on the electronic circuit wiring of the printed circuit board 10. The COB type mounting part 11 which protrudes from the surface becomes obstructive. Therefore, the uneven metal mask 20 specially manufactured to form the protrusion 21 for accommodating and protecting the COB-type mounting part 11 is required, which requires a lot of time and money in mounting work. .

Referring to FIGS. 1 and 2, the process of applying the solder paste S to the electronic circuit wiring of the printed circuit board 10 through the squeegee device 100 of the conventional screen printer is as follows. First, when the printed circuit board 10 is transferred to the backup plate 31 by a transfer device (not shown) such as a robot arm, the backup plate 31 is lifted by the actuator 30 to be printed at the print position. Align the substrate 10.

Next, the metal mask (or screen) 20 is positioned to cover the top of the printed circuit board 10 by a separate transfer device (not shown) while being supported by the support frame 23. . The metal mask 20 is formed in a concave-convex shape provided with a protrusion 21 for accommodating and protecting the COB-type mounting part 11 which is mounted on the printed circuit board 10 and protrudes from the surface thereof. In addition, the metal mask 20 has an opening opened so that the conductor layer has the same pattern as the print pattern of the pad P on which the printed circuit board 10 is bonded to the general mounting parts in the electronic circuit wiring of the printed circuit board 10. 22) is formed.

Subsequently, a solder paste supply device (not shown) provided in the screen printer supplies the solder paste 1 to a predetermined position of the metal mask 20. Accordingly, the squeegee 130 coupled to the holder 120 installed to allow the lifter and the linear reciprocating motion is lowered by the driving unit 110 provided in the squeegee device 100 of the screen printer, and the metal mask 20 is lowered. By sliding the solder paste S while sliding the surface, the solder paste S flows through the opening 22 to be uniformly applied to the pad P to which the general mounting parts are bonded.

After the solder paste is applied in this way, in the subsequent component mounting process, for example, a chip mounter (not shown) is mounted on the pad to which the solder paste S is applied to cure the solder paste S. As a result, component mounting is completed.

However, in the screen printing squeegee device for applying the solder paste to the COB mixed printed circuit board 10 described above, the squeegee 130 usually uses a single plate-shaped metal material to slide on the metal mask 20. As shown in FIG. 2, the periphery of the protrusion 21 is raised to form a gap X. Therefore, since the squeegee 130 cannot contact the gap X, the solder paste S is not properly supplied to the opening 22 formed around the protrusion 23b, so that the pad P around it is not provided. ), There is a problem in that the solder paste S is not applied or is unevenly applied, thereby causing a connection failure of the mounting component.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the squeegee device of the conventional screen printer as described above. When applying a solder paste to a COB mixed printed circuit board, a plurality of squeegees are used to form a mask. It is an object of the present invention to provide a squeegee device for a screen printer that can improve the connection reliability of mounting components by uniformly applying solder paste by increasing adhesion to the periphery of the uneven portion.

1 is a cross-sectional view schematically showing the main portion to explain the squeegee device of a conventional screen printer;

Figure 2 is a schematic front view showing a cross-section taken along the line II-II of Figure 1 in the direction of the arrow A,

Figure 3 is a perspective view schematically showing the main part of the squeegee device of the screen printer according to the present invention,

4 is a schematic side view of the cross-sectional view of FIG. 3;

5 is a cross-sectional view schematically showing the main part of the squeegee device of the screen printer according to another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawing>

10 ... Printed Circuit Board 11 ... COB Mounting Components

30 ... actuator 31 ... backup plate

200 ... mask 201 ... through

202 pattern opening 210 mask support frame

301 ... 1st squeegee 302a, 302b ... 2nd squeegee

310, 321, 322 ... Driver h ... Squeegee holder

P ... pad S ... solder

The squeegee device of the screen printer according to the present invention for achieving the above object is stacked on the printed circuit board having a pattern opening opened to have a pattern portion at least matching the pattern of the electronic circuit wiring printed on the printed circuit board. A mask disposed in a state and a squeegee installed to slide the upper surface of the mask to apply solder paste to the electronic circuit wiring of the printed circuit board through the pattern opening by pressing the solder paste supplied to the upper surface of the mask. In the squeegee device of the screen printer, the mask has an opening opening to allow the through-projection of at least one flip chip component pre-mounted on the printed circuit board, respectively, and the squeegee is capable of lifting and lowering the mask A first squeegee provided with the first squeegee Juxtaposed with one surface and fingers parallel state is characterized by including a serial plurality of second squeegee are arranged in a straight line in spaced apart from each other by the width state to pass through the said flip-chip component.

In addition, the squeegee device of another screen printer of the present invention for achieving the above object, has a pattern opening that is opened to have a pattern portion at least matching the pattern of the electronic circuit wiring printed on the printed circuit board on the printed circuit board A mask disposed in a stacked state and a squeegee installed to slide the upper surface of the mask to press the solder paste supplied to the upper surface of the mask to apply solder paste to the electronic circuit wiring of the printed circuit board through the pattern opening. In the squeegee device of the screen printer comprising a, the mask has an opening opening to allow the through protrusion of the flip chip component pre-mounted on the printed circuit board, the squeegee is lifted and driven separately with respect to the mask A first squeegee and a third squeegee, the first squeegee and a third Disposed in side-by-side parallel state between the rake fingers, and is characterized in that it comprises a serial plurality of second squeegee are arranged in a straight line in spaced apart from each other by the width state to pass through the said flip-chip component.

According to the squeegee device of the screen printer according to the present invention, it is preferable that the plurality of second squeegee is provided to be separately moved along one surface of the first squeegee, so that the mutual spacing can be adjusted.

Hereinafter, with reference to the accompanying drawings will be described in detail the squeegee device of the screen printer according to an embodiment of the present invention.

Referring to FIGS. 3 and 4, the squeegee device 300 of the screen printer according to the present invention includes a flat plate disposed to cover the printed circuit board 10 on which the COB type mounting component 11 is mounted in advance. The mask 200, the first squeegee 301 is provided in parallel with the one surface of the first squeegee 301 and the lifting and linear reciprocating movement with respect to the mask 200 is arranged in parallel A pair of second squeegees disposed in series in a straight line in a state spaced apart from each other by their widths so as to pass through the COB-type mounting parts, and separately provided to allow the driving and linear reciprocating motions to the mask 200 separately. 302a) 302b.

Here, reference numerals 310, 321, and 322 denote driving units for lifting and lowering the holder h supporting the first squeegee 301 and the pair of second squeegee 302a, 302b, respectively. Conventional lifting and driving means such as a cylinder can be used.

The first and second squeegee 301 and the pair of second squeegee 302a and 302b are installed to be connected to a general linear reciprocating means such as an XY robot, for example. Lifting and straight reciprocating movements are possible.

Accordingly, the pair of second squeegee 302a and 302b are provided to be separately moved along one surface of the first squeegee 301 so as to be able to adjust the spacing therebetween.

Also, reference numeral 31 denotes a backup plate for supporting the printed circuit board 10 to align the solder paste S at a position for printing, and 30 denotes an actuator for driving the backup plate 31 up and down. Indicates.

According to the present invention, the upper surface of the mask 200 is formed in a flat plate shape, the through-hole 201 opened so that the COB-type mounting parts 11 previously mounted on the printed circuit board 10 are protruded. The pattern opening 202 is formed to have the same pattern as the print pattern of the pad P on which the conductor layer is printed so that general mounting parts are bonded in the electronic circuit wiring of the printed circuit board 10. It is.

According to another aspect of the present invention, the second squeegee 302a, 302b is spaced apart from each other or have a different distance from each other to form a predetermined distance from each other three or more according to the mounting amount of the COB-type mounting component 11 It can be installed in a divided state.

Process of applying the solder paste (S) to the pad (P) of the electronic circuit wiring to which the general surface-mounting component of the COB mixed printed circuit board 10 is bonded by the squeegee device of the screen printer according to the present invention having the above configuration. The following is an overview.

First, when the printed circuit board 10 is transferred to the backup plate 31 by a transfer device (not shown) such as a robot arm, the backup plate 31 is lifted by the actuator 30 to be printed at the print position. Align the substrate 10.

Next, the metal mask 200 is positioned to cover the upper portion of the printed circuit board 10 by a separate transfer device (not shown) while being supported by the support frame 210. At this time, the COB type mounting part 11, which is mounted on the printed circuit board 10 and protrudes from the surface thereof, protrudes through the through hole 201 formed in the mask 200.

Subsequently, a solder paste supply device (not shown) provided in the screen printer supplies the solder paste S to a predetermined position of the metal mask 200. Accordingly, the first squeegee 301 and the second squeegee 302a and 302b are lowered by driving the driving units 310, 321 and 322 provided in the squeegee device 300 of the screen printer. The tip is positioned to contact the mask 200.

Thereafter, for example, the solder paste S is swept by sliding the upper surface of the metal mask 200 while moving linearly from the left side to the right side of the figure. At this time, when the first squeegee 301 and the second squeegee 302a and 302b reach around the COB-type mounting part 11, the COB-type mounting part 11 is the second squeegee 302a. The first squeegee 301 is moved up so that the first squeegee 301 is not caught by the COB-type mounting part 11, and then descends again after passing completely through the COB-type mounting part 11. By sliding the (200) phase, the above solder paste coating operation is performed as it is.

By the above process, the solder paste S is uniformly flowed into the pattern opening 202 of the mask 200 and uniformly applied on the pad P to which the general mounting parts are bonded.

On the other hand, the lifting motion of the first squeegee 301 may be automatically controlled by detecting a close position of the COB-type mounting part 11 by, for example, a sensor, or may be performed manually by a switch operation or the like.

According to the present invention, since the second squeegee 302a and 302b slide in a state in which the second squeegee 302a and 302b are closely adhered to the COB-type mounting part 11, in particular, the solder is also formed at the peripheral corners of the COB-type mounting part 11. It has an effect which can apply | coat paste S uniformly. In addition, since the sliding of the first squeegee 301 is continuously performed following the sliding movement of the second squeegee 302a and 302b, the solder paste S may be more uniformly coated.

After the solder paste is applied by the above process, the surface mounting component is seated on the pad P on which the solder paste S is applied, for example, by a chip mounter (not shown). Component mounting is completed by the hardening process of the solder paste (S).

5 is a view showing another embodiment of the present invention, in which the same reference numerals as those of the above-described drawings indicate the same components. The squeegee device of the screen printer according to this embodiment is provided with a single plate-shaped first squeegee 301, which is lifted and driven separately with respect to the mask 200, in parallel with each other so as to maintain a constant distance therefrom. The single plate-shaped third squeegee 303 and the second squeegee 302a and 302b in the squeegee device of the embodiment disclosed in FIGS. 3 and 4 are formed of the first squeegee 301 and the third squeegee 303. It is installed in between.

The first squeegee 301 and the third squeegee 303 are supplied while sliding the solder paste S by sliding only the upper left and right surfaces of the metal mask 200 around the COB type mounting part 11.

For example, when the first, second and third squeegees are moved from the left side to the right side of the drawing, the first squeegee 301 is a metal mask 200 for the left side of the COB type mounting part 11. Sliding the upper surface of the), in this case the third squeegee 303 is moved to a state not in contact with the metal mask 200 in an elevated state.

In addition, the first squeegee 301 moves up to reach the COB type mounting part 11, while the third squeegee 303 descends as soon as it passes through the COB type mounting part 11. The upper surface of the metal mask 200 on the left side of the COB type mounting part 11 is slid.

On the other hand, the lifting motion of the first squeegee 301 and the third squeegee 303 may be automatically controlled by detecting a close position of the COB type mounting part 11 by, for example, a sensor or the like. You can also do it manually.

In the present embodiment, the second squeegee 302a and 302b have the same operation as in the above-described embodiment regardless of the action of the first squeegee 301 and the third squeegee 303. do.

As described above, the squeegee device of the screen printer according to the present invention has high adhesion to the periphery of the COB mounting parts protruding from the flat mask when applying the solder paste to the COB mixed printed circuit board, and almost the entire surface of the mask. Since phosphorus contact is possible, the solder paste is uniformly applied to improve connection reliability of the mounting component, thereby providing a high quality printed circuit board.

Claims (4)

A mask disposed in a stacked state on the printed circuit board, having a pattern opening that is open to have a pattern portion that at least matches the pattern of the electronic circuit wiring printed on the printed circuit board, and installed to slide the upper surface of the mask; In the squeegee device for applying a solder paste of a screen printer comprising a squeegee for applying a solder paste to the electronic circuit wiring of the printed circuit board by pressing the solder paste supplied to the upper surface of the mask, The mask has through holes open to allow through projections of at least one flip chip component pre-mounted on the printed circuit board, respectively. The squeegee is arranged in parallel with the first squeegee provided to be capable of elevating driving with respect to the mask and in parallel with one surface of the first squeegee, and spaced apart from each other by the width thereof so that the flip chip component passes therethrough. A squeegee device for applying solder paste to a screen printer, comprising a plurality of second squeegee disposed therein. The method of claim 1, The plurality of second squeegee is provided so as to be movable separately along the one surface of the first squeegee, the squeegee device for applying the solder paste of the screen printer, characterized in that the mutual gap adjustment is possible. A mask disposed in a stacked state on the printed circuit board, having a pattern opening that is open to have a pattern portion that at least matches the pattern of the electronic circuit wiring printed on the printed circuit board, and installed to slide the upper surface of the mask; In the squeegee device for applying a solder paste of a screen printer comprising a squeegee for applying a solder paste to the electronic circuit wiring of the printed circuit board by pressing the solder paste supplied to the upper surface of the mask, The mask has a through hole opened to allow through protrusion of a flip chip component pre-mounted on the printed circuit board, The squeegees are arranged parallel to each other between the first squeegee and the third squeegee and the first squeegee and the third squeegee, each of which is lifted and driven separately with respect to the mask, and each other by the width thereof so that the flip chip component passes. Squeegee device for applying a solder paste of a screen printer, characterized in that it comprises a plurality of second squeegee arranged in series in a spaced state. The method of claim 1, The plurality of second squeegee is provided so as to be movable separately along the one surface of the first squeegee, the squeegee device for applying the solder paste of the screen printer, characterized in that the mutual gap adjustment is possible.