KR20070078855A - Epoxy dispensing control apparatus - Google Patents

Abstract

An epoxy dispensing control apparatus is provided to uniformly apply a constant amount of epoxy on an accurate position by opening a dispensing unit by using a pressure and an elastic property of a pressurized air. An epoxy dispensing control apparatus includes a syringe(110), a dispensing unit(120), a bypass fluid path(170), and a switch. A vacuum/air inlet tube is connected to an upper end of the syringe. The hole opening unit is connected to a lower portion of the syringe and opens/closes an epoxy flow. The bypass fluid path bypasses the pressurized air which is inputted to the syringe. The bypass fluid path applies a pressure at one side of the hole opening unit. The switch controls the epoxy flow according to a pressurizing pressure which is inputted through the bypass fluid path, and a counter force which counteracts the pressurizing pressure.

Description

Epoxy dispensing control apparatus

1A and 1B are schematic views showing a conventional epoxy discharging apparatus, and showing a process of discharging epoxy using the same.

2 is a schematic view showing an epoxy discharge control apparatus according to the present invention, showing a process of discharging epoxy,

3 is a view showing in detail the structure of the discharge opening and closing means provided in the epoxy discharge control apparatus according to the present invention,

4 is a schematic view showing an epoxy discharge control apparatus according to the present invention, showing a state of blocking the discharge of the epoxy,

5A and 5B are cross-sectional views taken along line A-A of FIG. 3, respectively, and are enlarged views individually showing a state in which the ejection opening and closing means of the epoxy ejection control apparatus according to the present invention operates.

* Description of the symbols for the main parts of the drawings *

10, 110: Syringe 30, 140: Buoy / Air inlet pipe

20, 130: needle 40, 150: epoxy

120 discharge opening and closing means 50 first mechanism

123: elastic body

The present invention relates to an epoxy discharge control apparatus for semiconductor die bonding.

In order to attach the semiconductor chip, an adhesive liquid epoxy is applied to the chip attaching region of the circuit board in advance, and the equipment for applying epoxy and attaching the semiconductor chip is called a die attach equipment. That is, in the die attach equipment, a process of dispensing a certain amount of liquid epoxy on a circuit board and then attaching a semiconductor chip to an upper surface thereof is integrally performed.

In general, a semiconductor die attach equipment includes a bonding table for performing a die bonding operation, a PCB supply means for supplying a printed circuit board to the bonding table, and an epoxy ejection device for supplying an epoxy liquid resin to a pad of the printed circuit board. And die bonding means for bonding the chip to the upper surface of the printed circuit board.

In addition, a needle dispenser is generally used for discharging epoxy, and a syringe and needle for spraying epoxy on a pad of a printed circuit board, and a printed circuit seated on the bonding table. It consists of a drive unit for raising / lowering the epoxy spray nozzle to adjust the distance to the substrate.

As shown in FIG. 1A, the epoxy discharging device is coupled to one end of the syringe 10 formed with a syringe 10 formed as a storage space so that a predetermined amount of epoxy can be enclosed therein, and a printed circuit board 50. It is composed of a needle (20) for injecting epoxy to the.

Referring to the operation of applying the epoxy on the upper surface of the printed circuit board using a conventional epoxy discharge device sequentially as follows.

First, as shown in FIG. 1A, after mounting the printed circuit board 50 on the bonding table, the epoxy discharging device is positioned on the epoxy coating point of the printed circuit board 50.

At this time, since the upper portion of the syringe 10 containing the epoxy 40 is connected to the barrel / air supply pipe 30, and the lower portion thereof is connected to the needle 20, compressed air is discharged from the bulb / air supply pipe 30. When supplied, the epoxy 40 contained in the syringe 10 is pushed toward the needle 30 at a predetermined pressure, and is applied onto the pad of the printed circuit board 50.

After the epoxy 40 has been applied, as shown in FIG. 1B, the vacuum is operated from the vacuum / air supply pipe 30 to suck the remaining amount of epoxy remaining in the needle 20, and then the printed circuit board 50 is removed. The work is completed by mounting the chip on the pad and electrically bonding the chip to the printed circuit board 50 using a bonding tool (not shown).

That is, the epoxy 40 contained in the syringe 10 is discharged through the needle 20 by the pressure flowing from the vacuum / air supply pipe 30, and after the predetermined amount of epoxy 40 is discharged, the epoxy ( 40) When the discharge is to be prevented, the pressure flowing through the puff / air inlet pipe 30 is generally stopped.

However, after pressurizing the air pressure to the syringe 10 to discharge a certain amount of epoxy, even if the pressure applied to the syringe 10 is stopped, the residual pressure (residual air) due to the compressed air present in the syringe 10 is stopped. The epoxy 40 does not stop but continues to be discharged.

In this way, if the epoxy 40 is continuously discharged by the residual pressure, it is not only contaminated by the epoxy residue on the printed circuit board, but also the thickness of the epoxy applied to the printed circuit board is not constant, When less applied, the interface between the semiconductor chip and the circuit board may be separated in a high temperature environment, thereby preventing electrical reliability of the semiconductor device.

Epoxy is a thermoset adhesive with viscosity, so the residual pressure of the liquid remains after discharge, causing the liquid to sag for a certain time.

In order to accurately control the amount of epoxy discharge, various variables such as time, pressure, and needle diameter selection exist, but control of compressed air is an important parameter.

According to the present invention, when the compressed air flowing into the syringe is blocked to precisely control the opening and closing of the discharge pipe installed in the epoxy discharge control device, the inside of the syringe flows quickly to discharge the compressed air to the outside, thereby quantitatively discharging epoxy. Make this possible.

In addition, the present invention is to improve the bonding reliability of the semiconductor device by applying the correct amount of epoxy to the circuit board.

Epoxy discharge control device according to the present invention is a syringe / air inlet pipe connected to the upper; Discharge opening and closing means connected to a lower portion of the syringe to open or block an epoxy flow; Bypassing the compressed air flowing into the syringe to discharge or open or block the epoxy flow by the bypass flow path for applying pressure to one side of the discharge opening and closing means and the compression force introduced through the bypass flow path and the repulsive force responsive thereto And opening and closing means.

In addition, the ejection opening and closing means of the epoxy ejection control apparatus according to the present invention is formed to have a body having a predetermined size and the bypass passage is connected to one side, and has a diameter smaller than the body is installed inside the body and a predetermined position And a discharge plate having a discharge hole formed therein, and an elastic body installed on the body to apply a spring force to one side of the discharge plate.

The residual pressure discharge hole of the epoxy discharge control device according to the present invention may allow the bypass passage and the body of the discharge opening and closing means to pass through when the discharge hole is separated from the shaft passing through the syringe and the needle. It is a flow path passing through the discharge plate.

2 is a schematic view showing an epoxy discharge control apparatus according to the present invention, a view showing a process of discharging epoxy using this, Figure 3 is a view showing in detail the structure of the epoxy discharge control apparatus according to the present invention.

As shown in FIG. 2, the epoxy discharge control apparatus 100 according to the present invention includes a syringe 110 containing an epoxy 150 and a vacuum / air inlet pipe 140 installed on the syringe 110. And, the injection opening and closing means 120 and the needle 130 is discharged the epoxy interposed below the syringe 110.

In addition, the epoxy discharge control apparatus 100 is introduced into the needle 130 from the syringe 110 by using compressed air introduced into the syringe 110 through the vacuum / air inlet pipe 140. In order to control the amount of the inflow of the epoxy, the syringe 110 and the discharge opening and closing means 120 further comprises a bypass flow path 170 is installed.

The bypass flow path 170 is to allow a compressive force to be applied to one side of the discharge opening and closing means 120, and a connection hole is formed at one side of the discharge opening and closing means 120.

On the other hand, the discharge opening and closing means 120 is for controlling the amount of epoxy interposed between the syringe 110 and the needle 130 to flow into the needle 130 side, as shown in Figure 3 Have

The discharge opening and closing means 120 according to the present invention is in communication with the lower side of the syringe 110, the bypass passage is connected to one side and the body 121 to form a space portion of a predetermined size, and than the body 121 It is formed to have a small diameter is installed in the body 121 and the discharge plate (124) is formed in the discharge hole (Hole, 125) at a predetermined position and to apply a spring force to one side of the discharge plate 124 It includes an elastic body 123 installed in the body.

In this case, the discharge plate 124 remains in the bypass flow path as well as the discharge hole 125 forming the flow path so that the epoxy 150 contained in the syringe 110 can flow into the needle 130. The remaining pressure discharge hole 127 for discharging the compressed air to the outside is also formed.

The residual pressure discharge hole 127 formed in the discharge plate is for connecting the discharge hole (126 in FIGS. 4A and 4B) and the bypass flow path 170 formed on the body 121 side, and according to a position to be set. It may be variously formed in the form of "a", etc., the diameter may also vary in accordance with the diameter of the bypass flow path.

In addition, the elastic body 123 is disposed on one side of the discharge plate 124 through the bypass flow path 170 in which the compressed air flowing into the syringe 110 is introduced through the puff / air inlet pipe 140. The purpose of providing a force opposed to the pressure applied to the other side of the discharge plate 124, to adjust the position of the discharge hole (125).

Since the discharge opening and closing means 120 according to the present invention having such a structure blocks the flow of the epoxy 150 flowing into the needle 130, the amount of epoxy accumulated on the needle 130 is always kept constant.

In addition, since the compressed air introduced into the syringe 110 through the puff / air inlet tube 140 is also blocked by the discharge opening and closing unit 120 except for the moment of discharging the epoxy 150, the amount of epoxy is the same. In the state, the same pressure is applied to the epoxy, so that the quantitative discharge of the epoxy is possible.

That is, it should be controlled according to the diameter of the needle 130, the discharge time, the pressure applied, etc., depending on the viscosity of the epoxy 150, blocking the epoxy flow between the needle 130 and the syringe 110 to the needle side Since the same epoxy is always gathered, it is possible to quantitatively discharge the epoxy only by precise control of the epoxy discharge opening and closing means 120.

The precise driving method of the discharge opening and closing means 120 according to the present invention will be described with reference to the accompanying drawings.

First, as shown in FIG. 2, after mounting a printed circuit board with a bonding table, an epoxy discharge device is positioned on an epoxy coating point of the printed circuit board).

Then, when compressed air is supplied to the syringe 110 containing the epoxy 150 through the vacuum / air supply pipe 140 connected to the upper portion thereof, the epoxy 150 inside the syringe 110 discharges and opens at a predetermined pressure. It is pushed to the (120) side.

At the same time, the compressed air introduced into the syringe 110 through the vacuum / air supply pipe 140 bypasses the pressure flowing into the vacuum / air inflow pipe 140 to control the discharge opening / closing means 120. Also introduced to the bypass flow path 170, as shown in FIG. 5A, a compressive force is applied to one side of the discharge plate 124 located inside the discharge opening / closing means 120.

At this time, a spring force is applied to the other side of the discharge plate 124 of the discharge opening and closing means 120 by an elastic body 123 provided on the other side of the discharge plate, and acts on one side of the discharge plate 124. When the spring reaction force applied by the elastic body 123 is balanced, the discharge plate 124 is positioned at a predetermined position within the body 121 of the discharge opening / closing means 120.

In this case, since the discharge hole 125 formed in the discharge plate 124 is present in the axial position penetrating the syringe 110 and the needle 130, the syringe 110 and the needle 130 communicate with each other. As a result, the epoxy 150 inside the syringe 110 flows into the needle side and the epoxy 150 is applied onto the pad of the printed circuit board by compressed air applied to the epoxy side.

That is, when the pressure by the compressed air flows into the bypass flow path 170, the discharge hole 125 of the discharge plate 124 is located at a position where the spring force applied to the pressure and the discharge plate 124 is equal to each other. Since the syringe 110 and the needle 130 communicate with each other along the discharge hole 125, the epoxy 150 may be discharged through the syringe 110 and the needle 130.

On the other hand, as shown in Figure 4, after discharging a certain amount of epoxy 150, when the compressed air flowing into the vacuum / air inlet pipe 140 when stopping the discharge of the epoxy 150 is blocked, the bypass The pressure branching to the flow path 170 is also cut off.

Accordingly, the force applied to one side of the discharge plate 124 located inside the discharge opening and closing means 120 is weakened by the compressed air introduced into the syringe 110 through the puff / air supply pipe 140, The discharge plate 124 is moved to a point where a force acting on one side of the discharge plate 124 and a spring repulsive force applied by the elastic body 123 are balanced.

Accordingly, the discharge plate 124 is positioned to be adjacent to the bypass flow path 170 in the body 121 of the discharge opening and closing means 120, as shown in Figure 5b, the discharge plate ( The discharge hole 125 formed in the 124 is separated from the shaft penetrating the syringe 110 and the needle 130.

That is, since the discharge hole 125 that communicates the syringe 110 and the needle 130 is moved, the flow of the epoxy 150 between the syringe 110 and the needle 130 is blocked and the epoxy Epoxy discharge is stopped because the applied compressive force also disappears.

Of course, the volume of the epoxy present between the needle 130 and the discharge opening and closing means 120 is always constant.

In this case, when the force acting on one side of the discharge plate 124 is reduced, the discharge plate 124 may block the epoxy flow at a higher speed by the spring repulsive force applied by the elastic body 123. The discharge plate 124 is provided with a residual pressure discharge hole 127 to discharge residual compressed air in the bypass flow path 170 to the outside.

The residual pressure discharge hole 127 communicates the discharge passage 126 formed in the body of the discharge opening / closing means and the bypass passage 170 only when the discharge plate 124 is moved toward the bypass passage 170. The compressed air in the bypass flow path 170 rapidly exits to the outside due to the pressure difference.

Accordingly, since the spring repulsion force applied by the elastic body 123 is greater than the force applied to one side of the discharge plate 124, the discharge plate 124 at a faster speed than the syringe 110 and the needle The communication between the 130 is quickly closed so that no more epoxy is introduced into the needle side positioned below the discharge plate.

At this time, the object forming the repulsive force against the compressed air on one side of the discharge plate may be composed of a magnetic material of the same polarity that can be maintained at a predetermined interval, may be a leaf spring applying a spring force in the plane direction. .

Accordingly, the semiconductor chip is adhered as the epoxy is applied to the printed circuit board, the wire bonding process or the flip chip process is accurately performed, and the void phenomenon of the epoxy is also removed, thereby minimizing the interface peeling phenomenon.

The present invention has been described above with reference to an embodiment, which is merely an example, and is not intended to limit the present invention, and those skilled in the art to which the present invention pertains may be used without departing from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible.

For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

As described above, the epoxy ejection control apparatus according to the present invention, when applying the viscous epoxy to the printed circuit board by the pressure of the compressed air, the discharge opening and closing means between the syringe containing the epoxy and the needle discharged epoxy By installing and opening and closing the ejection opening and closing means by the pressure and elastic force of the compressed air, it is possible to apply a certain amount of epoxy to the exact position of the printed circuit board with a uniform thickness and to simplify the structure of the epoxy ejection control device. You can save money.

Accordingly, the semiconductor chip is bonded to the exact position and range of the printed circuit board, the wire bonding process is performed correctly later, and the void phenomenon of the epoxy is also removed, thereby minimizing the interface peeling phenomenon.

Claims (6)

A syringe with a burr / air inlet pipe connected to the top; Discharge opening and closing means connected to a lower portion of the syringe to open or block an epoxy flow; Bypass flow path for bypassing the compressed air flowing into the syringe to apply pressure to one side of the discharge opening and closing means; And an ejection opening / closing means for opening or blocking the epoxy flow by the compressive force introduced through the bypass passage and the repulsive force repulsing thereto. The method of claim 1, The discharge opening and closing means has a body having a predetermined size and the bypass passage is connected to one side, the discharge plate is formed to have a smaller diameter than the body is installed inside the body and the discharge hole (Hole) formed in a predetermined position And an elastic body installed on the body to apply a spring force to one side of the discharge plate. The method of claim 2, And a residual pressure discharge hole for quickly discharging the compressed air remaining in the bypass flow passage to the discharge plate of the discharge opening / closing means. The method of claim 3, wherein The residual pressure discharge hole of the epoxy discharge control device penetrates through the discharge plate so as to pass through the bypass passage and the body of the discharge opening and closing means when the discharge hole is separated from the shaft passing through the syringe and the needle. Epoxy discharge control device, characterized in that the flow path. The method of claim 1, And the bypass flow passage is provided on one side of the syringe or one side of the vacuum / air inlet pipe. The method of claim 3, wherein The residual pressure discharge hole of the epoxy discharge control device blocks the inflow of compressed air into the syringe, and when the discharge plate is pushed toward the bypass flow path by the spring force of the elastic body, the bypass flow path communicates with the outside. Epoxy discharge control device characterized in that.

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