JP2001239196A - Paste applying device for die bonding and paste applying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paste applying device for die bonding which can be cleaned easily after paste application as well as a paste applying method. SOLUTION: This paste applying device for die bonding applies a paste 7 for die bonding to a substrate by discharging the paste 7 from an application nozzle 18. In this device, the paste 7 or a cleaning liquid is selectively supplied to a discharge pump 16a from a paste container 26A for storing the paste 7 and a cleaning liquid container 26B for storing the cleaning liquid which cleans the interior of a paste flow channel by selecting either of a second valve 28A, a third valve 39 or a fourth valve 28B. When the interior of the paste flow channel is cleaned after the end of applying the paste 7, the cleaning liquid is sucked with the discharge pump 16a and then is discharged from the application nozzle 18. Thus, it is possible to easily perform the cleaning operation of the interior of the paste flow channel after application without disassembling the paste applying device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die bonding paste coating apparatus and method for coating a substrate with a die bonding paste.

[0002]

2. Description of the Related Art In a die bonding process of manufacturing a semiconductor device, a die bonding paste (hereinafter simply referred to as "paste") for bonding a semiconductor chip to a substrate such as a lead frame is applied. The application of the paste is performed by guiding the paste discharged from the dispenser to an application nozzle and applying the paste into the application area of the substrate. A curable resin such as an epoxy resin is used for this paste, and the paste is applied in a state where the curing reaction is incomplete and has fluidity.

[0003]

Since this paste hardens with the passage of time, the paste flows into the paste flow path of the paste coating apparatus used for coating, that is, the inside of the dispenser or the pipe member connecting the dispenser and the coating nozzle. When the paste is left in a state where it remains, these pastes are hardened in the flow path and the coating apparatus becomes unusable. For this reason, in the paste application device, every time the application operation is completed, an operation of discharging and cleaning the paste in the flow path is required. Conventionally, this cleaning operation is performed by removing the application nozzle and disassembling the dispenser, so that there is a problem that the operation is complicated and the cleaning operation requires time and effort.

Accordingly, an object of the present invention is to provide a paste bonding apparatus and a coating method for die bonding that can easily perform a cleaning operation after the paste is applied.

[0005]

According to a first aspect of the present invention, there is provided a die bonding paste coating apparatus for discharging and applying a die bonding paste from a coating nozzle at a chip mounting position on a substrate. Pump means for discharging the paste, a paste container for storing the paste, a cleaning liquid container for storing a cleaning liquid for cleaning the inside of the paste flow path, and a paste or a cleaning liquid selectively from the paste container and the cleaning liquid container. A supply unit that supplies the paste to the pump unit; and an application nozzle that is connected to the pump unit via a pipe member and applies the paste discharged from the pump unit to the substrate.

According to a second aspect of the present invention, there is provided a die bonding paste application apparatus, wherein a gas supply means is connected to the supply means, and a gas supply means is connected to the pump means. It is possible to supply gas selectively.

According to a third aspect of the present invention, there is provided a paste bonding apparatus for die bonding, comprising gas pressure applying means for applying a gas pressure to the cleaning liquid container.

A die bonding paste application device according to claim 4, wherein the die bonding paste application device discharges and applies a die bonding paste from an application nozzle at a chip mounting position on a substrate, wherein the paste is applied to the die bonding paste application device. Pump means for discharging the paste, a paste container for storing the paste, a cleaning liquid container for storing a cleaning liquid for cleaning the inside of the paste flow path, a gas supply means for supplying gas to the cleaning liquid container, a pump means and a pipe member. A coating nozzle for applying the paste discharged from the pump means to the substrate and connected to the pump means, and a selective connection means for selectively connecting either the paste container or the cleaning liquid container to the pump means.

According to a fifth aspect of the present invention, in the paste applying apparatus for die bonding, the gas supply means supplies gas to the pump means after the cleaning liquid in the cleaning liquid container is supplied to the pump means.

According to a sixth aspect of the present invention, there is provided a die bonding paste coating apparatus according to any one of the first to fifth aspects, wherein the cleaning liquid discharged from the coating nozzle is provided by the cleaning liquid. A cleaning liquid circulating means for collecting and circulating in a container was provided.

A method for applying a paste for die bonding according to claim 7, wherein the paste for die bonding is applied by discharging a paste for die bonding from an application nozzle at a chip mounting position on a substrate, wherein the paste is applied. Pump means for discharging the paste is provided with selective connection means for selectively connecting either the paste container for storing the paste or the cleaning liquid container for storing the cleaning liquid for cleaning the inside of the paste flow path, and when applying the paste, the paste container is used as the pump means. The cleaning liquid container was connected to the pump means when the paste was applied and the inside of the paste flow path was cleaned after the paste application.

According to the present invention, a cleaning liquid container for storing a cleaning liquid for cleaning the paste flow path is provided, and during the cleaning operation after applying the paste, the cleaning liquid is supplied from the cleaning liquid container to the pump means to clean the inside of the paste flow path. Thereby, the work of cleaning the inside of the paste flow path after application can be easily performed without disassembling the paste application device.

[0013]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view of a die bonding apparatus according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a paste discharge dispenser according to one embodiment of the present invention, and FIG. 3 is die bonding according to one embodiment of the present invention. FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are block diagrams showing the configuration of the control system of the apparatus.

First, the structure of the die bonding apparatus will be described with reference to FIG. In FIG. 1, a wafer sheet 2 is held by a chip supply unit 1 by a holding table (not shown). A large number of chips 3 as semiconductor elements are attached to the wafer sheet 2. A transport path 5 is provided on the side of the chip supply unit 1, and the transport path 5 transports a lead frame 6 as a substrate, and positions the lead frame 6 at a paste application position and a bonding position. A bonding head 4 is provided above the chip supply unit 1, and the bonding head 4 is moved horizontally and vertically by a moving mechanism (not shown).

A paste application section 9 is provided on the side of the transport path 5. The paste application unit 9 is configured by mounting an application nozzle 18 on a moving table 10 via an L-shaped bracket 15. The application nozzle 18 is connected to a dispenser 16 which is a paste discharging means fixedly arranged on a stationary plate 21 by a tube 17 which is a flexible tube member.

The moving table 10 is constructed by stacking an X-axis table 12 on a Y-axis table 11 and further vertically connecting a Z-axis table 14 via an L-shaped bracket 13. . The Y-axis table 11, the X-axis table 12, and the Z-axis table 14
1a, an X-axis motor 12a, and a Z-axis motor 14a. By driving the X-axis motor 12a, the Y-axis motor 11a, and the Z-axis motor 14a, the application nozzle 18 moves horizontally and vertically on the lead frame 6. Therefore, the moving table 10 serves as moving means for moving the application nozzle 18 relatively to the lead frame 6.

The mounting position of the chip 3 on the upper surface of the lead frame 6 is an application area 6a where the paste 7 is applied. Position the application nozzle 18 in the application area 6a,
By moving the application nozzle 18 while discharging the paste 7 from the application nozzle 18, the paste 7 for chip bonding is drawn and applied in a predetermined drawing pattern in the application area 6a.

After the paste is applied, the lead frame 6 is sent to the bonding position 8 on the transport path 5 and positioned. Then, the paste 7 applied in the application area 6a
The chip 3 picked up from the chip supply unit 1 is bonded thereon by the nozzle 4a of the bonding head 4.

Next, a supply system for supplying the paste 7 to the dispenser 16 and a discharge pump (pump means) 16a built in the dispenser 16 will be described with reference to FIG. In FIG. 2, the discharge pump 16a for discharging paste includes a cylinder portion 29, a piston 31 fitted into the cylinder portion 29, and a reciprocating mechanism for reciprocating the piston 31. The reciprocating mechanism includes a motor 34, a feed screw 35 and a nut 36, and the feed screw 35
Is rotated by a motor 34, whereby the piston 31 coupled to the nut 36 reciprocates in the cylinder portion 29.

The cylinder portion 29 is provided with a suction port 29a and a discharge port 29b. Discharge port 2
9 b is connected to the application nozzle 18 via the first valve 30 and the tube 17. The suction port 29a is connected to a first supply pipe 37a for supplying the paste 7, a cleaning liquid described later, and the like. The second valve 28 is connected to the first supply pipe 37a.
A paste container 26A which is a container for storing the paste 7 is connected via A.

The second supply pipe 37b connected to the first supply pipe 37a via the third valve 39 has a fourth valve 28B
Is connected to a cleaning liquid container 26B for storing a cleaning liquid for cleaning the paste flow path. A third supply pipe 37c is further connected to the second supply pipe 37b via a fifth valve 38, and the third supply pipe 37c is connected to the air supply source 32.

The upper part of the paste container 26A is connected to an air supply source 32 as a gas supply means via a sixth valve 27A and a regulator 33A. Cleaning liquid container 2
The upper part of 6B is the seventh valve 27B, the regulator 33B
Is connected to the air supply source 32 via the.

Next, the configuration of the control system of the die bonding apparatus will be described with reference to FIG. In FIG. 3, a pump driving unit 40 drives a motor 34 that drives the piston 31. The valve driving unit 41 includes a first valve 30, a second valve 28A, a third valve 39, a fourth valve 28B, and a
Of the paste 7 by the discharge pump 16a is controlled.

The Z-axis motor drive unit 42, the Y-axis motor drive unit 43, and the X-axis motor drive unit 44
Axis motor 14a, Y axis motor 11a, X axis motor 12a
Are respectively driven. Bonding head drive unit 45
Is a bonding head 4 for bonding the chip 3
Drive. The storage unit 46 stores programs and application pattern data necessary for the operation and processing of each unit. The control unit 47 controls the operation of each unit based on the program stored in the storage unit 46. The operation unit 48 is an input unit such as a keyboard and a mouse, and inputs control commands and data. The display unit 49 is a display device, and displays a screen when an operation is input.

Next, the paste application operation will be described.
In FIG. 2, a paste 7 for die bonding is stored in a paste container 26A.
A is opened, and the paste container 26 is
By applying air pressure from above A, the paste 7 inside is pressurized. When the second valve 28A is opened and the piston 31 is raised, the paste container 26
The paste 7 in A is supplied from the suction port 29a to the cylinder 2
It is inhaled into 9. At this time, the first valve 30 and the third valve 39 are in a closed state.

The suction pressure of the paste is regulated by a regulator 3.
By adjusting the air pressure by 3A, it is possible to set an appropriate pressure. By this suction operation, the lead frame 6 by the application nozzle 18 is provided inside the cylinder portion 29.
The paste corresponding to the application amount for performing the paste application to the n times is sucked.

Next, when the cylinder 34 is lowered by driving the motor 34 with the second valve 28A closed and the first valve 30 opened, the paste 7 is discharged from the discharge port 29b.
Is discharged. Then, the discharged paste 7 is pressure-fed to the coating nozzle 18 via the first valve 30 and the tube 17, discharged from the tip of the coating nozzle 18, and applied to the upper surface of the lead frame 6. In this coating operation, by changing the driving speed of the motor 34, the discharge port 2
The discharge flow rate of the paste 7 discharged from 9b changes, and a discharge flow rate proportional to the driving speed is obtained.

Next, the cleaning operation will be described with reference to FIG. In this cleaning operation, after the paste application operation is completed, the paste 7 remaining in the discharge pump 16a, the tube 17, and the application nozzle 18 is discharged, and the paste 7 remaining in the paste flow path is removed by the cleaning liquid. Done for. This cleaning operation is performed by supplying the cleaning liquid in the cleaning liquid container 26B to the discharge pump 16a and driving the discharge pump 16a to discharge the cleaning liquid.

First, in FIG. 4, the first valve 30 and the second valve
With the valve 28A and the fifth valve 38 closed, the third valve 39 and the fourth valve 28B are opened, and the piston 31 is raised. Thus, the cleaning liquid in the cleaning liquid container 26B is sucked into the cylinder portion 29 from the suction port 29a. Next, the first valve 30 is opened, and the fourth valve 30 is opened.
When the piston 31 is moved down with the valve 28B closed, the cleaning liquid in the cylinder 29 is discharged from the discharge port 29b.
From the application nozzle 18 through the tube 17. The discharged cleaning liquid is collected in a collection container 50.
Collected inside. This washing operation is repeated a plurality of times as necessary.

By this cleaning operation, the discharge pumps 16a,
The liquid contacting parts in the paste flow path, such as the first valve 30, the tube 17, and the application nozzle 18, are washed with a washing liquid to remove the adhered paste 7. After the cleaning is completed, the first valve 30, the third valve 39, and the fifth valve 38 are opened with the second valve 28A and the fourth valve 28B closed, and the third supply pipe 37c, the second supply pipe 37b, 1 supply pipe 37a
Air is blown into the cylinder portion 29 via the tube 17 and is ejected from the application nozzle 18 via the tube 17.

As a result, the cleaning liquid and the paste residue remaining inside are removed by air blowing, and the paste flow path is dried. As described above, conventionally, after the paste is applied, the application nozzle 18 is removed or the discharge pump 16 is removed.
The washing operation of the paste 7 that requires the decomposition of a can be automatically performed, and the operation can be simplified and labor can be saved.

In the above-described cleaning operation, the discharge pump 16a may be driven to discharge the cleaning liquid from the application nozzle 18, and vibration may be applied to the application nozzle 18 by vibration applying means. Thereby, the vibration is transmitted to the tube 17, and the paste 7 attached to the inner wall surface of the tube can be efficiently removed.

As described above, the paste applying apparatus according to the present embodiment comprises a paste container 26A and a cleaning liquid container 26.
B, and either the paste or the cleaning liquid is selectively supplied to the discharge pump 16a from the paste container 26A and the cleaning liquid container 26B. In the present embodiment, the first supply pipe 37a, the second supply pipe 37
b, second valve 28A, third valve 39, fourth valve 2
8B is a supply unit that selectively supplies either the paste 7 or the cleaning liquid from the paste container 26A and the cleaning liquid container 26B to the discharge pump 16a.

In the example shown in the above embodiment, the cleaning liquid used in the cleaning operation is recovered in the recovery container 50. However, in order to perform more efficient cleaning, it is desirable to circulate the cleaning liquid. Hereinafter, an example of the circulating use of the cleaning liquid will be described with reference to FIGS.

In FIG. 5, at the bottom of the collection container 50,
A cleaning liquid circulation pipe 51 is connected. Circulation piping 51
The filter 52, the pressure pump 53, and the check valve 54 are provided in this order from the collection container 50 side, and the tip of the circulation pipe 51 is connected to the cleaning liquid container 26B.

The collection container 50 discharged from the application nozzle 18
The cleaning liquid stored therein is returned to the cleaning liquid container 26B via the check valve 54 by the pressure feed pump 53 after the foreign matter is removed by the filter 52. Then, it is sucked and discharged again by the discharge pump 16a and stored in the collection container 50. By circulating the cleaning solution in this way,
Good cleaning results can be obtained by repeatedly performing cleaning with a limited amount of cleaning liquid.

In the example shown in FIG. 6, the circulating pipe 51 'is connected directly to the coating nozzle 18 when the cleaning liquid is circulated.
This is an example of connection to the end of a. The cleaning liquid discharged from the application nozzle 18 by driving the discharge pump 16a is
In this example, the circulation pipe 5
The liquid is guided to 1 ′ and returned to the cleaning liquid container 26B via the filter 52 and the check valve 54. Also in this example, good cleaning can be performed using a limited amount of cleaning liquid, and in this example, the cleaning liquid is circulated using the discharge pressure of the discharge pump 16a. And the configuration of the circulation system can be simplified.

Further, in the example shown in the above embodiment, both the paste container 26A and the cleaning liquid container 26B are fixedly connected to the suction port 29a of the discharge pump 16a, as shown in FIG. Paste container 26A
And the cleaning liquid container 26B may be replaced and used each time. In this case, the second valve 28A and the sixth valve 28A
The valve 27A has a one-touch joint structure that can be connected to either the paste container 26A or the cleaning liquid container 26B.

At the time of applying the paste, the paste container 26A is mounted and the paste 7 is supplied to the discharge pump 16a. At the time of cleaning, the cleaning liquid container 26B is mounted and the cleaning liquid is supplied to the discharge pump 16a and discharged from the application nozzle 18. To collect in the collection container 50. That is, the second valve 28A and the sixth valve 27A are selective connection means for selectively connecting the paste container 26A and the cleaning liquid container 26B to the discharge pump 16a. When the cleaning is completed, air is supplied through the third supply pipe 37c as in the example shown in FIG. 5, and foreign matter is removed by air blowing and drying is performed.

In the above cleaning operation, the cleaning liquid container 2
If the amount of the cleaning liquid in 6B is set to the amount consumed in one cleaning operation and the cleaning liquid container 26B is completely emptied when the cleaning operation is completed, the third supply pipe 37c is omitted. be able to. That is, in this case, the cleaning liquid is continuously supplied from the air supply source 32 into the cleaning liquid container 26B, and the first supply pipe 3 is supplied through the second valve 28A.
Since air can be sent to 7a, the air supply pipe can be simplified.

[0041]

According to the present invention, a cleaning liquid container for storing a cleaning liquid for cleaning the paste flow path is provided, and the cleaning liquid is supplied from the cleaning liquid container to the pump means to clean the paste flow path during the cleaning operation after applying the paste. As a result, it is possible to easily perform a cleaning operation in the paste flow path after the application without disassembling the paste application device.

[Brief description of the drawings]

FIG. 1 is a perspective view of a die bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a paste dispenser according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a control system of the die bonding apparatus according to one embodiment of the present invention;

FIG. 4 is an explanatory diagram of a paste flow path cleaning method using a paste discharge dispenser according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a paste flow path cleaning method using a paste discharge dispenser according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a paste flow path cleaning method using a paste discharge dispenser according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram of a paste flow path cleaning method using a paste discharge dispenser according to an embodiment of the present invention.

[Explanation of symbols]

 3 Chip 6 Lead frame 6a Application area 7 Paste 10 Moving table 16a Discharge pump 18 Application nozzle 26A Paste container 26B Cleaning liquid container 32 Air supply source

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D075 AC07 AC84 AC95 BB65Z CA47 DA06 DB14 DC22 EA35 4F041 AA05 AB01 BA05 BA32 BA60 4F042 AA07 BA06 CB10 CC04 CC08 CC10 5F047 AA11 BA21 BB11 FA02 FA08 FA22

Claims (7)

[Claims] 1. A die bonding paste coating apparatus for discharging and applying die bonding paste from a coating nozzle at a chip mounting position on a substrate, comprising: a pump means for discharging the paste; and a reservoir for storing the paste. A paste container, a cleaning liquid container for storing a cleaning liquid for cleaning the inside of the paste flow path, a supply unit for selectively supplying a paste or a cleaning liquid from the paste container and the cleaning liquid container to the pump unit, and a pump unit and a pipe member. And a coating nozzle for connecting the paste discharged from the pump means to the substrate. 2. The paste application for die bonding according to claim 1, wherein gas supply means is connected to said supply means, and gas can be selectively supplied to said pump means. apparatus. 3. The paste applying apparatus for die bonding according to claim 1, further comprising gas pressure applying means for applying a gas pressure to said cleaning liquid container. 4. A die bonding paste coating apparatus for discharging and applying die bonding paste from a coating nozzle at a chip mounting position on a substrate, comprising: a pump means for discharging the paste; and a reservoir for storing the paste. A paste container, a cleaning liquid container for storing a cleaning liquid for cleaning the inside of the paste flow path, a gas supply unit for supplying gas to the cleaning liquid container, a pump connected to the pump unit and a pipe member, and a paste discharged from the pump unit. A paste bonding apparatus for die bonding, comprising: a coating nozzle for coating on the substrate; and selective connection means for selectively connecting either the paste container or the cleaning liquid container to the pump means. 5. The paste application for die bonding according to claim 4, wherein said gas supply means supplies gas to the pump means after the cleaning liquid in the cleaning liquid container has been supplied to the pump means. apparatus. 6. A paste for die bonding according to claim 1, further comprising a cleaning liquid circulating means for collecting and circulating a cleaning liquid discharged from said coating nozzle in said cleaning liquid container. Coating device. 7. A paste bonding method for die bonding, wherein a paste for die bonding is discharged from a coating nozzle at a chip mounting position on a substrate, and the paste is stored in a pump means for discharging the paste. Alternatively, it is provided with selective connection means for selectively connecting any one of the cleaning liquid containers for storing the cleaning liquid for cleaning the inside of the paste flow path, connecting the paste container to the pump means at the time of applying the paste, and performing the paste flow path performed after completion of the paste application. A paste applying method for die bonding, wherein a cleaning liquid container is connected to a pump means for cleaning the inside of the inside.