JPH0644142U - Wire bonding equipment - Google Patents

Abstract

(57) [Summary] [Structure] The heater plate 11 of the wire bonding apparatus has a first vacuum suction port 13 and a second vacuum suction port 19 on its surface. Each of them is connected to the exhaust port 15 inside the heater plate 11 through a tunnel-shaped hole 17. [Effect] In the electrical connection between the electrode provided on the semiconductor device and the inner lead, unnecessary movement of the inner lead and the die stage can be suppressed. Therefore, deformation of the metal wire can be prevented, precise shape control can be performed, and product quality and reliability can be improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wire bonding device for connecting a metal wire between a semiconductor device and a lead frame.

[0002]

[Prior art]

 The structure of the lead frame will be described with reference to FIG. The lead frame 20 is composed of a die stage 21 to which a semiconductor device is attached, an inner lead 23 for connecting a metal wire to an electrode of a semiconductor device, a rail 25, a tie bar 27, and a suspension lead 29.

The rail 25 supports the die stage 21 with suspension leads 29. In addition, the rail 25 supports the inner lead 23 with a tie bar 27.

The die stage 21 and the inner leads 23 to which the semiconductor device is attached are partially plated with gold or silver.

As a material of the lead frame 20, for example, an alloy of iron and nickel called 42 alloy, a copper alloy, or the like is widely used.

The method of manufacturing the lead frame 20 includes a method of forming a pattern of the lead frame 20 using the principle of photography, and chemically etching the pattern of the lead frame 20, and a mold. There is a press method created by punching out unnecessary parts.

Next, a state in which the semiconductor device is attached to the die stage will be described. FIG. 3 is a plan view showing a state in which the semiconductor device 31 is attached to the die stage 21 of the lead frame 30 and metal wire connection is performed by the wire bonding device.

As shown in FIG. 3, the semiconductor device 31 and the inner leads 23 of the lead frame 30 are electrically connected by a metal wire 35.

Here, the configuration of the wire bonding apparatus will be described. The wire bonding apparatus is a semiconductor manufacturing apparatus for electrically connecting an electrode of a semiconductor device and an inner lead of a lead frame to which the semiconductor device is attached with a metal wire.

A method of electrically connecting the electrode of the semiconductor device and the inner lead of the lead frame with a metal wire will be described with reference to FIGS. 4 to 7.

As shown in FIG. 4, the capillary 41 is inserted into a capillary mounting hole 45 penetrating the transducer 43 and fixed by a capillary mounting bolt 47. A through hole 49 penetrates through the center of the capillary 41, and a metal wire 42 penetrates through the through hole 49.

When electric discharge is performed between the electric torch 44 and the metal wire 42 extending from the tip portion 46 of the capillary 41, a ball 48 is formed at the tip of the metal wire 42.

Next, as shown in FIG. 5, the capillary 41 descends, and the ball 48 is pressure-bonded to the electrode 33 provided on the semiconductor device 31 which has been heated in advance.

Next, as shown in FIG. 6, the capillary 41 is moved to the inner lead 23 of the lead frame 30 which has been heated in advance. At this time, the metal wire 42 is paid out from the through hole 49 penetrating the tip portion 46 of the capillary 41. The capillary 41 crimps the metal wire 42 to the inner lead 23 of the lead frame 30.

After the pressure bonding between the metal wire 42 and the inner lead 23 of the lead frame 30 is completed, the capillary 41 is lifted and the metal wire 42 is cut off from the inner lead 23 as shown in FIG.

FIGS. 8A and 8B are explanatory views showing a fixed state of the lead frame 30 in this series of operations.

As shown in FIG. 8, the lead frame 30 is fixed by being sandwiched between the heater plate 85 and the pressing mask 81.

However, the inner portion of the opening 83 of the holding mask 81 is directly pressed and is not fixed, and the lead frame 30 is merely in contact with the heater plate 85.

That is, as shown in FIGS. 4 to 7, in the raising, moving, and lowering operations of the capillary 41, and in the payout process of the metal wire 42 associated therewith, as shown in FIGS. 9A and 9B, The contact between the die stage 21 having the semiconductor device 31 attached thereto and the heater plate 85, or the inner lead 23 and the heater plate 85 cannot be maintained.

First, the reason why the contact between the die stage 21 and the heater plate 85 is not maintained will be described with reference to FIGS. 17 and 18. FIG. 17 is an explanatory diagram showing the movement operation of the capillary 41 in the metal wire connection between the electrode 33 provided on the semiconductor device 31 and the inner lead 23. 18 is a sectional view showing the tip end portion 46 of the capillary 41. Hereinafter, description will be made by alternately using FIG. 17 and FIG.

After the ball 48 is pressure-bonded to the electrode 33 provided on the semiconductor device 31, the capillary 41 raises, moves, and descends at a high speed while feeding the metal wire 42.

At this time, friction resistance occurs between the metal wire 42 and the through hole 49 of the capillary 41. In particular, the friction resistance generated between the through hole 49 and the metal wire 42 at the tip portion 46 of the capillary 41 is large.

Therefore, the metal wire 42 is pulled and the contact between the die stage 21 and the heater plate 85 cannot be maintained during the high-speed ascending / descending / moving operation of the capillary 41 and the unwinding of the metal wire 42 accompanying it.

Next, the reason why the contact between the inner lead 23 and the heater plate 85 is no longer maintained will be described with reference to FIGS. 6 and 7.

After the metal wire 42 is pressure-bonded to the inner lead 23, the capillary 41 is raised to separate the metal wire 42 from the inner lead 23. At this time, the inner lead 23 is merely in contact with the heater plate 85.

Therefore, until the capillary 41 rises and just before the metal wire 42 is cut off from the inner lead 23, the metal wire 42 is pulled up with the rise of the capillary 41, and at the same time, the inner lead 23 is also pulled up. Will end up. As a result, the contact between the inner lead 23 and the heater plate 85 cannot be maintained.

[0027]

[Problems to be solved by the device]

 As shown in FIGS. 9A and 9B, in the wire bonding apparatus using the conventional heater plate 85 and the holding mask 81, as described above, the die stage 21 to which the semiconductor device 31 is attached and the heater plate 85, or The contact between the inner lead 23 and the heater plate 85 cannot be maintained.

In order to perform loop control (hereinafter referred to as shape control) of the metal wire 87, the locus of movement of the capillary 41 is determined by the die stage 21 and the heater plate 85 to which the semiconductor device 31 is attached, or the inner lead 23 and the heater. The wire bonding device is set in advance on the assumption that the contact with the plate 85 is maintained.

However, as described above, if the contact between the die stage 21 having the semiconductor device 31 attached thereto and the heater plate 85 cannot be maintained, it is impossible to control the shape of the expected metal wire.

Similarly, if the contact between the inner lead 23 and the heater plate 85 is no longer maintained, after the electrical connection between the electrode 33 provided in the semiconductor device 31 and the inner lead 23 by the metal wire 87 is completed. Until the metal wire 42 is cut off from the inner lead 23, the inner lead 23 is also pulled up as the capillary 41 rises.

In other words, the inner lead 23 will move. The movement of the inner lead 23 deforms the loop shape of the metal wire 87.

That is, in the metal wire connection under such a condition, it becomes very difficult to precisely control the shape of the metal wire 87 that connects the electrode 33 provided on the semiconductor device 31 and the inner lead 23.

Here, a plastic resin-sealed package will be described as an example. FIG. 10 is a sectional view of a package sealed with a plastic resin.

In the case of a surface mount type package, particularly a thin type package, it is difficult to maintain a wide space 93 between the metal wire 87 and the upper surface of the plastic sealing resin 91 because the package thickness 95 is very thin.

Therefore, it is required to keep the metal wire 87 low with respect to the semiconductor device 31 and the inner lead 23 by controlling the shape precisely.

As described above, if the contact between the die stage 21 having the semiconductor device 31 shown in FIGS. 9A and 9B and the heater plate 85 or the inner lead 23 and the heater plate 85 cannot be maintained, It becomes difficult to control the shape of the metal wire precisely.

As a result, as shown in FIG. 11, the metal wire 87 is exposed from the surface of the plastic encapsulating resin 91, resulting in deterioration of product quality and reliability.

The present invention solves the above problems, securely fixes the die stage and the inner lead of the lead frame, enables precise shape control of the metal wire, and improves the product quality and reliability of the wire bonding. The purpose is to provide a device.

[0039]

[Means for Solving the Problems]

 In order to solve the above problems, the wire bonding apparatus of the present invention adopts the configuration described below.

The wire bonding apparatus of the present invention is characterized in that the heater plate is provided with a vacuum suction port.

[0041]

[Action]

 The wire bonding device of the present invention has a vacuum suction port for vacuum-fixing and fixing the die stage of the lead frame and the inner lead to the heater plate.

This ensures that the die stage and the inner lead are fixed in the operation of the capillary in the metal wire connection between the electrode provided in the semiconductor device and the inner lead.

As a result, it is possible to precisely control the shape of the metal wire and improve the product quality and reliability.

[0044]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an embodiment of a heater plate according to the present invention.

As shown in FIG. 1, a first vacuum suction port 13 and a second vacuum suction port 19 are opened on the surface of the heater plate 11. Each of these vacuum suction ports is connected to the exhaust port 15 through a tunnel-shaped hole 17 inside the heater plate 11. The exhaust port 15 is for connecting an exhaust device such as a vacuum pump.

As shown in FIG. 12, when the lead frame 30 is fixed by being sandwiched between the heater plate 11 and the holding mask 81, the first vacuum suction port 13 causes the inner lead 23 to be vacuumed by the heater plate 11. It is provided on the surface of the heater plate 11 so that it can be adsorbed.

The size of the opening of the first vacuum suction port 13 for vacuum-sucking the inner lead 23 should be smaller than the width of the inner lead 23 when the opening has a circular shape, for example. .

The shape of the opening of the first vacuum suction port 13 is not limited to the circular shape, and may be a polygonal shape.

Further, the number of the first vacuum suction ports 13 is not limited to one for one inner lead 23, but may be plural.

Similarly to the first vacuum suction port 13, the second vacuum suction port 19 is provided on the surface of the heater plate 11 so that the heater plate 11 can vacuum-suck the die stage 21.

The size of the opening of the second vacuum suction port 19 for vacuum-sucking the die stage 21 must be smaller than the width of the die stage 21 when the shape of the opening is circular, for example.

Further, the shape of the opening of the second vacuum suction port 19 is not limited to a circular shape, and may be a polygonal shape.

Further, with respect to the die stage 21, the number of the second vacuum suction ports 19 is not limited to one and may be plural.

Next, a method of electrically connecting the electrodes of the semiconductor device by the wire bonding apparatus according to the present invention and the inner leads of the lead frame with a metal wire will be described with reference to FIGS. 4 and 13 to 15.

As shown in FIG. 4, the capillary 41 is inserted into a capillary mounting hole 45 penetrating the transducer 43 and fixed by a capillary mounting bolt 47.

A through hole 49 penetrates through the center of the capillary 41, and a metal wire 42 penetrates through the through hole 49. When electric discharge is performed between the electric torch 44 and the metal wire 42 extending from the tip 46 of the capillary 41, a ball 48 is formed at the tip of the metal wire 42.

Next, as shown in FIG. 13, the capillary 41 descends, and the balls 48 are pressure-bonded to the electrodes 33 provided on the semiconductor device 31 which has been heated in advance. At this time, exhaust is performed from the exhaust port 15 by an exhaust device such as a vacuum pump.

As a result, since the second vacuum suction port 19 and the exhaust port 15 are connected to each other through the tunnel-shaped hole 17, the die stage 21 having the semiconductor device 31 attached thereto is suction-fixed to the heater plate 11. .

Next, as shown in FIG. 14, the capillary 41 is moved to the preheated inner lead 23. At this time, the metal wire 42 is paid out from the through hole 49 penetrating the tip portion 46 of the capillary 41. The capillary 41 presses the metal wire 42 onto the inner lead 23 of the lead frame 30.

At this time as well, the die stage 21 remains adsorbed and fixed to the heater plate 11. Further, like the die stage 21, the inner lead 23 is fixed to the heater plate 11 by suction through the first vacuum suction port 13.

After the crimping of the metal wire 42 and the inner lead 23 is completed, as shown in FIG. 15, the capillary 41 is raised and the metal wire 42 is cut off from the inner lead 23.

At this time as well, the inner leads 23 are still adsorbed and fixed to the heater plate 11.

In this series of operations, as shown in FIGS. 8 (a) and 8 (b), the lead frame 30 is sandwiched between the heater plate 85 and the holding mask 81 and is fixed by the conventional wire. It is similar to the bonding device.

However, in the inner portion of the opening portion 83 of the pressing mask 81, that is, as shown in FIGS. 16A and 16B, the die stage 21 is fixed by vacuum suction by the second vacuum suction port 19. Is performed.

Similarly, the inner lead 23 is also fixed by vacuum suction by the first vacuum suction port 13.

As described above, since the die stage 21 and the inner lead 23 are securely fixed to the heater plate 11, when the capillary 41 is moved up, moved, and lowered, and the metal wire 42 is fed out, the movement of the metal wire 42 shown in FIG. As shown in a) and (b), the contact between the die stage 21 to which the semiconductor device 31 is attached and the heater plate 85, or the inner lead 23 and the heater plate 85 cannot be maintained.

In order to control the shape of the metal wire 87, the trajectory of the movement of the capillary 41 is premised on that the contact between the die stage 21 and the heater plate 85 or the inner lead 23 and the heater plate 85 is maintained. The wire bonding machine is set in advance.

Therefore, as described above, in the heater plate 11 according to the present invention, the die stage 21 and the inner leads 23 can be securely fixed to the heater plate 11 as shown in FIGS. Precise shape control of the line 87 is possible.

[0069]

[Effect of device]

 As is clear from the above description, in the wire bonding apparatus according to the present invention, it is possible to securely fix the heater plate, the inner lead of the lead frame and the die stage. As a result, unnecessary movement of the inner lead and the die stage can be suppressed in the electrical connection between the electrode provided on the semiconductor device and the inner lead by the metal wire. By suppressing this unnecessary movement, it is possible to prevent deformation of the metal wire, enable precise shape control, and improve product quality and reliability.

[Brief description of drawings]

FIG. 1 is a plan view showing a heater plate according to an embodiment of the present invention.

FIG. 2 is a plan view showing a lead frame.

FIG. 3 is a plan view showing a state in which a lead frame and a semiconductor device are connected using a metal wire connection.

FIG. 4 is a side view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a conventional wire bonding device.

FIG. 5 is a side view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a conventional wire bonding device.

FIG. 6 is a side view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a conventional wire bonding device.

FIG. 7 is a side view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a conventional wire bonding device.

FIG. 8 is an explanatory diagram showing a method of connecting a metal wire between a lead frame and a semiconductor device by a conventional wire bonding device.

FIG. 9 is a cross-sectional view showing a method for connecting a metal wire between a lead frame and a semiconductor device by a conventional wire bonding device.

FIG. 10 is a cross-sectional view showing a package sealed with a plastic resin.

FIG. 11 is a cross-sectional view showing a package sealed with a plastic resin.

FIG. 12 is a plan view showing a wire bonding apparatus according to an embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a wire bonding device according to an embodiment of the present invention.

FIG. 14 is a sectional view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a wire bonding device according to an embodiment of the present invention.

FIG. 15 is a sectional view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a wire bonding apparatus according to an embodiment of the present invention.

FIG. 16 is a sectional view showing a method of connecting a metal wire between a lead frame and a semiconductor device by a wire bonding apparatus according to an embodiment of the present invention.

FIG. 17 is an explanatory view showing the operation of the capillary by the conventional wire bonding apparatus.

FIG. 18 is a cross-sectional view showing a tip portion of a capillary.

[Explanation of symbols]

 11 Heater Plate 13 First Vacuum Suction Port 19 Second Vacuum Suction Port 15 Exhaust Port 81 Holding Mask

Claims (1)

[Scope of utility model registration request] 1. A wire bonding apparatus comprising a heater plate provided with a vacuum suction port.