KR20130024423A - Ultrasonic bonding apparatus having elastic part to align the pressure surface - Google Patents

Abstract

PURPOSE: An ultrasonic bonding device equipped with an elastic member for the alignment of a pressurization plane is provided to use the unbalanced load transmission to align a pressurization plane with a contact plane in parallel, thereby preventing unnecessary loss of vibration energy caused by the point contact between the pressurization plane and the contact plane. CONSTITUTION: A jig base(10) is provided to be vertically movable. A pressurization member(20) has a pressurization plane(20a) pressurizing a connected object formed on the lower part. An elastic member(30) is combined between the jig base and the pressurization member and provides the elastic force between the pressurization member and the jig base. The elastic member combines the pressurization member movably with the jig base. An ultrasonic horn(40) is combined to the pressurization member in order to deliver vibration through the pressurization plane of the pressurization member to the connected object.

Description

Ultrasonic bonding apparatus having elastic part to align the pressure surface

The present invention relates to an ultrasonic bonding apparatus, and more particularly, to an ultrasonic bonding apparatus having an elastic member for precise alignment of the pressing surface.

Printed Circuit Boards (PCBs) are now widely used in electronic devices, and various methods of bonding circuit chips to printed circuit boards have been implemented.

One method for bonding a circuit chip to a printed circuit board is die bonding the circuit chip onto a lead frame, and wire-bonding the electrode and the lead frame of the IC chip to a resin. Surface Mount Technology (SMT) was used to form a package by molding and then print a cream solder onto a circuit board and perform a reflow process.

This has a problem that the process is long, requires a long time for production, and it is difficult to miniaturize the circuit board.

Therefore, in order to shorten the process and reduce the size and weight, a method of directly mounting a bumped circuit chip on a printed circuit board has been used.

In particular, in the process of thermally fusion mounting the bumped circuit chip on a printed circuit board, anisotropic conductive film (ACF) is first applied on the printed circuit board, and then the circuit chip is vibrated at an ultrasonic frequency range. It was shown that the thermal bonding to the circuit board by the thermal energy through the vibration energy.

However, the error in placing the chip on the circuit board, the error in installing the stage where the circuit board is located, and the pressing member transmitting the vibration, the error in the thickness of the anisotropic conductive adhesive for bonding the circuit board and the chip, or uneven coating The pressing surface and the bonding object are not arranged in parallel due to the like.

Since the contact surface of the pressurized surface and the object to be bonded does not exactly match, vibration energy is transmitted in the point contact state instead of the surface contact, and energy loss occurs. Furthermore, the conversion of thermal energy through the vibration energy is not sufficient. There was a problem that a defect occurred.

In order to solve the problem, there is also a problem that damage may occur due to the application of a high load to the chip in the case of additionally applying a load to the surface contact the point contact.

Furthermore, even if the chip and the pressing surface in parallel contact, there was also a problem that the alignment of the pressing surface and the bonding surface may occur due to the application of the vibration of the ultrasonic horn due to the application of the vibration of the pressing surface and the bonding surface.

The present invention is to solve the above-mentioned problems, ultrasonic bonding apparatus that the pressure surface can be changed to form a horizontal direction and a certain angle according to the load applied to the pressure surface due to the unbalance between the pressing surface and the contact object. In providing.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

Ultrasonic bonding apparatus of the present invention for solving the above problems is a jig base moving in the vertical direction, the pressing surface for pressing the bonding object is formed in the lower portion, the jig base and the pressing member is coupled between the pressing It provides an elastic force between the member and the jig base, the elastic member for coupling the pressing member to the jig base to be movable so that the pressing surface is in surface contact with the bonding object and vibrating according to the applied frequency, the pressing It includes an ultrasonic horn coupled to the pressing member so that vibration is transmitted to the bonding object through the pressing surface of the member.

The pressing member may include a pressing part having a pressing surface and an elastic member fixing part protruding along a circumference of the pressing part, and the elastic member may be coupled between the fixing part and the jig base.

In addition, an insertion hole is formed in the jig base, and a fixing hole is formed in the fixing part, and the elastic member is supported on the upper surface of the support base to be inserted into the insertion hole, one end of which is fixed to the shaft support part. And the other end of which is fixed to the fixing hole and a spring that is inserted into the shaft to provide an elastic force between the support base and the fixing part.

And an ultrasonic horn fixing portion into which the ultrasonic horn is inserted is formed on an upper surface of the pressing member, an insertion hole into which the ultrasonic fixing part is inserted is formed, and an insertion portion into which the ultrasonic horn fixing portion is inserted is formed. It may further include a fixing member coupled to the top of the horn to fix the ultrasonic horn to the upper surface of the pressing member.

And a sensing unit provided at the pressing surface to determine whether the rigid pressing surface and the contact object are in contact with the surface, and a controller configured to control the up and down movement of the jig base according to the sensing result of the sensing unit.

Ultrasonic bonding apparatus according to the present invention having the above configuration has the following effects.

First, the pressing surface is aligned to form a parallel to the bonding surface by using an unbalanced load transfer of the pressing surface caused by the unbalance of the bonding object and the pressing surface. Therefore, it is possible to prevent unnecessary loss of vibration energy due to the point contact between the pressing surface and the bonding surface according to various situations.

Second, there is an advantage that it is possible to simply correct the change in alignment that may occur between the pressing surface and the contact surface due to the vibration of the ultrasonic horn.

Third, there is an advantage that the pressing surface can be restored to its original state at the same time as the separation of the pressing surface and the contact surface by using the elastic force.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims.

1 is a perspective view of an ultrasonic bonding device according to an embodiment of the present invention;
Figure 2 is an exploded perspective view of the ultrasonic bonding device according to an embodiment of the present invention;
Figure 3 is a cross-sectional view of the ultrasonic bonding device according to an embodiment of the present invention;
4 to 6 are views showing a process of bonding a circuit chip to a printed circuit board using an ultrasonic bonding apparatus according to an embodiment of the present invention;
7 is a cross-sectional view showing a state in which the ultrasonic bonding apparatus according to an embodiment of the present invention is arranged to form a predetermined angle with the vertical axis in the vertical direction;
8 is a view showing a state in which the elastic member of the ultrasonic welding apparatus according to an embodiment of the present invention moved to form a predetermined angle with respect to the vertical axis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In describing the present embodiment, the same designations and the same reference numerals are used for the same components, and further description thereof will be omitted.

1 is a perspective view of an ultrasonic bonding apparatus according to an embodiment of the present invention, Figure 2 is an exploded perspective view of the ultrasonic bonding apparatus according to an embodiment of the present invention, Figure 3 is an ultrasonic bonding according to an embodiment of the present invention Section of the device.

1 to 3, the ultrasonic bonding apparatus 1 of the present invention is a device for bonding a circuit chip to a printed circuit board, etc., the jig base 10, the pressing member 20, the elastic member 30 and Ultrasonic horn 40 is included.

The jig base 10 is provided to be movable in the up and down directions, and presses the circuit chip C to the printed circuit board P located in the stage 100 while moving up and down. Specifically, in this embodiment, the force applied to the jig base 10 is transmitted to the pressing member 20 through the elastic member 30 to be described later, the pressing member 20 is a circuit chip on the printed circuit board (P) (C) is pressurized.

Meanwhile, the jig base 10 has an insertion hole 12 to which the elastic member 30 is coupled, and the coupling relationship between the insertion hole 12 and the elastic member 30 will be described later.

The pressing member 20 is formed with a pressing surface 20a for pressing the circuit object C, that is, the circuit chip C in this embodiment. The pressing surface 20a may be formed in various forms to transmit vibrations of the ultrasonic horn 40 to the bonding object and to form a wide contact surface with the bonding object. Although not shown, a suction port for sucking the circuit chip C may be formed on the pressing surface.

On the other hand, the pressing surface 20a should be in surface contact with the bonding object in order to effectively transmit the vibration of the ultrasonic horn 40 to the bonding object. Therefore, the pressing surface 20a in the present invention is aligned again according to the bonding surface of the bonding object by the elastic member 30 which couples the pressing member 20 to the jig base 10 to be movable.

In addition, a sensing unit (not shown) may be provided on the pressing surface 20a to determine whether the pressing surface 20a and the circuit chip C make surface contact. The sensing unit is installed with a variety of sensors to determine whether the pressing surface (20a) is in accurate surface contact with the circuit chip (C).

For example, when a plurality of contact sensors are provided on the pressing surface 20a, downward movement of the jig base 10 may be appropriately adjusted until a contact signal is input through all the contact sensors. Therefore, when the pressing surface 20a and the circuit chip C do not make an accurate contact, the jig base 10 may be moved downward, and when the contact is made correctly, the jig base 10 may be stopped to stop the circuit chip C. Excessive load on) can be prevented.

As a result, the ultrasonic bonding apparatus 1 of the present invention may further include a controller (not shown) that can control the up and down movement of the jig base 10 according to the signal of the sensing unit. In addition, as the sensing unit, various sensing means for determining whether the pressing surface 20a, such as a pressure sensor, may be applied.

The pressing member 20 in the present embodiment includes a pressing portion 21 and the elastic member fixing portion 22.

The pressing part 21 is provided with a pressing surface at the bottom, and provides a movement path of the vibration so as to transmit the vibration transmitted through the ultrasonic horn 40 to the bonding object through the pressing surface 20a.

The elastic member fixing portion 22 protrudes along the circumference of the pressing portion 21. And one end of the elastic member 30 is fixed. Specifically, four fixing holes 22a into which the lower ends of the shaft 31 of the elastic member 30 are inserted are formed in the elastic member fixing part 20.

On the other hand, the ultrasonic horn 40 to be described later may be coupled to various positions to transmit the vibration generated by the ultrasonic wave to the pressing member 20, in this embodiment, the ultrasonic wave can be fixed to the upper surface of the pressing member 20 The Hongo government can be formed, in this embodiment, the ultrasonic fixing portion 23 is formed to protrude upward on the upper surface of the pressing member 20 so that the insertion hole 40a of the ultrasonic horn 40 can be fitted.

The elastic member 30 is coupled between the jig base 10 and the pressing member 20 to provide an elastic force between the pressing member 20 and the jig base 10, the pressing surface 20a is in surface contact with the bonding object The pressing member 20 is coupled to the jig base 10 so as to be movable.

Specifically, the elastic member 30 in the present embodiment includes a shaft support 34, a shaft 31, a spring 32, and a bush 33.

The shaft support part 34 is fitted to the insertion hole 10a while being supported by the upper surface of the jig base 10. That is, the upper part of the shaft support part 34 is formed to have a cross-sectional area larger than the cross-sectional area of the insertion hole 10a and is supported on the upper surface of the jig base 10, and the lower part is inserted into and fixed to the insertion hole 10a. And the shaft support portion 34 is formed with a hole that is fitted so that the upper portion of the shaft can be moved finely in the up, down direction.

The shaft 31 has an upper end coupled to the shaft support 34 to allow fine movement. Specifically, in the present embodiment, the upper portion of the shaft 31 is inserted into the hole formed in the shaft support portion 34 is inserted.

Meanwhile, the size of the circumference of the shaft 31 and the size of the hole of the shaft support part 34 remain fixed when the shaft 31 is fitted into the hole of the shaft support part 34 and no external force is applied. When an external force of magnitude or more is applied, the shaft 31 is formed to have a size capable of moving finely upward through the hole of the shaft support part 34.

That is, as the specific shaft 31 of the plurality of shafts 31 finely moves upward according to the imbalance of the force input through the pressing surface 20a, the pressing member 20 moves finely on the horizontal plane. Accordingly, the pressing surface 20a is arranged to form an angle with the horizontal surface.

When the pressing surface 20a and the circuit chip C come into surface contact with the movement of the pressing surface 20a, the external force applied through the pressing surface 20a is uniformly applied to the pressing surface 20a, and the shaft ( 31) no longer moves.

And as the pressing surface 20a is separated from the circuit chip C, the external force through the pressing surface 20a is removed, and the shaft 31 moved upward is returned to its original position by the elastic force of the spring 32. You will come back.

The other end of the shaft 31 is fixed to the fixing hole 22a of the pressing member 20. As a result, the pressing member 20 and the ultrasonic horn 40 are coupled to the jig base 10 by the shaft 31.

The spring 32 has an inner diameter larger than that of the shaft 31 to be fitted to the shaft 31, and the bush 32 is fitted to the upper portion of the spring 32 to fix the spring 32 to the shaft 31. do.

And the spring 32 is to provide an elastic force between the jig base 10 and the pressing member 20. Therefore, pressure is applied through the pressing surface 20a to make a surface contact with the bonding object while the pressing surface 20a is changed, and then the pressing surface 20a is restored to its original position by the elastic force of the spring 32. do.

The ultrasonic horn 40 vibrates at a specific frequency by the supplied energy. Then, the vibration energy is transmitted to the pressing member 20, and the transmitted vibration energy is transferred to the anisotropic conductive film positioned between the circuit chip C and the printed circuit board P through the pressurizing surface. Thermal fusion is induced.

Specifically, the ultrasonic horn 40 in the present embodiment is formed with a insertion hole 40a through which the ultrasonic horn fixing part 23 of the pressing member 20 is fitted. In the present invention, the ultrasonic horn 40 is fixed to the pressure member 20 while the fixing member 50 having the insertion portion 50a in which the ultrasonic horn fixing portion 40 is fitted is coupled to the upper portion of the ultrasonic horn 40. Let's go.

4 to 6 are views illustrating a process of bonding a circuit chip to a printed circuit board using an ultrasonic bonding apparatus according to an embodiment of the present invention.

4 and 6, a process in which the pressing surface 20a makes surface contact with the bonding object by using the ultrasonic bonding apparatus according to the present invention will be described.

Referring to FIG. 4, when the circuit chip C is located at the mounting point of the printed circuit board P, the mounting process of the circuit chip C, the horizontal maintenance when the stage 100 is arranged, and the printed circuit board P ) And the bonding surface of the circuit chip C contacting the pressing surface 20a is not arranged in parallel depending on the nonuniform coating or thickness of the anisotropic conductive film between the circuit chip and the circuit chip C. In this case, the bonding surface of the circuit chip C forms a horizontal line and a first angle α.

As the jig base 10 moves downward, the contact surface between the pressing surface 20a and the circuit chip C is primarily in point contact. In this case, if the pressing surface 20a is disposed horizontally, the bonding surface of the pressing surface 20a and the circuit chip C also forms a first angle α.

In this case, a touch signal is applied to some of the touch sensors of the above-described sensing unit (not shown), and the control unit (not shown) may apply the touch signal to the corresponding touch sensor so as to check the surface contact. Until the jig base 10 is moved further down. (See Figure 5).

Figure 7 is a cross-sectional view showing a state in which the ultrasonic bonding apparatus according to an embodiment of the present invention is arranged to form a predetermined angle with the vertical axis in the up and down direction, Figure 8 is an ultrasonic bonding apparatus according to an embodiment of the present invention Figure is a view showing a state in which the elastic member is moved to form a predetermined angle with respect to the vertical axis.

Referring to FIGS. 7 and 8, an external force is applied at a point where the pressing surface 20a primarily contacts the bonding surface of the circuit chip C as the jig base 10 moves downward. And as the external force is applied to the portion away from the center of the pressing surface (20a) receives a force from the lower portion to the upper portion of the elastic member 20 located in the portion to which the external force is applied.

Therefore, the shaft 31, which is fitted to the shaft fixing part 34 so as to be finely moved, is finely moved upward, and thus the pressing member 20 is inclined on the horizontal plane.

According to the nonuniform point contact between the pressing surface 20a and the circuit chip c described above, a nonuniform load is applied to a specific point of the pressing surface 20a, and the As the external force is applied, the specific shaft 31 moves upward.

As a result, the heights of the upper ends of the plurality of shafts 31 are different from each other. Accordingly, the pressing member 20 fixed to the lower ends of the shafts 31 is arranged to form a predetermined angle with the horizontal plane.

Therefore, when the pressing surface 20a comes into surface contact with the bonding surface of the circuit chip C, and the ultrasonic horn 40 vibrates after the surface contact, the vibration energy is transmitted through the pressing surface 20a. It is uniformly transmitted to the bonding surface of, so that the entire printed circuit board P and the circuit chip C are bonded more precisely.

On the other hand, when the pressing surface 20a is separated from the circuit chip C after the bonding, the spring 32 is restored by the elastic force that has been deformed, and the shaft 31 that has moved upward has its original position by the elastic force. Will be restored.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. It is obvious to them. Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive, and thus, the present invention is not limited to the above description and may be modified within the scope of the appended claims and their equivalents.

10: jig base 20: pressing member
20a: pressing surface 21: pressing portion
22: fixing unit 23: ultrasonic horn fixing unit
30: elastic member 31: shaft
32: spring 34: shaft support
40: ultrasonic horn 50: fixing member

Claims (5)

Jig base moving in the up and down direction;
A pressing member having a pressing surface for pressing the object to be joined;
An elastic force coupled between the jig base and the pressing member to provide an elastic force between the pressing member and the jig base, and to couple the pressing member to the jig base such that the pressing surface is in surface contact with a bonding object. absence; And
An ultrasonic horn which vibrates according to the applied frequency and is coupled to the pressing member so that the vibration is transmitted to the bonding object through the pressing surface of the pressing member;
Ultrasonic bonding apparatus comprising a. The method of claim 1,
The pressing member includes a pressing portion formed with a pressing surface, the elastic member fixing portion protruding along the circumference of the pressing portion,
The elastic member is an ultrasonic bonding device coupled between the fixing portion and the jig base. The method of claim 2,
An insertion hole is formed in the jig base, and a fixing hole is formed in the fixing part.
The elastic member is supported on the upper surface of the support base and the shaft support portion to be inserted into the insertion hole, one end is fitted to be movable to the shaft support portion, the other end is fitted to the shaft and the shaft fixed to the fixing hole Ultrasonic bonding apparatus further comprises a spring to give an elastic force between the support base and the fixing portion. The method of claim 1,
On the upper surface of the pressing member is formed an ultrasonic horn fixing portion into which the ultrasonic horn is inserted,
The ultrasonic horn is formed with an insertion hole into which the ultrasonic fixing part is fitted.
And an inserting portion into which the ultrasonic horn fixing portion is fitted, the fixing member being coupled to an upper portion of the ultrasonic horn to fix the ultrasonic horn to the upper surface of the pressing member. The method of claim 1,
The ultrasonic bonding apparatus further includes a sensing unit provided on the pressing surface to determine whether the steel pressing surface and the contact object is in contact with the surface, and a controller for controlling the up and down movement of the jig base according to the sensing result of the sensing unit.

Images