KR20110034057A - Electric connecting structure for preventing short circuiting and method of manufacturing the same - Google Patents

Abstract

PURPOSE: An electric connection structure for preventing a short and a manufacturing method thereof are provided to prevent the short by forming an electric conductive path though continuously arranged conductive balls between bumps. CONSTITUTION: An electrical connection unit(42) is formed on a substrate(40) to apply an electric signal. An anisotropic conductive adhesive layer(30) is formed on the upper side of the substrate and the electrical connection unit. The anisotropic conductive adhesive layer includes an adhesive resin(32) and a plurality of conductive balls(34). A chip(10) is formed on the upper side of the anisotropic conductive adhesive layer. A first insulation layer(20) is formed between the anisotropic conductive layer and the chip.

Description

ELECTRIC CONNECTING STRUCTURE FOR PREVENTING SHORT CIRCUITING AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to an electrical bonding structure for preventing an electrical short circuit and a method of manufacturing the same, and more particularly, even if the electrical connection portion of the substrate and the bump portion of the chip is bonded at a fine pitch by using an anisotropic conductive adhesive. It relates to a bonded structure and a method of manufacturing the same that can prevent the occurrence of an electrical short.

BACKGROUND In the field of semiconductor packaging or flat panel display, various adhesive materials are used for fixing electronic components or for electrical connection between substrates and chips. For example, the conductive particles are dispersed in an adhesive in the electrical connection between the flat panel glass and the tape carrier package (TCP), the electrical connection between the TCP and the printed circuit (PCB), or the various flexible printed circuits (FPC) and the PCB. The anisotropically conductive adhesive agent made is used as a circuit connection material. In addition, in the case of mounting a semiconductor silicon chip on a substrate, so-called flip chip and chip on board (COB) mounting in which a semiconductor silicon chip is directly mounted on a substrate instead of a conventional wire bond is faced. In the manufacture of a display and an RFID tag, a process of mounting an IC in the form of a chip on glass (COG) or a chip on film (COF) has been performed, but the use of an anisotropic conductive adhesive is also known here.

In the process of using an anisotropic conductive adhesive, it is required to shorten the connection time gradually in order to improve the production efficiency. For example, a circuit connection material that can be connected in 10 seconds or less is required. Long time circuit connection materials for electric and electronic are continuously being developed.

In particular, in recent years, in order to meet the tendency of light and short electric and electronic products, various devices and circuits are becoming more and more dense, and accordingly, the pitch of the electrical connection is increasingly finer, so that the fine pitch is effectively increased. There is an increasing interest in the process of electrical connection of a compatible anisotropic adhesive.

1 is a cross-sectional view showing a part of the electrical bonding structure according to the prior art, a cross-sectional view showing a region in which the pad portion and the connecting portion of the electrical bonding structure contact.

Referring to FIG. 1, a pad unit 120 for applying an electrical signal is positioned on a substrate 100. The pad part 120 may include a plurality of conductive pads 120a and an insulating part 120b positioned between the plurality of conductive pads.

In addition, the connection part 150 is positioned to face the pad part 120. A plurality of leads 160 corresponding to the plurality of pads 120a are positioned in a predetermined region of the connection unit 150 contacting the pad unit 120. Here, the connector 150 is a tape carrier package (TCP) or a chip on film (COF) is used. Although not shown, one side of the connection unit 150 may be connected to a PCB including a driving circuit unit. Alternatively, the connection unit 150 may include a driving circuit unit.

In addition, the conductive adhesive layer 180 is positioned between the pad part 120 and the connection part 150. Anisotropic conductive film (ACF) may be used as the conductive adhesive layer 180, and the anisotropic conductive film includes an adhesive resin 180a and conductive balls 180b dispersed in the adhesive resin.

The pad part 120 and the connection part 150 as described above are used to provide high temperature and high pressure to the conductive adhesive layer 180 positioned between the pad part 120 and the connection part 150 using equipment such as a head tip. It can be bonded by adding. That is, the conductive adhesive 180 located between the pad part 120 and the connection part 150 is cured by the adhesive resin 180a by high temperature, and the conductive balls 180b are pressed by the high pressure, so that the pad part 120 is pressed. And the connecting portion 150 are bonded and energized at the same time.

However, as shown by reference numeral A, when the conductive balls 180b are agglomerated in a region between the leads 160 of the connection part 150 in the bonding process, a short circuit between the leads 160 of the connection part 150. (short) may occur. This may not be able to apply an accurate electrical signal to the display unit there is a problem that can not express the desired video image.

As another example, Korean Laid-Open Patent Publication No. 2007-0034676 (published on March 29, 2007) includes an adhesive resin layer having insulation and an electric charge distributed in the adhesive resin layer, having the same polarity, and insulating on the surface. An anisotropic conductive film comprising a plurality of conductive balls having a layer is disclosed.

The conductive balls of the anisotropic conductive film have electric charges of the same polarity, and an insulating layer is formed on the surface so that a short circuit does not occur between the microelectrodes formed on the terminal of the chip. It is difficult to obtain a constant contact resistance, and sometimes there is a problem that a large contact resistance can be obtained.

Therefore, the first object of the present invention does not cause a change in the contact resistance value because no insulating material is interposed at the interface of the electrical joint in the bonding process using an anisotropic conductive adhesive, and a short circuit at the electrical joint is simply performed by adding a simple process. It is to provide an electrical junction structure for preventing an electrical short circuit that can prevent the occurrence of (short circuiting).

In addition, the second object of the present invention does not cause a change in the contact resistance value because no insulating material is interposed at the interface of the electrical junction in the bonding process using an anisotropic conductive adhesive, and short-circuit at the electrical junction just by adding a simple process It is to provide a method of manufacturing an electrical junction structure for preventing an electrical short circuit that can be prevented from occurring.

In order to achieve the first object of the present invention described above, in one embodiment of the present invention; An electrical connector provided on the substrate and configured to apply an electrical signal; A conductive adhesive layer provided on the substrate and the electrical connection part, the conductive adhesive layer including an adhesive resin and a plurality of conductive balls; A chip provided on the conductive adhesive layer and electrically connected to the electrical connection part through the conductive ball, the chip including a bump part formed at a position corresponding to the electrical connection part; And a first insulating layer provided on a surface of the chip and a side surface of the bump except for the bottom surface of the bump corresponding to the electrical connection unit.

In addition, in order to achieve the second object of the present invention, in an embodiment of the present invention (i) forming a first insulating layer on a chip provided with a bump; (Ii) removing the first insulating layer formed on the bottom surface of the bump part; (Iii) forming a conductive adhesive layer including an adhesive resin and a plurality of conductive balls on the substrate on which the electrical connections are formed; And (iii) adhering the chip having the bump part corresponding to the electrical connection part to the surface on which the conductive adhesive is formed and thermally compressing the chip.

According to the present invention, in the bonding process using an anisotropic conductive adhesive, an insulating layer is formed on the bump side of the chip, and the conductive balls are pulled, so that the bumps of the chip and the neighboring bumps or the bumps of the chip are electrically connected to the diagonal substrate. The short circuit does not occur even when physically connected by the additional conductive ball.

In addition, the present invention is not provided with an insulating layer on the bottom surface of the bump portion formed in the terminal of the chip, it is possible to obtain a constant contact resistance of the bump portion when the bump portion and the electrical connection portion of the substrate is in contact with the conductive ball Provide advantages.

Hereinafter, an electrical bonding structure (hereinafter, referred to as an 'electric bonding structure') and a method of manufacturing the same for preventing an electrical short circuit in an adhesive process using an anisotropic conductive adhesive according to preferred embodiments of the present invention will be described in detail. .

2 is a cross-sectional view showing a portion of an electrical junction structure according to an embodiment of the present invention.

2, an electrical junction structure according to an embodiment of the present invention includes a substrate 40, an electrical connection portion 42 provided on an upper portion of the substrate 40, the substrate 40 and an electrical connection portion ( 42 is an anisotropic conductive adhesive layer 30 provided on the upper portion of the chip, the chip 10 is provided on the anisotropic conductive adhesive layer 30 and the bump portion 12 is formed in a position corresponding to the electrical connection 42, The first insulating layer 20 is formed between the anisotropic conductive adhesive layer 30 and the chip 10.

The electrical junction structure according to the present invention can be used in the manufacturing process of various electronic products such as displays, computers, portable communication devices and the like.

An electrical junction structure according to an embodiment of the present invention includes a substrate 40.

The substrate 40 may be any substrate as long as it is a substrate commonly used in the art, but is preferably silicon, glass, polycarbonate (PC), polyethylenenaphthalate (PEN), polynor Polyenebornene (PC), Polyacrylate, Polyvinylalcohol (PVA), Polyimide (PI), Polyethyleneterephthalate (PET), Polyethersulfone (PES) and Transparent It is preferable to use a substrate composed of a polymer.

The electrical junction structure according to one embodiment of the present invention includes an electrical connection 42.

2 and 3, the electrical connection 42 is provided on the substrate 40 and is formed on the substrate 40 to apply an electrical signal. In this case, the electrical connection 42 includes a plurality of pads, leads, wires, or a plurality of bumps.

That is, as shown in FIG. 3, a plurality of pads, leads, and wires may be used as the electrical connection part 42, and a plurality of bumps may be used as shown in FIG. 4.

As shown in FIG. 4, when the electrical connection portion 42 is formed of a plurality of bumps, the bottom surface 43 of the electrical connection portion, that is, the sides of the bumps except the bottom surface of each bump and the upper portion of the substrate are made of insulating material. Since the second insulating layer 22 is formed, a short circuit can be prevented as the electrically conductive passage is formed in a continuous arrangement of the conductive balls 34 between the bump and the neighboring bump or the bump and the diagonal bump. .

In other words, the second insulating layer 22 may be provided on the surface of the substrate 40 and the bump side surface except for the bottom 43 of the electrical connection portion facing the chip 10.

The second insulating layer 22 is formed by firing an insulating material, and a material such as a polymer, ceramic, or carbon may be used as the insulating material. Here, the polymer insulating material may be polyimide, polyacrylic, benzocyclic butene, novolac, or epoxy resin, and the price is relatively cheap compared to other insulating materials.

In addition, the second insulating layer 22 may be made of an inorganic material such as silicon oxide or silicon nitride. Although the thickness of the second insulating layer 22 may be free depending on the purpose of use, the thickness of the second insulating layer 22 is preferably several μm.

The electrical bonding structure according to the embodiment of the present invention includes an anisotropic conductive adhesive layer 30.

Referring to FIG. 2, the anisotropic conductive adhesive layer 30 is provided on the substrate 40 and the electrical connection part 42, and includes an adhesive resin 32 and a plurality of conductive balls 34.

The adhesive resin 32 may be made of a thermosetting resin, a UV curable resin, or the like. Preferably, the adhesive resin 32 may be made of a thermosetting resin, and specifically, may be made of an epoxy resin.

The conductive balls 34 are regularly distributed in the adhesive resin 32 of the anisotropic conductive adhesive layer 30, and serve to electrically connect the chip 10 and the substrate 40 after the bonding process. If necessary, the conductive balls 34 can be configured to have electric charges of the same polarity as that of the other conductive balls 34, so that the conductive balls 34 can be prevented from being pulled out.

In addition, the anisotropic conductive adhesive layer 30 may be formed using an anisotropic conductive adhesive such as an anisotropic conductive paste (ACP) or an anisotropic conductive film (ACF).

More specifically, in the case of using the anisotropic conductive film to bond the substrate 40 and the chip 10, the base film of the anisotropic conductive film should be removed, and the pressing process should also be carried out by dividing the pressing process and the main compression process This can be cumbersome. However, when the chip 10 and the substrate 40 are bonded together using the anisotropic conductive paste, the step of removing the base film may be omitted, and the process of pressing as heat for bonding may also be performed by pressing and main pressing. This main compression can be solved only, so that the process can be simplified. In addition, since the anisotropic conductive paste is cheaper than the anisotropic conductive film, the manufacturing cost is also reduced.

An electrical junction structure according to an embodiment of the present invention includes a chip 10.

Referring to FIG. 2, the chip 10 is provided on the conductive adhesive layer 30 and includes a bump part 12 formed at a position corresponding to the electrical connection part 42. It is electrically connected to the electrical connection part 42 through the conductive ball 34. In this case, the bump part 12 includes a plurality of arranged bumps.

The bump part 12 is electrically connected to the electrical connection part 42 of the substrate 40 through the anisotropic conductive adhesive layer 30, and is preferably formed of a metal material because it must be formed of a conductor for signal transmission.

An electrical junction structure according to an embodiment of the present invention includes a first insulating layer 20.

2 to 4, the first insulating layer 20 may have the surface of the chip 10 and the bump 12 except for the bottom surface 14 of the bump part 12 corresponding to the electrical connection part 42. As formed on the side, the insulating material is formed by firing. In other words, the first insulating layer 20 is finally formed in a portion other than a portion electrically connected to the electrical connection portion 42 of the substrate by the conductive ball 34.

The insulating material forming the first insulating layer 20 is the same as the insulating material of the second insulating layer 22.

The thickness of the insulating layer 20 may be free depending on the purpose of use, but is preferably formed to a few μm.

As shown in FIG. 1, the conventional electrical bonding structure has conductive balls between the bumps of the chip and the neighboring bumps of the chip or between the bumps of the chip and the electrical connections of the substrate on the diagonal line due to the tipping of the conductive balls, which may occur during the bonding process. There is a problem in that the electrical short circuit occurs as the electrically conductive passage is formed in a continuous arrangement. However, the present invention includes a first insulating layer 20 between the bump portion 12 of the chip 10 and the anisotropic conductive adhesive layer 30, and the bump portion 42 and the anisotropic conductive adhesive layer 30 of the substrate 40. The second insulating layer 22 is selectively provided between the layers) to prevent the occurrence of an electrical short circuit by the formation of the electrically conductive passage.

In the present invention, the insulating layers 20 and 22 are not provided on the bottom surface 14 of the bump part 12 of the chip 10 and the bottom surface 43 of the bump part 42 of the substrate 40. Therefore, when the insulating layer is formed on the bottom surface of the bump, there is no problem that the contact resistance value becomes high or it is difficult to secure a uniform contact resistance value.

In addition, according to the present invention, since the first insulating layer 20 and the second insulating layer 22 are formed to have a thickness of several micrometers by using a coating method such as spray spray coating or spin coating, the conductive material between the bump and the neighboring bumps is electrically conductive. It is easy to secure a space for accommodating the ball 34, there is an advantage that can further delay the electrical short. That is, the present invention is compared with the conventional electrical bonding structure in which the insulating layer 120b is formed in the same thickness as the pad 120a and is bonded to the lead 160, so that a space in which the conductive balls can be dispersed after adhesion is provided. Since the conductive balls can be more dispersed between the bumps and neighboring bumps, the occurrence of electrical short circuits can be delayed more than twice as compared to conventional electrical bonding structures when the same level of conductive ball pull-out occurs in the bonding process. Can be.

Referring to the manufacturing method of the electrical junction structure according to an embodiment of the present invention having the above-described configuration as follows.

In the electrical bonding structure according to the embodiment of the present invention, the insulating layer 20 is first formed by applying an insulating material to the upper portion of the chip 10 having the bump part 12, and the bottom surface 14 of the bump part. The first insulating layer 20 formed is removed. In addition, the conductive adhesive 30 is coated on the substrate 40 having the electrical connection part 42 and thermocompressed in contact with the chip 10 provided with the bump part 12 to manufacture the electrical bonding structure. do.

Hereinafter, exemplary embodiments will be described in more detail with reference to the accompanying drawings.

5 to 7 are cross-sectional views illustrating a method of forming an electrical junction structure according to an embodiment of the present invention.

5 and 6, the first step S110 is to form the first insulating layer 20 on the chip 10 on which the bump part 12 is formed, and the bump part 12 is formed. An insulating material is coated on the chip 10, and the first insulating layer 20 is formed by firing the insulating material. In this case, the insulating material may be a material such as polymer, ceramic, carbon, etc., and the coating of the insulating material may be applied on the chip 10 by various methods such as spray spraying, spin coating, and vacuum deposition. Can be. In addition, it is preferable that the forming step of the first insulating layer proceeds in a wafer state.

In one embodiment, the polymeric material can be easily coated using a spray spray coating method or a spin coating method before the curing of the fluid state. Here, the spray spray coating method has the advantage that the conformal coating (conformal) even in a state where the step of the bump is large, it is preferable to use the spin coating method when the step of the bump is small.

As another embodiment, when a ceramic or carbon material is used as the insulating material, vacuum deposition such as sputtering and chemical vapor deposition may be mainly used, but is not limited thereto.

In addition, when the thermosetting polymer is used as the insulating material, any heating method may be used to cure the insulating material, and when the UV curable polymer is used as the insulating material, the insulating material may be cured through UV irradiation.

Since the deposition and firing processes of the polymer, ceramic, and carbon materials are general to those skilled in the art to which the present invention pertains, further description thereof will be omitted.

Referring to FIG. 7, the second step S120 is to remove the first insulating layer 20 formed on the bottom surface 14 of the bump part of the chip 10, and the bottom surface 14 of the bump part is conductive. The first insulating layer 20 formed between the bottom surface 14 of the bump part and the conductive ball 34 is removed so that electricity can be smoothly applied when the ball 34 is in contact with the ball 34.

 The first insulating layer 20 is preferably removed through a polishing process. In this case, the polishing process uses a method of removing the first insulating layer 20 through physical contact with the grinder material.

If necessary, in order to improve the efficiency of the polishing process, the polishing process may be performed using a chemical corrosion solution.

In addition, it is preferable to proceed with the removal of a 1st insulating layer in a wafer state. Since the polishing process for removing the first insulating layer corresponds to a general content to those skilled in the art, further description thereof will be omitted.

The third step (S130) is to form an anisotropic conductive adhesive layer 30 on the substrate 40 on which the electrical connection portion 42 is formed, the anisotropic conductive adhesive layer 30 is the adhesive resin 32 and a plurality It consists of two conductive balls 34. At this time, an anisotropic conductive adhesive, for example, an anisotropic conductive paste or an anisotropic conductive film may be used as the anisotropic conductive adhesive layer 30.

In a particular embodiment, in this step, an ACP, which is an anisotropic conductive paste material including a conductive ball 34, is applied on the top of the substrate 40 on which the electrical connection part 42 is formed, using a dispenser (not shown). If an anisotropic conductive film is used, the anisotropic conductive adhesive layer is arranged by the pressure bonding method as described above.

Referring to FIG. 4, a step S132 of forming a second insulating layer 22 between the second step and the third step and removing a part of the added second insulating layer 22 (S134). ) May be further included. In this case, a plurality of bumps are used as the electrical connection 42. That is, as shown in FIG. 3, when a plurality of pads, leads, and wires are used as the electrical connection part 42, the second insulating layer 22 may not be formed.

More specifically, the step (S132) is coated with an insulating material on the surface of the substrate 40 having a plurality of bumps to the electrical connection portion 42, and by firing the insulating material to form a second insulating layer 22 The step S134 is to remove the second insulating layer 22 formed on the bottom surface 43 of the electrical connection unit.

The insulating material is preferably used the same insulating material as the insulating material used in the first step (S130) described above. In addition, the method of removing the second insulating layer 22 is also preferably the same method as the second step (S120) described above.

The fourth step (S140) is a step of attaching the chip 10 provided with the bump portion 12 to the surface on which the anisotropic conductive adhesive layer 30 is applied using a thermocompression bonding method, and the like. The chip 10 is brought into contact with the bump part 12 at a position corresponding to 42.

The thermal compression is preferably carried out for several seconds to several tens of seconds at a temperature of 100 to 180 ℃.

As such, when the chip 10 is attached to the substrate 40 by the thermocompression bonding method, the conductive ball 34 is interposed between the bump part 12 and the electrical connection part 42 in a deformed state, and the remaining adhesive resin (32), for example, the polymer adhesive component is thermoset to form the final anisotropic conductive adhesive layer 30.

More specifically, in this step, the anisotropic conductive adhesive layer 30 is disposed between the substrate 40 and the chip 10, and heat is applied to the bonding portion using predetermined equipment, and a pressure is applied in the vertical direction. More specifically, the conductive ball 34 between the bump 12 of the chip 10 and the electrical contact 42 of the substrate 40 is captured and collapsed by the bump 12 and the electrical contact 42. By being crushed, the bump 12 and the electrical connection 42 are energized. At this time, the conductive ball 34 that is not captured flows in the adhesive resin layer 32 by pressing, and moves around the electrical coupling portion of the substrate 40 and the chip 10.

In this case, electrical conduction is made through the conductive ball 34 interposed between the bump part 12 and the electrical connection part 42, and bumps and neighboring bumps are caused by the pulling phenomenon of the conductive ball 34 in the bonding process. An electrically conducting passage can be formed in a continuous arrangement of conductive balls 34 between the inner or bump and diagonal electrical connections. However, electrical shorts generated by the formation of the electrically conductive passages are blocked by the first insulating layer 20.

Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

1 is a cross-sectional view showing an electrical junction structure according to the prior art.

2 is a cross-sectional view showing an electrical junction structure according to an embodiment of the present invention.

3 is an enlarged cross-sectional view partially illustrating FIG. 2.

Figure 4 is an enlarged cross-sectional view showing an electrical junction structure according to another embodiment of the present invention.

5 is a plan view illustrating a chip on which a bump part is formed according to an exemplary embodiment of the present invention.

6 is a cross-sectional view illustrating a chip coated with an insulating layer according to an embodiment of the present invention.

7 is a cross-sectional view illustrating a partially polished bump part according to an exemplary embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10 chip 12 bump part

14 bottom surface of bump part 20 first insulating layer

22: second insulating layer 30: anisotropic conductive adhesive layer

32: adhesive resin 34: conductive ball

40: substrate 42: electrical connection

43 bottom surface of electrical connection

Claims (8)

Board; An electrical connector provided on the substrate and configured to apply an electrical signal; An anisotropic conductive adhesive layer provided on the substrate and the electrical connection part and including an adhesive resin and a plurality of conductive balls; A chip provided on the anisotropic conductive adhesive layer and electrically connected to the electrical connection part through the conductive ball and including a bump part formed at a position corresponding to the electrical connection part; And And a first insulating layer provided between the chip and the anisotropic conductive adhesive layer except for the bottom surface of the bump corresponding to the electrical connection part. The method of claim 1, wherein the anisotropic conductive adhesive layer An electrical bonding structure for preventing an electrical short circuit, characterized in that formed with an anisotropic conductive paste or an anisotropic conductive film. The method of claim 1, The electrical connection part is a bump, and the electrical junction structure for preventing an electrical short circuit, characterized in that the second insulating layer made of an insulating material formed on the side of the bump and the top of the substrate except the bottom surface of the bump facing the chip. . (Iii) forming a first insulating layer on the chip with bumps; (Ii) removing the first insulating layer formed on the bottom surface of the bump part; (Iii) forming an anisotropic conductive adhesive layer comprising an adhesive resin and a plurality of conductive balls on the substrate on which the electrical connections are formed; And (Iii) adhering a chip having a bump portion corresponding to the electrical connection portion to a surface on which the conductive adhesive is formed and bonding the thermocompression bonding to a chip. 5. The method of claim 4, wherein the step (ii) Coating an insulating material on a surface of the substrate provided with the electrical connection, and firing the insulating material to form a second insulating layer, and And removing the second insulating layer formed on the bottom surface of the electrical connection part. The method of claim 5, The electrical connection unit is a manufacturing method of the electrical junction structure for preventing an electrical short circuit, characterized in that consisting of a plurality of bumps. The method of claim 4, wherein The removal of the insulating layer in the step (ii) is carried out by a polishing process, the method of manufacturing an electrical bonding structure for preventing an electrical short. The method of claim 7, wherein The polishing process is a method of manufacturing an electrical bonding structure for preventing an electrical short, characterized in that using a chemical corrosion solution.

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