CN1925146A - Driver chip package structure and driver chip using multilayer bump bonding - Google Patents

Abstract

The invention relates to a drive chip packaging structure and a drive chip which are jointed by utilizing a plurality of layers of bumps. The packaging structure of the driving chip connected by the multilayer bumps comprises a circuit film and a driving chip, wherein a conductive circuit layer of the circuit film is provided with a plurality of connecting ends, the driving chip is provided with an active surface, a plurality of welding pads are formed on the active surface, a plurality of multilayer bumps are arranged on the active surface of the chip and used for hot-pressing the connecting ends, each multilayer bump comprises a basic metal layer and a bonding metal layer, the basic metal layers are arranged on the welding pads, the bonding metal layers are formed on the basic metal layers and the hardness of the bonding metal layers is smaller than that of the basic metal layers, and when the bonding metal layers are in hot-pressing eutectic bonding with the connecting ends of the circuit film, the basic metal layers can prevent the connecting ends from being excessively collapsed into the multilayer bumps.

Description

Driver chip package structure and driver chip using multilayer bump bonding

technical field

The invention relates to a driving chip packaging structure, in particular to a driving chip packaging structure utilizing multi-layer bump bonding and a driving chip with multi-layer bumps.

Background technique

The existing conventional driver chip packaging structures include Tape Carrier Package (TCP) or Chip On Film (COF), in which gold bumps are first formed on the pads of the driver chip, and then Thermal compression bonding to tape or film, and during the packaging process, because the hardness value of the gold bump changes too much, the process parameters must be controlled within a small range, that is, the process window (process window) ) is small, and the hardness value of the conventional gold bump is between Vickers hardness (Hv) 35 to 65, that is, the variation range is Vickers hardness 30, and the allowable inner lead bond (ILB) The parameter changes are small.

A known bump structure is as disclosed in Taiwan Patent Announcement No. 488052 "Process of Forming Metal Bumps with More than Two Layers by Electroless Plating". Inner metal bumps, the material of the inner metal bumps is nickel, and its height is more than 15 μm, and a peripheral metal layer made of gold completely covers the outer periphery of the inner metal bumps, so that the double layer The total thickness of the above metal bumps is more than 18μm. After the bumps are formed on a plurality of solder pads of a chip, the wafer test step must be performed. During the wafer test process, the probes must be inserted into these solder pads. For the metal bumps with more than two layers on the pad, because the height of the peripheral metal layer (gold) is less than one-fifth of the inner layer metal bump (nickel), that is, the thickness of the gold layer is thinner, and the probe will be easily pierced. Penetrating the gold layer and touching the harder nickel layer makes the probe easy to wear. In severe cases, even the thickness of the gold layer is too thin, making the material of the entire bump too hard so that the probe cannot be inserted into the bump and cannot be inserted into the bump. For wafer testing, in addition, since the thermal compression bonding between the bump and the inner lead is to use gold and the tin plated on the inner lead to produce eutectic (eutectic) bonding, if the thickness of the gold layer of the metal bump with more than two layers If it is too thin, it will make the eutectic poor and affect the strength of the inner pin joint.

It can be seen that the above-mentioned existing driver chip package structure obviously still has inconveniences and defects in structure and use, and needs to be further improved urgently. In order to solve the problems existing in the packaging structure of the driver chip, the relevant manufacturers have tried their best to find a solution, but no suitable design has been developed for a long time, and there is no suitable structure for general products to solve the above problems. Obviously, it is a problem that relevant industry players are eager to solve. Therefore, how to create a driver chip package structure with a new structure has become a goal that needs to be improved in the current industry.

In view of the defects in the above-mentioned existing driver chip packaging structure, the inventor actively researches and innovates based on years of rich practical experience and professional knowledge in the design and manufacture of such products, and cooperates with the application of academic theories, in order to create a new type of driver chip. Utilizing the driver chip package structure and driver chip bonded by multi-layer bumps can improve the general existing driver chip package structure and driver chip, making it more practical. Through continuous research, design, and after repeated trial samples and improvements, the present invention with practical value is finally created.

Contents of the invention

The purpose of the present invention is to provide a new driver chip packaging structure and driver chip utilizing multi-layer bump bonding. The technical problem to be solved is to prevent the connecting terminals from Excessive collapse in these multi-layer bumps is more suitable for practical use.

Another object of the present invention is to provide a novel drive chip package structure and drive chip utilizing multilayer bump bonding. The technical problem to be solved is to reduce the variation range of the hardness values of these multilayer bumps, and It can have a larger process window (process window) when thermally pressing the driver chip, so it is more suitable for practical use.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. According to the present invention, a driving chip packaging structure utilizing multi-layer bump bonding includes: a circuit film, which includes an electrically insulating soft film body and a conductive circuit layer, and the conductive circuit layer is formed on the electrically insulating The soft film body has a plurality of connection ends; a driving chip has an active surface, and the active surface is formed with a plurality of welding pads; and a plurality of multi-layer bumps are arranged on the active surface of the driving chip For thermal compression bonding of the connecting ends, each multi-layer bump includes a basic metal layer and a bonding metal layer, the basic metal layers are set on the pads, and the bonding metal layers are formed on These basic metal layers and its hardness is less than these basic metal layers, when the connection terminals of the circuit film are eutectically bonded to the bonding metal layers, these basic metal layers can prevent the connection terminals from being too Parts are collapsed in the multi-layer bumps.

The purpose of the present invention and the solution to its technical problems also adopt the following technical measures to further realize.

In the aforementioned driving chip package structure using multi-layer bump bonding, the basic metal layers include nickel, and the bonding metal layers include gold.

In the aforementioned driving chip package structure utilizing multi-layer bump bonding, the hardness of the basic metal layers is not less than the hardness of the connection ends of the circuit film.

In the aforementioned driver chip package structure utilizing multi-layer bump bonding, the thickness of the base metal layers is not greater than twice the thickness of the bonding metal layers.

In the aforementioned driving chip package structure utilizing multi-layer bump bonding, the Vickers hardness (Hv) of the base metal layers is between 280-350, and the Vickers hardness (Hv) of the bonding metal layers is It is between 45 and 75.

In the aforementioned driver chip package structure utilizing multi-layer bump bonding, an UBM layer is formed on the pads.

The aforementioned driver chip package structure utilizing multi-layer bump bonding further includes an encapsulant encapsulating the multi-layer bumps.

The aforementioned driving chip package structure utilizing multi-layer bump bonding, wherein the circuit film is a tape (Tape) of a tape carrier package (TCP), the circuit film has an opening, and the connecting ends are formed in the air in the opening.

The purpose of the present invention and the solution to its technical problem also adopt the following technical solutions to achieve. According to the present invention, a driver chip with multi-layer bumps has an active surface, and the active surface is formed with a pad, and the pad is formed with a multi-layer bump, and the multi-layer bump includes a A basic metal layer and a bonding metal layer, the basic metal layer is bonded to the pads, and the bonding metal layer is formed on the basic metal layer, the hardness of the basic metal layer is greater than that of the bonding metal layer, and the The thickness of the basic metal layer is not greater than twice the thickness of the bonding metal layer.

The purpose of the present invention and the solution to its technical problems also adopt the following technical measures to further realize.

In the aforementioned driver chip with multi-layer bumps, an under-bump metal layer is formed between the pad and the basic metal layer.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. As can be seen from above technical scheme, main technical content of the present invention is as follows:

In order to achieve the above object, the present invention provides a driver chip packaging structure utilizing multi-layer bump bonding, which includes a circuit film, the circuit film includes an electrically insulating soft film body and a conductive circuit layer, the conductive circuit layer is It is formed on the main body of the electrically insulating soft film, and has a plurality of connecting ends to electrically connect a driving chip. The driving chip has an active surface, and the active surface is facing the connecting ends of the conductive circuit layer. A plurality of welding pads are formed on the surface, and the welding pads are corresponding to the connecting ends, and a plurality of multi-layer bumps are formed between the connecting ends and the welding pads, and each multi-layer bump includes a The basic metal layer and a bonding metal layer, the hardness of the basic metal layers is greater than that of the bonding metal layers, the Vickers hardness (Hv) of the basic metal layers is between 280-350, and the Vickers hardness (Hv) of the bonding metal layers is The hardness ranges from 45 to 75. Using the difference in hardness of the multi-layered metal (gradually hardening towards the bottom of the bump), the effect of maintaining the general shape of the bump (that is, the base layer) and the eutectic bonding (bonding layer) is achieved. The basic metal layers are bonded to the pads, and the bonding metal layers are eutectic bonded to the connecting ends, so that the bonding pads of the driver chip are electrically connected to the connecting ends of the circuit film. connect.

By virtue of the above technical solutions, the novel driver chip packaging structure and the driver chip with multi-layer bumps have at least the following advantages:

The present invention uses a plurality of multi-layer bumps to be formed on a plurality of welding pads of a driver chip, each multi-layer bump includes a base metal layer and a bonding metal layer, and the base metal layers are bonded to the drive chip A plurality of welding pads, when the driver chip and the circuit film are thermocompressed, the bonding metal layers are eutectically bonded to a plurality of connection ends of a circuit film, because the hardness of the basic metal layers is greater than that of the bonding The metal layer can prevent the connecting ends from being excessively collapsed in the multi-layer bumps, and will not affect the bonding strength of the inner pins due to poor eutectic.

The present invention utilizes a plurality of multilayer bumps to be formed on a plurality of welding pads of a driver chip, each multilayer bump includes a basic metal layer and a bonding metal layer, and the hardness of the basic metal layers is greater than that of the bonding metal layer, so that the bonding metal layers of these multi-layer bumps can surely bond the connection ends without excessive collapse, and can have a larger process window when a circuit film and the driver chip are thermocompressed ( process window).

To sum up, the drive chip packaging structure and drive chip with the special structure of the present invention using multi-layer bump bonding have the above-mentioned many advantages and practical value, and there is no similar structural design published or published in similar products. It is indeed an innovation because of its use, which has greatly improved both in product structure and function, and has made great progress in technology, and has produced easy-to-use and practical effects, and is more advanced than the existing driver chip packaging structure and The driver chip has multiple enhanced functions, so it is more suitable for practical use, and has wide application value in the industry. It is a novel, progressive and practical new design.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments are specifically cited below, and are described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic cross-sectional view of a driving chip package structure utilizing multi-layer bump bonding according to the present invention.

FIG. 2 is a partially enlarged schematic cross-sectional view of the packaging structure of the driving chip of the present invention.

100: driver chip package structure

110: Circuit film 111: Electric insulation soft film body

112: Conductive circuit layer 113: Opening

114: Connection terminal 120: Driver chip

121: active surface 122: protective layer

123: Welding pad 124: UBM layer

130: Multi-layer bump 131: Basic metal layer

132: Joint metal layer 140: Sealant

Detailed ways

In order to further explain the technical means and effects of the present invention to achieve the intended purpose of the invention, in conjunction with the accompanying drawings and preferred embodiments, the driving chip packaging structure and the driving chip using multi-layer bump bonding proposed according to the present invention will be described below. Specific embodiments, structures, features and effects thereof are described in detail below.

Please refer to FIG. 1 and FIG. 2, which is a specific embodiment of the present invention. The driving chip package structure 100 utilizing multi-layer bump bonding includes a circuit film 110, and the circuit film 100 can be carried by a tape The tape (Tape) of packaging (TCP) or the film (Film) of chip-on-film packaging (COF) is exemplified by tape in this embodiment. The circuit film 110 includes an electrically insulating soft film body 111 and A conductive circuit layer 112, and the electrical insulation soft film body 111 has an opening 113, the material of the electrical insulation soft film body 111 is polyimide (polyimide, PI) or polyester (polyester, PET), the conductive circuit The material of layer 112 can be copper and other metals, and is formed on the electrical insulation soft film body 111, and the conductive circuit layer 112 has a plurality of connecting ends 114. Preferably, these connecting ends 114 are electroplated with a tin layer (Fig. not shown), the connecting ends 114 are formed in the opening 113 to electrically connect a driving chip 120;

The driving chip 120 has an active surface 121, the active surface 121 is facing the connecting ends 114 of the conductive circuit layer 112, the active surface 121 is formed with a protection layer 122 and a plurality of welding pads 123, the welding pads An UBM layer 124 is formed on the 123, and the pads 123 correspond to the connection terminals 114;

A plurality of multi-layer bumps 130 are formed on the UBM layer 124 of the solder pads 123 and disposed between the connection terminals 114 and the solder pads 123, and the height of the multi-layer bumps is between 15 to 30 μm, each multi-layer bump 130 includes a base metal layer 131 and a bonding metal layer 132, these base metal layers 131 are bonded to the UBM layer 124 of the solder pads 123, and the bonding The metal layer 132 is eutectically bonded to the connection ends 114, so that the pads 123 of the driving chip 120 are electrically connected to the connection ends 114 of the circuit film 110. In this embodiment, the bases The hardness of the metal layer 131 is greater than that of the joining metal layers 132. The Vickers hardness (Hv) of the basic metal layers 131 is between 280-350, such as nickel and other hard materials, and the Vickers hardness (Hv) of the joining metal layers 132 is The Vickers hardness is between 45-75, such as softer materials such as gold, so that the Vickers hardness of the multi-layer bumps 130 is between 80-100, and the thickness of the basic metal layers 131 is not greater than the The double thickness of the bonding metal layers 132 is preferable, that is, the thickness of the basic metal layers 131 is no more than two-thirds of the height of the multilayer bumps 130. Preferably, the driving chip package structure 100 is also An encapsulant 140 is included, and the encapsulant 140 is disposed on the opening 113 to cover the multi-layer bumps 130 and the connecting ends 114 .

Since the hardness of the base metal layers 131 bonded to the pads 123 is greater than that of the bonded metal layers 132 bonded to the connection terminals 114, when the driver chip 120 is thermally bonded to the circuit film 110, it can Preventing the connecting ends 114 from excessively collapsing into the multi-layer bumps 130 can effectively control the combined height of the multi-layer bumps 130 . Therefore, the permissible variation range of the process parameters when the driver chip 120 and the circuit film 110 are thermocompressed is relatively large, and has a relatively large process window.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the structure and technical content disclosed above to make some changes or modifications to equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention, Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims (10)

1. A driving chip packaging structure utilizing multilayer bump bonding, characterized in that it comprises: A circuit film, which includes an electrical insulation soft film body and a conductive circuit layer, the conductive circuit layer is formed on the electrical insulation soft film body and has a plurality of connection terminals; A driving chip, which has an active surface, and the active surface is formed with a plurality of welding pads; and A plurality of multi-layer bumps are arranged on the active surface of the driver chip, each multi-layer bump includes a basic metal layer and a bonding metal layer, and the basic metal layers are arranged on the pads, The joining metal layers are formed on the base metal layers and their hardness is less than that of the base metal layers. layer prevents the connection terminals from excessively collapsing into the multilayer bumps. 2. The driver chip package structure utilizing multi-layer bump bonding according to claim 1, wherein the basic metal layers include nickel, and the bonding metal layers include gold. 3. The driving chip package structure utilizing multi-layer bump bonding according to claim 1, wherein the hardness of the basic metal layers is not less than the hardness of the connection ends of the circuit film. 4. The driver chip package structure utilizing multi-layer bump bonding according to claim 1, wherein the thickness of the basic metal layers is not more than twice the thickness of the bonding metal layers. 5. The driver chip package structure utilizing multi-layer bump bonding according to claim 1, wherein the Vickers hardness (Hv) of the basic metal layers is between 280-350, and the The Vickers hardness (Hv) of the bonding metal layer is between 45-75. 6 . The driver chip package structure utilizing multi-layer bump bonding according to claim 1 , wherein an under bump metal layer is formed on the solder pads. 7 . The driver chip package structure utilizing multi-layer bump bonding according to claim 1 , further comprising an encapsulant encapsulating the multi-layer bumps. 8. The driving chip package structure utilizing multi-layer bump bonding according to claim 1, wherein the circuit film is a tape (Tape) of a tape carrier package (TCP), and the circuit film has An opening, the connecting ends are suspended in the opening. 9. A driver chip with multi-layer bumps, which has an active surface, and a welding pad is formed on the active surface, and the welding pad is formed with a multi-layer bump, and the multi-layer bump includes a basic metal layer and A bonding metal layer, the basic metal layer is bonded to the pads, and the bonding metal layer is formed on the basic metal layer, characterized in that the hardness of the basic metal layer is greater than that of the bonding metal layer, and the basic The thickness of the metal layer is not greater than twice the thickness of the bonding metal layer. 10. The driving chip with multi-layer bumps according to claim 9, wherein an under bump metal layer is formed between the pad and the basic metal layer.

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