Metal bump structure and manufacturing method thereof and driving substrate

Abstract

The present invention provides a metal bump structure and a manufacturing method thereof and a driving substrate. The manufacturing method of the metal bump structure comprises the following steps. A driving substrate is provided. At least one pad and an insulating layer are formed on the driving substrate. The pad is formed on the configuration surface of the driving substrate and has an upper surface. The insulating layer covers the configuration surface of the driving substrate and the pad and exposes a portion of the upper surface of the pad. A patterned metal layer is formed on the upper surface of the pad exposed by the insulating layer and extends to cover a portion of the insulating layer. A chemical plating procedure is performed to form at least one metal bump on the patterned metal layer. The first extension direction of the metal bump is perpendicular to the second extension direction of the driving substrate. The metal bump structure and the manufacturing method thereof of the present invention have the advantages of simple process, low cost and no environmental pollution.

Description

Technical Field

[0001] The invention relates to a bump structure and a manufacturing method thereof and a substrate, and in particular to a metal bump structure and a manufacturing method thereof and a driving substrate having the metal bump structure. Background Art

[0002] Currently, most of the active driving (AM Driving) micro LED displays (Micro LED Display) use thin film transistor (Thin Film Transistor, TFT) glass substrates to drive the light-emitting diodes. However, the thin film transistor is a thin film process, and the metal wires on it and the indium tin oxide (Indium Tin Oxide, ITO) in the light-emitting area (pixel area) are only nanometers. Therefore, when the light-emitting diode or surface mount device (Surface Mount Device, SMD) is to be soldered (Solder Bonding) on ​​the indium tin oxide conductive layer, it is impossible to form a reliable intermetallic compound (Intermetallic Compound, IMC) to bond together. In order to solve the above problems, electroplating (Electrodeplating) is currently used to form a thick copper layer on the indium tin oxide conductive layer. However, the process of electroplating thick copper is lengthy and complicated. In addition to increasing the manufacturing cost, it is also easy to cause environmental pollution because it is a wet process. Summary of the invention

[0003] The present invention is directed to a metal bump structure and a manufacturing method thereof, which has the advantages of simple manufacturing process, low cost and no environmental pollution.

[0004] The present invention is directed to a driving substrate including the above-mentioned metal bump structure, which can have better structural reliability.

[0005] According to an embodiment of the present invention, a method for manufacturing a metal bump structure includes the following steps. A driving substrate is provided. At least one pad and an insulating layer are formed on the driving substrate. The pad is formed on the configuration surface of the driving substrate and has an upper surface. The insulating layer covers the configuration surface of the driving substrate and the pad and exposes a portion of the upper surface of the pad. A patterned metal layer is formed on the upper surface of the pad exposed by the insulating layer and extends to cover a portion of the insulating layer. An electroless plating (ELP) process is performed to form at least one metal bump on the patterned metal layer. The first extension direction of the metal bump is perpendicular to the second extension direction of the driving substrate.

[0006] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the step of forming the patterned metal layer includes forming a catalyst layer on the insulating layer and the upper surface of the pad exposed by the insulating layer, and performing an activation process and a patterning process on the catalyst layer to form a patterned metal layer.

[0007] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the method for forming the catalyst layer includes an inkjet printing method.

[0008] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the material of the catalyst layer includes nano-palladium (Nano-Pd), or any nano-metal that can reduce chemical copper, such as nano-gold or nano-silver.

[0009] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the activation process includes a laser activation process or a heating process.

[0010] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the material of the patterned metal layer includes palladium, gold or silver.

[0011] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the material of the metal bump includes copper, gold, tin or nickel.

[0012] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the cross-sectional shape of the metal bump includes a quasi-circular or rectangular shape.

[0013] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the material of the pad includes indium tin oxide (ITO), or any sputtered metal layer such as titanium, copper, molybdenum, aluminum or chromium.

[0014] In the method for manufacturing the metal bump structure according to the embodiment of the present invention, the thickness of the metal bump is between 1 micrometer and 10 micrometers.

[0015] According to an embodiment of the present invention, a metal bump structure is configured on a driving substrate. A pad and an insulating layer are configured on the driving substrate. The pad is configured on the configuration surface of the driving substrate and has an upper surface. The insulating layer covers the configuration surface of the driving substrate and the pad and exposes a portion of the upper surface of the pad. The metal bump structure includes a patterned metal layer and a metal bump. The patterned metal layer is configured on the upper surface of the pad exposed by the insulating layer and extends to cover a portion of the insulating layer. The metal bump is configured on the patterned metal layer, wherein a first extension direction of the metal bump is perpendicular to a second extension direction of the driving substrate.

[0016] In the metal bump structure according to the embodiment of the present invention, the material of the patterned metal layer includes palladium, or any nano-metal that can reduce chemical copper, such as gold and silver.

[0017] In the metal bump structure according to the embodiment of the present invention, the material of the metal bump includes copper, gold, tin or nickel.

[0018] In the metal bump structure according to the embodiment of the present invention, the cross-sectional shape of the metal bump includes a quasi-circular or rectangular shape.

[0019] In the metal bump structure according to the embodiment of the present invention, the thickness of the metal bump is between 1 micrometer and 10 micrometers.

[0020] According to an embodiment of the present invention, a driving substrate includes a driving substrate, at least one active component, at least one pad, an insulating layer and at least one metal bump structure. The driving substrate has a configuration surface. The active component is configured on the configuration surface of the driving substrate. The pad is configured on the configuration surface of the driving substrate and has an upper surface. The insulating layer covers the configuration surface of the driving substrate, the active component and the pad, and the insulating layer exposes a portion of the upper surface of the pad. The metal bump structure includes a patterned metal layer and a metal bump. The patterned metal layer is configured on the upper surface of the pad exposed by the insulating layer and extends to cover a portion of the insulating layer. The metal bump is configured on the patterned metal layer. The first extension direction of the metal bump is perpendicular to the second extension direction of the driving substrate.

[0021] In the driving substrate according to the embodiment of the present invention, the material of the patterned metal layer includes palladium, and the material of the metal bump includes copper, gold, tin or nickel.

[0022] In the driving substrate according to the embodiment of the present invention, the cross-sectional shape of the metal bumps includes a quasi-circular or rectangular shape.

[0023] In the driving substrate according to the embodiment of the present invention, the thickness of the metal bump is between 1 micrometer and 10 micrometers.

[0024] In the driving substrate according to the embodiment of the present invention, the material of the pads includes indium tin oxide, or any sputtered metal layer such as titanium, copper, molybdenum, aluminum or chromium.

[0025] Based on the above, in the method for making the metal bump structure of the present invention, the metal bump is formed by a chemical plating process. Compared with the existing wet process electroplating process to form the metal bump, the present invention adopts a dry process to form the metal bump, which has the advantages of simple process, low cost and no environmental pollution. In addition, when the driving substrate using the metal bump structure of the present invention is subsequently bonded to the light-emitting element, a good interface metal compound can be formed between the light-emitting element and the metal bump structure, which can have better structural reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figures 1A to 1D is a cross-sectional schematic diagram of a method for manufacturing a metal bump structure according to an embodiment of the present invention;

[0027] Figure 2 A schematic cross-sectional view of a metal bump structure according to another embodiment of the present invention is shown;

[0028] Figure 3A A cross-sectional schematic diagram showing a driving substrate according to an embodiment of the present invention;

[0029] Figure 3B Shown as Figure 3A A cross-sectional schematic diagram of a light-emitting element configured on a driving substrate.

[0030] Description of Reference Numerals

[0031] 100: driving substrate;

[0032] 110: driving substrate;

[0033] 112: configuration surface;

[0034] 120: pad;

[0035] 122: upper surface;

[0036] 130: insulating layer;

[0037] 140: active component;

[0038] 200a, 200b: metal bump structure;

[0039] 210: patterned metal layer;

[0040] 210a: catalyst layer;

[0041] 220a, 220b: metal bumps;

[0042] 222: upper surface;

[0043] 300: light emitting element;

[0044] D1: first extension direction;

[0045] D2: second extension direction;

[0046] T: thickness. DETAILED DESCRIPTION

[0047] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0048] Figures 1A to 1D is a cross-sectional schematic diagram of a method for manufacturing a metal bump structure according to an embodiment of the present invention. Figure 1A Regarding the method for manufacturing the metal bump structure of the present embodiment, first, a driving substrate 110 is provided. At least one pad (two pads 120 are schematically shown) and an insulating layer 130 are formed on the driving substrate 110. The pad 120 is formed on the configuration surface 112 of the driving substrate 110 and has an upper surface 122. The insulating layer 130 covers the configuration surface 112 of the driving substrate 110 and the pad 120 and exposes a portion of the upper surface 122 of the pad 120. Here, the driving substrate 110 is, for example, a thin film transistor (TFT) glass substrate, and the material of the pad 120 is, for example, indium tin oxide, or any sputtered metal layer such as titanium, copper, molybdenum, aluminum or chromium. That is, the pad 120 and the pixel electrode on the driving substrate 110 belong to the same layer and are both made of indium tin oxide.

[0049] Next, please refer to Figure 1C , forming a patterned metal layer 210 on the upper surface 122 of the pad 120 exposed by the insulating layer 130 and extending to cover a portion of the insulating layer 130. For details, the steps of forming the patterned metal layer 210, please refer to Figure 1B , forming a catalyst layer 210a on the insulating layer 130 and the upper surface 122 of the pad 120 exposed by the insulating layer 130. The orthographic projection of the catalyst layer 210a on the driving substrate 110 is larger than the orthographic projection of the corresponding pad 120 on the driving substrate 110. Here, the method of forming the catalyst layer 210a is, for example, inkjet printing, and the material of the catalyst layer 210a is, for example, nano-palladium, or any nano-metal that can reduce chemical copper, such as nano-gold or nano-silver.

[0050] Afterwards, please refer to Figure 1B and Figure 1C, the catalyst layer 210a is activated and patterned to form a patterned metal layer 210. The orthographic projection of the patterned metal layer 210 on the driving substrate 110 is smaller than the orthographic projection of the corresponding pad 120 on the driving substrate 110. Here, the activation process is, for example, a laser activation process or a heating process. If nano palladium (which is in ionic state) is used as the catalyst layer 210a, metal palladium can be formed through the activated catalyst layer 210a, and then, the metal palladium can be patterned to form the patterned metal layer 210 through a patterning process. Therefore, the material of the patterned metal layer of this embodiment is palladium, or any nano metal that can reduce chemical copper, such as gold or silver.

[0051] Finally, please refer to Figure 1D , a chemical plating process is performed to form at least one metal bump (two metal bumps 220a are schematically shown) on the patterned metal layer 210. The mechanism of chemical plating is through redox reaction, which has low cost and short production time, and can be selectively grown into a desired shape according to demand. The first extension direction D1 of the metal bump 220a is perpendicular to the second extension direction D2 of the driving substrate 110. Here, the material of the metal bump 220a is, for example, copper, gold or nickel. The cross-sectional shape of the metal bump 220a is, for example, a rectangle, and the thickness T of the metal bump 220a is, for example, between 1 micron and 10 microns. At this point, the production of the metal bump structure 200a has been completed.

[0052] In terms of structure, please refer to Figure 1D , the metal bump structure 200a is configured on the driving substrate 110. The driving substrate 110 is configured with a pad 120 and an insulating layer 130. The pad 120 is configured on the configuration surface 112 of the driving substrate 110 and has an upper surface 122. The insulating layer 130 covers the configuration surface 112 of the driving substrate 110 and the pad 120 and exposes a portion of the upper surface 122 of the pad 120. The metal bump structure 200a includes a patterned metal layer 210 and a metal bump 220a. The patterned metal layer 210 is configured on the upper surface 122 of the pad 120 exposed by the insulating layer 130 and extends to cover a portion of the insulating layer 130, wherein the material of the patterned metal layer 210 is, for example, palladium, or any nanometal that can reduce chemical copper, such as gold or silver. The metal bump 220a is configured on the patterned metal layer 210, wherein the first extension direction D1 of the metal bump 220a is perpendicular to the second extension direction D2 of the driving substrate 110. Here, the material of the metal bump 220 a is, for example, copper, gold, or nickel, and the cross-sectional shape of the metal bump 220 a is, for example, a rectangle, and the thickness T of the metal bump 220 a is between 1 micrometer and 10 micrometers.

[0053] Since the metal bump 220a is formed by a chemical plating process in this embodiment, compared with the existing wet process electroplating process to form the metal bump, the metal bump structure 200a of this embodiment adopts a dry process to form the metal bump 220a, which has the advantages of simple process, low cost and no environmental pollution.

[0054] It must be noted that the following embodiments use the same component numbers and some contents of the previous embodiments, wherein the same number is used to represent the same or similar components, and the description of the same technical contents is omitted. The description of the omitted parts can refer to the previous embodiments, and the following embodiments will not be repeated.

[0055] Figure 2 FIG. 2 is a cross-sectional schematic diagram of a metal bump structure according to another embodiment of the present invention. Figure 1D and Figure 2 The metal bump structure 200b of this embodiment is similar to the metal bump structure 200a described above, and the difference between the two is that in this embodiment, the cross-sectional shape of the metal bump 220b of the metal bump structure 200b is embodied as a quasi-circular shape. In other words, the metal bump structure 200a can be further subjected to a high-temperature reflow process to form the desired shape of the metal bump 220b.

[0056] Figure 3A A cross-sectional schematic diagram of a driving substrate according to an embodiment of the present invention is shown. Figure 3B Shown as Figure 3A A cross-sectional diagram of a light-emitting element configured on a driving substrate. Figure 3AIn this embodiment, the driving substrate 100 includes a driving substrate 110, at least one pad (two pads 120 are schematically shown), an insulating layer 130, at least one active component (one active component 140 is schematically shown) and at least one metal bump structure (two metal bump structures 200a are schematically shown). The driving substrate 110 has a configuration surface 112, wherein the driving substrate 110 is, for example, a thin film transistor (TFF) glass substrate. The active component 140 is configured on the configuration surface 112 of the driving substrate 110, wherein the active component 140 is, for example, a thin film transistor, but not limited thereto. The pad 120 is configured on the configuration surface 112 of the driving substrate 110 and has an upper surface 122, wherein the material of the pad 120 is, for example, indium tin oxide, or any sputtered metal layer such as titanium, copper, molybdenum, aluminum or chromium. That is, the pad 120 and the pixel electrode on the driving substrate 110 belong to the same layer, and are both made of indium tin oxide. The insulating layer 130 covers the configuration surface 112 of the driving substrate 110, the active device 140 and the pad 120, and the insulating layer 130 exposes a portion of the upper surface 122 of the pad 120. The metal bump structure 200a includes a patterned metal layer 210 and a metal bump 220a. The patterned metal layer 210 is configured on the upper surface 122 of the pad 120 exposed by the insulating layer 130 and extends to cover a portion of the insulating layer 130. The metal bump 220a is configured on the patterned metal layer 210. The first extension direction D1 of the metal bump 220a is perpendicular to the second extension direction D2 of the driving substrate 110.

[0057] Please refer to Figure 3B , the light emitting element 300 is suitable for being arranged on the driving substrate 100, and forming a display with the driving substrate 100, wherein the light emitting element 300 is arranged on the metal bump 220a of the metal bump structure 200a. Further, the light emitting element 300 is, for example, a micro light emitting diode, wherein each light emitting element 300 is bonded to two metal bump structures 200a of the driving substrate 100 in a flip chip manner. The light emitting element 300 is structurally and electrically connected to the upper surface 222 of the metal bump 220a, and is electrically connected to the pad 120 through the metal bump 220a and the patterned metal layer 210. Since the present embodiment adopts a chemical plating process to form the metal bump 220a with a certain thickness, when the light emitting element 300 is welded to the metal bump structure 200a, a good interface metal compound can be formed between the light emitting element 300 and the metal bump structure 200a, thereby having better structural reliability.

[0058] In summary, in the method for making the metal bump structure of the present invention, the metal bump is formed by a chemical plating process. Compared with the existing wet process electroplating process to form the metal bump, the present invention adopts a dry process to form the metal bump, which has the advantages of simple process, low cost and no environmental pollution. In addition, when the driving substrate using the metal bump structure of the present invention is subsequently bonded to the light-emitting element, a good interface metal compound can be formed between the light-emitting element and the metal bump structure, which can have better structural reliability.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a metal bump structure, characterized in that: include: A driving substrate is provided, wherein at least one pad and an insulating layer are formed on the driving substrate, wherein the at least one pad is formed on a configuration surface of the driving substrate and has an upper surface, and the insulating layer covers the configuration surface of the driving substrate and the at least one pad and exposes a portion of the upper surface of the at least one pad; forming a patterned metal layer on the upper surface of the at least one pad exposed by the insulating layer and extending to cover a portion of the insulating layer; as well as A chemical plating process is performed to form at least one metal bump on the patterned metal layer, wherein a first extension direction of the at least one metal bump is perpendicular to a second extension direction of the driving substrate.

2. The method for manufacturing a metal bump structure according to claim 1, characterized in that: The step of forming the patterned metal layer comprises: forming a catalyst layer on the insulating layer and the upper surface of the at least one pad exposed by the insulating layer; and The catalyst layer is subjected to an activation process and a patterning process to form the patterned metal layer.

3. The method for manufacturing a metal bump structure according to claim 2, characterized in that: The method of forming the catalyst layer includes an inkjet printing method.

4. The method for manufacturing a metal bump structure according to claim 2, characterized in that: The material of the catalyst layer includes nano-palladium, nano-gold or nano-silver.

5. The method for manufacturing a metal bump structure according to claim 2, characterized in that: The activation process includes a laser activation process or a heating process.

6. The method for manufacturing a metal bump structure according to claim 1, characterized in that: The material of the patterned metal layer includes palladium, gold or silver.

7. The method for manufacturing a metal bump structure according to claim 1, characterized in that: The material of the metal bump includes copper, gold, tin or nickel.

8. The method for manufacturing a metal bump structure according to claim 1, characterized in that: The cross-sectional shape of the metal bump includes a quasi-circular or rectangular shape.

9. The method for manufacturing a metal bump structure according to claim 1, characterized in that: The material of the at least one pad includes indium tin oxide, titanium, copper, molybdenum, aluminum or chromium.

10. The method for manufacturing a metal bump structure according to claim 1, characterized in that: The thickness of the metal bump is between 1 micron and 10 microns.

11. A metal bump structure, arranged on a driving substrate, wherein a pad and an insulating layer are arranged on the driving substrate, the pad is arranged on a configuration surface of the driving substrate and has an upper surface, and the insulating layer covers the configuration surface and the pad and exposes a portion of the upper surface of the pad, wherein the metal bump structure is characterized in that: include: A patterned metal layer is disposed on the upper surface of the pad exposed by the insulating layer and extends to cover a portion of the insulating layer; as well as A metal bump is disposed on the patterned metal layer, wherein a first extension direction of the metal bump is perpendicular to a second extension direction of the driving substrate, The driving substrate is a thin film transistor glass substrate.

12. The metal bump structure according to claim 11, characterized in that: The material of the patterned metal layer includes palladium, gold or silver.

13. The metal bump structure according to claim 11, characterized in that: The material of the metal bump includes copper, gold, tin or nickel.

14. The metal bump structure according to claim 11, characterized in that: The cross-sectional shape of the metal bump includes a quasi-circular or rectangular shape.

15. The metal bump structure according to claim 11, characterized in that: The thickness of the metal bump is between 1 micron and 10 microns.

16. A driving substrate, characterized in that: include: A driving substrate having a configuration surface; At least one active component is disposed on the configuration surface of the driving substrate; At least one pad is disposed on the configuration surface of the driving substrate and has an upper surface; an insulating layer, covering the configuration surface of the driving substrate, the at least one active component and the at least one pad, and the insulating layer exposes a portion of the upper surface of the pad; as well as At least one metal bump structure, comprising: A patterned metal layer is disposed on the upper surface of the pad exposed by the insulating layer and extends to cover a portion of the insulating layer; as well as A metal bump is disposed on the patterned metal layer, wherein a first extension direction of the metal bump is perpendicular to a second extension direction of the driving substrate, The driving substrate is a thin film transistor glass substrate.

17. The driving substrate according to claim 16, characterized in that: The material of the patterned metal layer includes palladium, and the material of the metal bump includes copper, gold, tin or nickel.

18. The driving substrate according to claim 16, characterized in that: The cross-sectional shape of the metal bump includes a quasi-circular or rectangular shape.

19. The driving substrate according to claim 16, characterized in that: The thickness of the metal bump is between 1 micron and 10 microns.

20. The driving substrate according to claim 16, characterized in that: The material of the at least one pad includes indium tin oxide, titanium, copper, molybdenum, aluminum or chromium.

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