Connection wiring structure and method for forming same

Abstract

The present invention discloses a connection wiring structure and a method for forming the same, the connection wiring structure includes a passivation layer, a metal layer disposed on the passivation layer, and a protective layer disposed on the metal layer. In the present invention, a simple design of a single-layer wiring may be adopted, and a multi-layer three-dimensional wiring design may be adopted to realize high-speed transmission. The MEMS process allows the connection wiring to be designed in a straight line or a bent arrangement, and the connection wiring in the bent arrangement has better adaptability due to its flexibility.

Description

[Technical Field]

[0001] The present invention relates to the field of interconnects, and more particularly to interconnect structures and methods for forming the same. [Background technology]

[0002] Flexible flat cable (FFC) allows the number and spacing of conductors to be freely selected, facilitating wiring connections and enabling electronic products to be miniaturized. It is suitable for use as a data transmission cable between moving parts and motherboards, between PCB boards, and within small electrical equipment.

[0003] Flexible cables are used to connect PCBAs (printed circuit boards + assemblies: electronic components made using electronic printing technology) to connectors in imaging modules. Signals from chips on PCBAs are connected to flexible flat cables through pins, and the flexible flat cables transmit signals to connectors, which are then connected to driver boards, processors, etc., realizing signal communication between the chips and the outside world.

[0004] MEMS technology is an emerging technology that uses silicon as its primary material and produces microelectromechanical devices characterized by internal dimensions of micrometers and submicrometers. MEMS technology makes it possible to create microdevices with complex three-dimensional structures, such as movable cantilevers. By using MEMS technology to manufacture signal transmission cables instead of conventional flexible flat cables, the size of the flat cables can be significantly reduced, leading to smaller product sizes. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a connection wiring structure and a method for forming the same that allows different MEMS arrangement designs depending on the desired transmission speed. [Means for solving the problem]

[0006] To achieve these and other objects and advantages of the present invention, an interconnect structure is provided, comprising a passivation layer, a metal layer disposed on the passivation layer, and a protective layer disposed on the metal layer.

[0007] In one embodiment, the metal layer includes at least one metal line.

[0008] In one embodiment, the shape of the metal wiring is linear, wavy, square wave or sawtooth.

[0009] In one embodiment, the interconnect structure includes at least two pads, the pads being located at both ends of the metal line.

[0010] In one embodiment, the connection wiring structure includes a plurality of metal layers and a plurality of protective layers, each of which is formed by alternately stacking the metal layers and the protective layers.

[0011] In order to achieve these objects and other advantages of the present invention, there is provided a method for forming an interconnect structure, said method comprising: Step A of forming a passivation layer on a substrate; Step B of forming a metal layer on the passivation layer; and step C of forming a protective layer on the metal layer, The interconnection structure is formed by a semiconductor process.

[0012] In one embodiment, the method further comprises removing a portion of the substrate.

[0013] In one embodiment, the method further includes using step B and step C to form a plurality of metal layers in which the metal layers and the protective layers are alternately stacked, and a plurality of protective layers.

[0014] In one embodiment, the method further includes forming a contact hole in the protective layer.

[0015] In one embodiment, the method further includes forming a pad while forming a first metal layer on the passivation layer.

[0016] (beneficial effects) The present invention has at least the following beneficial effects.

[0017] 1. By using MEMS technology to manufacture connecting wires, the internal size can be reduced to micrometer and sub-micrometer order, and the overall size of the connecting wires can be reduced by 2 to 4 orders of magnitude compared to conventional connecting wires, making it possible to miniaturize products.

[0018] 2. By using a multi-layer three-dimensional design, there is no need to reduce the number of conductors, and the overall size of the connection wiring can be further reduced.

[0019] 3. The metal wiring can be designed as a bent type, and the bent metal wiring has flexibility, so it can meet the connection between moving parts.

[0020] 4. MEMS interconnects are manufactured using MEMS technology, allowing for mass batch production, significantly reducing costs.

[0021] 5. MEMS interconnects can be fabricated using silicon-based processes or other semiconductor processes, but since the majority of current chips are fabricated using silicon-based semiconductor processes, MEMS interconnects are easier to integrate and fit into chips.

[0022] Other advantages, objects and features of the present invention will be apparent in part from the description which follows, and in part will become apparent to those skilled in the art through study and practice of the invention. [Brief explanation of the drawings]

[0023] [Figure 1] 3A to 3C are cross-sectional views showing the fabrication of a metal layer and pads on a substrate in Example 1. [Figure 2] FIG. 2 is a top view of a metal layer and a pad in the first embodiment. [Figure 3] 1 is a cross-sectional view showing the coating of a passivation protection layer in Example 1. FIG. [Figure 4] FIG. 4 is a plan view of FIG. 3. [Figure 5] FIG. 2 is a cross-sectional view of Example 1 in which a part of the substrate is removed. [Figure 6] FIG. 6 is a bottom view of FIG. 5. [Figure 7] 10A to 10C are cross-sectional views showing the fabrication of a first metal layer and a PAD in Example 2. [Figure 8] FIG. 8 is a plan view of FIG. [Figure 9] 10A to 10C are cross-sectional views showing the production of a second metal layer in Example 2. [Figure 10] FIG. 10 is a plan view of FIG. 9. [Figure 11] 10A to 10C are cross-sectional views showing the production of a third metal layer in Example 2. [Figure 12] FIG. 12 is a plan view of FIG. [Figure 13] FIG. 10 is a cross-sectional view showing an exposed pad in Example 2. [Figure 14] FIG. 14 is a plan view of FIG. [Figure 15] FIG. 10 is a cross-sectional view showing a state in which the base material under the first metal layer is removed to form a flexible connection wiring in Example 2. [Figure 16] FIG. 16 is a bottom view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will now be described in more detail with reference to the accompanying drawings so that those skilled in the art can practice the invention with reference to the contents of the specification.

[0025] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in more detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to interpret the present invention, and are not used to limit the present invention.

[0026] In addition, when an embodiment of the present invention has directional indications (e.g., up, down, left, right, front, back, etc.), the directional indications are used only to explain the relative positional relationships, movement status, etc. between each part in a specific posture (see figure), and when the specific posture changes, the directional indications also change accordingly.

[0027] Example 1 This embodiment provides a wiring structure including a passivation layer, a metal layer disposed on the passivation layer, and a protective layer disposed on the metal layer. The metal layer includes at least one metal wiring. That is, the metal layer includes one metal wiring, or the metal layer includes at least two metal wirings that are independent of each other. The wiring structure is formed by a semiconductor process including a MEMS process, and is flexible and bendable.

[0028] In a possible embodiment, the shape of the metal wiring is linear, wavy, square wave or sawtooth.

[0029] In another preferred embodiment, the connection wiring structure includes a plurality of layers of the metal layers and the protective layers, which are alternately stacked.

[0030] In this embodiment, the interconnect structure includes at least two pads, which are located at both ends of the metal line.

[0031] Example 2 In combination with Example 1, this Example: Step A of forming a passivation layer on a substrate; Step B of forming a metal layer on the passivation layer; and step C of forming a protective layer on the metal layer, The interconnection structure is formed by a semiconductor process.

[0032] After forming the metal layer and the protective layer, a portion of the substrate may be removed, leaving a portion of the substrate on both ends.

[0033] In a preferred embodiment, steps B and C are used to form multiple layers of metal layers and multiple layers of protective layers, with the metal layers and protective layers being alternately stacked.

[0034] Furthermore, a first metal layer is formed on the passivation layer, and at the same time, a plurality of pads are further formed, through which the corresponding units are electrically contacted.

[0035] After forming each of the protective layers, a plurality of contact holes are formed in the protective layer, each of which corresponds to a corresponding pad, and the projection of the contact hole in the first metal layer covers a portion of the corresponding pad. When a next metal layer is formed on the protective layer, the corresponding contact holes are filled with metal, thereby electrically connecting the metal layer to the corresponding pad. If the metal layer includes multiple metal wirings, both ends of each metal wiring are connected to the pads via the corresponding contact holes.

[0036] Example 3 In relation to the above-mentioned first and second embodiments, a method for manufacturing a single-layer interconnect structure using MEMS technology will now be described in detail.

[0037] As shown in FIGS. 1 and 2, a first metal layer 2 and pads 7 are fabricated on a substrate 1. The substrate 1 may be made of silicon, SOI, glass, or other suitable materials. In a preferred embodiment, a passivation layer for protecting the metal layer may be plated on the substrate 1 in advance. The metal layer may be made of a metal material such as titanium, aluminum, or copper, and includes at least one metal line. The metal line may be a linear metal line 4 or a bent metal line. The bent metal line may be a wavy metal line 5, a rectangular metal line 6, or a sawtooth metal line. The metal layer is fabricated using a MEMS process, and each metal line has a width of 0.1 μm to 50 μm. The pads 7 are used for external communication. The pads 7 and the metal layer are made of the same metal, and the pads 7 and the metal layer are simultaneously formed in a single process.

[0038] 3-4, a first protective layer 3, which may be SiO2 or Si3N4, is plated onto the first metal layer 2. The first protective layer 3 must be patterned using processes such as photolithography and etching to expose the pads 7.

[0039] 4 to 6, the substrate 1 under the first metal layer 2 is removed using photolithography, deep etching, or wet etching processes, leaving only parts of the substrate 1 at both ends, forming a cantilever connection wiring structure. The cantilever connection wiring structure is characterized by its flexibility and is suitable for signal connection between moving parts.

[0040] After forming the cantilever connection wiring structure using the MEMS process, an insulating layer can be applied to the upper and lower sides of the connection wiring structure to protect the connection wiring structure so that it is less likely to break and has better corrosion resistance and toughness.

[0041] Example 4 In connection with the above-mentioned first and second embodiments, a method for manufacturing a multi-layer interconnect structure using MEMS technology will be specifically described.

[0042] As shown in FIGS. 7 and 8, a first metal layer 2 and pads 7 are fabricated on a substrate 1. Similar to the single-layer connection wiring in Example 1, the metal layer includes at least one metal wire. The metal wiring may be a straight metal wiring 4, or a bent-type connection wiring. The bent-type connection wiring may be a wavy metal wiring 5, a rectangular metal wiring 6, or a sawtooth metal wiring. The metal layer is fabricated using an MEMS process, and each metal wiring has a width of 0.1 μm to 50 μm. The pads 7 are used for connection and communication with the outside, and the same metal is used for the pads 7 and the metal layer, and the pads 7 and the metal layer are formed simultaneously by a single process.

[0043] As shown in Figures 9 and 10, first, a first protective layer 3 is plated on a first metal layer 2, and the first protective layer 3 is etched to form a contact hole 8. Then, a second metal layer 9 is fabricated on the first protective layer 3, and the second metal layer 9 is connected to the pad 7 via the contact hole 8.

[0044] The position of the contact holes 8 and the method of filling the contact holes with metal can be referred to in the third embodiment, and therefore will not be described here.

[0045] 11 and 12, first, a second protective layer 10 is plated on the second metal layer 9, and the second protective layer 10 is etched to form a contact hole 8. Then, a third metal layer 11 is fabricated on the second protective layer 10, and a third protective layer 15 is plated on the third metal layer 11 for protection. Depending on the fabrication steps of the protective layer, contact hole 8, and metal layer, more metal layers, such as a fourth layer, a fifth layer, etc., may be subsequently designed.

[0046] As shown in FIGS. 13 and 14, after the fabrication of the multiple metal layers is completed, the passivation protection layer on the top surface is etched to expose pads 7 for use in electrical connection and communication with the outside.

[0047] 15 and 16, the material of the substrate 1 below the connection wiring is removed, leaving only the material of the substrate 1 on both ends, for the same purpose as removing the material of the substrate 1 in the single-layer MEMS connection wiring.

[0048] The method of manufacturing soft interconnects using MEMS technology according to the present invention can adopt a simple design of single-layer interconnects or a multi-layer three-dimensional interconnect design to achieve high-speed transmission. The MEMS process allows the interconnects to be designed in a straight or bent configuration, and the bent configuration of the interconnects has better adaptability due to its flexibility.

[0049] The above content has been described in more detail with reference to specific preferred embodiments of the present invention, and it should not be recognized that the specific implementation of the present invention is limited to these descriptions. A person skilled in the art to which the present invention pertains may make some simple deductions or substitutions without departing from the structure of the present invention, and all of them should be considered to fall within the protection scope of the present invention. [Explanation of symbols]

[0050] 1 board 2. First metal layer 3 First protective layer 4 Straight metal wiring 5. Wavy metal wiring 6 square metal wiring 7 Pads 8 Contact Holes 9 Second metal layer 10 Second protective layer 11 Third metal layer 12 Third protective layer

Claims

1. The semiconductor device includes a passivation layer, a metal layer provided on the passivation layer, and a protective layer provided on the metal layer. A connection wiring structure comprising:

2. The metal layer includes at least one metal wiring.

2. The interconnect structure according to claim 1.

3. The shape of the metal wiring is linear, wavy, square wave, or sawtooth.

3. The interconnect structure according to claim 2.

4. the interconnect structure includes at least two pads; The pads are located on both ends of the metal wiring.

3. The interconnect structure according to claim 2.

5. The connection wiring structure includes a plurality of metal layers and a plurality of protective layers formed by alternately stacking the metal layers and the protective layers.

2. The interconnect structure according to claim 1.

6. 1. A method for forming a connection wiring structure, comprising: Step A of forming a passivation layer on a substrate; Step B of forming a metal layer on the passivation layer; and C. forming a protective layer on the metal layer, The connection wiring structure is formed by a semiconductor process. A forming method comprising:

7. removing a portion of the substrate. The method of claim 6 .

8. The method further includes forming a multi-layer metal layer and a multi-layer protective layer in which the metal layer and the protective layer are alternately stacked using the steps B and C. The method of claim 6 .

9. forming a contact hole in the protective layer; The method of claim 8.

10. forming a first metal layer on the passivation layer and forming a pad at the same time. The method of claim 8.

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