Formation of protruding structures

Abstract

A technique for manufacturing a raised structure is disclosed. A substrate comprising a group of pads formed on its surface is prepared, the pads comprising a first conductive material. A metal adhesive layer is coated on each pad. A raised substrate is formed on each pad by sintering conductive particles using a molding layer, the conductive particles comprising a second conductive material different from the first conductive material.

Description

Technical Field

[0001] This invention relates to bumping technology, and more particularly to a method for manufacturing a bump structure, a bump structure, an electronic device including the bump structure, and a method for manufacturing the electronic device. Background Technology

[0002] 3D and 2.5D chip packaging are technologies that enable broadband signal transmission and short wiring lengths, and they have attracted attention for improving the performance of future computer systems. However, due to the finer bump spacing and bump size in 3D and 2.5D packages compared to traditional flip-chip packaging, reliability issues arise due to stress concentration at solder joints and their interfaces, as well as electromigration due to high current density.

[0003] Injection molding solder (IMS) technology is a bump-forming technique in which solder bumps are formed on a substrate by injecting molten solder directly into openings in a resist mask. IMS technology offers the advantage of flexibility in solder alloy compositions, leading to improvements in mechanical properties, electromigration resistance, and fine-pitch capabilities.

[0004] The recent trend towards high-density interconnects has led to the use of copper pillars (or pillar protrusions). However, expensive copper plating processes are required to manufacture the copper pillars beneath the solder caps. An alternative technique exists that allows the manufacture of pillar protrusions without the use of expensive electroplating processes, where the pillars are created by sintering conductive particles, typically provided in paste form. Sintered pillars exhibit good reliability when manufactured on contact pads made of the same material—that is, when sintered copper pillars are manufactured on copper pads.

[0005] However, when using conductive materials different from the pillars, especially aluminum, as the contact pad, the adhesion between the pillars and the contact pad is reduced even if the surface oxide of the aluminum pad is removed before the protrusion is formed.

[0006] Therefore, a novel protrusion forming technology is needed that can manufacture protrusion structures comprising a set of protrusions formed on a substrate, wherein the protrusions, formed by sintering conductive particles, are tightly bonded to a pad made of a conductive material different from the conductive particles. Summary of the Invention

[0007] According to embodiments of the present invention, a method for manufacturing a raised structure is provided. The method includes preparing a substrate comprising a group of pads formed on its surface, wherein the pads comprise a first conductive material. The method further includes coating each pad with a metal adhesive layer. The method further includes forming a raised structure on each pad by sintering conductive particles using a molded layer, wherein the conductive particles comprise a second conductive material different from the first conductive material.

[0008] This enables the fabrication of raised structures comprising groups of protrusions on a substrate, wherein even if the pad is made of a conductive material different from the conductive particles, the protrusions made by sintering the conductive particles are tightly bonded to the pad of the substrate.

[0009] In one embodiment, the molding layer has a set of openings, each of which is aligned with one of the pads. The method includes, while forming a protrusion on each pad, disposing the molding layer on a substrate and filling the openings of the molding layer with conductive particles. The conductive particles filling the openings of the molding layer are sintered to form a protruding substrate on each pad. The method also includes filling the remaining space in each opening of the molding layer above the protruding substrate with solder material to form a solder cap on each protruding substrate.

[0010] In this embodiment, the first conductive material includes Al, and the second conductive material includes Cu. Since semiconductor devices typically use an Al pad on the outermost layer, a sintered raised substrate tightly bonded to the pad can be fabricated for practical use.

[0011] In this embodiment, the conductive particles are provided in paste form. The raised substrate formed on each pad has a cup-shaped profile that conforms to the opening contour of the molded layer and is bonded to the bottom of the pad by a metallic adhesive layer. Therefore, even though the raised dimensions become finer compared to a flat-topped column, it allows us to maintain sufficient solder volume on the raised substrate. Furthermore, the cup-shaped raised substrate has advantages in terms of resistance to electromigration because the flow of current is dispersed within this shaped raised surface.

[0012] In an embodiment, the method further includes applying a resist layer to the surface of a substrate. The method also includes patterning the resist layer to create a molding layer. The method further includes depositing a metal adhesive material on the pads and molding layer to conform to the contours of the molding layer, and providing a metal adhesive layer coated on each pad. Because the process of removing the metal layer beneath the resist layer after resist stripping is eliminated, undercutting at the root of the protrusion is prevented.

[0013] In an embodiment, the method includes dissolving a metal binder material deposited on the top surface of the molding layer into the solder material during solder filling. This allows for the thorough removal of excess metal binder material while eliminating the need for a separate metal binder material removal process. In this preferred embodiment, the metal binder material can be selected from the group consisting of Cu, Ni, Au, and any combination thereof. During the solder filling process, Cu, Ni, and Au readily dissolve into the solder material, such as molten solder.

[0014] In an embodiment, the method further includes peeling the molding layer from the substrate to remove it, wherein the metal adhesive material on the top surface of the molding layer is peeled off and cleaned together with the molding layer. Therefore, it allows for the omission of additional metal adhesive material removal processes, regardless of the composition of the metal adhesive material. Thus, even if the material is insoluble in soldering materials (such as molten solder), it allows the use of other functional materials (such as a Ti barrier layer) as the metal adhesive material. Furthermore, the metal adhesive material conforming to the contour of the molding layer will serve as a sidewall barrier to prevent short circuits between protrusions due to ion migration.

[0015] In one embodiment, the method further includes removing the metal bond material deposited on the top surface of the molding layer using a technique selected from chemical mechanical polishing (CMP), mechanical polishing, fly cutting, and chemical etching. Although an additional metal bond material removal process is performed, the removal process of the metal layer after resist stripping, which would cause undercutting at the root of the protrusions, is eliminated. Even though the material is insoluble in soldering materials (such as molten solder), it allows the use of other functional materials (such as a Ti barrier layer) as the metal bond material. Furthermore, the metal bond material conforming to the contour of the molding layer will serve as a sidewall barrier to prevent short circuits between protrusions due to ion migration.

[0016] In an embodiment, the method further includes depositing a metal adhesive material on the surface of a substrate to have a first portion corresponding to a metal adhesive layer coated on each of the pads and a second portion formed on a peripheral region of the pad. The method includes applying a resist layer onto the metal adhesive material. The method further includes patterning the resist layer to create a molding layer. The method includes peeling the molding layer from the substrate, thereby leaving bumps on the substrate, wherein each bump includes a solder cap and a bump substrate formed on the pad. The method further includes removing the second portion of the metal adhesive material exposed from the bumps. Even if the material is insoluble in soldering materials (such as molten solder), it allows us to use other functional materials (such as a Ti barrier layer) as the metal adhesive material. In this embodiment, the metal adhesive material can be selected from the group consisting of Cu, Ti, Ni, Au, and any combination thereof.

[0017] In this embodiment, the filler solder material comprises injecting molten solder into each of the openings in the molded layer. In this embodiment, electroplating and electroless plating are not required to manufacture the assembly of the protrusions, thus avoiding the expensive pillar and solder cap manufacturing processes, costly equipment, and complex management of the electroplating process.

[0018] In an embodiment, the method includes removing surface oxides from the pads by backsputtering prior to applying the metal adhesive layer, the metal adhesive layer being applied to each pad by sputtering. The combination of backsputtering and sputtering of the metal adhesive layer preferably reduces the time interval between surface oxide removal and surface coating of the pads.

[0019] In one embodiment, the substrate includes a semiconductor device, and a group of pads is formed at least on the active surface of the semiconductor device. The method also includes interconnecting the semiconductor device to external circuitry using bumps, a method of manufacturing electronic devices. The high-temperature conditions of sintering help enhance the bonding between the sintered pillars and pads. However, semiconductor devices typically degrade under such high-temperature conditions. This makes it possible to enhance the bonding between the bumped substrate and the pads without using high-temperature conditions.

[0020] According to another embodiment of the present invention, a raised structure is provided. The raised structure includes a substrate, the substrate including a group of pads formed on its surface, wherein the pads include a first conductive material. The raised structure includes a group of raised protrusions, each of which is formed on one of the pads. Each raised protrusion includes a metal adhesive layer formed on the pad and a raised substrate formed on the metal adhesive layer. The raised substrate is a sintered body comprising conductive particles of a second conductive material different from the first conductive material.

[0021] Because the bumps, formed by sintering conductive particles, are tightly bonded to the pad, the bump structure according to embodiments of the present invention exhibits good reliability even if the pad is made of a conductive material different from the conductive particles. Furthermore, it allows for enhanced bonding between the bump substrate and the pad without the use of high-temperature conditions. Therefore, degradation of the semiconductor device due to the bumping process can be prevented.

[0022] In an embodiment, each protrusion further includes a solder cap formed on a protrusion substrate. The protrusion substrate has a cup-shaped shape, the cup having a bottom bonded to a pad via a metal adhesive layer, and the cup being filled with solder material from the solder cap. In a particular embodiment, the first conductive material may include Al, the second conductive material may include Cu, and the metal adhesive layer may include a material selected from Cu, Ti, Ni, Au, and combinations thereof.

[0023] In one embodiment, a metallic adhesive layer covers the side surfaces of the raised substrate as a sidewall barrier. Therefore, the sidewall barrier prevents short circuits between the raised sections due to ion migration.

[0024] In another embodiment of the invention, an electronic device is provided. The electronic device includes a semiconductor device comprising a group of pads formed on its active surface, wherein the pads comprise a first conductive material. The electronic device also includes a group of protrusions, each protrusion formed on one of the pads. Each protrusion includes a metal adhesive layer formed on the pad and a protrusion substrate formed on the metal adhesive layer, and the protrusion substrate is a sintered body comprising conductive particles of a second conductive material different from the first conductive material. The electronic device also includes circuitry interconnected with the semiconductor device via the group of protrusions.

[0025] The electronic devices according to embodiments of the present invention exhibit good durability because even if the pad is made of a different conductive material than the conductive particles used for the raised substrate, the raised parts formed by sintering the conductive particles are tightly bonded to the pad.

[0026] In one embodiment, a metallic adhesive layer covers the side surfaces of the raised substrate as a sidewall barrier. The sidewall barrier prevents short circuits between the raised sections due to ion migration.

[0027] In another embodiment of the invention, a method of manufacturing an electronic device is provided. The method includes fabricating a bumped semiconductor device. The bumped semiconductor device includes a substrate comprising a group of pads formed on its surface, wherein the pads comprise a first conductive material. The bumped semiconductor device also includes a group of bumps, each bump formed on one of the pads, wherein each bump includes a metal adhesive layer formed on the pad and a bump substrate formed on the metal adhesive layer, and the bump substrate is a sintered body comprising conductive particles comprising a second conductive material different from the first conductive material. The method further includes interconnecting the bumped semiconductor device to an external circuit via the group of bumps.

[0028] The electronic device provided by the method according to embodiments of the present invention exhibits good durability because even if the pad is made of a different conductive material than the conductive particles used for the raised substrate, the raised particles formed by sintering the conductive particles are tightly bonded to the pad.

[0029] Additional features and advantages are achieved through the technology of this invention. Other embodiments and aspects of the invention are described in detail herein and are considered part of the claimed invention. Attached Figure Description

[0030] The foregoing and other features and advantages of the invention will become apparent from the detailed description taken in conjunction with the accompanying drawings. Note that the dimensions and relative positions of the elements and layers in the drawings are not necessarily drawn to scale. Some of these elements or layers have been arbitrarily enlarged and positioned to improve readability. In the drawings:

[0031] Figure 1A and Figure 1B These are cross-sectional and top views of the protruding structure according to an embodiment of the present invention;

[0032] Figures 2A-2E This is a cross-sectional view (1 / 2) of the structure obtained at each step of the protrusion forming process according to an embodiment of the present invention;

[0033] Figures 3A-3D This is a cross-sectional view (2 / 2) of the structure obtained at each step of the protrusion forming process according to an embodiment of the present invention;

[0034] Figures 4A-4D This is a cross-sectional view (1 / 2) of the structure obtained at each step of the protrusion forming process according to another embodiment of the present invention;

[0035] Figures 5A-5D This is a cross-sectional view (2 / 2) of the structure obtained at each step of the protrusion forming process according to another embodiment of the present invention;

[0036] Figures 6A-6C This is a cross-sectional view of the structure obtained at each step of the protrusion forming process according to another embodiment of the present invention;

[0037] Figures 7A-7D This is a cross-sectional view of the structure obtained at each step of the protrusion forming process according to another embodiment of the present invention;

[0038] Figure 8A and 8B This is a cross-sectional view of the structure obtained in each step of the flip-chip bonding process according to an embodiment of the present invention;

[0039] Figures 9A-9E The process for forming the protrusions, including the pillars and solder caps, is shown.

[0040] Figures 10A-10E Another related protrusion formation process of IMS, including the electroplating of the pillars and the solder cap, is shown;

[0041] Figure 11A-11D Another related protrusion formation process of IMS, including electroless plating of the pillars and solder caps, is shown;

[0042] Figure 12A-12D Another related protrusion formation process (1 / 2) is shown, which is based on the sintering of a conductive paste without the use of a metal adhesive layer; and

[0043] Figures 13A-13C Another related protrusion forming process based on sintering without using a metal bonding layer is shown (2 / 2). Detailed Implementation

[0044] The present invention will now be described with reference to specific embodiments; however, those skilled in the art will understand that the embodiments described below are mentioned by way of example only and are not intended to limit the scope of the invention.

[0045] According to one or more embodiments of the present invention, there is a method for manufacturing a bump structure, a related bump structure, a related electronic device including the bump structure, and a related method for manufacturing an electronic device including the bump structure, wherein a set of bumps is realized to be tightly bonded to a corresponding pad on a substrate. In the following, reference is made to... Figure 1A and Figure 1B This describes a protrusion structure according to an exemplary embodiment of the present invention. Figure 1A A cross-sectional view of the protrusion structure 100 is shown. Figure 1B A top view of the protruding structure 100 is shown. Note that... Figure 1A The cross-sectional view shown corresponds to Figure 1B The section indicated by "A" in the top view.

[0046] The protrusion structure 100 shown in Figure 1 includes a substrate 110 with a group of pads 112 and a passivation layer 114 formed on the surface of the substrate 110. The protrusion structure 100 also includes a group of protrusions 120, each protrusion formed on a corresponding pad in the pads 112. Note that, for convenience, the reference numerals associated with protrusion 120 indicate only one representative protrusion in the figure and not all elements.

[0047] Substrate 110 can be any substrate made of semiconductor material. In a particular embodiment, substrate 110 is a wafer (or panel) in which multiple electronic devices are built-in. In this particular embodiment, the wafer can ultimately be divided into multiple chips (or dies). In other particular embodiments, substrate 110 is a chip separate from the wafer. In the embodiments described, both the wafer and the chip are semiconductor devices. Wafers and wafers can be made of silicon, III-V or II-VI compound semiconductor materials, or other semiconductor materials. Wafers and chips can be manufactured using any standard semiconductor process, including FEOL (front-end process) and BEOL (back-end process) processes. Although substrate 110 is described as a semiconductor device in the embodiments described, any other substrate such as ceramic substrates and glass substrates, printed circuit boards, or any other substrate can be used as substrate 110.

[0048] The pad 112 is made of a conductive material. Examples of conductive materials typically include metals such as aluminum (Al), copper (Cu), cobalt (Co), and other metallic materials. The following description primarily focuses on the case where the pad 112 is made of Al, as an example of the applicability of this bump-forming technique. The pads 112 can be disposed on the surface of the substrate 110 at a certain spacing (e.g., 20–300 micrometers). Figure 1BAs shown, the set of pads 112 is formed in a 2D array. The passivation layer 114 may include an insulating material, such as silicon oxide (SiO2).

[0049] although Figure 1A-1B As not shown, in addition to the group of bumps 120, substrate 110 may include electronic components, optoelectronic components such as photodiodes (PDs) and light-emitting diodes (LEDs), and / or multiple wiring layers connected to bumps 120. Substrate 110 may also have a stack of semiconductor substrates. Figure 1A The structure of each 120 protrusion is also described in more detail. For example... Figure 1A As shown, each protrusion 120 includes a metal adhesive layer 126 formed on a pad 112 and a protrusion base 122 formed on the pad 112 through the metal adhesive layer 126. Each protrusion 120 may also include a solder cap 124 formed on the protrusion base 122. Note that the metal adhesive layer 126 is an under-protrusion metal (UBM).

[0050] The raised substrate 122 is made of a conductive material, which may typically include copper (Cu), nickel (Ni), silver (Ag), gold (Au), or other metallic materials. Each raised substrate 122 is manufactured by sintering conductive particles using a molding layer or resist layer disposed on the substrate 110. Therefore, the raised substrate 122 is a sintered body comprising conductive particles of a conductive material different from the conductive material of the pad 112. In the following description, the case where the raised substrate 122 is made of copper will be primarily described as an example of the applicability of this raised substrate forming technique. Therefore, the conductive particles are copper particles, and the raised substrate 122 is a sintered body of copper particles.

[0051] In a preferred embodiment, copper nanoparticles, copper microparticles, and mixtures thereof are used for the formation of the raised substrate. The sintered body of the conductive particles will have a porous morphology. The particle size can range from 1 nm to 15 μm.

[0052] The raised substrate 122 has a cup-shaped form, and its bottom is bonded to the pad 112 via a metal adhesive layer 126. The cup-shaped part of the raised substrate 122 is filled with solder material of the solder cap 124.

[0053] The metal adhesive layer 126 is made of a metallic material selected from the group consisting of Cu, Ti, Ni, Au, and combinations thereof. The metal adhesive layer 126 may comprise a single layer or multiple layers (or stacks), wherein each layer comprises one or more of the aforementioned elements as a pure metal or as an alloy. In a particular embodiment, the metal adhesive layer 126 is a Ti / Cu stack, a layer or stack of Cu, Au, and / or Ni.

[0054] The solder material of the solder cap 124 can have any suitable composition. In one or more embodiments, any lead-free solder alloy can be used as the solder material, said lead-free solder alloy comprising binary, ternary, and quaternary systems of one or more elements selected from the group consisting of tin, bismuth, silver, indium, antimony, copper, zinc, nickel, aluminum, manganese, and palladium. Examples of lead-free solder alloys may include Bi-Sn, Sn-Ag, Sn-Ag-Bi, Sn-Ag-Cu, Sn-Cu alloys, to name just a few. With a high degree of freedom in the composition of the solder, any composition suitable for bump formation can be selected.

[0055] Please refer to the following. Figures 2A to 2E as well as Figures 3A to 3D The series illustrates the formation process of a protruding structure according to an embodiment of the present invention. Figures 2A-2E and Figures 3A-3D Cross-sectional views of the structure obtained at each step of the protrusion forming process are shown, which fabricates... Figure 1A and 1B The protruding structure 100 shown is illustrated.

[0056] like Figure 2A As shown, the bump formation process may include the step of fabricating a substrate 110, which includes a group of pads 112 and a passivation layer 114 formed on a surface 110A of the substrate 110. In a particular embodiment, the bump formation process is performed as a wafer-level process, and the substrate 110 is a wafer in which multiple integrated circuits are embedded. Each pad 112 may include a conductive material. When the pads 112 are formed of an easily oxidizable metal such as Al, the bump formation process may also include the step of removing surface oxides from the pads 112. The removal of surface oxides can be accomplished by virtually any standard method, including, for example, back sputtering or etching with an acidic solution.

[0057] like Figure 2BAs shown, the bump formation process may include the step of depositing a metal binder 128 on the surface 110a of a prepared substrate 110. The deposited metal binder 128 may include a first portion 128a and a second portion 128b. The first portion corresponds to a metal binder layer 126 coated on the pad 112. The second portion 128b is a portion formed on the outer region of the pad 112, where a passivation layer 114 may typically be formed. Any known seed layer typically used for electroplating pillars may be used as the metal binder 128. The metal binder is selected from Cu, Ti, Ni, Au, and combinations thereof. In a particular embodiment, the metal binder layer 126 is a Ti / Cu stack, a layer or stack of Cu, Au, and / or Ni. The deposition of the metal binder 128 can be performed by virtually any standard method, including, for example, sputtering and electroless plating. Note that sputtering can provide a metal binder layer over an entire area, while electroless plating can provide a metal binder layer over a limited area including the pad 112.

[0058] Although the removal of surface oxides and the deposition of the metal binder 128 can be performed by any standard method, when the pad 112 is formed of a metal that is easily and persistently oxidized (e.g., Al), a combination of anti-sputtering and sputtering of the metal binder is preferably used to reduce the time interval from the removal of surface oxides from the pad 112 to surface protection. A long time interval will lead to degradation of the bonding of the Al pad. Furthermore, this combination is advantageous from the viewpoint of eliminating the electroplating process, which is typically expensive and requires costly equipment and complex management.

[0059] like Figure 2C As shown, the protrusion forming process may also include the step of applying a resist layer 130 onto the metal adhesive material 128. Any known positive or negative liquid or thin-film photoresist can be used. The resist layer 130 can be applied by virtually any standard method, including spin coating and thin-film lamination.

[0060] like Figure 2DAs shown, the bump-forming process may further include the step of patterning the resist layer 130 to have a group of openings 130a formed through the resist layer 130. Each opening 130a is aligned with a corresponding pad 112. The openings 130a expose the surface of the metal adhesive material 128 on the pad 112. The patterned resist layer 130 can be used as a molding layer for shaping the material filling the openings 130a. The openings 130a can have any shape, including but not limited to circles, squares, rounded squares, and a few examples. Note that when electroless plating is used to deposit the metal adhesive material 128, electroless plating can be performed after this resist patterning. The resist layer 130 can be patterned by virtually any standard means, including photolithography. In a particular embodiment, the patterning step may include the sub-steps of exposing the photoresist material with a photomask 131 and developing the exposed photoresist material to open the openings 130a at the locations aligned with the pads 112. Figure 2D In the illustrated embodiment, photomask 131 is a dark field mask, and the resist material is positive and not limited.

[0061] The resist layer 130 can have a designed thickness that provides sufficient height for the formation of the protrusion. The diameter of the opening 130a can affect the size of the final protrusion 120. In one embodiment, the diameter of the opening 130a can range from 5 micrometers to 150 micrometers. Moreover, the space of the opening 130a can provide room to accommodate conductive material that will be filled by a subsequent filling step.

[0062] like Figure 2E As shown, the protrusion forming process may further include the step of filling conductive particles 132 into the openings 130a of the resist layer 130. The conductive particles 132 may include a conductive material different from the conductive material of the pad 112. Examples of conductive particles may include, for example, copper (Cu), nickel (Ni), silver (Ag), and gold (Au). In a preferred embodiment, the conductive particles may be copper (Cu) particles. Nanoparticles, microparticles, and mixtures thereof may be used as the conductive particles 132.

[0063] The diameter of the conductive particles can range from 1 nm to 15 μm.

[0064] In the described embodiment, the conductive particles are provided in the form of a paste. The filling of the conductive particles (hereinafter also referred to as conductive paste) 132 can be accomplished by virtually any standard means, including, for example, screen printing and injection molding techniques. The conductive particles can be immersed in an organic solvent. The viscosity of the conductive paste 132 and the particle ratio in the conductive paste 132 can be determined taking into account paste shrinkage; in other words, the thickness of the conductive layer obtained by sintering in the next step.

[0065] like Figure 3AAs shown, the protrusion forming process may further include the step of sintering the conductive paste 132. The conductive paste 132, filling each opening 130a of the resist layer 130, is sintered to form a protruding substrate 122 on each pad 112. Sintering of the conductive paste 132 in the openings 130a is performed by heating the conductive paste 132 at 100 to 250 degrees Celsius for 0.1 to 2.0 hours in a nitrogen or formic acid atmosphere to prevent oxidation of the metal surface after sintering. If sintering is performed in air, the oxide layer on the metal surface can be removed.

[0066] Sintering is a process of forming a solid block of material by heating and / or pressurizing without melting the material to its liquefaction point. In the sintering process, the conductive paste 132 shrinks, causing a raised substrate 122 to be formed to cover the sidewalls of the opening 130A of the resist layer 130 and the surface of the pad 112 (i.e., the metal bonding material 128), as... Figure 3A As shown. Consequently, the raised substrate 122 formed on each pad 112 will have a cup-shaped shape conforming to the contour of the opening 130a, and will be tightly bonded to the bottom of the pad 112 via a metallic adhesive 128. Since solder filling is performed in the next step without additional conductive paste coating, the volume shrinkage of the conductive paste 132 after sintering is optimized. The volume shrinkage rate of the conductive paste 132 depends on the designed value of the raised diameter / height, and is preferably, for example, 50% or greater.

[0067] The raised base 122 corresponds to a metal pillar (or strut). Space 136b is retained on the raised base 122 at the upper end reaching the opening 130a. The raised base 122 has a tapered surface, such as... Figure 3A As shown, the cross-section of the protruding bottom 122 has a conformal shape.

[0068] In the embodiment described, the steps of filling the conductive paste 132 and sintering the conductive paste 132 are performed simultaneously. However, when the thickness of the central portion of the raised substrate 122 is thinner than a predetermined thickness, for example, the predetermined thickness may be in the range of 1 to 50 μm, the conductive paste filling step and the sintering step are performed alternately multiple times to form one or more additional conductive layers, thereby ensuring the predetermined thickness of the raised substrate 122.

[0069] like Figure 3BAs shown, the protrusion forming process may further include the step of filling the remaining space 130B in each opening 130a above the protrusion substrate 122 with solder material to form a solder cap 124 on each protrusion substrate 122. In a preferred embodiment, the solder material can be filled by injecting molten solder into each opening 130a of the resist layer 130. The injection of molten solder can be accomplished, for example, by an IMS process. The presence of the protrusion substrate 122 covering the sidewalls of the openings 130a of the resist layer 130 facilitates the filling of the openings 130a with solder material. In the IMS process, molten solder is injected into each opening 130a under vacuum or reduced pressure conditions using a filling head. The injected molten solder solidifies in each opening 130a. The filling head includes a container for the molten solder and a channel through which the molten solder is injected. The solder cap 124 may have a convex top surface.

[0070] like Figure 3C As shown, the bump formation process may further include the step of peeling off the resist layer 130 from the substrate 110, thereby leaving a bump 120 on the substrate 110.

[0071] like Figure 3D As shown, the protrusion process may also include the step of removing a second portion 128b of the metal adhesive material 128 exposed from the protrusion 120. The removal of the metal adhesive material 128 can be accomplished by any standard method, including wet or dry etching.

[0072] Figure 3D The bump structure 100 can be used as an embodiment of the present invention. When the substrate 110 is a wafer, the bump structure 100 can be used for flip chip bonding after the substrate 110 is divided into multiple chips.

[0073] The bump formation process of the present invention enables the fabrication of a bump structure comprising a group of bumps 120 on a substrate 110, wherein even if the pad 112 is made of a different conductive material (i.e., Al in the embodiment) than the conductive particles used for sintering (i.e., Cu in the embodiment), the bumps 120 formed by sintering conductive paste 132 are tightly bonded to the pad 112 of the substrate 110. Typically, semiconductor devices include an outermost Al pad. Therefore, a sintered bump substrate 122 tightly bonded to the pad 112 can be fabricated for practical use.

[0074] Furthermore, since the raised substrate 122 is manufactured by sintering conductive particles 132 and the solder cap 124 is manufactured by injecting molten solder, no electroplating or electroless plating process is required to manufacture the raised main structure, thereby avoiding expensive column and solder cap manufacturing processes, expensive equipment and complex management of electroplating processes.

[0075] In the above embodiments, additional metal adhesive material is removed after the resist is peeled off. However, in other embodiments, the removal of the metal adhesive material may be omitted.

[0076] In the following text, referencing a series of... Figures 4A-4D and Figures 5A-5D This describes an improved protrusion forming process according to another embodiment of the invention, wherein the removal of the metal adhesive material is omitted. Figures 4A-4D and Figures 5A-5D Cross-sectional views of the structures obtained at each step of the improved protrusion forming process are shown.

[0077] like Figure 4A As shown, the bump formation process may include the step of preparing a substrate 110 on which a pad 112 and a passivation layer 114 are formed. Figure 2B As shown, the protrusion forming process may also include the step of applying a resist layer 130 on the surface 110a of the substrate 110.

[0078] like Figure 2C As shown, the bumping process may further include the step of patterning a resist layer 130 to have a group of openings 130a aligned with corresponding pads 112. The openings 130a expose the surface of the pads 112. A photoresist material is exposed with a photomask 131 and developed to open the openings 130a at the locations aligned with the pads 112. When the pads 112 are formed of an easily oxidizable metal such as Al, the bumping process may further include the step of removing surface oxides from the pads 112.

[0079] like Figure 4D As shown, the protrusion forming process may include the step of depositing a metal adhesive 128 on the surface of the pad 112 and the top surface of the resist layer 130. The metal adhesive 128 is deposited to conform to the contour of the resist layer 130. In this embodiment, the metal adhesive is selected from the group consisting of Cu, Ni, Au, and combinations thereof. In a particular embodiment, the metal adhesive layer 126 is a layer or stack of Cu, Au, and / or Ni.

[0080] Similar to the embodiments described above, when the pad 112 is formed of a metal that is easily and persistently oxidized (e.g., Al), a combination of anti-sputtering and sputtering of a metal bonding material is preferred.

[0081] like Figure 5A As shown, the protrusion forming process may include the step of filling the opening 130A of the resist layer 130 with conductive paste 132. Figure 5BAs shown, the protrusion forming process may include the step of sintering conductive paste 132. The conductive paste 132, filled in the opening 130a, is sintered to form a protruding substrate 122 on each pad 112. During the sintering process, the conductive paste 132 shrinks, causing the protruding substrate 122 to be formed to cover the sidewalls of the opening 130a and the surface of the pad 112, where both surfaces are now covered by a metallic adhesive 128, such as... Figure 5B As shown.

[0082] like Figure 5C As shown, the bump formation process may include the step of filling the remaining space 130b in each opening 130a above the bump substrate 122 with solder. In the embodiment, molten solder is injected into each opening 130a of the resist layer 130 to form a solder cap 124 on each bump substrate 122. The injection of molten solder can be accomplished, for example, by an IMS process. In this embodiment, during the IMS process, the metal binder 128 deposited on the top surface of the resist layer 130 dissolves in the molten solder because the metal binder 128 does not include any metals insoluble in the molten solder, such as Ti. After the IMS process, a portion of the metal binder 128 deposited on the sidewalls of the openings 130a of the resist layer 130 (referred to as sidewall metal 129) may be retained. In this embodiment, the sidewall metal 129 surrounds the bump substrate 122 and covers the side surfaces of the bump substrate 122. The sidewall metal 129 can be used as a sidewall barrier layer (e.g., Ni) to prevent short circuits between protrusions due to ion migration.

[0083] like Figure 5D As shown, the bump formation process may further include the step of peeling off the resist layer 130 from the substrate 110, thereby leaving a bump 120 on the substrate 110. (The details in...) Figures 2A-2E and Figures 3A-3D The step of removing the metal adhesive material 128 performed in the process shown.

[0084] Note that if a non-stripping type of resist is used to form the resist layer 130, the stripping step can be omitted. Therefore, Figure 5C The structure shown can also be used in subsequent flip-chip bonding processes without removing the resist layer 130.

[0085] exist Figures 2A-2E and Figures 3A-3D In the illustrated embodiment, due to the introduction of metal binder removal, even if the material is insoluble in solder materials such as molten solder, it has the advantage of being able to use other functional materials such as Ti barrier layers as metal binders. On the other hand, in Figures 4A-4D and Figures 5A-5DIn the illustrated embodiment, when a material insoluble in molten solder (such as Ti) is not used, the removal of the metal binder can be omitted, while sufficient removal of additional metal binder is achieved. Since the process of removing the metal layer beneath the resist layer after resist stripping is eliminated, undercutting at the root of the protrusion is preferably prevented. Related process costs can also be reduced. During the solder material filling process, Cu, Ni, and Au readily dissolve into the solder material, such as molten solder.

[0086] In the following text, referencing a series of... Figures 6A-6C This describes an alternative protrusion forming process according to another embodiment of the present invention. Figures 6A-6C Cross-sectional views of the structures obtained at each step of the alternative protrusion forming process are shown.

[0087] Note that the protrusion forming process also includes steps similar to those described in the above embodiments. Figures 4A-4D and Figure 5A The steps described herein. Therefore, in Figure 5A The steps will be described after they are completed.

[0088] like Figure 6A As shown, the protrusion formation process may include the step of sintering conductive paste 132. For example... Figure 6B As shown, the bumping process may include the step of filling solder into the remaining space 130b of each opening 130a above the bump substrate 122 to form a solder cap 124 on each bump substrate 122. In this embodiment, the metal bonding material 128 deposited on the top surface of the resist layer 130 remains even after the IMS process.

[0089] like Figure 6C As shown, the bump formation process may include the step of peeling off the resist layer 130 from the substrate 110. In this step, when the resist layer 130 is washed away, the metal adhesive material on the top surface of the resist layer 130 is peeled off and washed together with the underlying resist layer 130. The separate step of removing the metal adhesive material 128 is omitted. In this embodiment, the metal adhesive material 128 is selected from the group consisting of Cu, Ti, Ni, Au, and combinations thereof.

[0090] exist Figures 4A-4D , Figure 5A and Figures 6A-6C In the illustrated embodiment, with Figures 4A-4D and Figures 5A-5DThe illustrated embodiment is similar, and the removal of the metal adhesive material can be omitted regardless of its composition. Therefore, undercutting at the root of the bump is preferably prevented. This also reduces associated process costs. Consequently, other functional materials such as a Ti barrier layer are allowed to be used as the metal adhesive material. Furthermore, in this embodiment, the metal adhesive material conforming to the contour of the molding layer can serve as a sidewall barrier to prevent short circuits between bumps due to ion migration.

[0091] In the following text, referencing a series of... Figures 7A-7D Another alternative protrusion forming process according to another embodiment of the present invention will be described. Figures 7A-7D Cross-sectional views of the structures obtained at each step of the protrusion forming process are shown.

[0092] Note that the protrusion forming process also includes steps similar to those described in the above embodiments. Figures 4A-4D and Figure 5A The steps described herein. Therefore, in Figure 5A The steps will be described after they are completed.

[0093] like Figure 7A As shown, similar to the embodiments described above, the protrusion forming process may include the step of sintering conductive paste 132 to form a protruding substrate 122 on each pad 112. Figure 7B As shown, the protrusion formation process may include the step of removing the metal adhesive 128 deposited on the top surface of the resist layer 130. The removal of the metal adhesive 128 may be accomplished by techniques selected from the group consisting of: chemical mechanical polishing (CMP), mechanical polishing, fly cutting, and chemical etching.

[0094] like Figure 7C As shown, the bump formation process may include the step of filling the remaining space 130b in each opening 130a with solder to form a solder cap 124 on each bump substrate 122. Figure 7D As shown, the bump formation process may further include the step of peeling off the resist layer 130 from the substrate 110. In this embodiment, the metal adhesive material 128 is selected from the group consisting of Cu, Ti, Ni, Au, and combinations thereof.

[0095] exist Figures 4A-4D , Figure 5A and Figures 7A-7D In the illustrated embodiment, even though an additional metal adhesive removal process is performed before resist stripping, the removal process of the metal layer after resist stripping, which would cause undercutting at the convex root, is eliminated. This also allows us to use other functional materials such as a Ti barrier layer as the metal adhesive. Furthermore, in this embodiment, the metal adhesive conforming to the contour of the molded layer can serve as a sidewall barrier to prevent short circuits between protrusions due to ion migration.

[0096] In the following text, refer to Figure 8A and 8B This describes an electronic device according to exemplary embodiments of the present invention and a flip-chip bonding process for manufacturing the electronic device. Figure 8A and 8B Cross-sectional views of the structures obtained at each step of the flip-chip bonding process are shown.

[0097] like Figure 8A As shown, the flip-chip process may include the step of fabricating a raised semiconductor chip 310, the chip including a group of bumps 320 formed on its active surface. The flip-chip process may also include the step of fabricating an organic substrate 350, the organic substrate including and forming a group of solder resist 354 and contact pads 352 on its surface. The flip-chip process may further include the step of applying an underfill 356 to the surface of the organic substrate 350.

[0098] The bumped semiconductor chip 310 prepared in this step is manufactured using any of the aforementioned bumping processes. If the bumping process is performed at the wafer level, it is subsequently manufactured using a dicing process. (As already referred to...) Figure 1A and 1B As described, each protrusion 320 includes a metal adhesive layer 326 formed on a pad 312, a protrusion base 322 formed on the pad 312 via the metal adhesive layer 326, and a solder cap 324 formed on the protrusion base 322.

[0099] like Figure 8B As shown, the flip-chip process may include mounting a raised semiconductor chip 310 onto an organic substrate 350, such that the chip-side bumps 320 contact the substrate-side contact pads 352 respectively. The semiconductor chip 310 is flipped so that its active surface faces down and is configured such that the bumps 320 are aligned with the corresponding pads 352 on the organic substrate 350. Figure 8B As shown, the flip-chip process may also include the step of bonding bump 320 to pad 352 to obtain flip-chip joint 360. A suitable mounting and reflow method, or thermal compression method, may be used depending on the desired size and spacing of the joint. The flip-chip process may also include the step of curing underfill 356 to rigidly attach the semiconductor chip 310 to the organic substrate 350.

[0100] By performing the steps of mounting the raised semiconductor chip 310 and bonding the raised chip 320 to the pad 352, the raised semiconductor chip 310 is interconnected to an organic substrate 350 including external circuitry.

[0101] Electronic devices manufactured using the above-described flip-chip bonding process exhibit good durability because even if the pad 312 is made of a different conductive material than the conductive particles used to form the bumps, the bumps 320 formed by sintering the conductive particles are tightly bonded to the pad 312.

[0102] In the following text, referencing a series of... Figures 9A-9E , Figures 10A-10E , Figure 11A-11D , Figure 12A-12D and Figures 13A-13C This will describe various related protrusion forming processes.

[0103] Figures 9A-9E Cross-sectional views of the structure obtained at each step of the associated protrusion formation process, including the electroplating of the pillars and solder caps, are shown.

[0104] like Figure 9A As shown, a seed layer 516, such as a Ti / Cu layer, is formed on the surface of the prepared wafer 510. Figure 9B As shown, a resist mask 530 with a group of holes 530a is patterned on wafer 510. As... Figure 9C As shown, Cu is electroplated on the seed layer 516 in hole 530a to form a Cu pillar extending to the middle of hole 530a. Also as... Figure 9C As shown, a solder layer 524 is deposited on the Cu pillar 522 by electroplating solder material on the upper boundary of the hole 530b of the resist mask 530. Figure 9D As shown, the resist mask 530 is stripped from the wafer 510, and the seed layer 516 is etched. Figure 9E As shown, the solder layer 524 is then subjected to reflow using flux to form solder-covered bumps 520 on the wafer 810.

[0105] although Figures 9A-9E The illustrated protrusion forming process can manufacture Cu pillar protrusions; however, it is difficult to adjust the composition of the electroplated solder with a high degree of freedom. It is known that pure Sn or binary solder compositions can be stably manufactured by electroplating. Furthermore, both pillars and solder caps require expensive electroplating, costly equipment, and complex management of the electroplating process. Moreover, removing the seed layer 516 after resist stripping will cause undercutting at the root of the protrusion 520.

[0106] Figures 10A-10E Cross-sectional views of the structures obtained at each step of the IMS process, including the electroplating of the pillars and the solder caps, are shown.

[0107] like Figure 10A As shown, a seed layer 616, such as a Ti / Cu layer, is formed on the surface of the wafer 610. Figure 10BAs shown, a resist mask 630 with a group of holes 630a is patterned on the wafer 610. As... Figure 10C As shown, Cu is electroplated on the seed layer 616 in hole 630a to form a Cu pillar extending to the middle of hole 630a. Figure 10D As shown, the remaining space of the holes 630a in the resist mask 630 is filled with solder material using an IMS process to form a solder cap 624 on the Cu pillar 622. Figure 10E As shown, the resist mask 630 is stripped from the wafer 610 and the seed layer 616 is etched.

[0108] Despite Figures 10A-10E The protrusion forming process shown can omit expensive solder plating, but still requires expensive copper pillar plating, expensive equipment, and complex plating process management. Moreover, removing the seed layer 616 after resist stripping will result in undercutting at the root of the protrusion 620.

[0109] Figure 11A-11D Cross-sectional views of the structures obtained at each step of the IMS process, including the electroless plating of the pillars and the solder caps, are shown.

[0110] like Figure 11A As shown, a resist mask 730 with a group of holes 730a is patterned on a wafer 710 including a group of pads 712 and a passivation layer 714. Figure 11B As shown, Ni is deposited on the pad 712 in the hole 730a by electroless plating to form a Ni pillar 722 extending to the middle of the hole 730a, and an Au metal layer 728 is deposited on the Ni pillar 722. Figure 11C As shown, the remaining space of the holes 730a in the photoresist mask 730 is filled with solder material using an IMS process to form a solder cap 724 on the Ni pillar 722. Figure 11D As shown, the resist mask 730 is stripped from the wafer 710, leaving a group of Ni pillar bumps 720 including Ni pillars 722 and solder caps 724 on the wafer 710.

[0111] Although the removal of the seed layer after resist stripping can be omitted, it still requires expensive electroless plating of Ni pillars, costly equipment, and complex electroplating process management.

[0112] Figure 12A-12D and Figures 13A-13C Cross-sectional views of the structures obtained at each step of the associated protrusion process based on conductive paste sintering without the use of a metal adhesive layer are shown.

[0113] like Figure 12A As shown, in the relevant bump formation process, a wafer 810 is provided, including a pad 812 and a passivation layer 814. As... Figure 12BAs shown, a resist mask 830 is then formed on the surface of the wafer 810. (As illustrated...) Figure 12C As shown, a photomask 831 is used to pattern a resist mask 830 into a group having holes 830a. Each hole 830a is aligned with a corresponding pad 812.

[0114] like Figure 12D As shown, Cu paste 832 is filled into the holes 830a of the resist mask 830 until the upper boundary of the holes 830a. Figure 13A As shown, the Cu paste 832 filling the hole 830a solidifies to form a cup-shaped pillar 822 as a sintered body of Cu particles. Note that since this process uses a sintering process to manufacture the copper pillar, the seed layer required for copper electroplating is unnecessary. Instead, from a cost point of view, these unnecessary steps, including seed layer deposition and seed layer removal after resist stripping, can be avoided. Furthermore, seed layer removal after resist stripping may cause undercutting at the convex root.

[0115] like Figure 13B As shown, the remaining space of the hole 830a in the resist mask 830 above the cup-shaped pillar 822 is then filled with solder material using an IMS process to form a solder cap 824 on the cup-shaped pillar 822. Figure 13C As shown, the resist mask 830 is stripped from the wafer 810, leaving a group of Cu pillar bumps 820 on the wafer 810, each Cu pillar bump including a cup-shaped pillar 822 and a solder cap 824.

[0116] pass Figure 12A-12D and Figures 13A-13C The raised process shown avoids the expensive electroplating of the two copper pillar solder caps, the costly equipment, and the complex management of the electroplating process.

[0117] However, this process is limited when the pads 812 and pillars 822 are made of the same material, particularly copper. The inventors conducted in-depth research and found that even after removing the native oxide film by backsputtering, it is difficult to bond the sintered body of the conductive paste to a pad made of a different conductive material at atmospheric pressure; for example, it is difficult to bond sintered copper to an Al pad. The high-temperature conditions of sintering are expected to help enhance the bonding between the sintered pillars and pads. However, semiconductor devices typically degrade under such high-temperature conditions, exceeding the temperatures of typical reflow processes, such as >300 degrees Celsius.

[0118] and Figure 12A-12D and Figures 13A-13CCompared to the aforementioned bump formation processes shown, the technology according to one or more embodiments of the present invention enables enhanced bonding between the bump substrate and the pad without using high-temperature conditions. Even when a conductive material different from conductive particles is used as the pad material, the metal bonding layer or UBM layer formed between the pad 112 and the conductive paste 132 (or the sintered bump substrate 122) maintains good adhesion. Therefore, degradation of the semiconductor device due to the bump formation process can be prevented.

[0119] Similarly with Figures 9A-9E , Figures 10A-10E , Figure 11A-11D In contrast to the aforementioned protrusion forming process shown in the figure, the protrusion forming process according to one or more embodiments of the present invention eliminates the necessity of expensive electroplating of the protrusion substrate and solder cap, as well as the complex management of the electroplating process, thereby reducing the production cost of the protrusion.

[0120] As described above, according to one or more embodiments of the present invention, a novel bump forming technique is provided capable of manufacturing a bump structure comprising a group of bumps formed on a substrate, wherein the bumps made by sintering conductive particles are tightly bonded to a pad made of a conductive material different from the conductive particles.

[0121] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, steps, layers, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, layers, elements, components, and / or combinations thereof.

[0122] If present, all means or steps plus functional elements in the following claims are intended to include any structure, material, action, and equivalent for performing a function in combination with other claimed elements of the particular claim. For purposes of illustration and description, one or more aspects of the invention have been described, but are not intended to be exhaustive or to limit the invention to the forms disclosed.

[0123] Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein is chosen to best explain the principles of the embodiments, their practical application, or improvements to existing technologies on the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for manufacturing a protruding structure, the method comprising: Prepare a substrate comprising a group of pads formed on its surface, the pads comprising a first conductive material; A metal adhesive layer is coated on each of the gaskets, wherein the metal adhesive layer is formed directly on the gaskets; as well as A protrusion with a raised base is formed on each of the gaskets by using a molded layer sintered conductive particles. The raised base is formed directly on the metal adhesive layer. The conductive particles include a second conductive material different from the first conductive material. The metal adhesive layer covers the entire top surface of the pad and forms a sidewall barrier that further covers the side surface of the raised substrate to provide ion migration short-circuit protection.

2. The method according to claim 1, wherein, The molded layer has a group of openings, each of which is aligned with one of the gaskets, and the protrusion formed on each of the gaskets includes: The molding layer is disposed on the substrate; Conductive particles are filled into the openings of the molded layer, and the conductive particles filled into the openings of the molded layer are sintered to supply the raised substrate on each of the gaskets; and Solder material is filled into the remaining space in each of the openings in the molding layer above the raised substrate to form a solder cap on each raised substrate.

3. The method according to claim 1, wherein the first conductive material comprises Al, and the second conductive material comprises Cu.

4. The method according to claim 2, wherein, The conductive particles are provided in the form of a paste, and the raised substrate formed on each of the pads has a cup shape that conforms to the contour of the opening of the molded layer and is bonded to the bottom of the pad by the metal adhesive layer.

5. The method according to claim 2, wherein the method further comprises: A resist layer is applied to the surface of the substrate; Pattern the resist layer to create the molding layer; as well as Metallic adhesive material is deposited on the liner and the molding layer to conform to the contour of the molding layer and to provide the metallic adhesive layer coated on each of the liner.

6. The method of claim 5, wherein filling the solder material comprises: The metal bonding material deposited on the top surface of the molded layer is dissolved into the solder material.

7. The method according to claim 6, wherein the metal adhesive material is selected from the group consisting of Cu, Ni, Au, and any combination thereof.

8. The method of claim 5, wherein the method further comprises: The molding layer is peeled off from the substrate to remove it, wherein the metal adhesive material on the top surface of the molding layer is peeled off and cleaned together with the molding layer.

9. The method of claim 5, wherein the method further comprises: The metal adhesive material deposited on the top surface of the molding layer is removed using a technique selected from the group consisting of chemical mechanical polishing (CMP), mechanical polishing, fly cutting, and chemical etching.

10. The method of claim 2, wherein the method further comprises: A metal adhesive material is deposited on the surface of the substrate to have a first portion corresponding to the metal adhesive layer coated on each of the pads and a second portion formed on the peripheral region of the pads. Apply a corrosion resist layer to the metal adhesive material; Pattern the resist layer to create the molding layer; The molding layer is peeled off from the substrate to leave the protrusions on the substrate, each protrusion including the solder cap and the protrusion base formed on the pad; as well as Remove the second portion of the metal adhesive material exposed from the protrusion.

11. The method according to claim 10, wherein the metal adhesive material is selected from the group consisting of Cu, Ti, Ni, Au, and any combination thereof.

12. The method of claim 2, wherein filling the solder material comprises: Molten solder is injected into each of the openings in the molded layer.

13. The method of claim 1, wherein the method further comprises: Prior to applying the metal adhesive layer, surface oxides are removed from the pads by reverse sputtering, and the metal adhesive layer is applied to each of the pads by sputtering.

14. The method of claim 1, wherein the substrate comprises a semiconductor device, the group of pads is formed at least on the active surface of the semiconductor device, and the method further comprises: The method of interconnecting the semiconductor device to an external circuit using the bumps is a method of manufacturing electronic devices.

15. A protruding structure, comprising: A substrate, the substrate comprising a group of pads formed on its surface, wherein the pads comprise a first conductive material; as well as A group of protrusions, each of which is formed on one of the gaskets, wherein each of the protrusions includes a metal adhesive layer formed directly on the gasket and a protrusion substrate formed directly on the metal adhesive layer, and the protrusion substrate is a sintered body comprising conductive particles of a second conductive material different from the first conductive material. The metal adhesive layer covers the entire top surface of the pad and forms a sidewall barrier that further covers the side surface of the raised substrate to provide ion migration short-circuit protection.

16. The protrusion structure of claim 15, wherein each of the protrusions further comprises a solder cap formed on the protrusion base, the protrusion base having a cup shape, the cup having a bottom of the pad bonded via the metal adhesive layer, and the cup being filled with solder material of the solder cap.

17. The protrusion structure of claim 15, wherein the first conductive material comprises Al, the second conductive material comprises Cu, and the metal adhesive layer comprises a material selected from the group consisting of Cu, Ti, Ni, Au, and combinations thereof.

18. An electronic device comprising: A semiconductor device having a protrusion structure according to any one of claims 15 to 17; And circuitry interconnected with the substrate via the group of protrusions.

19. The electronic device of claim 18, wherein each of the protrusions further comprises a solder joint connecting each protrusion base to a terminal contact of the circuit, the protrusion base having a cup shape, the cup having a bottom of the pad bonded via the metal adhesive layer, and the cup being filled with solder material of the solder cap.

20. A method for manufacturing an electronic device, the method comprising: Fabricating a bumped semiconductor device, wherein fabricating the bumped semiconductor device comprises a method for manufacturing a bumped structure according to any one of claims 1 to 14; as well as The bumped semiconductor device is interconnected to an external circuit via the group of bumps.

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