Sinter ready multilayer wire / ribbon bond pads and method for die top attachment

Abstract

A method for manufacturing a bond pad for connecting a die to a copper ribbon or copper wire on a printed circuit board comprises the steps of: providing a sheet of copper foil having a first main surface opposite to a second main surface; providing a sinterable film of metal particles; laminating the first main surface with the sinterable film to form a laminated sheet; and punching a bond pad from the laminated sheet.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a bond pad for connecting a die to a copper ribbon or copper wire, a bond pad, a sinterable silver film, a method for connecting a die to a copper wire and / or copper ribbon, a method for manufacturing an electronic device, an electronic device, and a method for assembly. Background Technology

[0002] In conventional power modules, for example, bond wires connecting the semiconductor / die and the substrate are typically formed of aluminum. As power density requirements for power modules have increased, manufacturers have begun using copper bond wires, which provide additional current carrying capacity and better thermal conductivity and dissipation. The conditions for welding copper wires to the semiconductor / die tend to be stricter than those for aluminum wires, which can cause damage to the underlying semiconductor / die. Consequently, it is common practice to attach a thin film of copper, known as a "bond pad," to the top of the die. The bond pad provides uniform current distribution and better heat dissipation (e.g., under short-circuit conditions) and can prevent substantial damage to the underlying die when the die is welded to the copper wire.

[0003] The technology described in US10079219B2 comprises a flexible contact film (bond pad) sintered over an area of ​​varying thickness of a sintered layer applied to the top side of a die or other substrate. The sintered material is applied in a paste form, dried into an undulating pattern, and sintered onto a metal molded body. Additionally, wires or ribbons are ultrasonically welded to the flexible contact film. There are significant difficulties in implementing this technology in the mass production of semiconductor devices. For example, the application of the sintered layer is typically performed via stencils, screens, or other types of printing. Printing small areas, such as the top side of a die, is a difficult and poorly controlled process. Misprinting or paste spills occur frequently, which can damage the device by shorting electrical terminals or creating other defects. Furthermore, the top side of the die is typically patterned with the help of a dielectric barrier layer that protrudes 10 to 15 microns above the surface, further complicating the printing process. Creating paste deposits that are reproducible with printing of various thicknesses on a die as small as 5 x 5 mm cannot be achieved in a high-volume manufacturing (HVM) environment.

[0004] Instead of applying the sintering paste to the top side of the die, it is possible to provide the sintering paste at the base of the bond pad. This can be achieved by printing the sintering paste onto the base or by applying the paste to copper foil and then cutting the copper foil into individual bond pads. The former is susceptible to the problems discussed above, while the latter may require the use of precise cutting, for example, using a laser. This can make the manufacturing method more complex. Additionally, the final bond pad may not be robust enough to be processed using conventional tape-and-reel technology and may instead require the use of dicing tape.

[0005] The present invention aims to solve at least some of the problems associated with the prior art or to provide a commercially acceptable alternative.

[0006] In a first embodiment, the present invention provides a method for manufacturing a bond pad for connecting a die to a copper ribbon or a copper wire, and the method is,

[0007] A step of providing a sheet of copper foil having a first main surface opposite to a second main surface;

[0008] A step of providing a sinterable film of metal particles;

[0009] A step of forming a laminated sheet by laminating a first main surface with a sinterable film; and

[0010] It includes the step of punching a bond pad from a laminated sheet.

[0011] Each of the embodiments or examples defined herein may be combined with any other embodiment(s) or example(s) unless otherwise clearly indicated. In particular, any feature indicated as preferred or advantageous may be combined with any other feature indicated as preferred or advantageous.

[0012] The present method can produce a bond pad having a high-quality bond line between a copper foil and a sinterable film. Advantageously, compared to conventional methods, the method of the present invention may be less complex. In particular, the present method may not require the use of precise printing and / or cutting techniques.

[0013] Compared to conventional bond pads, bond pads manufactured using this method can be more robust. As a result, they can be handled more easily without damage, thereby reducing the considerations required during use in the manufacturing of electronic devices such as power modules or printed circuit boards.

[0014] Bond pads are intended to connect the die to a copper ribbon or copper wire. This can be in the same context as a power module or a printed circuit board. That is, bond pads are intended to connect the die to a copper ribbon or copper wire within a power module and / or may be intended to connect the die to a copper ribbon or copper wire within a printed circuit board. The copper ribbon or copper wire can be considered an interconnect; that is, the copper ribbon or copper wire can be a copper ribbon interconnect or a copper wire interconnect.

[0015] Bond pads may be suitable for storage in waffle packs or tapes typically used in pick-and-place equipment. Therefore, bond pads may be particularly suitable for use in high-speed manufacturing lines.

[0016] The method includes the step of providing a sheet of copper foil having a first main surface opposite to a second main surface. "First main surface" and "second main surface" refer to two sides of the sheet, i.e., two surfaces having the largest area.

[0017] The method comprises the step of providing a sinterable film of metal particles. "Sinterable" means that the film can undergo sintering when heat and / or pressure is applied to form a metallic joint between two surfaces. The sinterable film is free-standing. That is, the sinterable film can substantially maintain its integrity when handled. This allows the film to be distinguished from a dried layer of sintering paste applied to the surface, which would normally be susceptible to breakage when handled or transferred from one surface to another. The sinterable film contains metal particles. The sinterable film may contain species other than metal particles. The metal particles may be in the form of one or more of spheres, rods, and plates. The metal particles may include nanoparticles, that is, having an average maximum dimension of 1 to 1,000 microns when measured using TEM or laser diffraction. Examples of suitable sinterable films and methods for manufacturing the same are described in US10535628B2 and US10710336B2, the disclosures of which are incorporated herein by reference. A commercial example of a suitable sinterable film is MacDermid Alpha Sinter Ready Film.

[0018] The method includes the step of forming a laminated sheet by laminating a first main surface with a sinterable film. Thus, the laminated sheet comprises a sheet of a sinterable film and a sheet of copper foil. The sinterable film is laminated onto the first main surface. The sinterable film is also not laminated onto the second main surface. In effect, the second main surface is typically kept uncoated. This allows the copper foil to be welded to a copper ribbon or copper wire.

[0019] The method includes the step of punching (out) a bond pad from a laminated sheet. Punching techniques and punching equipment are known in the art. A commercial example of a suitable punching press is the Lingshen punching press. Suitable punching presses are also provided by Kaka Industry, Samhoor, etc. Punching is sometimes referred to as "stamping" in the art.

[0020] The copper foil preferably contains copper or a copper alloy and / or is a multilayer structure. This can produce a particularly effective bond bed.

[0021] The copper foil has a thickness of 10 to 200 μm, more preferably 50 to 150 μm. Thicker foil can increase the cost of the method and / or excessively increase the thickness of the bond pad, thereby excessively increasing the size of the printed circuit board or power module formed using the bond pad. Thinner foil can cause damage to the underlying die when the copper ribbon or wire is welded to the copper foil. However, the copper foil can preferably have a thickness of less than 50 μm, for example, 10 μm to less than 50 μm.

[0022] The copper foil preferably has a hardness HV of 50 to 100 using a 300 g load. A higher hardness value may make it more difficult to weld a copper ribbon or copper wire to the copper foil. A lower hardness value may cause damage to the underlying die when the copper ribbon or wire is welded to the copper foil.

[0023] The copper foil is preferably 10 to 20 K -1 It has a coefficient of thermal expansion (CTE). This can prevent undesirable levels of thermal stress during sintering and / or welding.

[0024] The copper foil may not be perforated. Alternatively, the copper foil is preferably perforated. In use, this can provide stress relief to a device containing bond pads. In this regard, the copper foil may contain a number of perforations and / or may be porous and / or mesh-like.

[0025] The metal particles preferably comprise one or more of silver particles, copper particles, silver-coated copper particles, copper-coated silver particles, gold particles, palladium particles, aluminum particles, silver-palladium alloy particles, and gold-palladium alloy particles, more preferably silver particles. The metal particles preferably have a maximum dimension of 1 to 1000 nm.

[0026] The sinterable film preferably comprises silver particles having a maximum dimension of 1 to 1000 nm and a polymer binder. The silver particles can exhibit particularly desirable sintering properties and can produce sintered joints having particularly desirable electrical and thermal conductivity. Smaller particles may be difficult to handle. Larger particles may require undesirably high sintering temperatures and / or pressures, which can reduce the energy efficiency of the method and / or cause damage to the die or substrate. If the particles are in the form of spheres, the maximum dimension is the diameter of the sphere. The maximum dimension can be measured using TEM or laser diffraction. The use of a binder can ensure that the film can be "freestanding".

[0027] The sinterable film comprises, preferably, 0.1 to 2 weight percent of a polymer binder and, preferably, 0.5 to 1 weight percent of a polymer binder based on the total weight of the sinterable silver film.

[0028] Polymer binders preferably include amide polymers, more preferably poly(N-vinyl acetamide). These species are particularly effective binders.

[0029] The silver particles (or metal particles) preferably have a maximum dimension of 5 to 500 nm, preferably 10 to 100 nm, and more preferably 30 to 60 nm. This can produce particularly desirable sintering and handling characteristics. The maximum dimension can be measured using TEM or laser diffraction.

[0030] Preferably, silver particles (or metal particles) in the sinterable film form fine particles having a D90 of 1000 nm or less, preferably 500 nm or less, more preferably 100 nm or less, even more preferably 60 nm or less; and / or a D10 of 1 nm or more, more preferably 5 nm or more, even more preferably 10 nm or more, and even more preferably 30 nm or more. This particle size distribution can result in particularly desirable sintering and handling characteristics.

[0031] The sinterable film comprises, based on the total weight of the sinterable film, preferably 90 to 99 weight percent of silver particles (or metal particles), more preferably 92 to 98 weight percent of silver particles (or metal particles), and even more preferably 94 to 96 weight percent of silver particles (or metal particles). Higher levels of particles may result in the sinterable film exhibiting undesirable mechanical / handling properties. Lower levels of particles may result in high levels of species other than silver (e.g., binders or their remnants) being present in the final sintered joint, thereby having an undesirable effect on its mechanical and / or electrical and / or thermal properties.

[0032] The sinterable film preferably comprises a halogenated alcohol activator having a melting point of 80 to 150°C. Such a sinterable film can be particularly effective for bonding bond pads to a die in a method of manufacturing electronic devices. Surprisingly, the inventors discovered that the sinterable silver film can be "hot tacked" to the die during a method of connecting the die to a copper wire or copper ribbon. This avoids the need to use an adhesive on residues that may remain in the final sintered joint and reduce its integrity.

[0033] As used herein, the term "thermal adhesion" may encompass a process in which a sinterable film is adhered to a surface by the application of heat and, typically, also pressure. This adhesion occurs without substantial sintering of the metal particles within the sinterable film. Thus, the sinterable film can be maintained in a desired position during the adhesion method while retaining its ability to form a joint between the bond pad and the surface of the die. Without being bound by theory, thermal adhesion is considered to be achieved by limited metallic diffusion between the sinterable film and the surface being "adhered," such as the top of the die.

[0034] The presence of a halogenated alcohol activator can remove oxides from the surface to which the sinterable film is to be adhered, for example, the top surface of a die. This ensures that adhesion can occur at a temperature low enough to allow the sinterable film to adhere to the surface, but low enough to prevent substantial sintering of the metal particles contained in the sinterable film. Without being bound by theory, this is considered to be due to an increased level of metallic diffusion possible as a result of the removal of surface oxides.

[0035] In addition, the presence of a halogenated alcohol activator can make it easier to laminate the first main surface into a sinterable film, which may mean that such lamination can occur under milder conditions. Also, it may not be necessary to use a metal plating layer (e.g., a silver plating layer) on the first main surface, which would normally facilitate metallic diffusion during lamination.

[0036] The sinterable film comprises, preferably, 0.05 to 1 weight% of a halogenated alcohol activator based on the total weight of the sinterable film, and more preferably, 0.1 to 0.2 weight% of a halogenated alcohol activator.

[0037] The halogenated alcohol activator preferably has a melting point of 85 to 140°C, more preferably 90 to 130°C, and even more preferably 100 to 120°C. This allows the activator to be "active" at typical lamination and / or heat bonding temperatures. At lower temperatures, the activator will be solid, which means there will be no change in the mechanical properties of the sinterable film, which would affect the ability to be handled as a result of the melting of the activator.

[0038] The halogenated alcohol activator has a molecular weight of at least 150, preferably at least 200; and / or 500 or less, preferably 400 or less, more preferably 300 or less; and / or 150 to 500, preferably 200 to 300.

[0039] Halogenated alcohols preferably include brominated alcohols, and more preferably

[0040] It includes dibrominated alcohols. Halogenated alcohols preferably include 3 to 5 carbon atoms. Halogenated alcohols preferably include monohydroxy alcohols. Halogenated alcohols may be linear or branched. Halogenated alcohols preferably include 3,4-dibromo-2-butanol and / or 1,4-dibromobutan-2-ol. These alcohols may be particularly effective in removing surface oxides.

[0041] Preferably, the sinterable film further comprises partially hydrogenated gum rosin in an amount of 0.1 to 0.3 weight percent based on the total weight of the sinterable silver film; and / or preferably, micronized wax in an amount of 0.2 to 0.4 weight percent based on the total weight of the sinterable silver film.

[0042] The step of laminating the first main surface with a sinterable film preferably includes the step of bringing the sinterable film into contact with the first surface; and the step of applying heat and pressure to the sheet of copper foil and the sinterable film.

[0043] The first surface preferably comprises a metal plating layer, and the step of contacting a sinterable film with the first surface includes the step of contacting the metal plating layer with a sinterable silver film. This may allow lamination to occur at a lower temperature and / or pressure. Without being bound by theory, this may be because metallic diffusion between the metal particles and the metal plating layer may be more pronounced than between the metal particles and the copper foil.

[0044] The metal plating layer preferably comprises silver, a nickel-gold alloy and / or ENIG, more preferably silver. If the sinterable film comprises silver particles, the metal plating layer preferably comprises silver. The diffusion of silver into the silver plating layer may be more pronounced than the diffusion into the copper foil.

[0045] The metal plating layer preferably has a thickness of 1 to 5 μm. A smaller thickness may not adequately promote metallic diffusion. A larger thickness may excessively increase the size of the device formed using the bond pad.

[0046] The step of applying heat and pressure to the sheet of copper foil and the sinterable film comprises: applying a pressure preferably at least 0.5 MPa, preferably at least 0.8 MPa, more preferably 0.5 to 2 MPa, more preferably 0.8 to 1.2 MPa, and even more preferably about 1 MPa; and / or heating the sheet of copper foil and / or the sinterable film to a temperature of 100 to 200°C, preferably 120 to 170°C, more preferably 140 to 160°C, and even more preferably about 150°C, preferably for 1 to 60 seconds, more preferably 2 to 40 seconds, more preferably 5 to 15 seconds, and even more preferably about 10 seconds. This may result in an appropriate level of adhesion between the sheet of copper foil and the sinterable film without causing substantial sintering of the sinterable film.

[0047] Preferably, the method further comprises the step of applying an adhesive to a sinterable film on a laminated sheet, and punching is performed such that the adhesive is present on the sinterable film on the bond pad. This may enable "cold tacking" of the bond pad to the die, i.e., tacking at a temperature below 100°C or below 90°C. This may be advantageous when the die is attached to a substrate that may be damaged and oxidized at higher temperatures. The tacking agent may be applied in any shape, but is typically applied to a number of individual zones. That is, a number of individual tacking deposits may be applied. After punching, each bond pad may contain, for example, one to four individual tacking deposits. The tacking may be applied using hot melt jetting with commercially available equipment such as the Nordson Unity PJ30XT. It is preferable to apply the adhesive before punching because it is easier to apply it to a continuous strip, but the adhesive can be applied after punching.

[0048] The adhesive preferably comprises a diphenyl compound having a melting point of 50 to 90°C; and / or preferably a triphenyl compound having a melting point of 50 to 90°C; and / or preferably a fatty alcohol having a melting point of 30 to 60°C. In a preferred embodiment, the adhesive comprises a polyvinyl ether. Such species may exhibit a high level of "adhesion" at typical low-temperature adhesion temperatures, but exhibit a limited level of adhesion at lower temperatures, thereby making them easier to handle. Such species may evaporate substantially at typical sintering temperatures, which means that such species are substantially absent from the final sintered joint.

[0049] In a further embodiment, the present invention provides a bond pad manufactured according to the method described herein.

[0050] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0051] In a further embodiment, the present invention provides a sinterable silver film, and the sinterable silver film is,

[0052] Silver particles having a maximum dimension of 1 to 1000 nm,

[0053] Polymer binder, and

[0054] It includes a halogenated alcohol activator having a melting point of 80 to 150°C.

[0055] The advantages and desirable features of the first embodiment apply equally to this embodiment. The sinterable film may be particularly suitable for attaching bond pads to the die.

[0056] The silver particles preferably have a maximum dimension of 5 to 500 nm, preferably 10 to 100 nm, and more preferably 30 to 60 nm.

[0057] The silver particles in the sinterable silver film form fine particles having a D90 of preferably 1000 nm or less, preferably 500 nm or less, more preferably 100 nm or less, more preferably 60 nm or less; and / or a D10 of 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, more preferably 30 nm or more.

[0058] The sinterable silver film comprises, preferably, 90 to 99 weight percent of silver metal particles, more preferably 92 to 98 weight percent of silver metal particles, and even more preferably 94 to 96 weight percent of silver metal particles, based on the total weight of the sinterable film.

[0059] The sinterable silver film comprises, preferably, 0.1 to 2 weight percent of a polymer binder based on the total weight of the sinterable silver film, and more preferably, 0.5 to 1 weight percent of a polymer binder.

[0060] The polymer binder preferably comprises an amide polymer, more preferably poly(N-vinyl acetamide).

[0061] The sinterable silver film comprises, preferably, 0.05 to 1 weight% of a halogenated alcohol activator based on the total weight of the sinterable silver film, and more preferably, 0.1 to 0.2 weight% of a halogenated alcohol activator.

[0062] The halogenated alcohol activator preferably has a melting point of 85 to 140°C, more preferably 90 to 130°C, and even more preferably 100 to 120°C.

[0063] The halogenated alcohol activator preferably has a molecular weight of at least 150, preferably at least 200; and / or 500 or less, preferably 400 or less, more preferably 300 or less; and / or 150 to 500, preferably 200 to 300.

[0064] Halogenated alcohols preferably include brominated alcohols, and more preferably

[0065] It includes dibrominated alcohols. The halogenated alcohol preferably includes 3 to 5 carbon atoms. The halogenated alcohol preferably includes monohydroxy alcohols. The halogenated alcohol preferably includes 3,4-dibromo-2-butanol and / or 1,4-dibromobutan-2-ol.

[0066] Preferably, the sinterable silver film comprises partially hydrogenated gum rosin in an amount of 0.1 to 0.3 weight percent based on the total weight of the sinterable silver film; and / or preferably, finely pulverized wax in an amount of 0.2 to 0.4 weight percent based on the total weight of the sinterable silver film.

[0067] In a further embodiment, the present invention provides a bond pad for connecting a die to a copper wire or a copper ribbon, wherein the bond pad is,

[0068] copper foil,

[0069] A sinterable silver film described herein, laminated onto a copper foil, and

[0070] Optionally includes a metal plating layer sandwiched between a copper foil and a sinterable silver film.

[0071] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0072] The copper foil preferably contains copper or a copper alloy and / or is a multilayer structure.

[0073] The copper foil has a thickness of 10 to 200 μm, more preferably 50 to 150 μm.

[0074] Copper foil preferably has a hardness Hv of 50 to 100.

[0075] The copper foil is preferably 10 to 20 K -1 It has a coefficient of thermal expansion (CTE).

[0076] The copper foil is preferably perforated.

[0077] The metal plating layer preferably comprises silver, a nickel-gold alloy, and / or ENIG (electroless nickel immersion gold).

[0078] The metal plating layer preferably has a thickness of 1 to 5 μm.

[0079] The bond pad preferably further comprises an adhesive on the outer surface of a sinterable silver film.

[0080] The adhesive preferably comprises a diphenyl compound having a melting point of 50 to 90°C; and / or preferably a triphenyl compound having a melting point of 50 to 90°C; and / or preferably a fatty alcohol having a melting point of 30 to 60°C.

[0081] The adhesive preferably contains polyvinyl ether.

[0082] In a further embodiment, the present invention provides a method for connecting a die to a copper wire and / or copper ribbon, and the method is,

[0083] Step of providing the die,

[0084] Step of providing the bond pad described herein,

[0085] A step of bringing the sinterable film of the bond pad into contact with the die,

[0086] A step of heating a sinterable film to connect a bonding pad to a die; and

[0087] It includes the step of welding copper wire and / or copper ribbon to the copper foil of the bond pad.

[0088] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0089] The reference to the sinterable film corresponds to a sinterable silver film or a sinterable film of metal particles, depending on which bond pad (an aspect of the present invention) is used. The step of contacting the sinterable film of the bond pad with the die can be performed using standard die pick-and-place equipment, such as, for example, a Datacon 2200EVO or an Infotech Die Bonder.

[0090] The welding step preferably includes ultrasonic welding and / or laser welding. This welding step can form a particularly strong connection between the die / bond pad and the copper wire and / or copper ribbon.

[0091] The step of welding copper wire and / or copper ribbon to the copper foil of the bond pad typically includes the step of welding copper wire and / or copper ribbon to the second main surface of the copper foil.

[0092] The step of heating a sinterable film to connect a bonding pad to a die typically involves sintering the sinterable film, thereby forming a metallic joint between the bonding pad and the die.

[0093] The heating step is preferably performed at a temperature of 200 to 300°C, more preferably 220 to 280°C, and even more preferably 240 to 260°C. Higher temperatures may cause damage to the die or the substrate to which the die is attached. Lower temperatures may result in improper sintering of the sinterable film, which may cause weak joints.

[0094] The heating step is preferably performed under a pressure of 2 to 20 MPa, more preferably 5 to 15 MPa, even more preferably 8 to 12 MPa, and even more preferably 10 MPa. Higher pressure may cause damage to the die or the substrate to which it is attached. Lower pressure may result in improper sintering of the sinterable film, which may cause weak joints.

[0095] The heating step is preferably performed for 10 to 180 seconds, more preferably 30 to 120 seconds, even more preferably 50 to 100 seconds, and even more preferably 60 to 90 seconds. Longer times may be unnecessary and may not result in a higher level of adhesion. Shorter times may result in improper sintering of the sinterable film, which may cause weak joints.

[0096] The die preferably comprises a metallized surface, more preferably silver, gold and / or palladium, and the step of contacting a sinterable film of a bond pad with the die comprises contacting the sinterable film of the bond pad with the metallized surface of the die. This may result in a strong joint.

[0097] The step of contacting the sinterable film of the bond pad with the die preferably comprises the step of preheating the die to a temperature of 130 to 180°C, and the step of contacting the preheated die with the sinterable film with a force of 50 to 150 N, more preferably 70 to 130 N, more preferably 80 to 100 N, and even more preferably about 90 N and / or a batch time of 100 to 2000 ms, more preferably 200 to 1000 ms. The application of such heat and pressure can promote limited metallic diffusion between the sinterable film and the die, thereby allowing the bond pad to be fixed to the die (so-called "thermal bonding"). Thus, the bond pad can be fixed in a desired position during the method.

[0098] Preferably, the die comprises an adhesive on its surface; the step of contacting the sinterable film of the bond pad with the die comprises contacting the sinterable film of the bond pad with the adhesive; and the step of contacting the sinterable film of the bond pad with the die is performed using a pick-and-place tool preheated to 50 to 90°C. The adhesive can fix the bond pad in a desired position during the method (so-called "low-temperature adhesion"). This can be achieved at a lower temperature than "thermal adhesion" (e.g., room temperature), which may be advantageous if the die and / or the substrate to which it is attached could be damaged at higher temperatures. Typically, the adhesive will exhibit "adhesion" at the temperature of the pick-and-place machine. The placement time can be as short as, for example, 50 to 100 milliseconds, which can enable a high production speed.

[0099] In a further aspect, the present application provides a method for manufacturing an electronic device comprising the step of connecting a die to a copper wire and / or copper ribbon according to the method described herein.

[0100] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0101] In a further embodiment, the present invention provides an electronic device manufactured according to the method described herein.

[0102] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0103] In a further embodiment, the present invention provides an electronic device manufactured by including and / or using the bond pad described herein.

[0104] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0105] The electronic device preferably includes a power device or a power module.

[0106] The electronic device preferably further includes a substrate connected to a die through a sintered silver film.

[0107] In a further embodiment, the present invention provides a method for manufacturing a bond pad as described herein, and the method is,

[0108] Step of providing copper foil;

[0109] A step of providing a sinterable silver film as described herein;

[0110] A step of bringing a copper foil into contact with a sinterable silver film;

[0111] A step of applying heat and pressure to a copper foil and a sinterable silver film to laminate the sinterable silver film onto the copper foil to provide a laminated copper foil; and

[0112] It includes the step of punching a bond pad from a laminated copper foil.

[0113] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0114] The sinterable silver film preferably comprises a metal plating layer, and the step of contacting a copper foil with the sinterable silver film includes the step of contacting the metal plating layer with the sinterable silver film.

[0115] Preferably, the step of applying heat and pressure to the copper foil and the sinterable silver film comprises: applying a pressure of at least 0.5 MPa, preferably at least 0.8 MPa, more preferably 0.5 to 2 MPa, more preferably 0.8 to 1.2 MPa, and even more preferably about 1 MPa; and / or heating the copper foil and / or the sinterable silver film to a temperature of 100 to 200°C, preferably 120 to 170°C, more preferably 140 to 160°C, and even more preferably about 150°C, preferably for 1 to 60 seconds, more preferably 2 to 40 seconds, even more preferably 5 to 15 seconds, and even more preferably about 10 seconds.

[0116] In a further embodiment, the present invention provides an assembly method, and the method is,

[0117] A step of providing a substrate having a die on top, wherein the substrate and the die are separated by a sinterable film;

[0118] Step of providing a bond pad as described herein;

[0119] A step of bringing the bond pad into contact with the die through a sinterable film of the bond pad;

[0120] Step of sintering a sinterable film;

[0121] Step of providing copper ribbon or copper wire;

[0122] It includes the step of connecting a copper ribbon or copper wire to the die and optionally to the substrate as well.

[0123] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0124] The step of providing a bond pad preferably includes the step of providing a bond pad on a tape-and-reel assembly, and the step of contacting the bond pad with a die is preferably performed using a pick-and-place machine. The sintering step may be performed, for example, in a sintering press. Sintering conditions may include, for example, a pressure of 1 to 15 MPa (e.g., 10 MPa), a temperature of 200 to 300°C (e.g., 250°C), and a time of 1 to 180 seconds (e.g., 60 to 90 seconds).

[0125] In a further embodiment, the present invention provides a bond pad for connecting a die to a copper wire or a copper ribbon, wherein the bond pad is,

[0126] Copper foil having a metal plating layer; and

[0127] It includes a sinterable silver film described herein that is laminated onto a metal plating layer.

[0128] The advantages and desirable features of the first embodiment apply equally to this embodiment.

[0129] The present invention will now be further described with reference to the numbered clauses below.

[0130] 1. As a sinterable silver film,

[0131] Silver particles having a maximum dimension of 1 to 1000 nm,

[0132] Polymer binder, and

[0133] A sinterable silver film comprising a halogenated alcohol activator having a melting point of 80 to 150°C.

[0134] The longest dimension is measured, for example, by TEM. The particle may be in the form of, for example, a sphere, plate, or rod. If the particle is in the form of a sphere, the longest dimension is the diameter of the sphere.

[0135] 2. In Clause 1, the silver particles are a sinterable silver film having a maximum dimension of 5 to 500 nm, preferably 10 to 100 nm, more preferably 30 to 60 nm.

[0136] 3. A sinterable silver film according to Clause 1 or Clause 2, comprising 0.1 to 2 weight percent of a polymer binder, preferably 0.5 to 1 weight percent of a polymer binder, based on the total weight of the sinterable silver film.

[0137] 4. In any one of Clauses 1 to 3, the polymer binder comprises an amide polymer, preferably poly(N-vinyl acetamide), a sinterable silver film.

[0138] 5. A sinterable silver film comprising, in any one of Clauses 1 to 4, 0.05 to 1 weight% of a halogenated alcohol activator based on the total weight of the sinterable silver film, preferably 0.1 to 0.2 weight% of a halogenated alcohol activator.

[0139] 6. A sinterable silver film having a melting point of 85 to 140°C, preferably 90 to 130°C, more preferably 100 to 120°C, in any one of Clauses 1 to 5, wherein the halogenated alcohol activator has a melting point of 85 to 140°C, preferably 90 to 130°C, more preferably 100 to 120°C.

[0140] 7. A sinterable silver film having a molecular weight of at least 150, preferably at least 200, more preferably at least 300, more preferably at least 400, and even more preferably at least 500 in any one of Clauses 1 to 6, wherein the halogenated alcohol activator has a molecular weight of at least 150, preferably at least 200, more preferably at least 300, more preferably at least 400, and even more preferably at least 500.

[0141] 8. A sinterable silver film, wherein in any one of Clauses 1 to 7, the halogenated alcohol comprises a brominated alcohol.

[0142] 9. In any one of Clauses 1 to 8, the halogenated alcohol is a sinterable silver film comprising 3 to 5 carbon atoms.

[0143] 10. In any one of Clauses 1 to 9, the halogenated alcohol is a sinterable silver film that is linear or branched.

[0144] 11. A sinterable silver film, wherein in any one of Clauses 1 to 10, the halogenated alcohol comprises 3,4-dibromo-2-butanol and / or 1,4-dibromobutan-2-ol.

[0145] 12. In any one of Articles 1 through 11,

[0146] Preferably, partially hydrogenated gum rosin in an amount of 0.1 to 0.3 weight percent based on the total weight of the sinterable silver film; and / or

[0147] A sinterable silver film, preferably further comprising finely divided wax in an amount of 0.2 to 0.4 weight percent based on the total weight of the sinterable silver film.

[0148] 13. As a bond pad for connecting a die to a copper wire or copper ribbon,

[0149] copper foil,

[0150] A sinterable silver film of any one of Clauses 1 to 12, laminated to a copper foil, and

[0151] A bond pad comprising a metal plating layer optionally sandwiched between a copper foil and a sinterable silver film.

[0152] 14. In Clause 13, the copper foil is a bond pad comprising copper or a copper alloy and / or a multilayer structure.

[0153] 15. In Clause 13 or Clause 14, the copper foil has a thickness of 10 to 200 μm, preferably 50 to 150 μm, a bond pad.

[0154] 16. In any one of Clauses 13 to 15, the copper foil is a bond pad having a hardness Hv of 50 to 100.

[0155] 17. In any one of Clauses 13 to 16, the copper foil is a bond pad having a coefficient of thermal expansion (CTE) of 10 to 20 ppm.

[0156] 18. In any one of Clauses 13 through 17, the copper foil is perforated, forming a bond pad.

[0157] 19. In any one of Clauses 13 to 18, the metal plating layer comprises silver, a nickel-gold alloy, and / or ENIG (electroless nickel immersion gold), a bond pad.

[0158] 20. A bond pad, wherein, in any one of clauses 13 to 19, the metal plating layer has a thickness of 1 to 5 μm.

[0159] 21. A bond pad comprising, in any one of Clauses 13 to 20, an adhesive further comprising on the outer surface of a sinterable silver film.

[0160] 22. In Clause 21, the adhesive is,

[0161] Preferably, a diphenyl compound having a melting point of 50 to 90°C; and / or

[0162] Preferably, a triphenyl compound having a melting point of 50 to 90°C; and / or

[0163] A bond pad comprising a fatty alcohol having a melting point preferably of 30 to 60°C.

[0164] 23. In Clause 21 or Clause 22, the adhesive is a bond pad comprising polyvinyl ether.

[0165] 24. As a method for connecting a die to copper wire and / or copper ribbon,

[0166] Step of providing the die,

[0167] Step of providing a bond pad of any one of Clauses 13 to 23,

[0168] A step of bringing the sinterable silver film of the bond pad into contact with the die,

[0169] A step of heating a sinterable silver film to connect a bonding pad to a die, and

[0170] A method comprising the step of welding copper wire and / or copper ribbon to copper foil of a bond pad.

[0171] 25. In Clause 24, the welding step comprises ultrasonic and / or laser welding.

[0172] 26. A method according to Clause 24 or Clause 25, wherein the heating step is performed at a temperature of 200 to 300°C, preferably 220 to 280°C, more preferably 240 to 260°C.

[0173] 27. A method in which, in any one of provisions 24 to 26, the heating step is performed under a pressure of 2 to 20 MPa, preferably 5 to 15 MPa, more preferably 8 to 12 MPa, and more preferably about 10 MPa.

[0174] 28. A method in which, in any one of provisions 24 to 27, the heating step is performed for 10 to 180 seconds, preferably 30 to 120 seconds, more preferably 50 to 100 seconds, and more preferably 60 to 90 seconds.

[0175] 29. A method wherein, in any one of clauses 24 to 28, the die preferably comprises a metallized surface comprising silver, gold and / or palladium, and the step of contacting a sinterable silver film of a bond pad with the die comprises the step of contacting a sinterable silver film of a bond pad with the metallized surface of the die.

[0176] 30. In any one of Clauses 24 to 29, the step of contacting the sinterable silver film of the bond pad with the die is

[0177] A step of preheating the die to a temperature of 130 to 180°C, and

[0178] A method comprising the step of contacting a preheated die with a sinterable silver film with a force of 50 to 150 N, preferably 70 to 130 N, more preferably 80 to 100 N, more preferably about 90 N and / or a batch time of 100 to 2000 ms, preferably 200 to 1000 ms.

[0179] 31. A method in which, in any one of clauses 24 to 30, the step of contacting the sinterable silver film of the bond pad with the die is performed using a pick-and-place tool preheated to 50 to 90°C.

[0180] 32. A method in any one of clauses 24 to 31, wherein the die comprises an adhesive on its surface, and the step of contacting a sinterable silver film of a bond pad with the die comprises the step of contacting the sinterable silver film of the bond pad with the adhesive.

[0181] 33. A method for manufacturing an electronic device comprising the step of connecting a die to a copper wire and / or copper ribbon according to any one of the methods of Clauses 24 to 32.

[0182] 34. Electronic device manufactured in accordance with Clause 33.

[0183] 35. An electronic device comprising and / or manufactured using any one of the bond pads of Clauses 13 through 23.

[0184] 36. In Clause 34 or Clause 35, the electronic device is an electronic device comprising a power device or a power module.

[0185] 37. In any one of Articles 34 through 36,

[0186] Copper wire or copper ribbon welded to copper foil; and

[0187] An electronic device further comprising a substrate connected to a die through a sintered silver film.

[0188] 38. A method for manufacturing a bond pad according to any one of Clauses 13 to 23,

[0189] Step of providing copper foil;

[0190] A step of providing a sinterable silver film;

[0191] A step of bringing a copper foil into contact with a sinterable silver film;

[0192] A step of applying heat and pressure to a copper foil and a sinterable silver film to laminate the sinterable silver film onto the copper foil to provide a laminated copper foil; and

[0193] The method includes the step of punching a bond pad from a laminated copper foil, and

[0194] Sinterable silver films are,

[0195] Silver particles having a maximum dimension of 1 to 1000 nm,

[0196] Polymer binder, and

[0197] A method comprising a halogenated alcohol activator having a melting point of 80 to 150°C.

[0198] 39. In Clause 38, the sinterable silver film comprises a metal plating layer, and the step of contacting a copper foil with the sinterable silver film comprises the step of contacting the metal plating layer with the sinterable silver film.

[0199] 40. In Clause 38 or Clause 39, the step of applying heat and pressure to the copper foil and the sinterable silver film is,

[0200] A step of applying a pressure of at least 0.5 MPa, preferably at least 0.8 MPa, more preferably 0.5 to 2 MPa, even more preferably 0.8 to 1.2 MPa, and even more preferably about 1 MPa; and / or

[0201] Copper foil and / or sinterable silver film to a temperature of 100 to 200°C, preferably 120 to 170°C, more preferably 140 to 160°C, and even more preferably about 150°C,

[0202] A method comprising the step of heating for preferably 1 to 60 seconds, more preferably 2 to 40 seconds, even more preferably 5 to 15 seconds, and even more preferably about 10 seconds. Brief explanation of the drawing

[0203] The present invention will now be further described with reference to the following drawings. FIG. 1 is a schematic diagram of a bond pad according to the present invention. FIG. 2 is a schematic diagram of an electronic device according to the present invention. Figure 3 is a photograph of an electronic device according to the present invention. Referring to FIG. 1, a bond pad (generally (1)) according to the present invention is illustrated. The bond pad comprises a copper foil (2) having a plating layer (3) on its surface. A sinterable silver film (4) is laminated onto the copper foil (2) through the plating layer (3). An adhesive (5) is placed on the outer surface of the sinterable silver film (4). Referring to FIG. 2, an electronic device (generally (6)) according to the present invention is illustrated. A bond pad (1) according to the present invention is attached to a die (7) through a sinterable silver film (not shown) of the bond pad. The die (7) is attached to a substrate (9) through a sinterable silver film (8). The substrate comprises a ceramic core (10) and a copper surface layer (11). A copper wire (12) is welded to the top of the bond pad (1) and the copper surface layer (11). Specific details for implementing the invention

[0204] The present invention will now be further explained with reference to the following examples.

[0205] Examples

[0206] An electronic device was manufactured according to the following method. A substrate having a die on top was provided, and the substrate and the die were separated by a sinterable film. A bond pad with a thickness of 50 μm was manufactured, comprising a metal-plated hard copper foil laminated with a sinterable silver film on top. The bond pad was placed on top of the die through the sinterable film. The resulting blank was transferred to an oven, where the sinterable film was sintered to form metallic joints between the bond pad and the top of the die, and between the die and the substrate. A copper ribbon was ultrasonically welded to the top of the board pad. The result is shown in Fig. 3, where the bond pad is labeled 13, the die 14, the substrate 15, and the copper ribbon 16.

[0207] The same electronic device was manufactured, but the copper foil here contains soft copper.

[0208] The connection between the bond pad and the copper ribbon of both devices was subjected to shear testing using industrially acceptable shear tests as described in Technical Bulletin DVS 2811. The results are as follows:

[0209]

[0210] In both cases, the shear strength was excellent and significantly exceeded the recommended values. The failure mode was between the copper ribbon and the pad, as recommended by the standard.

[0211] The foregoing detailed description is provided for illustrative and illustrative purposes only and is not intended to limit the scope of the appended claims. Many variations of the presently preferred embodiments exemplified herein will be apparent to those skilled in the art and are maintained within the scope of the appended claims and their equivalents.

Claims

Claim 1 A method for manufacturing a bond pad for connecting a die to a copper ribbon or copper wire, comprising the steps of: providing a sheet of copper foil having a first main surface opposite to a second main surface; providing a sinterable film of metal particles; laminating the first main surface with the sinterable film to form a laminated sheet; and punching a bond pad from the laminated sheet. Claim 2 A method according to claim 1, wherein the copper foil comprises copper or a copper alloy and / or is a multilayer structure. Claim 3 The method according to claim 1 or 2, wherein the copper foil has a thickness of 10 to 200 μm, preferably 50 to 150 μm; a hardness Hv of 50 to 100; and / or a coefficient of thermal expansion (CTE) of 10 to 20 ppm. Claim 4 A method in which, in any one of paragraphs 1 to 3, the copper foil is perforated. Claim 5 A method according to any one of claims 1 to 4, wherein the sinterable film comprises silver particles having a maximum dimension of 1 to 1000 nm and a polymer binder. Claim 6 In claim 5, the sinterable film comprises 0.1 to 2 weight percent of a polymer binder, preferably 0.5 to 1 weight percent of a polymer binder, based on the total weight of the sinterable silver film. Claim 7 A method according to claim 5 or 6, wherein the polymer binder comprises an amide polymer, preferably poly(N-vinyl acetamide). Claim 8 A method according to any one of claims 5 to 7, wherein the silver particles have a maximum dimension of 5 to 500 nm, preferably 10 to 100 nm, more preferably 30 to 60 nm. Claim 9 A method according to any one of claims 5 to 8, wherein the silver particles in the sinterable film form fine particles, and the fine particles have D90 of 1000 nm or less, preferably 500 nm or less, more preferably 100 nm or less, more preferably 60 nm or less; and / or D10 of 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, more preferably 30 nm or more. Claim 10 A method according to any one of claims 1 to 9, wherein the sinterable film comprises 90 to 99 weight% of silver particles, preferably 92 to 98 weight% of silver particles, more preferably 94 to 96 weight% of silver particles, based on the total weight of the sinterable film. Claim 11 A method according to any one of claims 1 to 10, wherein the sinterable film comprises a halogenated alcohol activator having a melting point of 80 to 150°C. Claim 12 A method according to claim 11, wherein the sinterable film comprises 0.05 to 1 weight% of a halogenated alcohol activator, preferably 0.1 to 0.2 weight% of a halogenated alcohol activator, based on the total weight of the sinterable film. Claim 13 A method according to claim 11 or 12, wherein the halogenated alcohol activator has a melting point of 85 to 140°C, preferably 90 to 130°C, more preferably 100 to 120°C. Claim 14 A method according to any one of claims 11 to 13, wherein the halogenated alcohol activator has a molecular weight of at least 150, preferably at least 200; and / or 500 or less, preferably 400 or less, more preferably 300 or less; and / or 150 to 500, preferably 200 to 300. Claim 15 A method according to any one of claims 11 to 14, wherein the halogenated alcohol comprises a brominated alcohol. Claim 16 A method according to any one of claims 11 to 15, wherein the halogenated alcohol comprises a dibrominated alcohol. Claim 17 A method according to any one of claims 11 to 16, wherein the halogenated alcohol comprises 3 to 5 carbon atoms. Claim 18 A method according to any one of claims 11 to 17, wherein the halogenated alcohol comprises a monohydroxy alcohol. Claim 19 A method according to any one of claims 11 to 18, wherein the halogenated alcohol comprises 3,4-dibromo-2-butanol and / or 1,4-dibromobutan-2-ol. Claim 20 A method according to any one of claims 11 to 19, further comprising: partially hydrogenated gum rosin in an amount of 0.1 to 0.3 weight percent based on the total weight of the sinterable silver film; and / or preferably micronized wax in an amount of 0.2 to 0.4 weight percent based on the total weight of the sinterable silver film. Claim 21 A method according to any one of claims 1 to 20, wherein the step of laminating the first main surface with the sinterable film comprises: the step of bringing the sinterable film into contact with the first surface; and the step of applying heat and pressure to the sheet of copper foil and the sinterable film. Claim 22 A method according to claim 21, wherein the first surface comprises a metal plating layer, and the step of contacting the sinterable film with the first surface comprises the step of contacting the metal plating layer with the sinterable silver film. Claim 23 In claim 22, the method wherein the metal plating layer comprises silver, a nickel-gold alloy, and / or ENIG (electroless nickel immersion gold). Claim 24 A method according to any one of claims 21 to 23, wherein the metal plating layer has a thickness of 1 to 5 μm. Claim 25 A method according to any one of claims 21 to 24, wherein the step of applying heat and pressure to the sheet of copper foil and the sinterable film comprises: applying a pressure of at least 0.5 MPa, preferably at least 0.8 MPa, more preferably 0.5 to 2 MPa, more preferably 0.8 to 1.2 MPa, and even more preferably about 1 MPa; and / or heating the sheet of copper foil and / or the sinterable film to a temperature of 100 to 200°C, preferably 120 to 170°C, more preferably 140 to 160°C, and even more preferably about 150°C, preferably for 1 to 60 seconds, more preferably 2 to 40 seconds, even more preferably 5 to 15 seconds, and even more preferably about 10 seconds. Claim 26 A method according to any one of claims 1 to 25, further comprising the step of applying an adhesive to a sinterable film on the laminated sheet, wherein the punching is performed such that the adhesive is present on the sinterable film on the bond pad. Claim 27 In claim 26, the adhesive comprises: a diphenyl compound having a melting point of 50 to 90°C; a triphenyl compound having a melting point of 50 to 90°C; and / or a fatty alcohol having a melting point of 30 to 60°C. Claim 28 A method according to claim 26 or 27, wherein the adhesive comprises polyvinyl ether. Claim 29 A bond pad manufactured according to the method of any one of claims 1 to 28. Claim 30 A sinterable silver film comprising silver particles having a maximum dimension of 1 to 1000 nm, a polymer binder, and a halogenated alcohol activator having a melting point of 80 to 150°C. Claim 31 In claim 30, the silver particles are a sinterable silver film having a maximum dimension of 5 to 500 nm, preferably 10 to 100 nm, more preferably 30 to 60 nm. Claim 32 A sinterable silver film according to claim 30 or 31, wherein the silver particles of the sinterable silver film form fine particles, and the fine particles have D90 of 1000 nm or less, preferably 500 nm or less, more preferably 100 nm or less, more preferably 60 nm or less; and / or D10 of 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, more preferably 30 nm or more. Claim 33 A sinterable silver film according to any one of claims 30 to 32, comprising 90 to 99 weight% of silver metal particles, preferably 92 to 98 weight% of silver metal particles, more preferably 94 to 96 weight% of silver metal particles based on the total weight of the sinterable film. Claim 34 A sinterable silver film according to any one of claims 30 to 33, comprising 0.1 to 2 weight percent of a polymer binder, preferably 0.5 to 1 weight percent of a polymer binder, based on the total weight of the sinterable silver film. Claim 35 A sinterable silver film according to any one of claims 30 to 34, wherein the polymer binder comprises an amide polymer, preferably poly(N-vinyl acetamide). Claim 36 A sinterable silver film according to any one of claims 30 to 35, comprising 0.05 to 1 weight% of a halogenated alcohol activator, preferably 0.1 to 0.2 weight% of a halogenated alcohol activator, based on the total weight of the sinterable silver film. Claim 37 A sinterable silver film according to any one of claims 30 to 36, wherein the halogenated alcohol activator has a melting point of 85 to 140°C, preferably 90 to 130°C, more preferably 100 to 120°C. Claim 38 A sinterable silver film according to any one of claims 30 to 37, wherein the halogenated alcohol activator has a molecular weight of at least 150, preferably at least 200; and / or 500 or less, preferably 400 or less, more preferably 300 or less; and / or 150 to 500, preferably 200 to 300. Claim 39 A sinterable silver film according to any one of claims 30 to 38, wherein the halogenated alcohol comprises a brominated alcohol. Claim 40 In claim 39, the halogenated alcohol comprises a dibrominated alcohol, a sinterable film. Claim 41 A sinterable silver film according to any one of claims 30 to 40, wherein the halogenated alcohol comprises 3 to 5 carbon atoms. Claim 42 A sinterable silver film according to any one of claims 30 to 41, wherein the halogenated alcohol comprises a monohydroxy alcohol. Claim 43 A sinterable silver film according to any one of claims 30 to 42, wherein the halogenated alcohol comprises 3,4-dibromo-2-butanol and / or 1,4-dibromobutan-2-ol. Claim 44 A sinterable silver film according to any one of claims 30 to 43, further comprising: partially hydrogenated gum rosin in an amount of 0.1 to 0.3 weight percent based on the total weight of the sinterable silver film; and / or preferably finely pulverized wax in an amount of 0.2 to 0.4 weight percent based on the total weight of the sinterable silver film. Claim 45 A bond pad for connecting a die to a copper wire or copper ribbon, comprising a copper foil, a sinterable silver film of any one of claims 30 to 44 laminated on the copper foil, and optionally a metal plating layer sandwiched between the copper foil and the sinterable silver film. Claim 46 In paragraph 45, the copper foil comprises copper or a copper alloy and / or is a bond pad having a multilayer structure. Claim 47 A bond pad according to claim 45 or 46, wherein the copper foil has a thickness of 10 to 200 μm, preferably 50 to 150 μm. Claim 48 A bond pad according to any one of claims 45 to 47, wherein the copper foil has a hardness Hv of 50 to 100. Claim 49 A bond pad according to any one of claims 45 to 48, wherein the copper foil has a coefficient of thermal expansion (CTE) of 10 to 20 ppm. Claim 50 In any one of paragraphs 45 to 49, the copper foil is a perforated bond pad. Claim 51 A bond pad according to any one of claims 45 to 50, wherein the metal plating layer comprises silver, a nickel-gold alloy, and / or ENIG (electroless nickel immersion gold). Claim 52 A bond pad according to any one of claims 45 to 51, wherein the metal plating layer has a thickness of 1 to 5 μm. Claim 53 A bond pad according to any one of claims 45 to 52, further comprising an adhesive on the outer surface of the sinterable silver film. Claim 54 A bond pad according to claim 53, wherein the adhesive comprises: a diphenyl compound having a melting point of 50 to 90°C; a triphenyl compound having a melting point of 50 to 90°C; and / or a fatty alcohol having a melting point of 30 to 60°C. Claim 55 In paragraph 53 or 54, the adhesive comprises a bond pad containing polyvinyl ether. Claim 56 A method for connecting a die to a copper wire and / or copper ribbon, comprising the steps of: providing a die; providing a bond pad according to any one of claims 29, 45 to 55; bringing a sinterable film of the bond pad into contact with the die; heating the sinterable film to connect the bonding pad to the die; and welding a copper wire and / or copper ribbon to a copper foil of the bond pad. Claim 57 In paragraph 56, the welding step comprises ultrasonic welding and / or laser welding. Claim 58 A method according to claim 56 or 57, wherein the heating step is performed at a temperature of 200 to 300°C, preferably 220 to 280°C, more preferably 240 to 260°C. Claim 59 A method according to any one of claims 56 to 58, wherein the heating step is performed under a pressure of 2 to 20 MPa, preferably 5 to 15 MPa, more preferably 8 to 12 MPa, and more preferably about 10 MPa. Claim 60 A method according to any one of claims 56 to 59, wherein the heating step is performed for 10 to 180 seconds, preferably 30 to 120 seconds, more preferably 50 to 100 seconds, and more preferably 60 to 90 seconds. Claim 61 A method according to any one of claims 56 to 60, wherein the die preferably comprises a metallized surface comprising silver, gold and / or palladium, and the step of contacting a sinterable film of the bond pad with the die comprises the step of contacting the sinterable film of the bond pad with the metallized surface of the die. Claim 62 A method according to any one of claims 56 to 61, wherein the step of contacting the sinterable film of the bond pad with the die comprises: preheating the die to a temperature of 130 to 180°C; and contacting the preheated die with the sinterable film with a force of 50 to 150 N, preferably 70 to 130 N, more preferably 80 to 100 N, more preferably about 90 N and / or a batch time of 100 to 2000 ms, preferably 200 to 1000 ms. Claim 63 A method according to any one of claims 56 to 62, wherein the die comprises an adhesive on its surface; the step of contacting the sinterable film of the bond pad with the die comprises the step of contacting the sinterable film of the bond pad with the adhesive; and the step of contacting the sinterable film of the bond pad with the die is performed using a pick-and-place tool preheated to 50 to 90°C. Claim 64 A method for manufacturing an electronic device comprising the step of connecting a die to a copper wire and / or copper ribbon according to the method of any one of claims 56 to 63. Claim 65 Electronic device manufactured in accordance with Paragraph 64. Claim 66 An electronic device comprising and / or manufactured using a bond pad according to any one of paragraphs 29, 45 through 55. Claim 67 In paragraph 65 or 66, the electronic device is an electronic device comprising a power device or a power module. Claim 68 An electronic device according to any one of claims 65 to 67, further comprising a substrate connected to the die through a sintered silver film. Claim 69 A method for manufacturing a bond pad according to any one of claims 45 to 55, comprising: providing a copper foil; providing a sinterable silver film according to any one of claims 30 to 44; bringing the copper foil into contact with the sinterable silver film; applying heat and pressure to the copper foil and the sinterable silver film to laminate the sinterable silver film onto the copper foil to provide a laminated copper foil; and punching a bond pad from the laminated copper foil. Claim 70 In claim 69, the sinterable silver film comprises a metal plating layer, and the step of contacting the copper foil with the sinterable silver film comprises the step of contacting the metal plating layer with the sinterable silver film. Claim 71 The method according to claim 69 or 70, wherein the step of applying heat and pressure to the copper foil and the sinterable silver film comprises: applying a pressure of at least 0.5 MPa, preferably at least 0.8 MPa, more preferably 0.5 to 2 MPa, more preferably 0.8 to 1.2 MPa, and even more preferably about 1 MPa; and / or heating the copper foil and / or the sinterable silver film to a temperature of 100 to 200°C, preferably 120 to 170°C, more preferably 140 to 160°C, and even more preferably about 150°C, preferably for 1 to 60 seconds, more preferably 2 to 40 seconds, even more preferably 5 to 15 seconds, and even more preferably about 10 seconds. Claim 72 A method of assembly comprising the steps of: providing a substrate having a die on top, wherein the substrate and the die are separated by a sinterable film; providing a bond pad according to any one of claims 29, 45 to 55; bringing the bond pad into contact with the die through the sinterable film of the bond pad; sintering the sinterable film; providing a copper ribbon or a copper wire; and connecting the copper ribbon or a copper wire to the die and optionally also to the substrate. Claim 73 In paragraph 72, the step of providing the bond pad comprises the step of providing the bond pad on a tape-and-reel assembly, and the step of bringing the bond pad into contact with the die is performed using a pick-and-place machine.

Images