JP2011198991A - Method for manufacturing electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for performing electric connection with excellent productivity between electrode terminals having a step.SOLUTION: The method includes a base film formation step of arranging a semiconductor element 4, where a first electrode 5 is formed on a substrate 2 with a second electrode 6 formed thereon; arranging a functional fluid so as to connect the first electrode 5 to the second electrode 6; then solidifying the functional fluid so as to form a base film 8; and conducting a chemical plating step of forming a metal film 9 on the base film 8 by chemical plating processing. The functional fluid contains a resin and a metal catalyst.

Description

  The present invention relates to an electronic device manufacturing method, and more particularly to a method of forming wiring between electrodes at a stepped place.

  When an electronic component such as a semiconductor chip is mounted on a substrate, a wire bonding method is widely used. However, the wire bonding method applies mechanical stress to the electronic component, and the connection reliability decreases as the wire becomes longer. Furthermore, productivity decreases when the number of connection terminals is large. A method for solving these problems is disclosed in Patent Document 1. According to this, the semiconductor chip is fixed to the substrate, and the resin material is applied and cured from the side surface of the semiconductor chip to the substrate to form a slope.

  Thereby, a slope is arranged between the electrode terminal on the semiconductor chip and the wiring pattern on the substrate. Then, a metal ink in which silver fine particles are dispersed in a dispersion medium is discharged as droplets from the electrode terminal to the wiring pattern to draw the wiring. Next, the metal ink ejected onto the substrate is baked to form the metal wiring that electrically connects the electrode terminal and the wiring pattern.

JP 2006-147650 A

  In the step of forming the slope, a step of applying a resin material and a step of curing are necessary. And in the process of forming metal wiring, the process of drawing the pattern corresponding to the metal wiring corresponding to each electrode terminal, and the process of baking metal ink and forming metal wiring are needed. Therefore, a method of electrically connecting the electrode terminal and the wiring pattern with high productivity has been desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A method of manufacturing an electronic device according to this application example, wherein an electronic element in which a first electrode is formed is disposed on a substrate on which a second electrode is formed, and the first electrode and the second electrode are connected to each other. A base film forming step of solidifying the functional liquid after disposing the functional liquid to form a base film, and a chemical plating step of forming a metal film on the base film by chemical plating, The functional liquid contains a resin and a metal catalyst.

  According to this method for manufacturing an electronic device, the functional liquid contains a resin and a metal catalyst. Since the functional liquid contains a resin, the functional liquid can be solidified. In the process of solidifying the functional liquid, the metal catalyst is lined up on the surface of the resin. In the chemical plating process, a metal film is formed with the metal catalyst arranged on the surface of the resin as a nucleus. As a result, a metal film is formed on the surface of the base film. Since the base film is disposed so as to connect the first electrode and the second electrode, the metal film can electrically connect the first electrode and the second electrode.

  When the electronic element is disposed on the base material, the electronic element has a thickness, so that a step is generated between the first electrode and the second electrode. Therefore, there is a method of disposing a metal film material between the first electrode and the second electrode after forming a slope between the electronic element and the substrate. This method requires a step of applying and solidifying a material for forming a slope and a step of forming a metal film and connecting the first electrode and the second electrode. When the metal film is formed on the inclined surface, drawing is performed using metal ink in which metal particles are dispersed in a dispersion medium at a place where the metal film is formed. In this drawing, the metal ink is arranged with high precision so that the metal particles are not biased, so that it takes time to draw the metal ink. In this application example, the base film is formed by drawing using a functional liquid that is easy to draw in the base film forming step. Then, after connecting the first electrode and the second electrode, in the chemical plating step, a metal film is formed on the base film by chemical plating. Even when there are a plurality of base films, a metal film can be formed simultaneously by a single chemical plating process. Therefore, the first electrode and the second electrode can be electrically connected with high productivity.

[Application Example 2]
In the electronic device manufacturing method according to the application example, the functional liquid further includes a leveling agent.

  According to this method for manufacturing an electronic device, the functional liquid contains the leveling agent. When the leveling agent acts on the functional liquid, the metal catalyst is uniformly distributed on the surface of the base film. Since the metal film is formed using the metal catalyst as a nucleus, the metal film is uniformly formed on the surface of the base film. Therefore, the dispersion of the film thickness of the metal film formed on the base film can be reduced.

[Application Example 3]
In the method for manufacturing an electronic device according to the application example, the metal catalyst is a silane coupling agent having a functional group containing a metal, and in the base film forming step, the functional liquid is solidified by heating or light irradiation. It is characterized by.

  According to this method of manufacturing an electronic device, since the metal catalyst is a silane coupling agent having a functional group containing a metal, the metal can be easily arranged on the surface of the functional liquid. Then, when heating or irradiating light to solidify the functional liquid, the metal is reduced from an ionic state to a metallic state. Therefore, the metal can be arranged on the surface of the base film.

[Application Example 4]
In the manufacturing method of the electronic device according to the application example, in the base film forming step, the functional liquid is arranged and solidified, and the functional liquid is arranged and solidified on the solidified functional liquid. Features.

  According to this method for manufacturing an electronic device, a plurality of functional liquids are arranged and solidified in the same place. That is, a solidified resin is formed, and the functional liquid is disposed and solidified on the resin. Thereby, the shape of resin can be formed thickly. Therefore, even when the thickness of the electronic element is large, the base film can be disposed so as to connect the first electrode and the second electrode.

[Application Example 5]
In the electronic device manufacturing method according to the application example, the functional liquid includes a photopolymerization initiator, and the functional liquid is solidified by irradiation with light.

  According to this method for manufacturing an electronic device, since the functional liquid contains a photopolymerization initiator, the liquid resin material can be solidified or gelled in a short time by irradiating the functional liquid with light. Therefore, when a plurality of functional liquids are arranged and solidified, they can be performed in a short time, so that the base film can be formed with high productivity.

FIG. 2A is a schematic perspective view showing the structure of an electronic device according to the first embodiment, and FIG. (A) is a schematic perspective view which shows the structure of a droplet discharge apparatus, (b) is a principal part schematic cross section which shows the structure of a droplet discharge head, (c) is a flowchart which shows the manufacturing process of an electronic device. The schematic diagram for demonstrating the process of manufacturing an electronic device. The schematic diagram for demonstrating the process of manufacturing an electronic device. In connection with the second embodiment, (a) is a schematic perspective view showing a structure of an electronic device, and (b) and (c) are schematic diagrams for explaining a process of manufacturing the electronic device. In relation to the third embodiment, (a) is a schematic side view showing a carriage, (b) is a schematic plan view showing the carriage, and (c) to (f) are for explaining steps of manufacturing an electronic device. FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In addition, each member in each drawing is illustrated with a different scale for each member in order to make the size recognizable on each drawing.

(First embodiment)
In this embodiment, first, an electronic device and a droplet discharge device will be described. Next, an example of a method of manufacturing an electronic device that is characteristic of the present invention using this droplet discharge device will be described with reference to FIGS. There are various types of droplet discharge devices, but a device using an ink jet method is preferable. The ink jet method is suitable for microfabrication because it can eject fine droplets.

(Electronic device)
FIG. 1A is a schematic perspective view showing the structure of an electronic device. First, the electronic device 1 will be described with reference to FIG. The electronic device 1 includes a substrate 2 as a square plate-like base material. The substrate 2 may be an insulating plate or sheet, such as a resin plate such as polypropylene, polyimide, or polyester, or a paper phenol substrate, a paper epoxy substrate, a glass composite substrate, or a glass epoxy substrate mixed with a resin and an insulating material. Etc. can be used. The substrate 2 is not limited to a rigid body and may be a flexible sheet. In this embodiment, for example, a polypropylene plate is adopted.

  A plurality of wirings 3 are formed radially on the substrate 2. A semiconductor element 4 as an electronic element is disposed at the center of the upper surface of the substrate 2, and the substrate 2 and the semiconductor element 4 are fixed by an adhesive. The upper surface of the semiconductor element 4 is an active surface 4a on which an electronic circuit made of a semiconductor is formed. A first electrode 5 is formed on the active surface 4 a along the outer periphery of the semiconductor element 4. The first electrode 5 is electrically connected to an electronic circuit and serves as a terminal for inputting and outputting electrical signals.

A portion other than the first electrode 5 on the active surface 4a is covered and protected by a passivation film. This passivation film is made of an electrically insulating material, and is formed of, for example, polyimide resin, silicone-modified polyimide resin, epoxy resin, silicone-modified epoxy resin, acrylic resin, phenol resin, BCB (benzocyclobutene), PBO (polybenzoxole), or the like. Is done. Alternatively, it can be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). In this embodiment, it is formed using a polyimide resin.

  A second electrode 6 is formed at one end of each wiring 3, and the second electrode 6 is disposed along the outer periphery of the semiconductor element 4. The pair of first electrode 5 and second electrode 6 are located at positions facing each other across a step, and the first electrode 5 and second electrode 6 are electrically connected by a resin wiring 7. FIG. 1B is a schematic cross-sectional view of a main part showing a resin wiring, and is a view cut along A-A ′ of FIG. As shown in FIG. 1B, the resin wiring 7 is composed of a base film 8 and a metal film 9 formed on the surface of the base film 8.

  The base film 8 is disposed between the first electrode 5 and the second electrode 6, and is disposed so as to connect the first electrode 5 and the second electrode 6. The metal film 9 is disposed so as to cover the surface of the base film 8, the first electrode 5, and the second electrode 6. Therefore, the metal film 9 electrically connects the first electrode 5 and the second electrode 6.

(Droplet discharge device)
FIG. 2A is a schematic perspective view showing the configuration of the droplet discharge device. A functional liquid containing a material constituting the base film 8 is discharged and applied by the droplet discharge device 12. As shown in FIG. 2A, the droplet discharge device 12 includes a base 13 formed in a rectangular parallelepiped shape. The longitudinal direction of the base 13 is the Y direction, and the direction orthogonal to the Y direction in the horizontal plane is the X direction. The vertical direction is the Z direction.

  A pair of guide rails 14 extending in the Y direction are provided on the base 13 so as to protrude over the entire width in the Y direction. On the upper side of the base 13, a stage 15 is attached as a moving unit having a linear motion mechanism (not shown) corresponding to the pair of guide rails 14. For this linear motion mechanism, for example, a linear motor is used.

  A suction-type substrate chuck mechanism is provided on the upper surface of the stage 15. An operator places the placement guide plate 16 on the stage 15 and positions it at a predetermined position. Thereafter, the placement guide plate 16 is fixed to the stage 15 by the substrate chuck mechanism. Fifteen substrates 2 are arranged and arranged on the placement guide plate 16. A plurality of recesses having the same shape as the outer shape of the substrate 2 are formed in the mounting guide plate 16. And the board | substrate 2 is being fixed to each recessed part.

  A gate-shaped support base 17 is erected so as to straddle the X direction of the base 13, and a guide rail 18 extending in the X direction is installed under the support base 17 over the entire width in the X direction. A carriage 19 that moves along the guide rail 18 is arranged. The carriage 19 includes a linear motion mechanism similar to the stage 15. A head unit 20 is disposed on the stage 15 side of the carriage 19, and a droplet discharge head (not shown) that discharges droplets is provided below the head unit 20.

  A pair of lifting devices 21 are arranged in the X direction of the head unit 20 so as to sandwich the head unit 20. The elevating device 21 includes a linear motion mechanism and has a function of elevating the head unit 20 with respect to the carriage 19. Although the linear motion mechanism of the raising / lowering apparatus 21 is not specifically limited, For example, the apparatus which combined the pulse motor and the ball screw can be used.

  A storage tank 22 is installed on the upper side of the carriage 19 in the drawing. The droplet discharge head of the head unit 20 and the storage tank 22 are connected by a tube (not shown), and the functional liquid in the storage tank 22 is supplied to the droplet discharge head via the tube.

  FIG. 2B is a schematic cross-sectional view of the main part showing the structure of the droplet discharge head. As shown in FIG. 2B, the droplet discharge head 23 includes a nozzle plate 25 in which nozzles 24 are formed. A cavity 26 is formed at a position above the nozzle plate 25 and facing the nozzle 24. The functional liquid 27 stored in the storage tank 22 is supplied to the cavity 26. Above the cavity 26, a vibration plate 28 that vibrates in the vertical direction and expands and contracts the volume in the cavity 26, and a piezoelectric element 29 that expands and contracts in the vertical direction and vibrates the vibration plate 28 are disposed.

  When the droplet discharge head 23 receives a nozzle drive signal for controlling and driving the piezoelectric element 29, the piezoelectric element 29 expands and contracts in the vertical direction. Since the piezoelectric element 29 vibrates the diaphragm 28, the volume of the cavity 26 adjacent to the diaphragm 28 is enlarged or reduced. As a result, the functional liquid corresponding to the reduced volume of the functional liquid supplied into the cavity 26 passes through the nozzle 24 and is discharged as droplets 30. The droplet discharge device 12 moves the stage 15 and the carriage 19 back and forth. A desired pattern can be drawn by discharging the droplet 30 when the nozzle 24 is positioned at a predetermined location.

(Electronic device manufacturing method)
Next, a process for manufacturing an electronic device using the above-described droplet discharge device 12 will be described with reference to FIGS. FIG. 2C is a flowchart showing the manufacturing process of the electronic device. 3 to 4 are schematic views for explaining a process for manufacturing the electronic device.

  In the flowchart shown in FIG. 2C, step S1 corresponds to a blending process. This step is a step of preparing the functional liquid discharged from the droplet discharge head. Next, the process proceeds to step S2. Step S2 corresponds to a substrate surface treatment process. This step is a step of cleaning the surface of the substrate. Next, the process proceeds to step S3. Step S3 corresponds to a drawing process. This step is a step of applying a functional liquid onto the substrate using a droplet discharge device. Next, the process proceeds to step S4. Step S4 corresponds to a base film solidifying step. This step is a step of solidifying the base film by heating and drying the applied functional liquid. Step S2 to step S4 are combined to form the base film forming step of step S11. Next, the process proceeds to step S5. Step S5 corresponds to a chemical plating step, and is a step of forming a metal film on the base film. Next, the process proceeds to step S6. Step S6 corresponds to a metal film curing step, and is a step of heating and dehydrating the metal film to cure the metal film. The process of manufacturing the electronic device is completed through the above processes.

  Next, a method for manufacturing an electronic device will be described in detail with reference to FIGS. 3 to 4 in association with the steps shown in FIG. The functional liquid 27 is prepared in the preparation step of step S1. The functional liquid 27 is mainly composed of a resin solution in which a resin is dissolved in a solvent and a catalyst solution in which a catalyst is dissolved in a solvent, and a leveling agent is added to the resin solution.

  The resin in the resin solution may be a material that forms a polymer by a polymerization reaction, and the type thereof is not particularly limited. For example, materials of silicone resin, polyamide resin, polyester resin, polycarbonate resin, polyimide resin, epoxy resin, urethane resin, and epoxy resin can be employed. In particular, a polyimide resin material is preferably used. As a form of the resin material, an oligomer is preferable, and a monomer is more preferable. A smaller molecular weight can be easily discharged as a droplet. The resin solvent that dissolves the resin material is not particularly limited as long as it can dissolve the resin. Various solvents such as hydrocarbons, chlorinated hydrocarbons, alcohols, acetate esters, ketones, cellosolves, glycol ethers, ethers and the like can be employed. For example, PEGMEA (1-methoxypur-2-acetate) and n-butanol can be suitably employed.

  The catalyst used in the catalyst solution may be a metal having a catalytic action, and the kind thereof is not particularly limited. As the metal having a catalytic action, for example, cobalt, nickel, copper, palladium, gold, silver, lead, platinum or the like can be employed. In addition, it is preferable to employ | adopt the metal which has a catalytic action easily which forms the metal film formed by chemical plating. For example, when forming a nickel film or a gold film, it is preferable to employ palladium or gold as the catalyst. When forming a silver film, it is preferable to employ palladium, gold, or silver as a catalyst. When forming a tin film, copper is preferably employed as the catalyst. When forming a copper film, it is preferable to employ palladium, gold, silver, or copper as the catalyst.

  As the leveling agent added to the resin solution, various acrylic, silicone, and fluorine leveling agents can be employed. The leveling agent is not particularly limited. For example, BYK-352 and BYK-354 manufactured by Big Chemie Japan Co., Ltd. for acrylics, Surfynol DF-58 manufactured by Nissin Chemical Industry Co., Ltd. for silicones, and DIC stocks for fluorine-based products Megafac F-482, F-483, and F-484 manufactured by the company can be suitably employed.

  When the leveling agent is not added to the functional liquid 27, the coffee stain phenomenon appears remarkably, and the catalyst may be unevenly distributed on a part of the polymerized resin surface. Thereafter, when chemical plating is performed, the metal is liable to deposit in a place where there is a large amount of catalyst. As a result, a part of the thickness of the metal film formed by chemical plating increases. When a leveling agent is added to the functional liquid 27, the catalyst spreads and is distributed over the entire surface of the polymerized resin. Thereby, dispersion | distribution of the film thickness of the metal film by chemical plating can be made small.

  A silane coupling agent having a functional group containing a catalytic metal is used for the catalyst solution. Such a silane coupling agent can be produced using a known method. For example, the method described in the pamphlet of International Patent No. WO2003 / 091476A1 can be referred to. According to this, a solution of a silane coupling agent having a functional group having a metal capturing ability is applied to a substrate, and further, an organic solvent solution of a metal compound is applied to the substrate. By this method, a silane coupling agent having a functional group containing a metal is formed. For example, by applying this method, a metal catalyst that is a silane coupling agent having a functional group containing a metal having a catalytic action can be produced. Similar to the solvent for dissolving the resin material, the solvent for dissolving the catalyst material can be selected from various solvents. The catalyst solvent for dissolving the catalyst material is not particularly limited as long as it can dissolve the catalyst. For example, octanol can be suitably employed.

  It is preferable to consider the boiling point of the solvent when selecting the solvent for the resin and the solvent for the catalyst. The solvent is selected so that the boiling point of the catalyst solvent is higher than the boiling point of the resin solvent. As a result, the catalyst solvent is less likely to volatilize, so that the catalyst material easily moves to the surface of the functional liquid 27 while the resin material undergoes a polymerization reaction. As a result, the catalyst can be easily arranged on the surface of the resin.

  In preparing the resin solution and the catalyst solution, it is preferable to consider the specific gravity of each solution. That is, the specific gravity of the resin solution in which the resin material and the leveling agent are dissolved in the resin solvent is adjusted so as to be larger than the specific gravity in which the catalyst material is dissolved in the catalyst solvent. After applying the functional liquid 27 to the substrate 2, gravity acts on the functional liquid 27. Thereby, since the catalyst solution moves to the liquid surface side of the functional liquid 27, the catalyst material easily moves to the surface of the solution. As a result, the catalyst can be easily arranged on the surface of the resin.

In this embodiment, for example, 0.06 g of silicone resin 13.2 g which is a resin material and Megafac F-482 manufactured by DIC Corporation which is a leveling agent are prepared. 46.04 g of a solvent was prepared by combining PEGMEA (boiling point 146 ° C.) and n-butanol (boiling point 118 ° C.) as the resin solvent. The resin material and the leveling agent were dissolved in the resin solvent to prepare a resin solution. The specific gravity of this resin solution was 1.09 g / cm ³ . Further, a silane coupling agent having palladium as a functional group was dissolved in octanol (boiling point 194 ° C.) as a catalyst solvent to prepare 118.6 g of a catalyst solution. The specific gravity of this catalyst solution was 0.83 g / cm ³ . A functional solution 27 was prepared by mixing the resin solution and the catalyst solution. In this preparation, the specific gravity of the resin solution is larger than the specific gravity of the catalyst solution. The boiling point of the resin solvent is lower than the boiling point of the catalyst solvent.

  FIG. 3A is a diagram corresponding to the substrate surface treatment process in step S2. As shown in FIG. 3A, in step S2, the surface of the substrate 2 is cleaned. The substrate 2 is placed inside the ultraviolet irradiation device 35 in which the mercury lamp 33 and the reflecting mirror 34 are arranged. Then, the substrate 2 is irradiated with ultraviolet rays 36 emitted from the mercury lamp 33. At this time, the substrate 2 is moved in a direction crossing the traveling direction of the ultraviolet rays 36 and the entire substrate 2 is irradiated with the ultraviolet rays 36. Energy is applied to the foreign matter adhering to the surface of the substrate 2 by the ultraviolet rays 36, and the foreign matter is detached from the substrate 2. Then, the surface of the substrate 2 is cleaned.

  Examples of the method for cleaning the substrate 2 include a hydrogen burner, an excimer laser, a plasma discharge part, and a corona discharge part in addition to the ultraviolet irradiation using a mercury lamp. In addition, cleaning such as ultrasonic cleaning may be performed. The surface state of the substrate 2 may be modified by adjusting the amount of energy applied to the substrate 2. By imparting liquid repellency or lyophilicity to the functional liquid 27, the shape of the droplets 30 that land on the substrate 2 can be controlled. The droplet 30 that has landed by imparting liquid repellency to the functional liquid 27 becomes nearly spherical, and the droplet 30 that has landed by imparting lyophilicity to the functional liquid 27 tends to spread.

  When using a hydrogen burner, the surface can be roughened by partially reducing the oxidized surface of the substrate 2, and when using an excimer laser, the surface of the substrate 2 is partially roughened by melting and solidifying. When plasma discharge or corona discharge is used, the surface of the substrate 2 can be roughened by mechanical cutting. In addition, surface modification may be performed by applying a surface treatment agent. For example, as a method for imparting liquid repellency, a film may be formed by applying a surface treatment agent containing EGC-1720 or fluoroalkylsilane (FAS) of Sumitomo 3M which is a fluorine-based surface treatment agent. Since this surface modification is a process for imparting lyophobic and lyophilic properties to the functional liquid 27, the degree of surface modification should be made smaller than the process for improving the adhesion. Can do. If the drawing can be performed in a predetermined shape without performing the surface treatment, the treatment for modifying the surface state may be omitted.

  FIG. 3B and FIG. 3C are diagrams corresponding to the drawing process in step S3. As shown in FIGS. 3B and 3C, in step S <b> 2, the operator places the placement guide plate 16 on which the substrate 2 is mounted on the stage 15 of the droplet discharge device 12. A semiconductor element 4 is bonded to the substrate 2. The droplet discharge device 12 drives the stage 15 and the carriage 19 to discharge the droplet 30 from the nozzle 24 while relatively moving the droplet discharge head 23 and the substrate 2. Then, the droplet 30 is landed so as to connect the first electrode 5 and the second electrode 6. The droplet discharge device 12 discharges and draws the droplet 30 while relatively moving the substrate 2 and the droplet discharge head 23 so that the functional liquid 27 applied on the substrate 2 has a desired shape.

  Since there is a step between the first electrode 5 and the second electrode 6, the droplet 30 landed on the substrate 2 and the droplet 30 landed on the active surface 4a are not connected when the carriage 19 is scanned once. There is. In this case, the droplet 19 may be ejected by scanning the carriage 19 a plurality of times. Thereby, the droplet 30 landed on the substrate 2 and the droplet 30 landed on the active surface 4a can be connected.

  FIGS. 3D to 4C are diagrams corresponding to the base film solidifying step in step S4. As shown in FIG. 3D, the substrate 2 on which the functional liquid 27 has been applied is placed inside the drying device 37 in step S4. The drying device 37 includes a drying chamber 38. The drying chamber 38 includes a mounting table 39, and the substrate 2 is installed on the mounting table 39. The drying chamber 38 is connected to a drying gas supply unit 42 via a supply pipe 40 and a supply valve 41 on the upper side in the drawing. Further, the drying chamber 38 is connected to the exhaust unit 45 via an exhaust pipe 43 and an exhaust valve 44 on the lower side in the drawing.

  The dry gas supply unit 42 supplies the dry gas 46 which is dried and heated to become hot air. The dry gas supply unit 42 has a temperature adjustment function, and controls the temperature of the dry gas 46 so that the temperature in the drying chamber 38 becomes a predetermined temperature. The dry gas 46 supplied from the dry gas supply unit 42 is supplied to the drying chamber 38 via the supply valve 41 and the supply pipe 40. Next, the dry gas 46 flows along the functional liquid 27 applied to the substrate 2. At this time, the dry gas 46 heats the functional liquid 27 to remove the solvent and the dispersion medium contained in the functional liquid 27 by evaporation. Thereby, the drying device 37 dries the functional liquid 27. Then, the functional liquid 27 is heated to undergo a polymerization reaction, and a base film is formed. Next, the dry gas 46 containing the solvent and the dispersion medium passes through the exhaust pipe 43 and the exhaust valve 44 and is exhausted to an exhaust processing device (not shown) by the exhaust unit 45. When the temperature of the drying chamber 38 is set to 200 ° C. or higher, an oxygen-free atmosphere such as a nitrogen atmosphere is preferable. This can prevent the metal catalyst 47 from being oxidized. The temperature condition and the heating condition are not particularly limited. In this embodiment, for example, the base film 8 is formed by blowing a dry gas 46 of 150 ° C. on the substrate 2 for 1 hour.

  FIG. 4A shows a state before the functional liquid 27 landed on the substrate 2 is solidified. In the functional liquid 27, the metal catalyst 47 is present randomly. A metal having a catalytic function is connected to one end of the metal catalyst 47 in a state of metal ions 47a. FIG. 4B shows a state where the functional liquid 27 that has landed on the substrate 2 is solidified. Gravity acts on the functional liquid 27, the ratio of the resin solution 27 a increases on the substrate 2 side of the functional liquid 27, and the ratio of the catalyst solution 27 b increases on the upper side of the functional liquid 27. Then, the resin solution 27a is heated and the polymerization reaction of the resin material proceeds. Since the solvent of the catalyst solution 27b has a higher boiling point than the solvent of the resin solution 27a, the metal catalyst 47 in the catalyst solution 27b easily moves even when the polymerization reaction of the resin material proceeds. Thereby, the metal catalyst 47 is easily moved to the surface of the functional liquid 27. Since the leveling agent is added to the functional liquid 27, the metal catalyst 47 is uniformly distributed on the surface of the functional liquid 27. The functional liquid 27 that has landed on the semiconductor element 4 is also in the same state.

  FIG. 4C shows a state in which the solidification of the functional liquid 27 that has landed on the substrate 2 has further progressed. On the surface of the functional liquid 27, the density of the metal catalyst 47 increases, and a plurality of metal ions 47a come into contact with each other. Then, the metal ions 47a are reduced by being heated in a state where the plurality of metal ions 47a are in contact with each other, and are deposited as metal particles 48. The base film 8 is formed by the polymerization reaction of the resin solution 27a to form a resin. The metal particles 48 are uniformly distributed on the surface of the base film 8. The functional liquid 27 that has landed on the semiconductor element 4 is also in the same state.

  FIG. 4D is a diagram corresponding to the chemical plating step of step S5. As shown in FIG. 4D, in step S <b> 5, the substrate 2 on which the base film 8 is formed is placed in the chemical plating bath 49. Metal ions 50 are dissolved in the chemical plating bath 49. When the metal ions 50 come into contact with the metal grains 48 of the base film 8, the metal is deposited on the surface of the base film 8, so that the metal film 9 is formed on the surface of the base film 8. Since the metal grains 48 are uniformly distributed on the surface of the base film 8, the film thickness of the metal film 9 is formed uniformly. Metal also precipitates on the surfaces of the first electrode 5 and the second electrode 6 to form a metal film 9.

  The plating bath is not particularly limited, but in this embodiment, for example, a redox-based neutral electroless copper plating solution and Sulcup PEA-3 manufactured by Uemura Kogyo were used. Although the plating conditions are not particularly limited, for example, in this embodiment, plating was performed using PEA-3 at a pH of 12.3 and a temperature of 33 ° C. for 20 minutes. The neutral electroless copper plating solution was plated for 2 hours at a pH of 6.85 and a temperature of 25 ° C., and both confirmed good precipitation.

  In the metal film curing process in step S6, the substrate 2 is placed in the drying device 37, as in the base film solidifying process in step S4. Then, the heated dry gas 46 is passed through the surface of the substrate 2 to dry the metal film 9. As a result, moisture is removed from the metal film 9, so that the metal film 9 is cured. Although heating conditions and drying time are not particularly limited, for example, in the present embodiment, drying is performed by spraying a dry gas 46 of 100 ° C. for 1 hour. Through the above steps, a metal film having a good appearance and high adhesion could be formed. With the above process, the process of manufacturing the electronic device is completed.

As described above, this embodiment has the following effects.
(1) According to this embodiment, the functional liquid 27 includes the resin material and the metal catalyst 47. Since the functional liquid 27 contains a resin, the functional liquid 27 can be solidified. In the process of solidifying the functional liquid 27, the metal catalyst 47 is arranged on the surface of the resin. In the chemical plating step of step S5, the metal film 9 is formed using the metal catalyst 47 arranged on the resin surface as a nucleus. As a result, a metal film 9 is formed on the surface of the base film 8. Since the base film 8 is disposed so as to connect the first electrode 5 and the second electrode 6, the metal film 9 can electrically connect the first electrode 5 and the second electrode 6.

  (2) According to the present embodiment, when the semiconductor element 4 is disposed on the substrate 2, the semiconductor element 4 has a thickness, so that a step is generated between the first electrode 5 and the second electrode 6. Therefore, there is a method of disposing a metal film material between the first electrode 5 and the second electrode 6 after forming a slope between the semiconductor element 4 and the substrate 2. In this method, a step of applying and solidifying a material for forming a slope and a step of connecting a plurality of first electrodes 5 and second electrodes 6 by arranging a metal film are required. In the present embodiment, after the base film forming step in step S11 for forming the base film 8 and connecting the first electrode 5 and the second electrode 6, chemical plating is performed on the base film in the chemical plating step in step S5. Thereby, the metal film 9 is formed. Even when there are a plurality of base films 8, the metal film 9 can be formed simultaneously by one chemical plating process. Therefore, the first electrode 5 and the second electrode 6 can be electrically connected with high productivity.

  (3) According to this embodiment, the functional liquid 27 contains a leveling agent. When the leveling agent acts on the functional liquid 27, the metal catalyst 47 is uniformly distributed on the surface of the base film 8. Since the metal film 9 is formed using the metal catalyst 47 as a nucleus, the metal film 9 is uniformly formed on the surface of the base film 8. Therefore, the dispersion of the film thickness of the metal film 9 formed on the base film 8 can be reduced.

  (4) According to this embodiment, since the metal catalyst 47 is a silane coupling agent having a functional group containing a metal, it is possible to easily arrange the metals on the surface of the functional liquid 27. And when heating in order to solidify the functional liquid 27, the metal ion 47a of the metal catalyst 47 is reduced from an ion state to a metal state. Accordingly, the metal grains 48 can be arranged on the surface of the base film 8.

  (5) According to the present embodiment, the resin wiring 7 is formed on the substrate 2 and the semiconductor element 4. When the thermal expansion coefficients of the substrate 2 and the semiconductor element 4 are different, the distance between the first electrode 5 and the second electrode 6 changes during heating. At this time, since the base film 8 of the resin wiring 7 is deformed, the metal film 9 is hardly broken. Therefore, it is possible to make it difficult to disconnect the wiring even when the electronic device 1 is heated.

  (6) According to the present embodiment, the resin wiring 7 is formed by performing chemical plating on the base film 8. There is a method of drawing a wiring by forming a slope between the substrate 2 and the semiconductor element 4 and discharging ink containing metal particles between the first electrode 5 and the second electrode 6. This method requires a gentle slope. Compared with this method, in the method of this embodiment, the metal film 9 can be formed even when the base film 8 has a steep gradient, so that the wiring can be arranged in a narrow range.

(Second Embodiment)
Next, an embodiment of an electronic device will be described with reference to FIG. This embodiment is different from the first embodiment in that semiconductor elements are stacked in multiple layers. Note that description of the same points as in the first embodiment is omitted.

  FIG. 5A is a schematic perspective view showing the structure of the electronic device. That is, in the present embodiment, as shown in FIG. 5A, the electronic device 53 includes a first semiconductor element 54, a second semiconductor element 55, a third semiconductor element 56, and a fourth semiconductor element 57. The first semiconductor element 54 to the fourth semiconductor element 57 are arranged in an overlapping manner and fixed with an adhesive. Each semiconductor element is formed in a plate shape that is long in one direction, and each semiconductor element is stacked with its longitudinal direction aligned. Therefore, the electronic device 53 has a shape that is long in one direction. The longitudinal direction of the first semiconductor element 54 is the X direction, and the direction orthogonal to the X direction on the plane of the first semiconductor element 54 is the Y direction. The thickness direction of the first semiconductor element 54 is taken as the Z direction.

  The −X side end face 55 a of the second semiconductor element 55 is disposed at a predetermined interval in the X direction from the −X side end face 54 a of the first semiconductor element 54. Similarly, the −X side end face 56 a of the third semiconductor element 56 is disposed at a predetermined interval in the X direction from the −X side end face 55 a of the second semiconductor element 55. The −X side end face 57 a of the fourth semiconductor element 57 is also arranged at a predetermined interval in the X direction from the −X side end face 56 a of the third semiconductor element 56. Thereby, the surface of the electronic device 53 on the −X side is stepped.

  When the surface on the Z side of the first semiconductor element 54 to the fourth semiconductor element 57 is an upper surface, an electrode 58 and an electronic circuit are formed on each upper surface, and portions other than the electrodes are covered with a passivation film. Six electrodes 58 are exposed on the upper surface of each semiconductor element. The electrodes 58 formed on the upper surfaces of the first semiconductor element 54, the second semiconductor element 55, the third semiconductor element 56, and the fourth semiconductor element 57 are replaced with the first element electrode 59, the second element electrode 60, and the third element electrode, respectively. 61 and the fourth element electrode 62. The electrodes of the first element electrode 59 to the fourth element electrode 62 are arranged in a matrix. Therefore, each electrode is arranged in the Y direction and the X direction.

  The column of the electrodes 58 arranged in the Y direction is referred to as a first electrode column 63 to a sixth electrode column 68 in order from the + Y direction side to the −Y direction side. Resin wiring 7 is arranged between the electrodes 58 in each of the first electrode row 63 to the sixth electrode row 68. Thereby, the electrodes 58 of each column are electrically connected.

  FIG. 5B and FIG. 5C are schematic views for explaining a process for manufacturing an electronic device. The manufacturing method of the electronic device 53 is manufactured in substantially the same process as in the first embodiment. The preparation step in step S1 and the substrate surface treatment step in step S2 are substantially the same as those in the first embodiment, and a description thereof will be omitted. FIG. 5B is a diagram corresponding to the drawing process of step S3. A state before the resin wiring 7 is formed in the electronic device 53 is a base material 69. The substrate 69 is formed by stacking and bonding the first semiconductor element 54 to the fourth semiconductor element 57.

  As shown in FIG. 5B, the base material 69 is set on the stage 15 in step S3. Then, by driving the stage 15 and the carriage 19, the base material 69 and the droplet discharge head 23 are relatively moved. Then, the liquid droplets 30 are ejected and drawn at a place where the resin wiring 7 is to be formed. Specifically, in each of the first electrode row 63 to the sixth electrode row 68, the droplet 30 is landed between the electrodes 58 and a part on the electrodes 58.

  The base film solidifying step in step S4 is substantially the same as in the first embodiment, and a description thereof is omitted. FIG. 5C is a diagram corresponding to the chemical plating step of step S5. As shown in FIG. 5C, the base film 8 is formed on the base material 69, and metal particles 48 are deposited on the surface of the base film 8. In step S <b> 5, the base material 69 is placed in the chemical plating bath 49. Metal ions 50 are dissolved in the chemical plating bath 49. When the metal ions 50 come into contact with the metal grains 48 of the base film 8, the metal is deposited on the surface of the base film 8, so that the metal film 9 is formed on the surface of the base film 8.

  In the metal film curing step of step S6, the metal film 9 is cured by drying and dehydrating the metal film 9. The electronic device 53 is completed through the above steps.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the resin wiring 7 is formed between the plurality of electrodes 58 of the base material 69 formed in multiple stages. After the resin wiring 7 is drawn by the droplet discharge device 12 and the base film 8 is formed, the metal film 9 is formed on the base film 8 by chemical plating. Since the metal films 9 are collectively formed on the plurality of base films 8, wiring can be performed with higher productivity as compared with a method of performing one place at a time such as wire bonding.

  (2) According to this embodiment, the base film 8 is formed of resin. Accordingly, even when the first semiconductor element 54 to the fourth semiconductor element 57 of the electronic device 53 are expanded by heat, the base film 8 is deformed, so that the metal film 9 can be hardly cracked.

(Third embodiment)
Next, an embodiment of an example of a droplet discharge device and a method of manufacturing an electronic device using the droplet discharge device will be described with reference to FIG. This embodiment is different from the first embodiment in that the functional liquid 27 is irradiated with ultraviolet rays and solidified. Note that description of the same points as in the first embodiment is omitted.

  FIG. 6A is a schematic side view showing the carriage. That is, in the present embodiment, as shown in FIG. 6A, the droplet discharge device 72 includes a carriage 19. A head unit 20 is installed in the center of the lower side of the carriage 19 in the figure, and lifting devices 21 are installed on both sides in the X direction of the head unit 20 with the head unit 20 interposed therebetween. Further, a curing unit 73 is installed on both sides in the X direction of the lifting device 21 with the lifting device 21 interposed therebetween.

  A photopolymerization initiator is added to the functional liquid 27. The photopolymerization initiator is an additive that acts on the crosslinkable group of the polymer to advance the crosslinking reaction. For example, benzyldimethyl ketal can be used as the photopolymerization initiator. The curing unit 73 is provided with an LED (Light Emitting Diode) for irradiating ultraviolet rays for curing the discharged droplets and a fan for cooling the LED. And the wind which a fan forms takes heat of LED, and is discharged as hot air. Accordingly, the curing unit 73 performs ultraviolet irradiation and hot air blowing.

  FIG. 6B is a schematic plan view showing the carriage. As shown in FIG. 6B, a blowing unit 74 and an irradiation window 75 are arranged in the curing unit 73 arranged in the carriage 19. The fan and the air outlet 74 are connected by a flow path, and the hot air formed by the fan and the LED is blown out from the air outlet 74 toward the droplet 30 landed on the substrate 2. The irradiation window 75 is located at a location facing the LED, and ultraviolet rays emitted from the LED are emitted from the irradiation window 75.

  Next, a method for manufacturing the electronic device 1 will be described. FIG. 6C to FIG. 6F are schematic views for explaining a process for manufacturing an electronic device. The preparation step in step S1 and the substrate surface treatment step in step S2 are the same as those in the first embodiment, and a description thereof will be omitted. FIG. 6C to FIG. 6E are diagrams corresponding to the drawing process in step S3. As shown in FIG. 6C, the substrate 2 is placed on the droplet discharge device 72 in step S3. A semiconductor element 76 is installed on the substrate 2 and fixed with an adhesive. The semiconductor element 76 is formed thicker than the semiconductor element 4 in the first embodiment.

  By driving the stage 15 and the carriage 19, the substrate 2 and the droplet discharge head 23 are relatively moved. Then, the liquid droplets 30 are ejected and drawn at a place where the resin wiring 7 is to be formed. Specifically, the droplet 30 is landed from a part on the first electrode 5 to a part on the second electrode 6. Then, warm air 77 is blown to the landed droplets 30, and further, ultraviolet rays 78 are irradiated.

  Thereby, the resin material in the droplet 30 is polymerized, and the metal ions 47a are reduced and deposited as metal particles 48. When the resin material is sufficiently cured and the metal particles 48 are deposited in the drawing process, the base film solidifying process in step S4 may be omitted. Furthermore, the base film 8 can be formed with high productivity.

  When the thickness of the semiconductor element 76 is large, the liquid droplet 30 cannot be connected from the upper surface 2a of the substrate 2 to the upper surface 76a of the semiconductor element 76 by one application. Therefore, as shown in FIG. 6D, the droplet 30 is discharged onto the side surface 76b of the semiconductor element 76. As a result, the droplet 30 is applied to the already solidified or gelled droplet 30. Therefore, the applied functional liquid 27 can be thickened. Further, the droplet 30 is solidified or gelled by blowing warm air 77 on the landed droplet 30 and irradiating it with ultraviolet rays 78. Subsequently, the droplet discharge device 72 repeatedly performs the steps of discharging the droplet 30 and irradiating the droplet 30 with the warm air 77 to irradiate the ultraviolet rays 78. As a result, as shown in FIG. 6 (e), the droplets 30 are connected in a solidified or gelled state from the upper surface 2 a of the substrate 2 to the upper surface 76 a of the semiconductor element 76.

  In the base film solidifying step in step S4, the droplet 30 is cured to form the base film 8. Metal particles 48 are deposited on the surface of the base film 8. In the chemical plating step in step S5, a metal film 9 is formed on the base film 8 as shown in FIG. Since the metal film 9 is formed from the first electrode 5 to the second electrode 6, the first electrode 5 and the second electrode 6 are electrically connected. In the metal film curing step of step S6, moisture is removed from the metal film 9 and cured. This step is the same as in the first embodiment, and a description thereof will be omitted. The manufacturing process of the electronic device is completed through the above steps.

As described above, this embodiment has the following effects.
(1) According to this embodiment, a plurality of ejections of the droplets 30 and solidification or gelation of the landed droplets 30 are performed. Then, a solidified or gelled resin film is formed, and the liquid droplet 30 is landed on the resin film, and then solidified or gelled. Thereby, the shape of the base film 8 can be formed high. Therefore, even when the thickness of the semiconductor element 76 is large, the base film 8 can be disposed so as to connect the first electrode 5 and the second electrode 6. Thereafter, the first electrode 5 and the second electrode 6 can be electrically connected by forming the metal film 9 on the base film 8. As a result, even when the thickness of the semiconductor element 76 is large, the first electrode 5 and the second electrode 6 can be electrically connected.

  (2) According to this embodiment, since the functional liquid 27 includes a photopolymerization initiator, the liquid liquid material can be solidified or gelled in a short time by irradiating the functional liquid 27 with light. Therefore, when the functional liquid 27 is arranged and solidified or gelled a plurality of times, it can be performed in a short time, so that the base film 8 can be formed with high productivity.

In addition, this embodiment is not limited to embodiment mentioned above, A various change and improvement can also be added. A modification will be described below.
(Modification 1)
In the first embodiment, the droplets 30 are ejected and drawn in the shape of the base film 8 using the droplet ejection device 12. The application method of the functional liquid 27 is not limited to this, and the functional liquid 27 may be applied onto the substrate 2 and the semiconductor element 4 using a syringe. In addition, the functional liquid 27 may be applied onto the substrate 2 and the semiconductor element 4 by drawing using a writing instrument such as a brush or a felt pen. You may employ | adopt the method which is easy to draw.

(Modification 2)
In the first embodiment, the semiconductor element 4 is arranged on the substrate 2 and wiring between the electrodes is performed. The wiring target is not limited to the semiconductor element 4, and other elements may be arranged. For example, capacitors, resistors, coils, batteries, various sensor elements, etc. can be arranged and wired.

(Modification 3)
In the second embodiment, the metal film 9 is formed by chemical plating, and the metal film 9 is used as a wiring. A metal film may be further laminated on the metal film 9 by electroplating. As a result, the cross-sectional area of the wiring can be increased and the electrical resistance of the wiring can be reduced.

(Modification 4)
In the third embodiment, the droplet 30 landed by adding a photopolymerization initiator to the functional liquid 27 was irradiated with ultraviolet rays. In addition, a thermal polymerization initiator may be added to the functional liquid 27 and polymerization may be started by heating. As the thermal polymerization initiator, for example, azobisisobutyronitrile can be used. Then, by repeating the discharge of the droplets 30 and the heating of the landed droplets 30, the base film 8 can be connected to a place with a large step.

  DESCRIPTION OF SYMBOLS 1 ... Electronic device, 2 ... Board | substrate as a base material, 4 ... Semiconductor element as an electronic element, 5 ... 1st electrode, 6 ... 2nd electrode, 8 ... Base film, 9 ... Metal film, 27 ... Functional liquid.

Claims (5)

An electronic element having the first electrode formed thereon is disposed on the substrate on which the second electrode is formed;
A base film forming step of forming a base film by solidifying the functional liquid after disposing the functional liquid so as to connect the first electrode and the second electrode;
A chemical plating step of forming a metal film on the base film by chemical plating treatment,
The method of manufacturing an electronic device, wherein the functional liquid includes a resin and a metal catalyst. A method of manufacturing an electronic device according to claim 1,
The method of manufacturing an electronic device, wherein the functional liquid further includes a leveling agent. A method of manufacturing an electronic device according to claim 2,
The method of manufacturing an electronic device, wherein the metal catalyst is a silane coupling agent having a functional group containing a metal, and the functional liquid is solidified by heating or light irradiation in the base film forming step. A method for manufacturing an electronic device according to claim 3,
In the base film forming step, the functional liquid is arranged and solidified, and the functional liquid is arranged and solidified on the solidified functional liquid. A method for manufacturing an electronic device according to claim 4,
The method of manufacturing an electronic device, wherein the functional liquid includes a photopolymerization initiator, and the functional liquid is solidified by irradiation with light.

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