JP5331929B2 - Electronic member, electronic component and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic member which can supply joint material at a fine pitch, and can be electrically connected. <P>SOLUTION: To one or more connection terminals provided on a circuit substrate, one or more electrodes provided on an electronic member is electrically joined through a joint layer. The joint layer is configured by mainly sintered silver. The whole area or a part of an electrode surface which is not contacted with the joint layer is a roughening layer of silver oxide. The thickness of the roughening layer of the silver oxide is 400 nm to 5 &mu;m, and the outermost surface of the layer of the silver oxide has a curvature radius smaller than 1 &mu;m. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to an electronic member on the premise that electrical bonding between electronic members (for example, bonding between a semiconductor element and a circuit member) is performed, and relates to an electronic component mounted with the electronic member and a mounting method thereof. Hereinafter, semiconductor elements, circuit members, and the like are collectively referred to as electronic members.

  In recent years, there has been an increasing demand for multi-functionality, high speed, lightness, thinness and miniaturization, including mobile devices. In order to achieve this, it is important to reduce the pitch and height of electrodes for inputting and outputting electrical signals.

  On the other hand, since heat generation per unit area and unit volume increases with high-density mounting, improvement in heat dissipation becomes important. At the same time, it is important to reduce the resistance of the joint as the electrode area decreases.

  Examples of connection techniques for electrically bonding electrodes between a plurality of electronic members include bonding using a conductive adhesive and solder, and metal pressure welding (bonding such as gold bumps). Furthermore, with respect to these preceding connection technologies, there has been reported a technology capable of realizing a joint having heat dissipation and heat resistance characteristics superior to solder and silver paste by using silver oxide particles (for example, non-patent literature). 1).

The joining technique using silver oxide particles is a technique in which silver oxide particles are reduced at a low temperature and the joint is made of silver having low resistance and high heat dissipation. As the bonding material, a composition in which silver oxide particles and a reducing agent capable of reducing it at a low temperature are mixed is used. Moreover, it can be divided into two, a composition containing a binder (Patent Document 1) and a composition not containing a binder (Patent Document 2).
In particular, when a composition that does not contain the latter binder is used as a bonding material, metal bonding is obtained with respect to the mating electrode to be bonded (Non-patent Document 1), and thus a bonded portion with excellent heat dissipation can be provided.

When a composition comprising silver oxide and a reducing agent is heated, silver particles having a small particle size are generated. Silver particles having a small particle size have excellent sintering ability even at low temperatures, and the organic components contained in the composition are decomposed by heat treatment, so that the generated silver particles are joined to the electrode of the electronic component to be connected. Sintering between silver particles is performed. Finally, the organic component is removed to complete an electronic component having a bonding layer composed of a metallic silver network. By being composed of metallic silver, the bonding layer has excellent heat dissipation characteristics. Since the heating temperature required for joining is approximately the same as that of a solder material widely used in electronics mounting, it has been attracting attention as a joining material for electronic parts capable of high heat dissipation.
However, in order to obtain a good bonded state, a pressure application step is required together with the heating step.

  It has been proposed that the particulate silver oxide bonding material listed above is supplied by the following method by adding a reducing agent for reducing silver oxide to silver at a low temperature.

  1) A method of adding various solvents for viscosity adjustment and printing in a paste state.

  2) A method of applying a paste to a plate and inserting it.

  3) A method of selecting a reducing agent that does not become liquid at room temperature, applying pressure to the solid powder, and inserting it in a sheet form.

JP 2003-309352 A JP 2007-335517 A Patent 4090778

14th Symposium on Microjoing and Assembly Technology in Electronics Proceedings, p.185

  In joining using silver oxide particles, joining at low temperature and low pressure is possible by producing silver particles having a small particle size during the reduction. This is because, as the particle size of the metal particles decreases, the curvature increases, so that the sintering ability improves, and a joining technique using this phenomenon has been invented. The metal particles are sintered by the surface tension acting on the neck portions between the particles and the neck growth. That is, by using particles having a large curvature for the bonding material, the surface tension increases from the bulk state, and electrical bonding is possible at low temperature and low pressure. However, as a result of diligent experiments regarding the technique of joining using particulate silver oxide particles, the inventors have found that there are the following problems.

  In order to supply the particulate composition at a fine pitch, a method of making a paste and printing is taken. Therefore, it is necessary to increase the fluidity in order to print with high accuracy. However, there is a problem that the amount of organic matter added in the composition increases. As a result, the silver oxide particles could not be supplied precisely, resulting in poor bonding. In addition, in joining using silver oxide particles, unlike the joining using solder, since the material does not melt, if there is a void before joining, there is a problem that the void tends to remain as a void after joining. In joining using silver oxide, it is necessary for the sintered silver layer, which becomes the joining layer after joining, to have a high density in order to achieve excellent heat dissipation and mechanical characteristics.

  Moreover, in order to print accurately, the method of reducing the particle diameter of a silver oxide particle and improving the dispersibility to an organic solvent was examined. However, there is a problem that the particles are aggregated if not coated with an organic substance after synthesis. Thus, for example, the surface of the silver oxide particles was coated with an organic substance for preventing the aggregation by the technique disclosed in Patent Document 3. However, since it is coated with an organic substance that is difficult to volatilize, the temperature for removing the organic substance rises when used as a bonding material, resulting in a problem that the bonding temperature increases. Thus, it has been found that the paste material is difficult to supply at a fine pitch and that there is a problem that reliable bonding cannot be performed.

  Next, a paste material was dip coated on the Au bumps of the LSI chip arranged at a fine pitch, and placed on a printed board having a solder resist between the connection terminals. There was no problem at the stage of installation. However, as a result of pressurizing at the time of bonding, the paste material has good fluidity, so that the bonding material spreads beyond the resist range, and the electrodes are short-circuited after bonding.

  Moreover, the drying process was performed before joining and the spreading | diffusion of the joining material by pressurization was prevented. However, the bonding layer in the region applied to the side surface of the bump is bonded without applying pressure, and the bonding strength to the Au bump cannot be obtained. After the bonding, the bonding layer peels off, and the peeled bonding layer contacts the adjacent electrode. A short circuit appeared.

  The present invention has been made in view of such problems. It is an object of the present invention to provide an electronic member that can be electrically connected by supplying a bonding material at a fine pitch.

  The present inventors investigated the behavior of silver oxide to silver reduction using a transmission microscope. As a result, it was confirmed that even when the curvature of silver oxide before reduction is small, the curvature of silver produced by reduction increases. This is because the phenomenon that silver oxide is reduced to silver and the volume is reduced does not shrink in a similar shape as shown in FIG. 1 (a), but a large number in silver oxide as shown in FIG. 1 (b). It was found that the metal silver nuclei formed and reduced into a skeleton while maintaining the original shape.

  By utilizing this fine particle formation mechanism, it was inferred that bonding is possible even if silver oxide is provided in a dense layer rather than in the form of particles. As a result of earnest experiments, it was confirmed that bonding was possible using silver oxide formed in layers. Thus, it discovered that the problem which arises by paste-izing can be solved by joining using the silver oxide formed in the layer form.

  Thus, in order to achieve the above object, the present invention provides an electronic member characterized in that an outermost surface of an electrode for inputting / outputting an electric signal or a connecting terminal for connecting an electric signal is a silver oxide layer. .

  The electronic member is characterized in that a silver layer is formed on the outermost surface of the electrode or the connection terminal, and further, the silver layer is oxidized to make all or part of the silver layer a silver oxide layer. It can produce with the manufacturing method of the electronic member to make.

  Further, a step of supplying a reducing agent to the silver oxide layer of the electronic member and applying heating at 100 ° C. to 400 ° C. to at least the bonding surface, and at least when the silver oxide is reduced to metallic silver, the bonding surface is reduced to 0.5. Provided is a method for mounting an electronic component, wherein electrodes are electrically joined by applying a pressure of 1 to 20 MPa.

  By the above technique, one or more connection terminals provided on the circuit board are electronic components in which one or more electrode terminals provided on the electronic member are electrically bonded via a bonding layer, The bonding layer is mainly composed of sintered silver having a crystal grain size of 1000 nm or less, and the entire surface or part of the electrode surface other than the bonding layer is a roughened layer of metallic silver, Can provide electronic parts.

In the present invention, a technique is adopted in which all or part of the Ag metallization is oxidized to the silver oxide layer.
Therefore, the pitch interval at which an Ag metallized electrode can be formed is the pitch interval that can be joined in the present invention. That is, the electronic member is almost free from a decrease in pitch interval due to the bonding material supply method. As described above, according to the present invention, it is possible to supply thin joints using silver oxide having high heat dissipation and high heat resistance at a fine pitch, and high-precision and high-density mounting is possible.

It is the cross-sectional schematic diagram which showed the behavior in which silver oxide reduces and produces | generates silver particles. It is the schematic diagram which showed the electronic member which has a silver oxide layer on the electrode surface which is one example which concerns on this invention, an electronic component using the same, and its preparation method. It is the graph which showed the relationship between the anodizing conditions which are one example which concerns on this invention, and the thickness of a silver oxide layer. It is the graph which showed the relationship between the thickness of the silver oxide layer which is one example which concerns on this invention, and normalized shear strength. It is a graph which shows the strength improvement with an adhesive agent when the surface which is one example which concerns on this invention is made into a sintered silver layer and a silver oxide layer. It is the graph which showed the relationship between joining temperature and holding time which are one example which concerns on this invention, and normalized shear strength. It is the graph which showed the relationship between the magnitude | size of the joining applied pressure which is one example which concerns on this invention, and normalized shear strength. FIG. 2 is a schematic cross-sectional view showing the structure of a lead frame having a silver oxide layer on the surface and a QFP using the lead frame as an example according to the present invention. FIG. 2 is a schematic cross-sectional view showing the structure of a lead frame having a silver oxide layer on the surface and a QFP using the lead frame as an example according to the present invention. It is the cross-sectional schematic diagram which showed the TAB carrier tape which has a silver oxide layer on the surface which is an example which concerns on this invention. It is the cross-sectional schematic diagram which showed the board | substrate with an RFID antenna which has a silver oxide layer on the surface which is an example which concerns on this invention, and the RFID tag using the same. It is the cross-sectional schematic diagram which showed the LED package which is one example which concerns on this invention. It is the cross-sectional schematic diagram which showed the electronic member which has a silver oxide layer on the surface which is an example which concerns on this invention. 1 is a schematic cross-sectional view showing a component built-in type multilayer wiring board as an example according to the present invention. 1 is a schematic cross-sectional view showing a component built-in type multilayer wiring board as an example according to the present invention. 1 is a schematic cross-sectional view showing a component built-in type multilayer wiring board as an example according to the present invention. It is the cross-sectional schematic diagram which showed the laminated chip which is one example which concerns on this invention. It is the graph which showed the relationship between the various electrodes which are one example which concerns on this invention, and normalized shear strength.

  One example of the present invention will be described with reference to FIG. FIG. 2A shows a circuit board 200 in which a wiring 202 is formed on a substrate insulating layer 201, an electrode 203 is formed in a portion to be a connection terminal (electrode) of the wiring 202, and a resist 204 is provided around the connection terminal. It is.

  (1) The electrode 203 of the electronic member is made of Ag metallization, or further, Ag metallization is provided on the outermost surface thereof.

  (2) Next, a silver oxide layer is formed with all or part of the Ag metallized layer remaining.

  From (1) and (2), it was found that the silver oxide layer 205 serving as a bonding material can be provided at a high density as shown in FIG. This is because a reaction mechanism accompanied by volume expansion is taken when oxidizing from Ag metallization to a silver oxide layer.

By bonding the LSI chip 209 (chip 206, electrode 207, metallized layer 208) to the circuit board shown in FIG. 2B by the mounting method described above, the sintered silver layer shown in FIG. An electronic component having 205a at the joint can be provided. Moreover, the sintered silver layer 205b which is not pressurized at the time of joining becomes a roughened layer. In the present invention, the silver oxide layer to be the bonding material is not fluid like the paste material, and has a certain strength against the underlying metallization, and further does not melt at the time of bonding like the solder material, There is no spread of the bonding material (conductive part) due to heating or pressing during bonding. In addition, since metal bonding can be obtained at a low pressure of 0.1 to 20 MPa per bonding surface, plastic deformation in the direction parallel to the bonding surface of the bump can be reduced as compared with the pressure bonding method.
In this way, the electronic component is hardly reduced in pitch interval when mounting an electronic member, which was a problem of the conventional method.

  The invention using this characteristic and the improvements will be described below.

  By supplying silver oxide in layers instead of particles, it is possible to give a certain strength to the supply surface. Thus, by giving the strength between the bonding material before bonding and the base, it is possible to prevent impact resistance and scattering of the bonding material during bonding. Further, by leaving a part of the Ag metallization after the processing from the Ag metallized layer to the silver oxide layer, that is, by making the base of the silver oxide layer Ag metallized, an adhesion force of 5 MPa or more is provided between the silver oxide layer and the base. Can be granted.

  Further, when bonding is performed in the above state, even in a non-pressurized state (region 205b in FIG. 2B), since it is integrated with the underlying Ag metallization (metal bonding), the strength of the Ag bulk state is obtained. This eliminates the need to remove the non-pressurized joining region (region 205b in FIG. 2B), which is a problem when using particulate silver oxide. This leads to a larger material supply area than the bonding area, and a more stable connection is possible.

  In joining using silver oxide, joining is performed by sintering silver particles generated during reduction. However, volume reduction occurs when reducing from silver oxide to metallic silver. For this reason, as the film thickness is increased, pressure is applied at the time of bonding so that the film is compressed in a direction perpendicular to the bonding surface and becomes dense. Although details will be described in Example 3, when the thickness of the silver oxide layer exceeds about 400 nm, a rapid increase in strength was observed. Therefore, the thickness of the silver oxide layer serving as the bonding layer is preferably 400 nm or more. However, if it exceeds 5 μm, it takes a long time to form silver oxide, and the time for reduction at the time of bonding also becomes longer, which is not preferable. Therefore, the thickness of the silver oxide layer serving as the bonding layer is preferably 5 μm or less.

  The electrode surfaces of the electronic parts to be joined have a small curvature, and sintering with silver particles reduced from silver oxide becomes difficult as compared with silver particles. As described above, the silver particles generated by reduction from silver oxide reflect the outer shape of the silver oxide before reduction, and therefore it is advantageous that the radius of curvature of the silver oxide before reduction is smaller. The curvature of silver oxide can be controlled by the oxidation treatment conditions. Moreover, it is preferable to control the curvature radius of the silver oxide layer to be 1 μm or less on the surface of the silver oxide layer so that the curvature of the silver particles to be generated becomes nanometer-sized particles. Furthermore, when two or more electronic members are stacked and pressed and joined, there is a frictional resistance on the surface, so that it is possible to suppress slipping of components when pressed.

  For the silver oxide layer, an organic metal (for example, a carboxylic acid silver salt) functions as a reducing agent. Therefore, by supplying this to the silver oxide layer, bonding for reducing the silver oxide is possible. The organic metal may be supplied by applying a solution or modifying a part of silver oxide. In addition, since the reduction temperature of silver oxide with an organic metal is 200 ° C. or lower, if an organic metal having a melting point of 200 ° C. or higher is used, a liquid layer cannot be formed at the time of bonding, and large voids are prevented from being formed in the bonding layer. It is possible.

  Similarly to the above, there is an organic substance as a material that functions as a reducing agent for the silver oxide layer. As the kind of organic substance, one or more kinds of organic substances selected from carboxylic acids, alcohols, and amines are preferable. Note that “class” includes ions, complexes, and the like derived from cases where organic substances are chemically bonded to metals. Moreover, the organic substance which coat | covers the metal particle with a particle size of nanometer size is also included. However, it is preferable to avoid organic substances containing sulfur or halogen elements because the elements may remain in the bonding layer after bonding and cause corrosion.

  Examples of carboxylic acids include acetic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, myristolein Acid, palmitoleic acid, oleic acid, elaidic acid, erucic acid, nervonic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, succinic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, Malic acid, adipic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, 2,4-hexadiyne carboxylic acid, 2,4-heptadiyne carboxylic acid, 2,4-octadiyne carboxylic acid, 2,4-decadiyne carboxylic acid, 2,4-dodecadiyne carbo Acid, 2,4-tetradecadiyne carboxylic acid, 2,4-pentadecadiyne carboxylic acid, 2,4-hexadecadiyne carboxylic acid, 2,4-octadecadiin carboxylic acid, 2,4-nonadecadin carboxylic acid Acid, 10,12-tetradecadiyne carboxylic acid, 10,12-pentadecadiyne carboxylic acid, 10,12-hexadecadiin carboxylic acid, 10,12-heptadecadin carboxylic acid, 10,12-octadecadiin carboxylic acid Acid, 10,12-tricosadiyne carboxylic acid, 10,12-pentacosadiyne carboxylic acid, 10,12-hexacosadiyne carboxylic acid, 10,12-heptacosadiyne carboxylic acid, 10,12-octacosadiyne Carboxylic acid, 10,12-nonacosadiyne carboxylic acid, 2,4-hexadiyne dicarboxylic acid, 3,5-octane Di Print acid, 4,6-deca-di Inge acid, 8,10-like octadecatienyl indicator acids.

  Examples of alcohols include ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, Examples include oleyl alcohol, linoleyl alcohol, ethylene glycol, triethylene glycol, and glycerin.

  Examples of amines include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecyl Amine, hexadecylamine, heptadecylamine, octadecylamine, oleylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, isopropylamine, 1,5 -Dimethylhexylamine, 2-ethylhexylamine, di (2-ethylhexyl) amine, methylenediamine, trimethylamine, triethyl Amine, ethylenediamine, tetramethylethylenediamine, hexamethylenediamine, N, N-dimethylpropan-2-amine, aniline, N, N-diisopropylethylamine, 2,4-hexadiynylamine, 2,4-heptadiynylamine, 2, 4-octadiynylamine, 2,4-decadiynylamine, 2,4-dodecadiynylamine, 2,4-tetradecadiynylamine, 2,4-pentadecadiynylamine, 2,4-hexadecadiynylamine, 2 , 4-octadecadiynylamine, 2,4-nonadecadiynylamine, 10,12-tetradecadiynylamine, 10,12-pentadecadiynylamine, 10,12-hexadecadiynylamine, 10,12-heptadeca Diinylamine, 10,12-octadecadiynylamino , 10,12-tricosadiynylamine, 10,12-pentacosadiynylamine, 10,12-hexacosadiynylamine, 10,12-heptacosadiynylamine, 10,12-octacosadiynylamine, 10,12- Nonacosadiynylamine, 2,4-hexadiynyldiamine, 3,5-octadiynyldiamine, 4,6-decadiynyldiamine, 8,10-octadecadiynyldiamine, stearic acid amide, palmitic acid amide, Examples thereof include lauric acid laurylamide, oleic acid amide, oleic acid diethanolamide, and oleic acid laurylamide.

  When the organic substance alone or the mixed composition listed above is supplied to the silver oxide layer, the reduction reaction rate with the silver oxide layer is higher than that in the solid state when it is in a liquid state at room temperature. Moreover, storage becomes difficult. Therefore, when it is not used for joining immediately after supply, it is preferable that it is solid at room temperature. These organic substances preferably have a molecular structure in which by-products are easily decomposed at a low temperature when reacted with silver oxide.

  Although details will be described in Example 6, the bonding material according to the present invention has a minimum heating temperature required for bonding of 100 ° C., which is very low compared to the solder material. From this, it is possible to introduce polyethylene terephthalate, polyethylene, or the like, which cannot be used from the viewpoint of heat resistance, into the electronic component in the joining using solder. In addition, if metallization is applied to the outermost surface of the electrode using vapor deposition or plating technology, the Ag metallization is oxidized, and a silver oxide layer is supplied, a silver oxide layer is supplied to metals and other inorganic substances such as organic substances and ceramics. Is possible.

  An electronic member that uses this characteristic and has a silver oxide layer on the surface of the electrode or connection terminal as a bonding material of the present invention includes TAB for CSP, COF carrier tape, lead frame, ceramic wiring board, organic wiring board, LSI There is a chip or a semiconductor package.

  The present invention can be applied to an electronic member for flip mounting. As described above, the present invention can achieve metal bonding at a low pressure of 0.1 to 20 MPa per bonding surface, thus enabling low pressure in flip chip mounting and reducing deformation of wiring and the like. can do.

  In the flip mounting technique, there is a case where a technique of assisting the strength of the entire joint portion by filling a gap between the joined members with a resin in order to reduce the joint area by fine pitch joining. Since the conventional paste-like bonding material has fluidity, there has been a problem that flip chip mounting cannot be performed by previously installing a resin. Therefore, in the case of a structure filled with resin, it is necessary to fill the resin after joining the members. On the other hand, since the bonding material of the present invention is integrated with the electrode, it is possible to perform flip chip mounting in a state where a resin is previously installed. Thereby, the process can be omitted as compared with the conventional method.

  In the flip mounting technology according to the present invention, a method in which a bump is formed as a protrusion type and inserted into a concave electrode, pressed against a planar electrode to destroy an oxide film of a bonding partner electrode, or a resin is previously inserted between bumps Can be taken. In a conventional paste material coating layer, the coating layer peels off due to the shearing force at the time of insertion, and this method cannot be taken. However, in the present invention, it is possible to improve the adhesion with the base by making silver oxide into a high-density layer. Further, the base is preferably Ag metallized because the strength of the silver oxide layer and the base becomes strong. Furthermore, when destroying the oxide film on the bonding partner electrode, the bump surface hardness is increased by making the surface of the protruding bump a silver oxide layer, and the surface is pressed lower than when Cu, Au, Ag, Al is used. It is possible to destroy the oxide film of the bonding partner electrode.

  By producing an electronic component using the joining member described above, for example, it is provided on the electronic member with respect to one or more connection terminals provided on the circuit board as shown in FIG. An electronic component in which one or more electrode terminals obtained are electrically bonded through a bonding layer, the bonding layer being mainly composed of sintered silver having a crystal grain size of 1000 nm or less. In addition, it is possible to provide an electronic component in which the entire surface or part of the electrode surface other than the bonding layer is a roughened layer of metallic silver.

  By being composed mainly of Ag, which has the highest thermal conductivity among metals, it is possible to ensure the heat dissipation necessary for higher density. Further, since the thickness of the bonding layer can be reduced and the electrical resistivity is low, the signal can be speeded up. Furthermore, since the electrode surface other than the bonding layer is formed as a roughened layer as a part of the electrode surface, there is no need to remove a region (FIG. 2 (c) 205b) that becomes a bonding defect when no pressure is applied. . Further, it is preferable that the base of the roughened layer is Ag metallized because the strength can be increased.

  In the case of the structure in which the resin is filled between the bonding members, the adhesion strength with the resin can be increased by making the electrode surface not corresponding to the bonding region also silver oxide. Thereby, it is possible to improve connection reliability. As described above, the resin can be filled before heating.

  In the filled resin, fillers having different thermal expansion coefficients such as alumina, aluminum nitride, and silicon nitride may be mixed. Thereby, the thermal stress which arises from the difference in the thermal expansion coefficient between Si chip and Cu wiring, for example can be relieved.

  As described above, for example, a thermal stress is generated between the Si chip and the Cu wiring due to the difference in the thermal expansion coefficient of the raw material when the electronic component is manufactured or the temperature of the usage environment increases. On the other hand, by reducing the density of the sintered silver that is the bonding layer and filling the resin inside the sintered silver, it is possible to further improve the absorption of thermal strain and reduce the stress applied to the Si chip. Is possible. The density of the sintered silver in the bonding layer can be controlled by reducing the pressure applied during bonding. The resin can be filled either before or after joining as described above.

  By selecting from Ag, Au, Cu, Pt, Ni, Co, Si, Fe, Ti, Mo, Al simple substance, alloy or mixture as the material of the electrode or connection terminal to be Ag metallized, It is possible to impart mechanical properties and chemical properties to the joint, including corrosion resistance.

  Moreover, since the junction part which concerns on this invention is comprised mainly by Ag, the melting | fusing point is much higher compared with a solder material. The current mounting method in the manufacturing process of a semiconductor device is mainly to use a hierarchical solder, and the solder used in the primary mounting is Sn-Ag-Cu solder mainly used in the secondary mounting. It is calculated | required to have melting | fusing point more than mounting temperature (230-260 degreeC). Therefore, conventionally, high-temperature solder (lead content: about 96%, melting point: about 300 ° C.) is often used. Therefore, from the viewpoint of this melting point, the group of Ag, Au, Cu, Pt, Ni, Co, Si, Fe, Ti, Mo, Al, which is a metal whose melting point exceeds 300 ° C. even when the base is alloyed with Ag. It is preferable that it is the simple substance chosen from these, its alloy, or its mixture. This makes it possible to make the high-temperature solder lead-free, which is difficult at present.

  For example, when a package having a semiconductor junction according to the present invention is further mounted on a circuit board, the junction does not melt even if it is joined using a solder material. Moreover, you may use for joining of a semiconductor package and a circuit board. Furthermore, it is also possible to join together.

  As described above, the bonding material according to the present invention has a minimum heating temperature required for bonding of 100 ° C., which is very low compared to the solder material. Therefore, in the case where heat resistance is not a problem, especially in a joint where stress relaxation is necessary, Sn or Sn alloy, or In or In alloy, which has a stress relaxation capability than sintered silver, can be included in the electrode configuration. That's fine. When strength is not required and heat resistance is required, Sn or Sn alloy, or In or In alloy is melted and reacted with silver particles generated by reduction from the silver oxide layer, resulting in a high melting point. An intermetallic compound may be used. At this time, since the silver particles generated from the silver oxide have a large surface area, there is an effect that the reaction time to become an intermetallic compound can be shortened.

  By including bumps in the electrode configuration, the distance between the electronic component and the circuit board can be easily controlled. Since the bonding can be performed at a pressure lower than the bonding pressure applied by the pressure bonding of the metal bumps, it is possible to reduce the deformation of the wiring and the like. In addition, since the amount of plastic deformation in the horizontal direction of the bumps is reduced, a finer pitch interval can be achieved.

  If the bump is made of a metal such as Al, Sn, Cu, Au, In, or Ag having a low hardness, a metal such as an alloy, a plastic, a resin, or the like, it is possible to further reduce the pressure applied at the time of joining.

  If bumps are made of bumps such as high hardness Al, Cu, Au, Ag, Ni, metals such as alloys or ceramics, and ceramic bumps, the oxide film of the mating electrode can be destroyed and bonded to achieve metal bonding. This is possible with low pressure. The hardness of the metal can be changed by heat treatment, strain application, and plating solution selection.

  In addition, in the present invention, since the bonding material can be supplied to bumps of various materials and shapes with high accuracy, it is possible to perform bonding with insulation by performing vapor deposition or plating on a part of plastic, resin, ceramic, etc. Become.

  One of the electronic components according to the present invention is an RFID tag. The RFID tag of the present invention has an effect that the thickness of the joint can be reduced as compared with the conventional one. Moreover, in the joining using solder, it is possible to introduce polyethylene terephthalate or polyethylene, which could not be used from the viewpoint of heat resistance, into the electronic component.

  Various shapes can be obtained by processing, casting, or welding the metallic silver before being oxidized to silver oxide. In addition, in consideration of pressurizing and joining after joining, annealing is performed after processing to reduce the hardness and facilitate plastic deformation during pressurizing during joining, thereby improving the adhesion of the joining surface and joining strength. Rises.

  In addition to the narrow pitch between electrodes and terminals of electronic components so far, in order to achieve a higher mounting area density, build-up wiring boards with built-in components, chip stacking within the same package, and stacking between packages Such a three-dimensional mounting technique has been proposed. In this technique, in addition to narrowing the pitch, as a countermeasure for increasing the height of signals by increasing the speed of signals and mounting in the vertical direction, it is particularly required to reduce the height of the joint compared to the conventional method.

  Unlike the paste material, the bonding material according to the present invention can suppress the supply of organic matter to the minimum necessary. Therefore, the amount of gas generated during bonding can be reduced. As a result, it is possible to perform bonding with less contamination of surrounding parts by the generated gas. This characteristic is an optimum bonding material for the above-described three-dimensional mounting.

  By applying the present invention, it is a multilayer wiring board in which one or more electronic components are built, and the bonding layer between the electrodes of the electronic component has a crystal grain size of 1000 nm or less. It is possible to provide a multilayer wiring board with built-in electronic components, characterized in that the electrode surface other than the bonding layer and the entire surface or part of the resin are interposed with a roughened layer of metallic silver or silver oxide. . Thereby, adhesiveness with resin can be improved with the shortening of a junction part.

  In addition, it is a laminated chip in which a plurality of LSI chips are laminated, and the electrodes between the chips are electrically bonded via a bonding layer, and the bonding layer has a crystal grain size of 1000 nm or less. It is possible to provide a multilayer chip which is mainly composed of silver and is characterized in that the entire surface or part of the electrode surface other than the bonding layer is a roughened layer of metallic silver.

  One embodiment of a method for manufacturing an electronic member or electronic component according to the present invention will be described below.

  The present invention provides an electronic member in which a silver layer is formed on the outermost surface of an electrode for inputting / outputting or connecting an electric signal, and further, the silver layer is subjected to oxidation treatment, and all or part of the silver layer is a silver oxide layer. Features a manufacturing method. By forming a silver layer, it is possible to supply silver oxide as a bonding material to conductors, semiconductors, and insulators of various shapes, and bond them at a low temperature and low pressure.

  In the above production method, the silver layer is formed by forging or welding.

  In the above production method, the silver layer is formed by vapor deposition or plating.

  In the above production method, the silver oxide layer is formed by anodization or ozone oxidation.

  If an anodic oxidation method is applied as a method for converting the silver layer into a silver oxide layer, the curvature and layer thickness of the surface of the silver oxide layer can be controlled with high accuracy. In the case of the electroless anodic oxidation method, the intended silver oxide layer can be produced by changing the solution to be produced and the temperature. In the case of the electrolytic anodic oxidation method, the target silver oxide layer can be produced by changing the solution to be produced, the current density, the potential, and the temperature. The solution may be made of an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide.

When the treatment in the liquid is difficult, a method of converting the silver layer into a silver oxide layer with ozone gas can be taken. The surface curvature and layer thickness of the silver oxide layer can be controlled with high accuracy also by ozone oxidation.
That is, the target silver oxide layer can be produced by changing the production temperature and ozone concentration.

  The present invention is a mounting method of an electronic component, wherein one or more connection terminals provided on a circuit board and one or more electrode terminals provided on an electronic member are electrically bonded via a bonding layer, At least one surface of the connection terminal or the electrode terminal is formed of a silver oxide layer, a reducing agent is supplied to the silver oxide layer, heating at 100 ° C. to 400 ° C. is applied to at least the bonding surface, and at least oxidation is performed. It is characterized by a method for mounting an electronic component that electrically joins the connection terminal and the electrode terminal by applying a pressure of 0.1 to 20 MPa to the joint surface when silver is reduced to metallic silver.

  In the above mounting method, the reducing agent is an alcohol, a carboxylic acid, or an amine.

  As an electrode that can be bonded to the bonding member (silver oxide layer) according to the present invention, if the metallized layer on the outermost surface of the electronic component is a simple substance or alloy of Au, Ag, Pt, Pd, Cu, Ni, a reducing agent is used. Metal bonding is possible by selecting. Further, it is possible to bond to a metal having a stable oxide film such as Al through the oxide film. Moreover, joining of silver oxide layers is also possible.

  By supplying the reducing agent only to the bonding surface of the electronic member, the portion other than the bonding surface can remain as the silver oxide layer. This is a technique in which the area where the reducing agent is not applied is left as silver oxide when bonding is performed in a non-reducing atmosphere such as in the air, nitrogen, or vacuum. Electricity using a large difference in resistance between silver oxide and metallic silver A circuit can be introduced.

  On the other hand, by supplying a reducing agent to the entire surface of the electrode of the electronic member, it is possible to make sintered silver other than the joint surface. When the base is Ag, the sintered silver other than the bonding layer is integrated and becomes a strong bond. In addition, since the surfaces other than the bonding surface are not pressurized, the surface is roughened. For example, when sealed with resin after bonding, the resin enters the roughened surface, which is more than the state of the normal Ag electrode. Adhesive strength is improved.

  As a method of reducing silver oxide, it is possible to use a gas in addition to using a reducing agent. That is, at least the bonding surface is heated to 100 ° C. to 400 ° C. in a reducing gas atmosphere, and at least when the silver oxide is reduced to metallic silver, a pressure of 0.1 to 20 MPa is applied to the bonding surface. The space can be electrically joined. The reducing atmosphere gas may be an atmosphere having a reducing effect on silver oxide such as hydrogen or formic acid. In addition, an effect of reducing or preventing oxidation of the oxide film existing on the outermost surface of the electrode of the electronic component can be expected. In particular, by reducing in a hydrogen atmosphere, the only gas generated is water, and the surrounding contamination is significantly reduced.

It is also possible to reduce silver oxide using a reducing agent and a reducing atmosphere (gas) in combination.
Although details will be described in Example 17, depending on the type of the reducing agent, the effect of electroless plating in which the reduced silver particles are dispersed in the reducing agent in a liquid state and deposited on the electrode is exhibited. Since this effect does not depend on the magnitude of the applied pressure, it is preferable to introduce a liquid phase even in a hydrogen atmosphere when joining at a low pressure.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described here, and may be combined as appropriate.

  In Example 1, Ag metallization is formed on the Cu wiring of the circuit board by electrolytic plating, and the thickness of the Ag metallization is 5 μm.

Next, Ag metallization was made into a silver oxide layer by anodic oxidation. In anodization, an aqueous solution of sodium hydroxide (NaOH) was used to keep the current density (mA / cm ² ) constant. A Ni electrode was used as the counter electrode.

  The pH was changed by changing the molar concentration of sodium hydroxide, the current density was changed by changing the current value, and the relationship between the pH, the current density, and the thickness of the silver oxide layer was examined. The thickness of the silver oxide layer was determined by cutting out a sample cross section, observing with a scanning electron microscope, and averaging 50 points in an arbitrary field of view. FIG. 3 shows the relationship between pH, current density, and silver oxide layer thickness.

  As shown in FIG. 3, it was found that the thickness of the silver oxide layer produced can be accurately controlled by the pH and current density values when the silver oxide layer is produced. When the current is low, the thickness of the silver oxide layer can be increased, and when the current is high, the thickness of the silver oxide layer can be reduced.

  An Ag metallization with a thickness of 5 μm was formed on the Cu wiring of the circuit board by electrolytic plating, and a silver oxide layer was formed by ozone oxidation. Ag metallization was sprayed with an ozone concentration of 5 vol% at 150 ° C. Thereby, it confirmed that the silver oxide layer produced | generated and the thickness of a silver oxide layer increased with the increase in the spraying time.

  In Example 3, the cross section of the silver oxide layer produced in Examples 1 and 2 was observed with a scanning microscope. As a result of observation at a magnification of 100,000, it was found that several voids of several to several tens of nanometers were scattered, and a silver oxide layer having almost no voids was formed. This is thought to be because the reaction increases in volume when the Ag metallized layer is oxidized to silver oxide.

As a comparison, a green compact in which a pressure of 100 MPa was applied to silver oxide particles having a size of 1 to 3 μm was produced. The produced green compact was filled with resin and the cross section was cut out, and the cross section was observed with a scanning microscope. As a result of observation at a magnification of 10,000, voids of several hundred nm to several μm were scattered.
As described above, it was found that the silver oxide serving as the bonding material can be supplied more densely when supplied in a layer form than in a particle form.

  In Example 4, the relationship between the thickness of the silver oxide layer on the surface of the electronic member according to the present invention and the joint strength of the joined body was examined. The Cu wiring of the circuit board was subjected to Ni plating and Ag plating from the Cu side by electrolytic plating (Ni plating thickness: 2 μm, Ag plating thickness: 3 μm). Next, this was anodized in the same manner as in Example 1 to produce a silver oxide layer. A sodium hydroxide aqueous solution having a molar concentration of 3 mol / L was used to control the current density and change the thickness of the silver oxide layer.

  The above-mentioned Si chip with Au metallized surface was bonded to the circuit board in the air. Before joining, the circuit board was sprayed with a triethylene glycol solution, and then a Si chip was installed, and joining was performed by applying a heating step and a pressurizing step. The bonding conditions are a maximum heating temperature of 250 ° C., a bonding time of 150 s, and a bonding pressure of 2.5 MPa. The joining time is the sum of the temperature rise from room temperature to the joining temperature and the time kept at the maximum heating temperature.

  Next, the joint strength under pure shear stress was measured for the Si chip joined body produced under the above joining conditions. For the shear test, a bond tester SS-100KP (maximum load 100 kg) manufactured by Seishin Shoji Co., Ltd. was used. The shear rate was 30 mm / min, the test piece was broken with a shearing tool, and the maximum load at the time of breaking was measured. The value obtained by dividing the maximum load thus obtained by the joint area is taken as the shear strength of the joint. Moreover, as an index of the shear strength when using the bonding material in the present example, a room temperature curable conductive paste was used, and the relative strength ratio to the shear strength of the bonded body joint according to the present invention was used. FIG. 4 shows the result. In the conductive paste, the main resin component is an epoxy resin, and the conductive filler is Ag flakes.

  As shown in FIG. 4, in the case of an Ag electrode in which a silver oxide layer is not formed, the bonding strength was not obtained. Further, the strength increased as the thickness of the silver oxide layer increased. Furthermore, it was found that the thickness is desirably 400 nm or more in order to exhibit strength higher than that of the conductive paste. This is because volume reduction occurs when silver oxide is reduced to metallic silver, and it is due to the need for a thickness to form a dense network when compressed in the direction perpendicular to the joint surface. Conceivable.

  In Example 5, the adhesion degree between the silver oxide layer and the Ag metallized when the base of the silver oxide layer was Ag metallized was examined. The bonded test piece used for the measurement is a cylindrical oxygen-free copper test piece having a diameter of 10 mm and a thickness of 25 mm on the upper side, and Ni plating and Ag plating are applied to the Cu surface by 2 μm each by electrolytic plating. ing. By the method of Example 1, 1 μm of a silver oxide layer was applied to one side, and the surfaces provided with the silver oxide layer were bonded together with an epoxy adhesive, and the tensile strength was measured. For comparison, the strength of Ag plating not subjected to oxidation treatment, and the sintered silver layer in the case of the surface where the bonding maximum heating temperature in hydrogen is 250 ° C. and the bonding time is heated for 300 s to sinter the silver oxide layer, The strength of was also measured. The results are shown in FIG.

  Moreover, it investigated by observing the destruction part with an optical microscope. As a result, it was destroyed at the interface between the adhesive and the Ag plating in the joined body of Ag plating, and was destroyed in the adhesive at the joined body of sintered silver or silver oxide layers. Therefore, it can be seen that the adhesion strength between the sintered silver or silver oxide layer and the underlying Ag is a tensile strength of 5 MPa or more. Moreover, it turns out that the adhesive strength of a sintered silver or silver oxide layer and an adhesive improves compared with the case of Ag plating. This is considered to be because the surface of the sintered silver or silver oxide layer is roughened and the adhesion area increases.

  In Example 6, the relationship between the joining temperature and the joint strength was examined. The examined samples were prepared in the same manner as in Example 4. The silver oxide layer was prepared to have a thickness of 1 μm. The bonding atmosphere is in hydrogen. The bonding conditions were such that the maximum heating temperature was 100, 150, 200, 250, and 300 ° C., the bonding pressure was constant at 1.0 MPa, and the holding time was constant at 100 s, and the influence of the maximum heating temperature was examined. Further, the maximum heating temperature was 100 ° C. and the holding time was 1800 s, and the influence of the holding time was examined. The strength of the joint was measured in the same manner as in Example 4. The result is shown in FIG.

  As shown in FIG. 6, the joint strength increased as the joining temperature increased, and a normalized shear strength of 1 or more could be exhibited at a joining temperature of 200 ° C. Further, it was found that the normalized shear strength of 1 or more can be exhibited by increasing the holding time even at a joining temperature of 100 and 150 ° C. Since the joint strength can be obtained even at a joining temperature of 100 ° C., it is possible to introduce an organic substance that cannot be used from the viewpoint of heat resistance into the structure of the joined body.

  In Example 7, the relationship between the joining pressure and the joint strength when the joining material according to the present invention was used was examined. As in Example 4, 5 μm thick Ag metallization was formed on the Cu wiring of the circuit board by electrolytic plating, and a 1 μm thick silver oxide layer was formed by anodic oxidation. If the applied pressure increases and the joint strength increases, the Si chip breaks when measuring the shear strength. Therefore, a Cu substrate with Au plating was used here.

  Before bonding, a mixed solution of cetyl alcohol and ethyl alcohol acting as a reducing agent was applied to the surface of the silver oxide, and then a Cu substrate was placed and bonded in the air by applying a heating step and a pressing step. The bonding conditions were such that the maximum heating temperature of the bonding was fixed at 250 ° C. and the bonding time was 150 s, and the effect of the bonding pressure was examined by changing the bonding pressure from 0.5 to 20 MPa. The results are shown in FIG.

  As shown in FIG. 7, there was a tendency for the strength to increase as the applied pressure increased. Further, it was found that when the joining temperature was 250 ° C. and the joining time was 150 s, the standardized shear strength was 1 or more when the joining pressure was about 1.0 MPa or more. However, as explained in Example 6, the strength can be improved by increasing the bonding temperature and increasing the holding time even with the same pressing force. If there is a pressing force of 0.1 MPa or more, the bonding temperature and holding time can be reduced. Increased metal bonding becomes possible.

  In the eighth embodiment, an example in which the bonding strength is increased by improving the configuration with respect to the configuration of the seventh embodiment will be described. As an improved sample A, an Ag bump was formed between the Cu wiring and the Ag metallized layer. Next, when joining was performed in the same manner as in Example 7 at a joining temperature of 250 ° C., a joining pressure of 0.5 MPa, and a joining time of 150 s, a normalized shear strength of 1.0 was obtained. As an improved sample B, curvature was given to the Ag bump. As a result, a normalized shear strength of 1.2 was obtained. Thus, it has been found that the strength is increased by applying bumps to form a shape in which pressure is easily applied to the joint surface.

  Next, the bump was made of Al. When a reducing agent was used as hydrogen gas and bonding was performed in the same manner as in Example 6 at a bonding temperature of 100 ° C., a bonding pressure of 1.0 MPa, and a holding time of 1800 s, a normalized shear strength of 1.3 was obtained. Next, when the bump was made of Sn-3.5Ag alloy, a normalized shear strength of 1.5 was obtained. Thus, it turned out that intensity | strength raises by providing a metal with high hardness and low hardness as a bump.

  As described in the seventh embodiment, it is possible to improve the strength of the joint by increasing the pressure applied at the time of joining. However, depending on the magnitude of the applied pressure, there is a possibility that the electronic member to be joined (for example, the semiconductor chip and the wiring and electrodes formed on the upper surface thereof) may be physically damaged. As shown in Table 1, when a pressure of 10 MPa or more was applied, the semiconductor chip to be bonded might be damaged. On the other hand, as described in Example 7, since bonding is possible even at a temperature of the bonding process of the present invention of about 100 ° C., an organic material having a stress buffering effect such as a synthetic resin is used to prevent damage to the semiconductor chip. It is possible to use. In order to confirm this effect, when a semiconductor chip protected with polypropylene was pressurized at 100 ° C., no damage was observed even at 20 MPa.

  In this embodiment, a lead frame according to the present invention and a semiconductor package (QFP) using the lead frame will be described. As the material of the lead frame, there are an Fe alloy and a Cu alloy.

FIG. 8A is a schematic cross-sectional view of a lead frame 300 according to the present invention. The lead frame includes a die pad 301 on which a die such as a Si chip is mounted, and leads 302 that input and output electrical signals. For example, the Ni-plating 303 is applied from the Cu side to the die pad portion 301 of the lead frame (thickness: 0.3 mm) made of a Cu—Cu ₂ O composite material with a thickness of 2 μm and the Ag plating 304 is applied to the thickness of 2 μm by electrolytic plating. ing. Next, the silver oxide layer 305 is applied in a thickness of 1 μm by further anodizing the Ag plating.

FIG. 8B is a schematic cross-sectional view of the QFP according to the present invention. Decanoic acid was applied to the silver oxide layer on the silver oxide layer shown in FIG. 8A, and the outermost surface of the silver oxide layer was a silver decanoate compound.
The silver decanoate compound functions as a silver oxide reducing agent. Subsequently, a Si element (size 1 mm × 1 mm × 0.3 mm) plated with Au was mounted on the surface as the semiconductor element 306. As a bonding process, a bonding temperature of 280 ° C. and a bonding pressure of 1.5 MPa are applied for 30 seconds, and the Si element is bonded by a bonding layer 307 mainly composed of sintered silver. Further, by this treatment, a roughened layer 308 made of sintered silver is formed on the die pad surface.

  The electrical connection between the electrode on the Si element 306 and the lead 302 is performed by ultrasonic bonding of an Au wire 309. Thereafter, the main part to which the Si element 306 and the Au wire 309 are applied is covered with an epoxy resin 310 by a transfer mold. At this time, the interfacial adhesion strength between the roughened layer 308 and the epoxy resin is improved as described above. The lead frame 300 is cut off when the molding with the epoxy resin 310 is completed, and functions as independent terminals are provided.

  In this embodiment, a lead frame according to the present invention and a semiconductor package (QFP) using the lead frame will be described.

  FIG. 9A is a schematic cross-sectional view of a lead frame 400 having a structure in which a silver oxide layer is also provided to the lead portion 302 of FIG. Ni plating 403 is applied to the entire surface of the die pad 401 and the lead 402 from the Cu side by a thickness of 2 μm, and an Ag plating 404 is applied by electrolytic plating to a thickness of 2 μm. Next, the silver oxide layer 405 is applied with a thickness of 1 μm by further anodizing the Ag plating.

  FIG. 9B is a schematic cross-sectional view of the QFP according to the present invention. As a pre-packaging process, the supply of the reducing agent to the surface of the silver oxide layer is limited to the bonding layer 407, the roughened layer 408a, and the roughened layer 408b other than the region where the package is mounted thereafter. The bonding conditions of the Si element 406 to the die pad 401 are a bonding temperature of 280 ° C., a bonding pressure of 1.5 MPa, a bonding time of 30 seconds, and the region where the package is mounted is not reduced as the silver oxide layer 411.

  The electrical connection between the electrode on the Si element 406 and the lead 402 is performed by ultrasonic bonding of an Au wire 409. Thereafter, similarly to the above, it is covered with an epoxy resin 410 by a transfer mold. At this time, the interfacial adhesion strength between the entire surface of the lead frame (roughened layer 408a and roughened layer 408b) and the epoxy resin is further improved than the above.

  The lead frame 400 is separated when the molding with the epoxy resin 410 is completed, and functions as independent terminals are provided. Next, the QFP is mounted on the electrodes on the circuit board by immersing, for example, triethylene glycol in the silver oxide layer 411 and applying heat and pressure.

  In this embodiment, a TAB tape carrier according to the present invention will be described. As shown in FIG. 10A, a Cu foil 503 is bonded to an insulating film 501 such as polyethylene terephthalate or polyimide film with an adhesive layer 502 interposed therebetween. Next, a photoresist 504 is formed on the Cu foil 503 as shown in FIG. As shown in FIG. 10C, exposure and development are performed. As shown in FIG. 10D, the copper foil 503 is etched to form a wiring pattern. In this embodiment, the Cu foil is bonded by the adhesive layer, but the conductor may be formed on the insulating film by using a technique of plating through a sputtering layer of Ni alloy, for example.

  In addition to the connection terminal region 505 of the wiring pattern, a resist 506 is applied and formed as an insulating layer. Then, Ag plating 507 is applied to the connection terminal region 505 that is the exposed region, and a part of the Ag plating is used as the silver oxide layer 508, thereby completing the TAB tape.

  The completed TAB tape is used by combining the Au bump of the Si chip and the silver oxide layer 508 on the device hole. Bonding can be performed by the above-described method, and an electronic component can be produced at a lower temperature and lower pressure than conventional thermocompression bonding. In addition, a COF (Chip on Film) that does not have device holes can be used as an electronic component mounting member by applying a silver oxide layer by a similar method.

  In this embodiment, an RFID according to the present invention will be described. FIG. 11A is a schematic cross-sectional view of an RFID antenna substrate. As shown in FIG. 11A, an antenna 602 made of metal such as Cu or Al is installed on an insulating film 601 such as polyethylene terephthalate or acrylonitrile butadiene styrene copolymer. As an antenna installation method, a method of forming a film by plating or vapor deposition and then etching, a method of printing and baking with conductive ink, a method of bonding a metal foil with an adhesive, and the like are taken.

  Next, an electrode 603 for mounting the RFID chip is formed. The surface of the metallized layer 603 to be an electrode is Ag metallized, and part or all of the Ag metallized is a silver oxide layer 604.

  FIG. 11B is a schematic cross-sectional view of an RFID tag. An RFID chip 605 is mounted on the silver oxide layer 604 of the antenna substrate shown in FIG. The bump electrode 606 of the chip 605 is flip-chip mounted according to the silver oxide layer 604. As described above, bonding is possible at a low temperature and low pressure compared to the conventional method. The antenna side electrode 603 and the bump electrode 606 are electrically connected by the bonding layer 607 mainly composed of sintered silver. Further, after mounting the chip, the underfill 608 is sealed with an epoxy resin or the like. At this time, since the roughened layer is formed on the antenna substrate electrode, the adhesion to the resin is improved. Finally, it is laminated with polyethylene terephthalate (609).

Further, bonding without a bump as shown in FIG. 2 is possible, and the height of the bonded portion can be reduced.
By forming an antenna with Ag, or forming an Ag metallized layer on the entire surface of the antenna to form a silver oxide layer, the entire surface becomes a roughened layer simultaneously with the bonding. Thereby, it is possible to make it the structure which improves the adhesiveness of resin or a laminate material.

  In this embodiment, an LED package according to the present invention will be described. FIG. 12 is a schematic cross-sectional view of an LED package. On the organic substrate 701 (ceramic substrate, organic film), an LED chip 702, metal wires 703 (leads, ribbons), and a metallized layer 705 for mounting the reflector 704 are formed. Reference numeral 706 denotes a wiring. Each component is mounted via a bonding layer 707 mainly composed of a sintered silver layer.

  In LED mounting, an increase in the amount of heat generation is a problem, but heat dissipation is improved by forming the joint portion with metallic silver. In addition, depending on the light emission region, ultraviolet light is irradiated to the joint, and there is a problem that the joint is deteriorated in the joint mainly made of resin. However, connection reliability improves because a junction part is comprised with metal silver.

  In the LED package, a reflector 704 with Ag metallization 708 may be used to improve the light irradiation efficiency. However, the Ag metallization is performed on the entire surface as shown in FIG. Can be mounted in a silver oxide layer. It is also possible to improve heat dissipation by using the metallized layer 705 and the joint 707 that are not electrically joined to the wiring. Further, a phosphor 709 is attached if necessary.

  In this embodiment, a component built-in type multilayer wiring board according to the present invention will be described. FIGS. 13A to 13C are schematic cross-sectional views of components built in a component built-in type multilayer wiring board. FIG. 13A is a schematic cross-sectional view of a passive component 803 such as an inductor, a capacitor, or a resistance component, in which a metallized layer 802 is formed on an electrode, and a silver oxide layer 801 is formed on the surface thereof. The metallized layer and the silver oxide layer can be produced by barrel plating.

  FIG. 13B is a schematic cross-sectional view of the LSI chip 804. The bump 805 provided on the electrode has a protruding shape, and a silver oxide layer 806 is further formed. FIG. 13C shows a schematic cross-sectional view between a partial core layer and an interlayer of a multilayer wiring board. Conduction in the height direction of the core 807 is performed by the wiring 809 on the surface of the through hole 808. Conduction of the prepreg 810 between the layers is performed by a bump-shaped through electrode 812 having a silver oxide layer 811 on the surface. The silver oxide layer 811 may be provided on the surface of the wiring 809 (interface between the prepreg 810 and the wiring 809).

FIG. 14 is a schematic cross-sectional view of a component built-in type multilayer wiring board manufactured using the above components. The passive component 803, the LSI chip 804, and the through wiring 812 are joined by silver particles produced by reduction of silver oxide by the method described above, and are mounted on the electrode through the sintered silver layer 813.
Moreover, since the silver oxide layer other than each joining location becomes the sintered silver roughened layer 814, the adhesion degree with the prepreg 810 can be improved. Further, by providing silver oxide having a high hardness on the bump surface such as the bump 805 and the through electrode 812, it is possible to break the oxide film to be bonded with low pressure.

  Also, as shown in FIG. 15, by connecting the electrodes of the electronic component in the vertical direction or in the parallel direction as shown in FIG. 16, the thickness of the multilayer substrate is minimized according to the dimensions of the electronic component. The design freedom is high because heat dissipation can be taken into account.

  In three-dimensional mounting, control in the height direction is important. In the bonding mode according to the present invention, there are effects that the height of the bonding layer can be reduced, there is no inclination, and less gas is generated during bonding. In addition, since each bonding layer is thin, there is an effect that a circuit with little delay of an electric signal can be obtained.

  In this example, a multilayer chip according to the present invention will be described. FIG. 17 is a schematic cross-sectional view of a multilayer chip. A through electrode 903 is formed in the semiconductor element 901 with an insulating layer 902 interposed therebetween. Further, Ag metallized 904 is provided on one side when the through electrode is formed, and a silver oxide layer is further formed. Using this silver oxide layer, a plurality of semiconductor elements are laminated via a bonding layer 905 mainly composed of sintered silver.

On the other hand, the semiconductor element 906 having Ag metallization formed on both sides is manufactured by first performing Ag plating after the through electrode is not Ag, for example, Cu, and then performing further Cu plating and then Ag plating. The semiconductor element is diced. By doing so, a part of the Ag metallized 907 can be anodized and the electrode 909 of the interposer 908 can be joined.
It is also possible to apply Ag metallization only on one side and join the interposer by brazing or crimping. Furthermore, regarding the bonding between the bump 910 provided on the interposer and the circuit board, the present invention may be used or other bonding methods may be used.

  In Example 17, the influence of the bonding partner electrode type on the joint strength was examined. The examined samples were prepared in the same manner as in Example 4. The silver oxide layer was prepared to have a thickness of 1 μm. The bonding atmosphere was in hydrogen. The surface electrode of the bonding partner was changed to Ag, Au, Pt, Pd, Cu, and Ni. The joining conditions were a maximum heating temperature of 250 ° C., a pressure of 2.5 MPa, and a holding time of 100 s.

  FIG. 18 shows the normalized shear strength values of a silver oxide sheet joined without a reducing agent and a silver oxide sheet further dropped with triethylene glycol. Except for the Ni electrode, the strength was almost the same, but in the case of joining with the Ni electrode, a significant increase in strength was observed by dropping triethylene glycol. This is because when the triethylene glycol is dropped, the reduced silver particles are dispersed in the triethylene glycol, and the effect of electroless plating is deposited on the electrode. Since this effect does not depend on the magnitude of the applied pressure, it is preferable to introduce a liquid phase even in a hydrogen atmosphere when joining at a low pressure.

DESCRIPTION OF SYMBOLS 101 Silver oxide 102 Silver particle 103 Silver oxide external shape 200 before reduction | restoration Circuit board 201 Insulating layer 202,706,809 wiring 203 Metallization layer (electrode)
204, 506 Resist 205, 305, 405, 411, 508, 604, 801, 806, 811 Silver oxide layer 205a Sintered silver layer (bonding layer)
205b Sintered silver layer (roughened layer)
206 Chip 207, 603, 909 Electrode 208, 705, 802 Metallized layer 209 LSI chip 300 Lead frame 301 Die pad 302, 402 Lead 303, 403 Ni plating 304, 404, 507 Ag plating 306, 901, 906 Semiconductor elements 307, 407, 607, 905 Bonding layer 308, 408a, 408b Roughening layer 309, 409 Au wire 310, 410 Epoxy resin 400 Lead frame 401 Die pad portion 406 Si element 501 Insulating film 502 Adhesive layer 503 Cu foil 504 Photoresist 505 Connection terminal region 601 Insulating film 602 Antenna 605 RFID chip 606 Bump electrode 608 Underfill 609 Laminate 701 Organic substrate 702 LED chip 703 Metal wire 704 Lector 707 Joint 708, 904, 907 Ag metallized 709 Phosphor 803 Passive component 804 LSI chip 805, 910 Bump 807 Core 808 Through hole 810 Prepreg 812, 903 Through electrode 813 Sintered silver layer 814 Sintered silver roughened layer 902 Insulation Layer 908 interposer

Claims (8)

An electronic component in which one or more electrodes provided on an electronic member are electrically bonded via a bonding layer to one or more connection terminals provided on a circuit board,
The bonding layer is mainly composed of sintered silver,
The whole or part of the electrode surface not in contact with the bonding layer is a roughened layer of silver oxide,
The thickness of the roughened layer of silver oxide is 400 nm or more and 5 μm or less,
The electronic component according to claim 1, wherein an outermost surface of the silver oxide layer has a radius of curvature smaller than 1 μm.   2. The electronic component according to claim 1, wherein the sintered silver is sintered silver having a crystal grain size of 1000 nm or less.   2. The resin according to claim 1, wherein a resin is filled between the circuit board and the electronic member, and an entire surface or a part of the electrode not in contact with the bonding layer is bonded to the resin through the silver oxide roughening layer. Electronic parts characterized by   2. The electronic component according to claim 1, wherein the sintered silver is porous, and a resin is filled in the pores of the sintered silver.   2. The connection terminal or the electrode according to claim 1, wherein the connection terminal or the electrode is made of at least one material selected from a simple substance, an alloy, or a mixture of Ag, Au, Cu, Pt, Ni, Co, Ti, Mo, Fe, Al, and Zn. Electronic parts characterized by being made.   The electronic component according to claim 1, wherein the connection terminal or the electrode is made of at least one material selected from a simple substance of Sn, an Sn alloy, or a mixture. A multilayer wiring board with one or more electronic components built therein,
The bonding layer between the electrodes of the electronic component is composed of sintered silver, and the entire surface or part of the electrode surface not in contact with the bonding layer is a roughened layer of silver oxide,
The roughened layer of silver oxide is 400 nm or more and 5 μm or less,
The outermost surface of the silver oxide layer has a radius of curvature smaller than 1 μm,
A multilayer wiring substrate with a built-in electronic component, wherein a resin is filled between electrodes of the electronic component. A plurality of LSI chips are laminated chips,
The electrodes between the chips are electrically bonded via a bonding layer,
The bonding layer is mainly composed of sintered silver,
The whole or part of the electrode surface not in contact with the bonding layer is a roughened layer of silver oxide,
The roughened layer of silver oxide is 400 nm or more and 5 μm or less,
The multilayer chip, wherein the outermost surface of the silver oxide layer has a radius of curvature smaller than 1 μm.