JP2009099669A - Mounting structure of electronic component, and mounting method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of a bare chip or chip-sized package low in conduction resistance, high in adhesion strength, and high in connection reliability; and to provide a mounting method thereof. <P>SOLUTION: A solder bump 3 is formed on each electrode terminal 1b of a semiconductor element 1, and the electrode terminal 1b of the semiconductor element 1 is connected to an electrode pad 2b of a mounting board 2 through the solder bump 3 and a conductive adhesive 4. Each conductive particle included in the conductive adhesive 4 contains an intermetallic compound using Sn being a metal material of solder as a constituent. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a mounting structure and mounting method for an electronic component such as a bare chip, CSP, and BGA, and particularly to an electronic device that performs connection between an electronic component and a mounting substrate using a solder bump or solder ball and a conductive adhesive. The present invention relates to a component mounting structure and a mounting method.

With the rapid development of electronic devices, semiconductor elements such as LSIs are required to have higher functionality than ever. As the number of multifunctional semiconductor elements increases, the number of input / output terminals of the semiconductor elements increases, and the wiring length for operating the semiconductor elements at high speed is required to be shortened. As a connection method developed to realize such a requirement, there is a flip chip connection. Flip chip connection is suitable for increasing the number of pins because connection pads can be provided in the form of areas on the wiring surface of a semiconductor element. In addition, compared with other semiconductor element connection methods such as wire bonding and tape automated bonding, the lead length is not required, so that the wiring length can be shortened.
For the reasons described above, the number of semiconductor devices used in electronic devices using flip chip connection is increasing.

At present, Au, solder, or the like is used as a material for a general bump electrode used for a flip chip. Examples of the solder material include Sn-Pb eutectic solder, but are not limited to Sn-Pb eutectic solder. For example, Sn-Pb (excluding eutectic), Sn-Ag, Sn-Cu, Sn-Zn. , Sn-Bi, and materials obtained by further adding a specific additive element to the above-described materials can be used as appropriate.
On the other hand, in many of the semiconductor elements that are flip-chip connected, in order to relieve stress due to the difference in thermal expansion between the semiconductor element and the substrate, it is necessary to ensure connection reliability by sealing the gap between the semiconductor element and the substrate. (For example, refer to Patent Document 1).

In the conventional example in which the flip chip bonding is performed only with the solder bump, a high stress is generated in the solder bump having a high elastic modulus due to the difference in thermal expansion between the semiconductor element and the substrate, and there is a problem of destroying the chip, the bump, the substrate, etc. in the vicinity of the bonding portion. is there. Therefore, the connection reliability can be improved by sealing the gap between the semiconductor element and the substrate with an underfill resin for the purpose of relaxing the stress applied to the bumps. However, since stress is concentrated on the bump bonding portion in the process before resin sealing, it is necessary to take measures against stress in the manufacturing process. This problem becomes more serious as the use of lead-free solder with a high elastic modulus and products using low-k films with low mechanical strength for chips increase. Even after sealing with the underfill resin, the elastic modulus of the solder bump is much higher than that of the underfill resin. For example, the elastic modulus of Sn-3Ag-0.5Cu solder is about 40 GPa. On the other hand, the elastic modulus of the underfill resin is about 10 GPa even when the elastic modulus is increased by mixing a filler. For this reason, there is a problem that stress is still concentrated on the solder joint portion having a high elastic modulus, and cracks are generated in the solder bump, the chip at the connection end, or the substrate due to repeated temperature changes.
In order to lower the elastic modulus of the solder bump bonding portion, it is conceivable to connect the solder bump using a conductive adhesive having a lower elastic modulus. Thus, it has been attempted to connect the solder bumps with a conductive adhesive (see, for example, Patent Documents 2 and 3). In the joining methods described in Patent Documents 2 and 3, a conductive adhesive is applied to a solder bump or an electrode pad on a substrate, a semiconductor element is mounted on the substrate, and the conductive adhesive is at a temperature lower than the melting point of the solder. Is cured and connected.
Japanese Patent Laid-Open No. 11-233558 JP-A-1-226161 JP 2001-44606 A

  In the joining method using the conventional conductive adhesive described in Patent Documents 2 and 3, it is difficult to realize low conduction resistance and high adhesive strength at the joining interface. The reason is as follows. In the conventional bonding structure, the conductive particles of the conductive adhesive and the solder bumps are merely in contact with each other, and no adhesive force can be obtained at this contact portion. The adhesive force is an insulating resin that is a base material of the conductive adhesive. Relied only on. When trying to reduce the conduction resistance at the interface, it is necessary to increase the contact area between the conductive particles of the conductive adhesive and the solder bumps, but to increase the contact area, it is necessary to increase the ratio of the conductive particles. Filling inevitably leads to a reduction in the base resin. On the other hand, in order to increase the adhesive strength, the ratio of the insulating resin must be increased. This inevitably leads to a reduction in the contact area between the conductive particles and the solder bumps. That is, in the conventional joining method, there was a trade-off relationship between low conduction resistance and high adhesive strength.

In order to cope with this point, the present inventor has devised a joining method in which solder is melt-joined with conductive particles of a conductive adhesive. According to this bonding method, not only the solder bump and the conductive particles can be bonded with low resistance, but also an adhesive force is developed between the solder bump and the conductive particles, so the above trade-off relationship is eliminated. It was thought that both reduction of conduction resistance and improvement of adhesive strength could be realized. However, when this junction structure was actually manufactured, it became clear that the conduction resistance did not drop as expected. As a result of examining the cause, it was found that the conductive particles in the vicinity of the bonding interface between the solder bump and the conductive adhesive are taken into Sn of the solder.
An object of the present invention is to solve the above-mentioned problems of the prior art, the purpose of which is to relieve stress caused by a difference in thermal expansion coefficient between a semiconductor element and a mounting substrate, and to bond with low resistance. It is to be able to provide a mounting structure for a high-strength electronic component.

  In order to achieve the above object, according to the present invention, in an electronic component mounting structure in which an electrode terminal of an electronic component and an electrode pad of a mounting substrate are connected via a solder bump and a conductive adhesive, Solder bumps are formed on one or both of the electrode pads and the electrode pads, the solder bumps and the electrode pads or electrode terminals, or the solder bumps are connected via a conductive adhesive, The bonding interface of the adhesive provides a mounting structure for an electronic component in which solder is melt-bonded to conductive particles in the conductive adhesive.

  And preferably, the electroconductive particle contained in the said electrically conductive adhesive contains the intermetallic compound. More preferably, the conductive particles contained in the conductive adhesive contain an intermetallic compound having a main constituent metal of the solder as a constituent element. Preferably, the periphery of the intermetallic compound is covered with a metal layer. Preferably, the conductive particles include well-conductive conductive particles of metal having better electrical conductivity than the intermetallic compound in addition to the intermetallic compound.

  In order to achieve the above object, according to the present invention, a step of forming a solder bump on at least one of an electrode terminal or an electrode pad of a mounting board on an electronic component, and one or both of the electronic component and the mounting board A step of supplying a conductive adhesive to the electrodes, an electronic component mounted on the mounting substrate, and the electrode terminals of the electronic component and the electrode pads of the mounting substrate are connected via the solder bumps and the conductive adhesive. There is provided a method for mounting an electronic component, comprising: a step of connecting; and a step of melting a solder bump to melt and bond with conductive particles of a conductive adhesive and proceeding to cure the conductive adhesive The

  In order to achieve the above object, according to the present invention, a step of forming a solder bump on at least one of an electronic component electrode terminal or an electrode pad of a mounting substrate, and one or both electrodes of the electronic component and the mounting substrate Supplying a conductive adhesive to the mounting board, positioning the electronic component on the mounting board, and connecting the electrode terminal of the electronic part and the electrode pad of the mounting board via the solder bump and the conductive adhesive A step of advancing the curing of the conductive adhesive, a step of injecting an underfill resin into the gap between the electronic component and the mounting substrate, and a step of melting the solder bump to melt-bonding with the conductive particles of the conductive adhesive And an electronic component mounting method characterized by comprising:

  In order to achieve the above object, according to the present invention, a step of forming a solder bump on at least one of an electrode terminal of an electronic component or an electrode pad of a mounting substrate, and one or both of the electronic component and the mounting substrate The process of supplying a conductive adhesive to the electrode and proceeding with the curing, the process of supplying the underfill resin on the mounting board, and mounting the electronic component on the mounting board, mounting it on the electrode terminal of the electronic component A method for mounting an electronic component, comprising: a step of connecting an electrode pad of a substrate to a solder bump through a conductive adhesive; and a step of melting the solder bump and melt-bonding the conductive bump to a conductive particle. Provided.

  According to the present invention, since the joint between the electronic component and the mounting substrate is constituted by the solder bump and the conductive adhesive, there is a difference in thermal expansion coefficient between the electronic component substrate (semiconductor substrate) and the mounting substrate. However, due to the stress relaxation effect of the conductive adhesive layer, it is possible to relax the stress caused by the difference in thermal expansion between the electronic component and the mounting substrate, and the occurrence of cracks and disconnections can be prevented. Further, according to the present invention, since the conductive adhesive solder bump is melt-bonded to the conductive particles of the conductive adhesive, the adhesive force of the solder is added in addition to the adhesive force of the conductive adhesive resin, High adhesive strength can be obtained between the conductive adhesive. Furthermore, since the conductive adhesive solder bump is melt-bonded to the conductive particles of the conductive adhesive, and the conductive particles in the conductive adhesive are not taken in and disappear by Sn in the solder bump, the solder The conduction resistance between the bump and the conductive adhesive can be kept low. Therefore, according to the present invention, even when a lead-free solder having a high elastic modulus is used and a low-k insulating film having a low mechanical strength is employed, not only the conduction resistance can be reduced and the adhesive strength can be improved. A highly reliable mounting structure can be realized.

Hereinafter, embodiments of the present invention will be shown by a flip chip connection method, but the electronic component to which the present invention is applied may be any form such as bare chip, CSP, BGA, and the like, and is not particularly limited.
[First embodiment (mounting structure)]
First, a first embodiment of a semiconductor element mounting structure according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing the main part of the first embodiment of the present invention, and FIG. 2 is a partially enlarged cross-sectional view showing the joint between the solder bump 3 and the conductive adhesive 4 of FIG. is there. Solder bumps 3 are formed on the electrode terminals 1b of the semiconductor element 1 having the electrode terminals 1b on the semiconductor substrate 1a. Examples of the solder bump material include Sn / Pb, Sn / Ag, Sn / Cu, Sn / Zn, Sn / Bi, and materials obtained by further adding specific additive elements to them, and these can be used as appropriate. it can. As a method for forming solder bumps, a solder paste containing flux may be printed on the electrode terminal using a metal mask, etc., reflowed and then washed with flux, or solder applied to the flux applied on the electrode terminal. A method of performing flux cleaning after transferring the ball and reflowing may be used. The mounting substrate 2 on which the semiconductor element 1 is mounted has a substrate 2a, electrode pads 2b formed on the surface thereof, and a solder resist 2c. The solder bump 3 on the electrode terminal 1b and the electrode pad 2b on the substrate 2a are connected by a conductive adhesive 4, and electrical connection between the semiconductor element 1 and the mounting substrate 2 is achieved. An example of the electrode pad 2b on the substrate 2a is one in which the surface of the copper wiring is nickel-plated and further gold-plated.

The insulating resin 4b serving as the base material of the conductive adhesive 4 is acrylic resin, melamine resin, epoxy resin, polyolefin resin, polyurethane resin, polycarbonate resin, polystyrene resin, polyether resin, polyamide resin, polyimide resin, fluorine resin, polyester. There are various materials such as a resin, a phenol resin, a fluorene resin, a benzocyclobutene resin, and a silicone resin, but there is no particular limitation, and these can be used alone or in combination of two or more. Epoxy resins that are excellent in terms of viscosity, cost, heat resistance, adhesion and the like are generally used, but resins that are liquid at room temperature of about 25 ° C. are desirable.
Furthermore, it is desirable that the insulating resin 4b of the conductive adhesive 4 includes an oxide film removing action. The reason is that when the solder bump 3 and the conductive adhesive 4 are joined, the oxide film on the surface of the solder bump 3 is removed, and the solder bump 3 and the conductive particles 4a contained in the conductive adhesive 4 are joined. This is because it can be improved. In order to give an oxide film removal action to epoxy resins, unsaturated acids such as (meth) acrylic acid and maleic acid, organic diacids such as oxalic acid and malonic acid, organic acids such as citric acid, and hydrocarbon side chains Further, it is possible to add at least one halogen group, hydroxyl group, nitrile group, benzyl group, carboxyl group or the like. These additives may be added in an amount of 3 to 10 wt% (weight%). As another method, the oxide film is removed by using the substance generated during the reaction between the curing agent of the epoxy resin and the main agent. It is also possible. The mixing ratio of the epoxy resin main agent and the curing agent is preferably 10 to 40 wt% with respect to 60 to 90 wt% of the main agent.

What is important here is that the conductive particles 4a contained in the conductive adhesive 4 contain an intermetallic compound. The reason for this is that the conductive particles 4a on the bonding interface that maintains electrical connection with the solder bump 3 at the bonding interface between the solder bump 3 and the conductive adhesive 4 shown in FIG. This is because the diffusion proceeds, and the conductive particles 4a at the bonding interface are taken into the solder bumps 3 and disappear, so that the electrical connection between the solder bumps 3 and the conductive adhesive 4 cannot be obtained. As an example, when Ag is used for the conductive particles 4a, the Ag particles at the bonding interface are taken in and disappear in the solder bumps 3, and are combined with Sn in the solder bumps 3 to form Ag ₃ Sn metal. It exists as an intercalation compound. Therefore, by using an intermetallic compound in the conductive particles 4a in advance, the disappearance of the conductive particles 4a at the bonding interface due to diffusion after mounting can be prevented, and a bump bonding structure with high connection reliability can be obtained. Examples of intermetallic compounds added as the conductive particles include AuSn, Ag ₃ Sn, Cu ₃ Sn, Cu ₆ Sn _{5 and the} like. Here, regarding the bonding state between the solder bump 3 and the conductive particles 4 a in the conductive adhesive 4, it is desirable that the solder is melt bonded to the conductive particles 4 a. The reason for this is that in terms of the adhesion strength at the bonding interface, in addition to the bonding strength between the insulating resin 4b and the solder, the bonding strength by fusion bonding of the solder and the conductive particles 4a can be obtained, so the bonding strength at the interface is dramatically increased. This is because it is possible to improve the bonding reliability and to obtain a good bonding interface with low conduction resistance at the bonding interface by melt bonding. With this effect, it is possible to easily realize both the reduction of electric resistance and the improvement of adhesion strength, which have been problems in connection with a conductive adhesive. More preferably, a metal layer with good conductivity should be formed around the conductive particles 4a made of an intermetallic compound. The reason is that the conduction resistance in the conductive adhesive can be reduced by forming a metal layer having better conductivity than the intermetallic compound itself in the conduction between the conductive particles 4 a in the conductive adhesive 4. This is because it becomes possible. Examples of the material for the metal layer include Au and Cu. The average particle diameter of the conductive particles 4a is about 10 μm. When a metal layer is formed around the conductive particles 4a, the standard thickness of the metal layer is 0.1 μm or less. However, when the bump pitch is fine, the particle diameter is small. Sometimes. In order to reduce the conduction resistance, it is desirable that the conductive particles 4a include metal particles made of a metal having higher electrical conductivity in addition to the intermetallic compound containing Sn. Examples of the metal material for this purpose include Ag, Au, Cu, Pd, and Ag—Pd alloy. It is desirable that the wt% of the conductive particles of the metal having higher electrical conductivity than the intermetallic compound containing Sn is in the range of 5 to 30%. This is because if the ratio is less than this, the effect of reducing the conduction resistance is small, and if the ratio of Ag, Au, etc. is further increased, the number of conductive particles taken into the solder increases and the conduction resistance is increased. The amount of the conductive particles 4a added to the conductive adhesive bumps varies depending on the particle shape, particle material, manufacturing method, etc., and thus cannot be specified in general. When considered in terms of the volume ratio of the conductive particles, it is preferably 20 to 50%.

If the semiconductor element is further miniaturized and the electrode terminal 1b is further miniaturized, there is a possibility that the solder bump and the wiring are destroyed by the thermal stress due to the difference in thermal expansion coefficient between the semiconductor substrate 1a and the substrate 2a. In this case, it is effective to protect the bump bonding portion by sealing the periphery of the solder bump, that is, the gap between the semiconductor element 1 and the mounting substrate 2 with an underfill resin. For the underfill resin, it is common to use an epoxy resin, like the insulating resin of the conductive adhesive, but silica filler or the like is added to lower the thermal expansion coefficient of the underfill resin and improve the elastic modulus. May be. As a sealing method using an underfill resin, in particular, when an underfill forming resin is applied on the mounting substrate 2 in advance before mounting the semiconductor element 1, the underfill forming resin includes an oxide film removing function. It is desirable that The reason is that by removing the oxide film of the solder bump 3 at the time of mounting, it is possible to realize good fusion bonding between the solder bump and the conductive particles 4a. As the means for adding the oxide film removing action to the underfill forming resin, the same means as that for adding the oxide film removing action to the insulating resin of the conductive adhesive described above can be used.
In the embodiment described above, solder bumps are formed on the semiconductor element 1 side. Conversely, solder bumps may be provided on the mounting substrate 2 side.

[Second Embodiment (Mounting Structure)]
FIG. 3 is a cross-sectional view of a main part showing a second embodiment of the mounting structure of the present invention. In FIG. 3, the same reference numerals are given to the members equivalent to those in FIG. 1 showing the first embodiment. The mounting structure of the present embodiment is a structure in which solder bumps 5 are also formed on the electrode pads 2b of the mounting substrate 2 with respect to the structure shown in FIG. The method of forming solder bumps on the mounting substrate 2 side and the solder material are the same as in the case of the solder bumps 3 on the semiconductor element 1 side described above. The solder material is preferably the same as that of the solder bump 3 on the semiconductor element side. The reason for this is that when the conductive particles 4a in the conductive adhesive 4, the solder bumps 3 and the solder bumps 5 are melt-bonded at the respective bonding interfaces, the melting point will be the same if the materials are the same. This is because it is efficient because both melt bonding can be performed.
Further, the bump configuration is a three-layer structure such as the solder bump 3, the conductive adhesive 4, and the solder bump 5 as in the structure of the present embodiment, so that the joint interface of the conductive adhesive 4 is all solder. In addition, since it is possible to perform melt bonding, it is possible to simultaneously reduce conduction resistance and improve adhesion at the bonding interface, and to obtain a conductive adhesive bonding structure that is strong and has low conduction resistance. This is a problem that is difficult to achieve with conventional conductive adhesive connection. The reason for this is that when the conduction resistance at the interface is to be reduced, it is necessary to increase the contact area between the conductive particles and the bumps. Only the adhesive force between the insulating resin of the conductive adhesive and the solder bumps is obtained. Therefore, if the contact area between the insulating resin and the solder bumps is increased in order to increase the adhesive force, the contact area between the conductive particles and the solder bumps inevitably decreases.
Also in the mounting structure of the present embodiment, the gap between the semiconductor element 1 and the mounting substrate 2 is sealed with an underfill resin, as in the structure of the first embodiment shown in FIG. The part can be protected.

[First Embodiment (Mounting Method)]
Next, a mounting method for realizing the mounting structure of the present invention will be described. FIG. 4 is a cross-sectional view in order of steps showing the first embodiment of the mounting method of the present invention. First, as shown in FIG. 4A, the semiconductor element 1 and the mounting substrate 2 are prepared, and the solder bump 3 is formed on the electrode terminal of the semiconductor element 1 and the solder bump 5 is formed on the electrode pad of the mounting substrate 2. . The solder bump can be formed by printing a solder paste containing flux on the electrode terminal (electrode pad) using a metal mask or the like, reflowing and then cleaning the flux, or electrode terminal (electrode pad). A method may be used in which the solder balls are transferred to the flux applied above and the flux is washed after reflow. In FIG. 4A, solder bumps are formed on the semiconductor element 1 side and the mounting substrate 2 side. However, even when solder bumps are formed only on one of them, the embodiment described below will be described. A mounting method can be used. Subsequently, the conductive adhesive 4 is supplied to the electrode portion on the mounting substrate 2 side. The supply method is generally supply by printing using a metal mask, but it is also possible to supply using a dispenser or the like. The conductive adhesive may be supplied to the semiconductor element 1 side. Or you may make it supply to both the semiconductor element 1 side and the mounting substrate 2 side. At this stage, the conductive adhesive 4 is left in an uncured state. Next, as shown in FIG. 4B, the semiconductor element 1 and the mounting substrate 2 are aligned, and then the semiconductor element 1 is mounted on the mounting substrate 2. At this time, the height adjustment is performed by using the mounting height position control function of the mounter so that the solder bumps 3 on the semiconductor element side and the solder bumps 5 on the mounting substrate side do not come into contact with each other.

Subsequently, the process proceeds to a step of proceeding with the curing of the conductive adhesive 4, and there are two mounting methods in the subsequent steps, and each will be described. First, in the first method, the solder bump is heated to a melting temperature in a state where the height is controlled, and the conductive adhesive 4 is cured while the solder bump is melted. At this time, the melted solder bumps on the semiconductor element side and the mounting substrate side are melt bonded to the conductive particles 4a in the conductive adhesive 4 and the insulating resin 4b is cured, so that the semiconductor element 1 and the mounting board 2 are The solder bumps 3, the conductive adhesive 4, and the solder bumps 5 are electrically connected via bumps having a three-layer structure. Subsequently, the underfill resin 6 is injected into the gap between the semiconductor element 1 and the mounting substrate 2 using a capillary phenomenon, and then the underfill resin 6 is cured, whereby the mounting of the present invention shown in FIG. A structure can be obtained.
Next, the second method will be described. In the case of this method, after the semiconductor element 1 is mounted on the mounting substrate 2, the conductive adhesive 4 is cured while the height is controlled, but the curing temperature is lower than the melting point of the solder bump. . Next, after the underfill resin 6 is injected into the gap between the semiconductor element 1 and the mounting substrate 2 by utilizing a capillary phenomenon, the underfill resin 6 is cured. Next, the solder bump is heated to a melting point or higher to melt the solder bump 3 and the solder bump 5, and melt-bonded to the conductive particles 4a in contact with the solder bump, whereby the present invention shown in FIG. The mounting structure is completed.

[Second Embodiment (Mounting Method)]
FIG. 5 is a sectional view in the order of steps showing a second embodiment of the mounting method of the present invention. First, as shown in FIG. 5A, a semiconductor element 1 and a mounting substrate 2 are prepared, solder bumps 3 are formed on electrode terminals of the semiconductor element 1, and a conductive adhesive 4 is supplied to the mounting substrate 2 side. To do. The solder bumps may be formed on the mounting substrate 2 side. Or you may make it form in both the semiconductor element 1 side and the mounting substrate 2 side. The conductive adhesive may be supplied to the semiconductor element 1 side. Or you may make it supply to both the semiconductor element 1 side and the mounting substrate 2 side. The method for forming the solder bump 3 and the method for supplying the conductive adhesive 4 are the same as those in the mounting method in FIG. Subsequently, the curing of the conductive adhesive applied to the mounting substrate 2 side is slightly advanced. Specifically, when the conductive adhesive insulating resin is an epoxy resin, it is preferably about 60 to 120 seconds at 150 ° C. The step of slightly curing the conductive adhesive 4 is necessary to prevent the conductive adhesive 4 and the underfill resin 6 from being mixed when the underfill resin 6 is applied on the mounting substrate. . Subsequently, an underfill resin 6 is applied to the mounting location of the semiconductor element 1 on the mounting substrate 2 side. Thereafter, the semiconductor element 1 and the mounting substrate 2 are aligned, and then the semiconductor element 1 is mounted on the mounting substrate 2. Thereafter, heating is performed to cure the conductive adhesive 4 and the underfill resin 6, but the heating method is to heat the melting point of the solder bump 3 or higher, and the solder bump 3 and the conductive particles 4a are melt-bonded simultaneously with the resin curing step. In the curing step of the conductive adhesive 4 and the underfill resin 6, the solder bump 3 is cured at a temperature not higher than the melting point of the solder bump 3 and heated to a temperature not lower than the melting point of the solder bump 3. 3 and the conductive particles 4a may be melt-bonded. With the above method, the mounting structure of the present invention shown in FIG. 5B is completed.

Sectional drawing which shows the mounting structure of the 1st Embodiment of this invention. The enlarged view of the joining interface part of a solder bump and conductive adhesive of FIG. Sectional drawing which shows the mounting structure of the 2nd Embodiment of this invention. Sectional drawing of the order of a process which shows the mounting method of the 1st Embodiment of this invention. Sectional drawing of the process order which shows the mounting method of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 1a Semiconductor substrate 1b Electrode terminal 2 Mounting substrate 2a Substrate 2b Electrode pad 2c Solder resist 3, 5 Solder bump 4 Conductive adhesive 4a Conductive particle 4b Insulating resin 6 Underfill resin

Claims (12)

In an electronic component mounting structure in which an electrode terminal of an electronic component and an electrode pad of a mounting substrate are connected via a solder bump and a conductive adhesive, a solder bump is provided on one or both of the electrode terminal and the electrode pad. The solder bump and the electrode pad or electrode terminal, or the solder bumps are connected to each other through a conductive adhesive, and the solder bump and the conductive adhesive are bonded at the bonding interface between the solder and the conductive adhesive. An electronic component mounting structure characterized by being melt-bonded to the conductive particles. The mounting structure for an electronic component according to claim 1, wherein the conductive particles contained in the conductive adhesive contain an intermetallic compound. 2. The electronic component mounting structure according to claim 1, wherein the conductive particles contained in the conductive adhesive include an intermetallic compound having a main constituent metal of the solder bump as a constituent element. . 2. The electronic component mounting structure according to claim 1, wherein the conductive particles contained in the conductive adhesive contain an intermetallic compound containing Sn as a constituent element. 5. The electronic component mounting structure according to claim 2, wherein the periphery of the intermetallic compound is covered with a metal layer. 6. The conductive particles according to any one of claims 2 to 5, wherein the conductive particles include, in addition to the intermetallic compound, highly conductive conductive particles of metal having better electrical conductivity than the intermetallic compound. Electronic component mounting structure. The mounting structure for an electronic component according to claim 1, wherein the insulating resin serving as a base material for the conductive adhesive includes a component for removing an oxide film. 8. The electronic component mounting structure according to claim 1, wherein the periphery of the solder bump and the conductive adhesive is sealed with an underfill resin. The electronic component mounting structure according to claim 8, wherein the underfill resin includes a component for removing an oxide film. Forming a solder bump on at least one of an electrode terminal or an electrode pad of the mounting board on the electronic component, supplying a conductive adhesive to one or both electrodes of the electronic component and the mounting board, and on the mounting board Positioning and mounting the electronic component, connecting the electrode terminal of the electronic component and the electrode pad of the mounting substrate via the solder bump and the conductive adhesive, and melting the solder bump to form the conductive adhesive And a step of melt-bonding with the conductive particles and advancing curing of the conductive adhesive. A step of forming a solder bump on at least one of an electronic component electrode terminal or an electrode pad of the mounting board, a step of supplying a conductive adhesive to one or both electrodes of the electronic component and the mounting board, and a position on the mounting board Mounting the electronic component together, connecting the electrode terminal of the electronic component and the electrode pad of the mounting substrate via the solder bump and the conductive adhesive, the step of promoting the curing of the conductive adhesive, the electronic An electronic component mounting method comprising: a step of injecting an underfill resin into a gap between a component and a mounting substrate; and a step of melting a solder bump and melt-bonding with a conductive particle of a conductive adhesive. Forming a solder bump on at least one of the electrode terminal of the electronic component or the electrode pad of the mounting substrate; and supplying the conductive adhesive to one or both electrodes of the electronic component and the mounting substrate to advance the curing to a certain extent; , Supplying the underfill resin onto the mounting substrate, positioning the electronic component on the mounting substrate, mounting the electronic component electrode terminals and the mounting substrate electrode pads with solder bumps and conductive adhesive An electronic component mounting method comprising: a step of connecting via a solder bump; and a step of melting and bonding a solder bump to a conductive particle.

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