Patent Application
20090008776
The present invention relates to an electronic component mounted body including an electronic component provided with solder bumps, and a solder resin mixed material used for the electronic component mounted body.
In order to respond to a recent demand for a higher density and a higher integration in a semiconductor integrated circuit (LSI) used for an electronic device, electrodes in an LSI chip each having a larger number of pins and narrower pitches are rapidly being developed. When LSI chips are mounted on a circuit substrate, flip-chip mounting is often adopted in order to lessen wiring delays. A conventional method of the flip-chip mounting is such that solder bumps are formed on electrodes of the LSI chip, and the electrodes of the LSI chips are bonded, like a single unit, with electrodes formed on the circuit substrate via the solder bumps.
In order to mount a next-generation LSI having more than 5,000 electrodes on the circuit substrate, however, it is necessary to form bumps corresponding to such narrow pitches as at most 100 μm, but it is difficult to meet such requirement using the currently available solder bump formation technologies. Further, it is necessary to form a large number of bumps corresponding to the number of electrodes, which makes it necessary to reduce a mounting tact per chip in order to achieve the cost reduction.
The conventional examples of the bump formation technology are the plating method, screen printing method and the like. The plating method is suitable for narrow pitches, however, disadvantageous in its complicated steps and productivity. The screen printing method is superior in its productivity, however, is not suitable for narrowing pitches because a mask is used therein.
In order to cope with these disadvantages, some technologies for selectively forming solder bumps on electrodes of an LSI chip or a circuit substrate were recently introduced. These technologies, which are not only suitable for the formation of minute bumps but also superior in productivity because the bumps can be formed by one operation, are attracting attention with the expectation that they can be suitably adopted when the next-generation LSIs are mounted on the circuit substrate.
One of these technologies is called the solder pasting method (for example, see the Patent Document 1). According to the technology, solder paste, in which metallic particles and flux are mixed, is solidly spread on to a surface of a substrate on which electrodes are formed, the substrate is heated so that the metallic particles are melted, and solder bumps are selectively formed on the electrodes which are highly wettable.
According to another technology called the super solder method (for example, see the Patent Document 2), a paste-like composition including organic acid lead salt and metallic tin as its main constituents (chemical reaction deposited solder) is solidely spread onto a surface of a substrate on which electrodes are formed, and the substrate is heated so as to generate a substitution reaction between Pb and Sn, and Pb/Sn alloy is selectively deposited on the electrodes.
In the solder pasting method and the super solder method wherein a paste-like composition is spread onto the substrate, however, variation in thicknesses and concentrations occurs locally. As a result, an amount of the deposited solder is different in each of the electrodes, which makes it not possible to obtain bumps having an even height. Further, according to these methods wherein the paste-like composition is applied onto the circuit substrate which is not flat due to the electrodes formed thereon, the electrodes, which constitute protrusions, cannot be supplied with an enough amount of solder, and it is thereby difficult to obtain dumps having a desirable height required in the flip-chip mounting.
Further, the flip-chip mounting, wherein the conventional bump formation technology is adopted, further requires a step of injecting resin called under-fill into between the semiconductor chip and the circuit substrate in order to fix the semiconductor chip to the circuit substrate after the semiconductor chip is mounted on the circuit substrate provided with the bumps thereon.
Accordingly, the flip-chip mounting technology using an anisotropic conductive material (for example, see the Patent Document 3) was developed as a method of simultaneously realizing two operations: the electrical connection between the electrodes of the semiconductor chip and the circuit substrate facing each other; and the fixation of the semiconductor chip to the circuit substrate. According to the technology, thermosetting resin including conductive particles is supplied to between the semiconductor chip and the circuit substrate, and the semiconductor chip is pressurized and the thermosetting resin is heated at the same time. Thus, the electrodes of the semiconductor chip and the circuit substrate can be electrically connected to each other, and the semiconductor chip can be fixed to the circuit substrate at the same time. The flip-chip mounting technology using the anisotropic conductive material is applicable not only to the electrical connection between the semiconductor chip and the circuit substrate but also to the connection between two circuit substrates.
In the flip-chip mounting and the inter-substrate connection wherein the anisotropic conductive material is used as described earlier, however, the electrical conduction between the electrodes is obtained by the mechanical contact via the conductive particles, which makes it difficult to stabilize the conduction.
Further, the conductive particles sandwiched by the electrodes facing each other are retained by the cohesion of the resin generated when thermally cured. Therefore, it is necessary to control the coefficient of elasticity and the coefficient of thermal expansion of the thermosetting resin and the distribution of particle diameters of the conducive particles.
Therefore, the flip-chip mounting technology using the anisotropic conductive material still includes a number of issues to be solved in terms of productivity and reliability when the technology is applied to the next-generation LSI chips each having more than 5,000 electrodes. There a real so a number of similar issues to be solved in the technology when used for the inter-substrate connection for which narrow pitches, connection of a large number of pins and a high reliability are now demanded.
The present invention was made in order to solve the problems thus described, and a main object thereof is to provide an electronic component mounted body which is reliably applicable to the flip-chip mounting for the next-generation LSIs and the inter-substrate connection.
An electronic component mounted body according to the present invention comprises
a first electronic component provided with a plurality of electrodes;
a second electronic component provided with a plurality of electrodes and facing the first electronic component in a state where the electrodes thereof face the electrodes of the first electronic component; and
solder connecters provided between the electrodes of the first electronic component and the electrodes of the second electronic component so as to electrically connect the electrodes of the first and second electronic component to each other, wherein the solder connecters include insulation filler.
Another electronic component mounted body according to the present invention comprises a first electronic component provided with a plurality of electrodes;
a second electronic component provided with a plurality of electrodes and facing the first electronic component in a state where the electrodes thereof face the electrodes of the first electronic component;
solder connecters provided between the electrodes of the first electronic component and the electrodes of the second electronic component so as to electrically connect the electrodes of the first and second electronic component to each other; and
a resin mixture provided between the first and second electronic components so as to bond the first and second electronic component, wherein the solder connecters and the resin mixture include insulation filler of the same constitution.
An electronic component provided with solder bumps according to the present invention comprises
a plurality of electrodes; and
solder bumps provided in the electrodes, wherein the solder bumps include insulation filler.
A solder resin mixture according to the present invention is a solder resin mixture including resin, solder powder and insulation filler, wherein the insulation filler is surface-processed in order to improve wettability thereof relative to the solder which is melted.
An electronic component mounting method according to the present invention is a method of mounting an electronic component wherein a first electronic component provided with a plurality of electrodes and a second electronic component provided with a plurality of electrodes are placed so that the electrodes of the respective electronic components face each other, and the electrodes of the first and second electronic components facing each other are electrically connected to each other via solder, including:
a first step in which a solder resin mixture including resin, solder powder and insulation filler is supplied to a surface of the first electronic component on which the electrodes are formed;
a second step in which the second electronic component is placed so as to face the first electronic component in the state where the electrodes of the respective electronic components face each other;
a third step in which the solder resin mixture is heated; and
a fourth step in which solder connecters are formed when the solder powder included in the solder resin mixture is self-assembled on the electrodes of the first and second electronic components so that the electrodes of the respective electronic components are electrically connected to each other, wherein
at least a part of the insulation filler is included in the solder connecters when the solder powder is self-assembled in the fourth step.
An electronic component manufacturing method according to the present invention is a method of manufacturing an electronic component wherein solder bumps are formed on a plurality of electrodes provided therein, including:
a first step in which a solder resin mixture including resin, solder powder and insulation filler is supplied to the electronic component; and
a second step in which the solder resin mixture is heated;
a third step in which the solder powder included in the solder resin mixture is self-assembled on the electrodes so that the solder bumps are formed on the electrodes, wherein
at least a part of the insulation filler is included in the solder connecters when the solder powder is self-assembled in the third step.
In the electronic component mounted body and the electronic component provided with the solder bumps according to the present invention, wherein the insulation filler having a small coefficient of thermal expansion is included in the solder connecters and the solder bumps, the reliability of the connection can be improved without the loss of the electrical characteristics.
According to the electronic component mounting method and the electronic component manufacturing method of the present invention, the insulation filler can be included in the solder connecters and the solder bumps as soon as they are formed. As a result, the electronic component can be manufactured with a shorter tact, which improves the productivity.
Hereinafter, preferred embodiments of the present invention are described referring to the drawings. In the drawings described below, components having substantively the same function are illustrated with the same reference symbols in order to simplify the description. The present invention is not necessarily limited to the embodiments described below.
As shown in
Then, as shown in
When the solder resin mixture 3 is heated, the solder powder 4 is self-assembled on the electrodes 6, and solder connecters 8 are thereby formed. In the formation, the insulation filler 5 in the solder resin mixture 3 is simultaneously included in the solder connecters 8. As a result, an electronic component mounted body having a structure shown in
In the self-assembly of the solder powder, the solder powder 4 may be assembled on the electrodes 6 and 6 of the electronic components 1 and 2 by utilizing a difference between the wettability of the solder powder 4 relative to the electrodes 6 and 6 and the wettability of the solder powder 6 relative to the surfaces of the electronic components 1 where the electrodes are not provided. Preferably, the solder powder 4 is self-assembled on the electrodes 6 and 6 of the electronic components 1 and 2 by an effect obtained by an air bubble generating agent added to the solder resin mixture in advance.
The Applicant of the present invention examined the flip-chip mounting method and the solder bump formation method applicable to the next-generation LSI chip, and proposed a novel method wherein the electrodes can be evenly connected to each other by means of the air bubble generating agent. In the method, the air bubble generating agent is included in the solder resin mixture 3 before the mounting. Below is described an example of an electronic component manufacturing method according to the preferred embodiment 1 in which the air bubble generating agent is used referring to
The air bubble generating agent (not shown) is included in the solder resin mixture 3, and the resulting solder resin mixture 3 is applied onto the surface of the first electronic component 1 on which the electrodes are formed (see
The solder connecters 8 may be formed in such a way that the solder powder 4 is self-assembled using the wettability of the melted solder powder 4. In that case, solder resin mixture not including the air bubble generating agent may be used.
Describing the self-assembly of the solder powder 4, the solder resin mixture 3 in which the solder powder 4 is evenly dispersed in the resin 7 is uniformly applied onto a surface including the sections where the solder connecters 8 are desirably formed, and the surface is subjected to a predetermined process such as heating. The self-assembly of the solder powder 4 is not necessarily limited to the foregoing manner, and any manner may be adopted as far as the solder connecters 8 are selectively formed at the desirable electrodes 6. More specifically, the self-assembly denotes a state where the probability that the solder powder, insulation filler and resin are present on the electrodes is high because they move as the air bubble generating agent is boiled and the air bubbles are thereby generated. The self-assembly is nothing to do with whether the solder powder is melted or not. In the case where the solder powder is melted, the solder powder, while being self-assembled and incorporating the insulation filler, wettingly spreads onto the electrodes. In the case where the solder powder is not melted, the solder powder wettingly spreads onto the electrodes while incorporating the insulation filler after the heating temperature is set to at least the melting temperature when the solder powder is self-assembled.
In the conventional mounting method wherein solder balls are mounted on the electrodes of the electronic component, it is not possible for the solder balls to include the insulation filler. In the mounting method according to the present invention wherein the solder powder is self-assembled, the insulation filler 5 is included in the solder resin mixture 3. As a result, the structure wherein the solder connecters 8 are formed and the insulation filler 5 is incorporated therein can be easily obtained. Accordingly, the mechanical strength of the electronic components can be significantly improved.
An average particle diameter of the insulation filler 5 is preferably smaller than an average particle diameter of the solder powder 4 included in the solder resin mixture 3 because the insulation filler 5 can be accordingly more easily incorporated in the solder connecters 8. This is because when the particle diameters of the solder powder are increased, an oxide coating film is thinner, which helps the solder powder easily wettingly extend on the electrodes, and the insulation filler 5 can be thereby more easily included in the solder connecters 8. Further, in the case where the particle diameters of the solder powder are larger than the particle diameters of the insulation filler, the solder powder 4 easily wettingly spreads onto the electrodes 6 so as to cover the insulation filler. As a result, the insulation filler can be easily incorporated in the solder connecters.
The average particle diameter of the insulation filler 5 is preferably smaller than an interval between the electrode 6 of the first electronic component 1 and the electrode 6 of the first electronic component because the insulation filler 5 can be easily included in the solder connecter 8 when the particle diameters of the insulation filler 5 are smaller than the interval between the electrodes 6.
After the solder powder 4 is thus self-assembled and the solder connecters 8 are formed, the resin 7 is preferably solidified so that the first electronic component 1 and the second electronic component 2 are integrally fixed. For example, thermoplastic resin is used as the resin 7, and heated up to at least a softening point and then cooled down after the solder powder 4 is self-assembled. Then, the resin 7 is solidified again, and the first electronic component 1 and the second electronic component 2 can be thereby integrally fixed. Further, a curing agent is preferably added to the solder resin mixture 3, and the resin 7 is cured after the solder powder 4 is self-assembled, so that the first electronic component 1 and the second electronic component 2 are integrally fixed. In this case, the respective steps are preferably separately performed in such a way that the resin 7 and the curing agent are cured at a speed slower than a speed at which the solder powder 4 is self-assembled. Preferable examples of the curing method which can be adopted are heat curing, photo-curing and the like. Referring to the curing process, the curing process does not need to be performed in one stage, and may be performed in two stages after the stage B.
In the preferred embodiment 1, a flip-chip mounted body wherein the first electronic component 1 is a circuit substrate and the second electronic component 2 is a semiconductor is a preferable embodiment. Further, an inter-substrate connection wherein the first electronic component 1 and the second electronic component 2 are circuit substrates is also a preferable embodiment. The first electronic component 1 is not limited to the circuit substrate, and it may be any electronic component conventionally used, such as a semiconductor, a module component, a passive component, or the like. In a similar manner, the second electronic component 2 is not limited to a semiconductor or circuit substrate, and it may be any electronic component conventionally used.
It is expected that the electronic component mounted body thus manufactured with the insulation filler 5 included in the solder connecters 8 can improve the connection reliability. In general, the solder connecters 8 in the electronic component mounted body is subject to the stress generated by a difference in coefficients of thermal expansion between the members constituting the electronic component mounted body. When the stress is repeatedly applied thereto, fatigue breakdown occurs in the solder, which results in a connection failure. In the flip-chip mounted body wherein the first electronic component 1 is a circuit substrate and the second electronic component 2 is a semiconductor, for example, the coefficient of thermal expansion of Si constituting the semiconductor is a few ppms, while that of the circuit substrate formed from resin is a few-dozen ppms. Further, in the mounting body comprising a large number of members such as electrodes of the semiconductor and the circuit substrate, the stress is repeatedly applied to the solder connecters 8 by the difference in coefficients of thermal expansion between the members due to heat resulting from the usage environment and the semiconductor. In the flip-chip mounted body, the semiconductor and the circuit substrate are conventionally fixed to each other with resin mixture including resin and insulation filler as an effort for scattering the stress applied to the solder.
In the preferred embodiment 1, wherein the insulation filler 5 is included in the solder connecters 8, the elongation percentage of the solder connecters 8 can be controlled, which improves the connection reliability. Further, the solder connecters 8 can have a shape in which the solder powder wettingly spreads because the insulation filler 5 is included therein, and the stress can be thereby scattered. In a constitution wherein only a part of the insulation filler 5 is included in the solder connecters 8 and the rest thereof is in contact with the resin 7, the insulation filler 5 has the effect in serving as a juncture between the solder connecters 8 and the resin 7. Due to these obtainable effects, the reliability of the electronic component mounted body can be improved when the insulation filler 5 is included in the solder connecters 8.
In the structure of the electronic component mounted body shown in
Further, as shown in
When the insulation filler 5 is included in the solder connecters 8, all of the insulation filler 5 may be absorbed and incorporated into the solder connecters 8, or at least a part of the insulation filler 5 may be absorbed and incorporated into the solder connecters 8. In the present invention, the term “include” is used in all of these possible structures. Further, the insulation filler 5 is not necessarily included in all of the solder connecters 8, and the insulation filler 5 may be included in at least a part of the plurality of solder connecters 8 in the electronic component mounted body.
The solder powder 4 preferably does not remain in the residual resin mixture 11 in which the self-assembly of the solder powder 4 does not occur; however, a small amount of solder powder may remain therein. Even in the case where the solder powder 4 remains in the residual resin mixture 11, the present invention can be fully implemented as far as the amount of the remaining solder powder does not adversely influence the insulation reliability and the like. In the case where a step of washing off the residual resin mixture 11 (see
At least one or more types of inorganic filler selected from crystalline silica, melted silica, alumina, and alumina oxide preferably constitutes the insulation filler 5 according to the preferred embodiment 1. The shape of the filler, which may be a plate shape, a needle shape or a spherical shape, is not particularly limited. When a surface of the insulation filler 5 is modified, it can be controlled how the filler is included in the solder connecter 8. As a preferable example of the modification of the surface of the insulation filler 5, it is made possible to control the hydrophobic nature, hydrophilic nature, wettability relative to the resin, and wettability relative to the solder of the surface using a surface processing agent such as a silane coupling agent or a titanate-based coupling agent. Further, a similar effect can be exerted when a surface roughness is changed.
Preferable examples of the solder powder 4 according to the preferred embodiment 1 are conventionally used lead-containing solder such as SnPb, and lead-free solders such as SnAgCu, SnAg, SnAgBiIn, SnSb and SnBi; however, the type of the solder powder 4 is not particularly limited. Further, the average particle diameter, which is preferably approximately 1-100 μm, is not particularly limited.
Preferable examples of the resin 7 according to the preferred embodiment 1 are thermosetting resins such as epoxy resin, phenol resin, silicon resin and melamine resin; thermoplastic resins such as polyamide, polycarbonate, polyethylene telephthalate, polyphenylene sulfide; and the like; however, the type of the resin 7 is not particularly limited. Further, in the case where there is the washing step as shown in
As shown in
When the solder resin mixture 3 thus supplied is heated, the solder powder 4 is self-assembled on the electrodes 6 so that solder bumps 9 are formed as shown in
Next, as shown in
In the self-assembly of the solder powder 4, the solder powder may be assembled on the electrodes 6 of the electronic component 1A using the wettability of the melted solder powder 4 in a manner similar to the electronic component mounted body according to the preferred embodiment 1. However, a method is preferably applicable in which an air bubble generating agent is added to the solder resin mixture 3, and the solder powder is self-assembled on the electrodes 6 of the electronic component 1A by an effect thereby obtained.
An electronic component manufacturing method wherein the air bubble generating agent is included in the solder resin mixture 3 is described referring to
In the case where the wettability of the melted solder powder is utilized for the self-assembly of the solder powder, solder resin mixture not including the air bubble generating agent may be used as the solder resin mixture 3. The meaning of the self-assembly of the solder powder 4 and the process of the generation of the self-assembly are as described in the preferred embodiment 1.
In the conventional mounting method wherein solder balls are mounted on the electrodes of the electronic component, it is not possible for the solder balls to include the insulation filler. In the present invention, the insulation filler 5 is included in the solder resin mixture 3 in the electronic component manufacturing method wherein the solder powder is self-assembled. As a result, the structure wherein the solder bumps 9 are formed on the electrodes 6 and the insulation filler 5 are included therein can be easily obtained.
As in the case of the preferred embodiment 1, the average particle diameter of the insulation filler 5 is preferably smaller than the average particle diameter of the solder powder 4 included in the solder resin mixture 3 because the insulation filler 5 can be thereby more easily included in the solder bumps 9. The average particle diameter of the insulation filler 5 is preferably smaller than an interval between the electrodes 6 of the electronic component 1A and the flat plate 12.
When the electronic component provided with the solder bumps thus manufactured is used, an electronic component mounted body can be manufactured according to the mounting method shown in
When the resin mixture 11 including the insulation filler 5 which is the same as the insulation filler 5 included in the solder bumps 9 is injected into between the two electronic components 1A and 2 in the step shown in
The electronic component mounted body shown in
The electronic component mounted body manufactured without the washing step after the self-assembly of the solder powder 4 may be used as it is on the condition that the resin mixture 11 including the insulation filler 5 and the resin 7 does not prevent the solder bumps 9 from being wet to form the solder connectors 8 on the electrodes 6 of the second electronic component.
The solder powder preferably does not remain in the resin mixture 11 after the self-assembly of the solder powder 4 as in the case of the preferred embodiment 1; however, a small amount of solder powder 4 may remain. In the case where the resin mixture 11 is washed off, the remaining solder powder 4 can also be removed.
The preferred embodiment 2 is preferably applicable to an electronic component such as a semiconductor, a module component, and a passive component. However, the electronic component is not particularly limited as far as it is conventionally used.
When the electronic component mounted body is manufactured using the electronic component provided with the solder bumps thus manufactured, the improvement of the connection reliability can be expected as in the case of the electronic component mounted body according to the preferred embodiment 1.
In the preferred embodiment 2, the insulation filler 5 is included in the solder bumps 9 as in the case of the preferred embodiment 1, and further, the insulation filler 5 is constituted as in the case of the preferred embodiment 1. Referring to materials of the solder powder 4, resin 7 and the like, the preferred embodiment can be realized based on materials similar to those adopted in the electronic component mounted body according to the preferred embodiment 1. The materials, therefore, are not particularly limited to those in the preferred embodiment 2 described earlier.
In solder resin mixture according to a preferred embodiment 3 of the present invention, the solder powder and the insulation filler are scattered in the resin. The insulation filler included in the solder resin mixture is surface-processed in order to improve the wettability relative to the melted solder so that it can be easily included in the solder connecters or solder bumps when the solder powder is self-assembled.
The inclusion of the air bubble generating agent which generates air bubbles when the solder resin mixture is heated is preferably adopted. In that case, it is made easier for the solder powder to be self-assembled on the electrodes by the action of the air bubble generating agent described in the preferred embodiments 1 and 2, which makes it easier to form the solder connecters or the solder bumps including the insulation filler.
These solder resin mixtures thus described can be useful in the mounting methods described in the preferred embodiments 1 and 2.
The solder resin mixture preferably has a paste-like shape or a sheet-like shape. The paste-like mixture can be supplied to an electronic component by means of a dispenser, or a printing or transfer method. Resin which is solid at room temperature may be used, or resin cured up to the stage B and formed into the sheet-like shape can be bonded to the electronic component.
At least one or more types of inorganic filler selected from crystalline silica, melted silica, alumina, and alumina oxide preferably constitutes the insulation filler 5 according to the preferred embodiment 3. The shape of the filler, which may be a plate shape, a needle shape or a spherical shape, is not particularly limited. When the surface of the insulation filler 5 is modified as described in the preferred embodiment 1, a similar effect can be obtained.
The materials to be sued for the preferred embodiment 3 such as solder powder and resin can be the same as those described in the preferred embodiment 1, and are not particularly limited to those recited in the preferred embodiment 3.
An amount of the insulation filler to be included in the solder connecters or the solder bumps is affected by an amount of the insulation filler included in the solder resin mixture; type, surface condition, particle diameter, and wettability relative to the melted solder of the insulation filler; material variable such as type of the solder powder or resin; an amount of time necessary for the self-assembly in the mounting process; temperature profile; electrode diameter; electrode pitch; and the like. It is necessary to take these factors into consideration during the designing process.
The amount of the filler (insulation filler or the like) incorporated into the solder connecters in the respective preferred embodiments may be very small (approximately 1-100 pieces). Such a small amount is enough for the effect to be fully exerted.
In Implementation Example 1, the electronic component mounted body shown in
A circuit substrate having the size of 10 mm×10 mm (ALIVH substrate supplied by Panasonic Electronic Devices Co., Ltd., electrode 100 μm, electrode pitch 200 μm, number of electrodes 10×10 (=100 pieces)) was prepared as the first electronic component 1, and a semiconductor TEG chip (electrode 100 μmφ, electrode pitch 200 μm, number of electrodes 10×10 (=100 pieces)) was prepared as the second electronic component 2.
25 wt % of epoxy-based resin of the bisphenol-F type (EPIKOTE 806 supplied by Japan Epoxy Resins Co., Ltd.)+an imidazole-based curing agent (supplied by SHIKOKU CHEMICALS CORPORATION) was used as the resin 7. 30 wt % of SnAgCu (particle diameter 17 μm) was used as the solder powder 4. 42 wt % of spherical silica filler (supplied by DENKI KAGAKU KOGYO KABUSHIKI KAISHA, FB-35, particle diameters 9 μm) was used as the insulation fillers 5, and 3 wt % of diethylene glycol dimethlether (supplied by Wako Pure Chemical Industries, Ltd.) was used as the air bubble generating agent. A solder resin mixture 3 in which these materials were mixed was prepared.
According to the mounting method shown in
The materials similar to those in the Implementation Example 1 were used, and the electronic component mounted body was manufactured according to the mounting method shown in
20 wt % of silicon-based resin (methyl phenyl silicon oil, KF54 supplied by Shin-Etsu Chemical Co., Ltd.) was used as the resin 7. 30 wt % of SnAgCu (particle diameter 17 μm) was used as the solder powder 4. 45 wt % of spherical silica filler (supplied by DENKI KAGAKU KOGYO KABUSHIKI KAISHA, FB-35, particle diameter 9 μm) was used as the insulation filler 5. 5 wt % of diethylene glycol dimethlether (supplied by Wako Pure Chemical Industries, Ltd.) was used as the air bubble generating agent. A solder resin mixture 3 in which these materials were mixed was prepared. The components used in the Implementation Example 1 were used as the first electronic component 1 and the second electronic component 2. Further, a glass plate (10 mm×10 mm×1 mm, supplied by Matsunami Glass Ind., Ltd.) was prepared as the flat plate 12.
The solder resin mixture 3 was spread onto the surface of the circuit substrate on which electrodes were provided based on the mounting method shown in
The semiconductor used in the Implementation Example 1 was mounted on the manufactured electronic component provided with the solder bumps at a determined position thereof so that the solder bumps 9 formed on the electrodes 6 of the circuit substrate and the electrodes 6 of the semiconductor faced each other. The resulting electronic component was heated at 240° C. for three minutes, and the electronic component mounted body shown in
According to the mounting method shown in
The electronic component mounting bodies according to the Implementation Examples 1-3 and the Comparative Example 1 were subjected to a gas-phase thermal impact test (one cycle: 125° C. for 30 minutes and −40° C. for 30) to evaluate the connection reliability. Test results showed that the connection resistance did not increase in any of the electronic component mounting bodies according to the Implementation Examples 1-3 even after the 1,000-cycle or more tests were conducted, while the increase of the resistance value was observed after 700-cycle tests at some sections in the electronic component mounted body according to the Comparative Example 1, indicating the occurrence of a connection failure. In these connection-failure sections, cracks were observed in the solder connecters 8. Thus, when the insulation filler 5 is included in the solder connecters 8, the electronic component mounted body superior in its connection reliability can be provided.
The electronic component mounted body, electronic component provided with solder bumps, solder resin mixture and mounting method according to the present invention are applicable to the flip-chip mounting for the next-generation LSIs, inter-substrate connection, and the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-057646 | Mar 2006 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/053357 | 2/23/2007 | WO | 00 | 8/29/2008 |
