TW201038349A - Metal filler, low-temperature-bonding lead-free solder and bonded structure - Google Patents

Abstract

Provided is a metal filler comprising a mixture of first metal particles with second metal particles, wherein the first metal particles are Cu-alloy particles containing Cu as the major component, which is an element being present at the highest ratio by mass, together with In and Sn; the second metal particles are Bi-alloy particles containing 40-70% by mass of Bi together with 30-60% by mass of one or more metals selected from among Ag, Cu, In and Sn; and the content of the second metal particles is 40-300 parts by mass per 100 parts by mass of the first metal particles. Also provided are a lead-free solder containing the aforesaid metal filler, a bonded structure formed by using the aforesaid lead-free solder, and a substrate to which a part provided with the aforesaid bonded structure is mounted.

Description

201038349 VI. Description of the Invention: [Technical Field] The present invention relates to a metal filler which can be used for connection of various electronic components, through-hole filling, etc., and a flux-free solder containing the metal filler, particularly for low temperature connection Use lead-free solder. Further, the present invention relates to a connection structure obtained by using the lead-free solder, and a substrate on which the connection structure and the substrate are mounted. [Prior Art] Ο 先前 Previously, as a flux used in reflow heat treatment, mp# crystal solder having a melting point of urc has hitherto been generally used. Further, as a high-temperature flux used in an electronic component requiring high heat resistance, a solid phase wire of 270 ° C and a liquidus 305 t 2 Sn_9 〇 pb high-temperature flux are widely used. However, in recent years, as the EU environmental regulations (WEEE, R〇Hs directive) show, the harmfulness of pb becomes a problem. Therefore, from the viewpoint of preventing environmental pollution, the error-free development of the flux is rapidly progressing. In this case, as a substitute for the 811_37 external eutectic tanning agent, the melting point of 22 (the Sn_3 〇Ag_〇5Cu contained in the rc is not wrong). The barium agent is more representative. As the reflow heat treatment condition of the materialless agent, the peak temperature is generally in the temperature range of about 24 〇t to 260 ° C. The lead-free flux containing Sn_3.〇Ag_〇5Cu having a melting point of about 22 〇t. Compared with the Sn-37Pb eutectic solder, the reflow heat treatment condition is also higher due to the higher melting point of the alloy. Recently, when it comes to problems such as depletion of fossil fuels and global warming, what is expected is to borrow The low-temperature process of reflow heat treatment is established to establish an energy-saving process and a low-carbon dioxide emission process. It is also expected that the temperature of the reflow heat treatment can be suppressed by 146300.doc 201038349 4 gas electronic equipment and substrate materials The substrate, the damage, and the substrate that can be used have a wide range. At present, as a representative example of a low-temperature fusion-bonding flux-free solder material, a Sn-measured eutectic solder (melting point 138) can be mentioned. 〇, In (melting point 157YM c ns 〇 „ " ), 811-52111 alloy flux (melting point) temple (refer to patent document (1)). However, after the welding of these flux materials, the flux is more than the melting point. At the time, there will be refining problems. a ^The trend of miniaturization, light weight, and high-powered electronic devices represented by mobile phones is amazing. Following this, high-density installation technology has continued to progress rapidly. Developed a variety of mounting techniques for the effective use of finite volume in which a part is housed in a substrate, or a plurality of LSIs are formed into a package. As a result, 尚 士 & ^ - Progress, the flux connection portion of the part incorporated into the interior of the substrate or the package portion is subjected to heat treatment in the subsequent step. Therefore, the flux is remelted in the subsequent step, from the part and the sealing tree.

The gap between the moon and the moon is generated, and a short circuit occurs between the electrodes of the parts. This problem is marked by D. Therefore, in the connection of the parts inside the substrate or inside the package, the knife is accepted even in the subsequent steps. The secondary heat treatment is also no longer molten lead-free flux material. ° QI fly j λ β Temple 曰k is a high heat-resistant flux material, in the non-synchronized flux back muscle heat treatment conditions, such as peak temperature 246. (The following is melt-bondable, and is not melted under the same heat treatment conditions after bonding (Patent Document 3). The metal particles contained in the flux material are the first metal particles and the second metal particles having a lower melting point than the first metal particles. In the technique of Patent Document 3, Sn 146300.doc 201038349 is used as the second metal particle, and the flux material is reflowed by a resizing point (23 rc) or more of, for example, 246 t, and the second metal is melted. The metal is diffused between the particles and the first metal particles to form a joint having excellent heat resistance. In view of the need for energy saving and low carbon dioxide emission, and the m-shape of the substrate material and the electronic device having low heat resistance, it is expected to be lower/ The material of the present invention is not re-melted under the reflow heat treatment condition of the lead-free solder after bonding. Therefore, the inventors of the present invention have proposed a flux material which can be melt-bonded at a low temperature of 149 C or higher, and after bonding at 26 〇t Heat resistance under heat conditions (Patent Document 4). The conductive filler contained in the bismuth material is a first metal particle and has a higher melting point than the first metal particle A mixture of the second metal particles, and a solder paste using a mixture of Cu powder and Sn-Bi powder as a solder paste containing a plurality of metal particles and capable of low-temperature bonding (see Patent Document 5). [PRIOR ART DOCUMENT] [Patent Document 1] JP-A-2001-334386 [Patent Document 2] JP-A-H11-239866 [Patent Document 3] International Publication No. 2006/109573 [Patent Document 4] JP-A-2008-183 582 [Patent Document 5] JP-A-2008-200718 SUMMARY OF INVENTION [Problems to be Solved by the Invention] 146300.doc 201038349 However, Patent Document 4 In the technique described, there is room for improvement in the CT strength at room temperature, especially in the technique described in J. 4, because of the use of the first metal particle. Ιη,士> 0 people Λ 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏 円仏Agglutination, if it is hygroscopic, it is stronger and agglomerated, because There is a problem in the preservation stability. Further, in the techniques described in Patent Documents 4 and 5, there is room for improvement in the degree of connection. The interface is particularly strong in the present invention. The present invention has been made in view of the above problems, and its object is to provide a metal. The filler ' can be joined at a lower temperature than the reflow heat treatment condition of the Sn_37Pb eutectic solder (10), such as a peak temperature of 16 () t:) (4), providing a good connection at room temperature and good strength. Further, an object of the present invention is to provide a solder-free flux of the metal filler, a connection structure obtained by using the flux-free solder, and a component mounting substrate having the connection structure and the substrate. [Technical means for solving the problem] [1] A filler comprising a mixture of a first metal particle and a second metal particle, wherein the first metal particle contains a halogen-containing material having a highest mass ratio as a main component. Further, it further contains Cu alloy particles of In and Sn, and the second metal particles contain Bi 40 to 70% by mass, and are selected from Ag,

In the Cu, In, and Sn groups, the metal particles of 3 or more metals are in the range of 3 to 6 % by mass, and the amount of the second metal particles is 40 to 300 parts by mass based on 100 parts by mass of the first metal particles. [2] The metal filler according to the above (1), wherein the second metal particles have Sn. [3] The metal filler according to the above (10) (2), wherein an average particle diameter of the first metal particles and the second metal particles is in the range of 5 to 25 divisions. [4] The metal filler according to any one of the above-mentioned, wherein the first metal particles further comprise a metal selected from the group consisting of Ag and a medium or higher. The metal filler according to the above (1) to (A), wherein the genus of the genus genus includes "5 to 15% by mass, Bi 2 to 8% by mass, ～ 49 to 8.1% by mass, and In 2 to 8 Mass %, and Sn 〇 20 20% by mass, the first metal particles exhibit at least one exothermic peak observed in the range of 230 to 3 〇〇 ° C under differential scanning calorimetry (DSC), and At least one endothermic peak observed in the range of 480 to 530 C. The interstitial material is contained in the above (1) metal filler. [7] A connection structure having a first electronic component and a second electron The zero-piece 'and the flux-joining portion for joining the i-th electronic component and the second electronic component' are formed by reflow heat treatment of the error-free solder described in the above [6]. The substrate having the substrate and the connection structure described in the above [7] mounted on the substrate. [Effect of the Invention] The metal filler of the present invention and the error-free flux containing the metal filler can be compared with, for example, W eutectic solder. The reflow heat treatment conditions are low temperature strips such as peak temperature (10). The above) the smelting joint, even after the jointing of the 146300.doc 201038349 after the bonding, the flux connecting portion will not be further (4), according to the invention, it is possible to prevent the flux generated between the electrodes of the parts. Further, the metal filler of the present invention and the flux-free solder containing the metal filler can provide good joint strength at room temperature after bonding. [Embodiment] <Metal filler> The metal filler of the present invention is a metal filler comprising a mixture of a first metal particle and a second metal particle, wherein the first metal particle contains a meta-fee having a highest mass ratio as a main component, and further Containing In (indium) and

Cu alloy particles of Sn (tin), the second metal particles are composed of (铋 川 质量 mass / / ' and selected from the group consisting of core (silver), Cu (copper), In (indium) and ^ (tin) The alloy particles of 30 to 6 % by mass of the metal of one or more kinds of the group, and the amount of the second metal particles is 40 to 300 parts by mass based on 100 parts by mass of the first metal particles. The metal 3 7Pb eutectic 2 is obtained by dissolving the particles to form a fixed alloy phase reflow heat, and the melting point of the second metal particles of the second metal particles and the second metal particles having the above composition is set to be higher than the melting point of the second metal particles. In the reflow heat treatment, the second financial 'first metal particle having a lower melting point than the first metal particle is thermally alloyed with the molten second metal particle to form a higher stability than the melting point of the second metal particle. In the case where the lead-free solder of the present invention is used, the ?! metal particles are not melted. Thereby, the lead-free solder containing the present filler can be used under low temperature conditions (typically lower than the reflow heat treatment conditions of the Sn_ solder) Fusion bonding, 146300.doc 201038 349 and after fusion bonding, it has the effect of no longer melting under heat treatment. It can be melted at a low temperature, making it possible to use in energy-saving processes and low-carbon dioxide emission processes, and to suppress electrical, electronic equipment and substrate materials for applications. It is advantageous in the point of thermal damage. In the present invention, the combination of the first metal particles and the second metal particles of the above composition can avoid the problem of agglomeration due to moisture absorption when using, for example, Cu powder. In the present invention, The first metal particles have CU as a main component, and the second metal particles contain a large amount of ruthenium. Thereby, it is possible to provide melt-bonding at a low temperature, and has good bonding strength at room temperature after bonding, and can be A metal filler which reduces the amount of use of a high-priced metal such as In, Ag, etc. [First metal particle] The first metal is mainly composed of Cu. That is, the element constituting the second metal particle has the highest mass ratio of Cu. In addition to Cu, In and Sri are further contained, whereby the first metal particles can form a quasi-stable alloy phase. The formation of the quasi-stable alloy phase promotes the i-th metal particles and the second metal. Since the combination of the particles is ruthenium, a good joint strength can be imparted at the time of fusion bonding at a low temperature.

One or more metals selected from the group consisting of Ag and Bi are preferred.

%. Furthermore, in addition, unavoidable impurities may be contained at this time. In the ruthlessness of the car, the first metal particle contains Ag 5 to 丨 5 mass%, then 2

Medium, with 230~300. (: observed in the range of not scanning calorimetry (DSC); J at least one exothermic peak, 146300.doc 201038349 and in the range of ~ (10) observed at least one of the peaks observed in the WC range of the absorption peak, The quasi-stable alloy phase of the metal particles is shown, and the endothermic peak observed in the range of 480 to 53 generations indicates the melting point of the first metal particles. Furthermore, the bright points described in the present specification indicate the differential scanning calorimetry. (DSC) analysis of the solidus temperature: In addition, the above-mentioned differential scanning calorimetry is typically performed under a nitrogen atmosphere at a positive rate of 1 (TC/min, which is carried out under the measurement range of (4) 。. · Better aspect In the middle, the i-th metal particle contains Ag 5 to 15 mass. Z. 'out of 2 8 mass%, CU 49 to 81 mass% by mass, and Sn i 〇 〜20 质 〇 〇 ° ° ° ° ° In the differential scanning calorimetry (DSC), at least one exothermic peak observed in the right side of 230 to 300 m, and at least one endothermic peak observed in the range of 480 to 530 ° C. The average diameter is preferably in the range of 2 to 3 Å. The average particle diameter of the i-th metal particles is 2 In the case of the metal filler of the present invention, for example, when a solder paste is formed by using a flux described later, the contact area between the first metal particles and the flux is reduced, and the life of the solder paste can be changed. In addition, the average of the first metal particles: when the diameter is 2 _ or more, in the reflow heat treatment, the reduction reaction of the metal filler in the source self-flux can be reduced (that is, the gas generated by the oxidation of the metal filler particles) The gap generated in the inside of the flux connection can be reduced. Further, the average diameter of the second metal particles is preferably 3 pm or less from the viewpoint of the adhesion of the solder paste. When the particle size is too large, the gap between the particles becomes large. It is easy to damage the flux paste. The part is easily detached from the time when the solder-bonded part is placed until the end of the reflow process. The average particle size of the second metal particle 146300.doc •10- 201038349 is better in the range of 5~25 μηη Further, the average particle diameter in the present specification is a value measured by a laser diffraction type particle diameter distribution measuring device. [Second metal particles] Second metal particle package Bi 4 〇 to 7 〇 mass%, and one or more metals selected from the group consisting of ^, ", ^, and Sn, 3 〇 to 6 〇 mass%. Further, in this case, unavoidable impurities may be contained. The metal particles can be melted in a reflow heat treatment by the above-described composition, and are favorably formed by alloying between the i-th metal particles and the molten second metal particles due to thermal diffusion. The content of the second metal particles is From the viewpoint of being able to be melt-bonded at room temperature and having good bonding strength at room temperature after bonding, it is preferably 4% by mass or more and 70% by mass or less. The above content is preferably 5 〇 to 6 〇% by mass. The content of the metal selected from the group consisting of Ag, Cu, In, and ^ in the second metal particle is 30 mass from the viewpoint of good alloying of the second metal particle and the second metal particle. % or more, from the viewpoint of the sufficient amount of the second metal particles to be melt-bonded at a low temperature, it is 60% by mass or less. The above content is preferably 4 〇 to 5 〇 mass%. In particular, it is preferable that the second metal particles contain Sn. In this case, a metal filler can be provided which has good low-temperature melting characteristics and bonding properties and can impart good bonding strength even at a low temperature. The Sn content in the second metal particles is preferably 40 to 50% by mass. When the second metal particles contain a metal selected from the group consisting of Ag, Cu, and ίη, the ductility can be improved, and the low melting point, mechanical strength, and the like can be improved. 146300.doc 11 201038349 Further, from the viewpoint of low-temperature meltability and splicability, the second metal particles are more preferably Sn-Bi-based alloy particles, and further preferably have a eutectic composition which is less likely to cause solidification defects and segregation (typically Sn_58Bi)2 Sn Bi-based alloy particles.

The Sn-Bi-based alloy particles are typically composed of only % and m as constituent elements (although they may contain unavoidable impurities), but are used for the purpose of improving ductility, improving low melting point and mechanical strength, and may be added in a trace amount from Ag, One or more metals of Cu and bismuth. The reason why the average particle diameter of the first metal particles is the same as that of the first metal particles is that the average diameter of the second metal particles is preferably in the range of 5 to 40 μm from the viewpoint of the reactivity with the flux and the dryness of the solder paste. The average particle diameter of the i-th metal particles is more preferably in the range of 5 to 25 μη. [Mixing of First Metal Particles and Second Metal Particles] The metal filler of the present invention contains a mixture of the second metal particles and the second metal particles. In the metal filler of the mixture, the amount of the second metal particles (hereinafter also referred to as "the mixing ratio of the second metal particles") is in the range of 40 to 300 parts by mass based on the mass fraction of the second metal particles (10). When the mixing ratio of the second metal particles is 4 enamel: When the amount is more than or equal to the above, the ratio of the presence of the fragrant component in the reflow heat treatment in the metal filler is increased, so that the fusion bonding at a low temperature can be favorably performed, and the bonding is performed, for example, as a bismuth agent. It can be given a good physical strength. On the other hand, when the mixing ratio of the second metal particles exceeds 100 parts by mass, a more favorable two-strength strength can be obtained. On the other hand, when the mixing ratio of the second metal particles exceeds 3 Å by mass, the presence ratio of the high melting = stable alloy phase formed by the reaction between the molten second metal particles and the second metal particles is small, and thus heat resistance cannot be obtained. From the viewpoint of the physical strength and heat resistance of the second flux joint portion, the mixing ratio of the second metal particles 146300.doc 12 201038349 is preferably in the range of 100 to 300 f parts. The particle size distribution of the first metal particles and the second metal particles can be defined according to the use of the tangent paste. For example, in the screen printing application, it is preferable to widen the particle size distribution under the problem that the transfer amount of the solder paste on the substrate is small, and the liquidity and the hole burying property are emphasized in the distribution use and the through-hole filling application. Next, it is preferable to sharpen the particle size distribution. As described above, the average particle diameters of the first metal particles and the second metal particles are from 2 to 30, and 5, respectively, from the viewpoints of the compatibility with the flux and the characteristics of the solder paste. The range of 〜40 _ is preferably, and more preferably, the average particle diameter of the first metal particles and the second metal particles is in the range of 5 to 25 μη. As will be described later, the metal filler of the present invention can form a paste-like benefit (for example) by, for example, a combination with a flux. When the component is mounted by using the flux-free solder, there is a case where a portion of the bead joint portion formed by the reflow heat treatment, particularly the surface of the bead portion, is formed with a thin paste. If the average particle size of the metal filler is small, the fine particles of the metal filler in the soldering sword layer are easy to follow in a floating state (ie, the metal particles are in a state of being separated from each other), and the flux-bonded parts are supplied to the subsequent help. In the tangent washing step, the particles of the metal filler in the washing liquid flow out and adhere to the parts. When the first-order metal particles and the second metal particles have a thousand-grain control of 5 _, when the parts are mounted, in the flux layer, the metal (four) W will not be able to follow the 'suppressable generation of floating particles in the auxiliary layer'. It can reduce the amount of particles flowing out of the washing liquid. On the other hand, when the average particle diameter of the wide metal particles and the second metal particles is less than or equal to Μ (4), it is preferable that the dryness of the bismuth cream is not easily impaired. The melting point of the second metal particles is 80 to 10 (10). The range of C is better, and more preferably it is the range of I46300.doc 201038349 100~150 c. In a typical embodiment, the second metal particles are melted at a reflow heat treatment temperature when the agent of the present invention is used. Further, the elements of the first metal particles and the second metal particles specified in the present specification are composed. For example, it can be inductively combined with plasma (ICp) luminescence analysis. Further, the elemental composition of the particle profile can be analyzed by SE. EDX (characteristic X-ray analysis device). As a method of producing the first metal particles and the second metal particles, respectively, a well-known method can be employed as the U private method, but a rapid solidification method is preferred. Examples of the method for producing the fine powder by the rapid solidification method include a water spray method, a gas spray method, and a centrifugal spray method. Among them, the gas spray method and the centrifugal spray method are more preferable in terms of suppressing the content of the ruthenium of the particles. In the gas spray method, an inert gas such as nitrogen, argon or helium is usually used. It is preferable to use a helium gas having a light specific gravity in order to increase the linear velocity at the time of gas spray and to accelerate the cooling rate. The cooling rate is 5〇〇~50〇〇. The range of (: / sec is preferred. In the centrifugal spray method, from the viewpoint of forming a uniform molten film on the rotating disc, the material is preferably Sylon (SlA1 〇 N), and the rotation speed of the disc is 10,000 The range of ~120,000 rpm is preferred. &lt;Lead-free solder&gt; The present invention also provides a lead-free solder hl containing the above-mentioned metal filler of the present invention, which is referred to as "lead-free" in accordance with the EU environmental regulations. The lead-free solder of the present invention is preferably a solder paste containing a metal filler component and a flux component. The lead-free 146300.doc -14· 201038349 Ο 焊 flux of the present invention is further improved. Typically, it comprises a metal filler component and a flux component. The metal filler component may also comprise the above-mentioned metal filler of the present invention, but may contain a small amount of other metal filler in the range of 1 &amp; without the effect of the present invention. The content ratio is preferably in the range of 84 to 94% by mass in the flux paste_% by mass from the viewpoint of solder paste characteristics. The range in which the content ratio is better can be determined depending on the use of the solder paste. In the printing application, when the amount of transfer of the solder paste on the substrate is small, the content ratio is preferably in the range of (4)% by mass, more preferably in the range of (10) or % by mass. The content of the above is preferably in the range of Μ to 89% by mass, more preferably in the range of 86 to 88% by mass. The flux component preferably contains rosin, a solvent, an active agent, and a (iv) agent. The surface treatment of the metal filler, that is, by removing the oxide film of the metal filler component in the solder paste during the heat treatment, the re-oxidation promotes the melting of the metal and the alloying due to thermal diffusion. As a component of the flux, A well-known material can be used. <Connection structure> The present invention also provides a connection structure having an ith electronic component, a second electronic component, and a bonding of the second component and the second electronic component The agent bonding portion 'forms the flux bonding portion by performing the reflow treatment of the lead-free solder of the present invention described above. As a combination of the second electronic component and the second electronic component, the substrate is electrically In combination with the mounting of the component electrode, etc., the interface method for forming the first electronic component and the second electron to form the connection structure of the present invention is as follows: applying a solder paste to the substrate electrode and mounting the component electrode Then, the method of joining by reflow heat treatment is performed. 146300.cJ〇c •15· 201038349 = pole: The substrate electrode is coated with a solder paste, and the winter electrode and the substrate electrode are placed by reflow heat, and heat-treated to join. In the above case, the electrode can be connected by the electrode „ ^ solder joint. The temperature of the reflow heat treatment is in the range of (10) ~ the scope of the gift - c. The reflow heat treatment temperature is typical 4: setting = brother 1 The melting point of the metal particles is equal to or higher than the melting point of the second metal particles. When the lead-free solder of the present invention is used, when the electrode for the remote electrode is used, and when the electrode for mounting the component and the right side of the substrate are given a thermal history of the melting point of the second metal particle, the metal particles of the 苐2 are melted, and the first metal particle is mounted. The part electrode is bonded to the substrate electrode. At this time, the thermal diffusion reaction proceeds between the first metal particles and the metal of the second metal particles, and a new stable alloy phase having a higher melting point than the melting point of the second metal particles is synthesized to form the first metal particles and the connection. A connection structure of the delivery electrode and the substrate electrode is mounted. The melting point of the new stable alloy phase is higher than that of the lead-free solder containing Sn-3.0Ag_0.5Cu, which is as high as 26 (TC or so), and the subsequent step does not melt even if it is subjected to a plurality of heat treatment fluxes. According to the present invention, it is possible to prevent a short circuit generated between the electrodes of the parts due to remelting of the flux. &lt;Parts-mounted substrate&gt; The present invention also provides a component mounting substrate having a substrate and the above-described connection structure of the present invention mounted on the substrate. [Examples] The present invention is specifically described by way of examples, but the invention is not limited thereto. 146300.doc -16. 201038349 [Example 1] (1) Production of first metal particles Cu 6.5 kg (purity of 99% by mass or more), Sn of 1.5 kg (purity of 99% by mass or more), Ag of 1.0 kg (purity of 99) % by mass or more), Bi 〇·5 kg (purity of 99% by mass or more) and in 0.5 kg (purity of 99% by mass or more) (ie, target constituent element, Cu: 65 mass%, Sn: 15 mass%, Ag: 1〇) quality%,

Bi: 5 mass%, and In: 5 mass%), graphite crucible was placed, and heated to 14 Torr by a high frequency induction heating device in an atmosphere of 99 vol / 〇 or more.匸

D is melted. Next, the molten metal is introduced into the spray chamber of the helium atmosphere from the tip end of the crucible, and then helium gas is discharged from a gas nozzle provided near the tip end of the crucible (purity of 99 volume/min or more, oxygen concentration of less than 〇丨 volume%, pressure 2 5 MPa) was atomized to produce the first metal particles. The cooling rate at this time is 260 〇ec / sec. The first metal particles were classified by a flow rate classifier (Nissin Project: TC-15N), and the large particle fraction was collected, and then the small particle fraction was fractionally collected by setting 〇 30 μm. The recovered alloy particles were measured by a laser diffraction particle diameter distribution measuring apparatus (HELOS &amp; RODOS), and the average particle diameter was 151 μηη. The i-th metal particles were measured by a differential scanning calorimeter (Shimadzu Corporation: DSC-50) under a nitrogen atmosphere at a temperature increase rate of 1 (Γ(:/min) in the range of 40 to 580 C, at 5〇2. And 521. The endothermic peak was detected under the armpit, and the plurality of melting points indicated thereby confirmed the existence of the complex alloy phase. Further, the exothermic peak was detected at 258t &amp; 282t, and the existence of the quasi-stable alloy phase was confirmed. The obtained i-th metal particles are hereinafter referred to as the first metal particles A. 146300.doc -17· 201038349 Similarly, the first metal particles obtained by atomization are classified by one measurement, and after the large particle fraction is recovered, The fraction was further classified by 2 Torr, and the small particle fraction was recovered. The recovered alloy particles were measured by a laser diffraction particle diameter distribution measuring device (HEL〇S &amp; RODOS) to obtain an average particle diameter of 8.1 μϊη. The obtained ruthenium metal particles are hereinafter referred to as ruthenium metal particles B. Similarly, the ruthenium metal particles obtained by atomization are classified by setting at 16 μm, and the large particle fraction is recovered, and then set again at 1 μm. Grading, recycling small particles The collected alloy particles were measured by a laser diffraction particle diameter distribution measuring device (HELOS &amp; RODOS), and the average particle diameter was 2·7 μηι. The obtained third metal particles were recorded as follows. In the same manner, the first metal particles obtained by atomization are classified by a setting of 3 μm to collect a large particle portion, and the collected alloy particles are subjected to a laser diffraction particle diameter distribution measuring device (HELOS &amp;; RODOS) measurement, the average particle size is 30.2 μηι. The obtained i-th metal particles are hereinafter referred to as i-th metal particles D. (2) Production of second metal particles The second metal particles are made of mountain metal ( Co., Ltd. has a particle size of 25 μιη to 45 μιη of the flux powder Bi_42Sn (element composition: 58 mass/〇, Sn: 42 mass%) (hereinafter referred to as second metal particle A), or mountain metal (month) Further, the company has a particle size of 1 〇 pm to 25 μηι of a tantalum powder 42Sn (element composition 'Bi: 58% by mass, Sn: 42 mass%./〇) (hereinafter referred to as a second metal particle B). Differential scanning calorimeter (Shimadzu Corporation) Dsc_ 146300.doc -18- 201038349 5〇) The melting point measured by the same measurement conditions as described above, the second metal particles a and the second metal particles B are both 138. Further, the second metal particles a and 2 The metal particles B were measured by a laser diffraction particle diameter distribution measuring device (HELOS &amp; RODOS), and the average particle diameter was found to be $35 _ and 20.4 μπι, respectively. (3) The production of the lead-free solder paste was mixed at a mass ratio of 100:300. Above! The metal particles VIII and the second metal particles ’ are used as a metal filler component. Next, a metal filler component of 89.5 mass% and a flux (Α) of 10.5% by mass were mixed, and a solder paste was prepared by sequentially applying a solder softening machine (MARUKOMU: SPS-1) and a defoaming kneader (Songo Industry: SNB_350). (4) Measurement of joint strength (shear strength) The above-mentioned solder paste was printed and applied on a Cu substrate having a size of 25 mm × 25 mm and a thickness of 0.25 mm, and a wafer having a size of 2 mm × 2 mm and a thickness of 〇 5 was placed in a nitrogen atmosphere. The sample was subjected to reflow heat treatment at a peak temperature of 16 〇t. The heat treatment apparatus used a reflux simulator (MARUKOMU: SRS-1C). The temperature distribution was ramped from 120 °/sec from the beginning of the heat treatment (normal temperature) to 120 C, and gradually increased from 120 ° C to 10 ° for 10 seconds. ^^^, the temperature is raised by 2-〇°c/sec, and the condition is maintained at the peak temperature}^^ for 15 seconds. The printing pattern was formed using a screen printer (Micr〇tek: MT-320TV). The printing cover is made of metal and the applicator is made of urethane. The cover opening size is 2 mm x 3.5 mm and the thickness is 〇·ΐ mm. The printing conditions were a speed of 5 〇 mm/sec, a press of 0.1 MPA, a squeegee pressure of 2 MPa, a back pressure of 〇·ΐ Mpa, and an attack angle of 20. , the spacing is 〇 mm, the number of printing is j times. 146300.doc •19· 201038349 Next, at normal temperature (25t), the shear direction of the sample prepared above: wafer: the strength of the bond is measured by the load measuring device at a pressing speed of 1 疋. The value per unit area is '1·4峨. Further, the sample prepared above was heated to a second order on a hot plate, and after holding for 3 minutes, the wafer bonding strength in the U-cut direction was measured to be a value per unit area in the same manner as described above, and was G 35 MPa. In this way, it was confirmed that the sample had a heat resistance of 26 (the TC can maintain the bonding strength while being heated. Further, the bonding strength can be maintained, which means that the bonding strength is not less than 2 MPa.) [Example 2 ～10, Comparative Examples 1 and 2] A solder paste was prepared in the same manner as in Example i using the metal filler component in which the mixing ratio of the first metal particles A and the second metal particles A was changed, and the wafer was measured in the same manner as in Example 1. The bonding strength is shown in Tables 2 to 5 and Comparative Example!. In addition, the metal filler composition of the same mixing ratio as in Example 5 is used, respectively, and the temperature distribution when the (four) sheet is joined is employed. .5 ° c / sec from the beginning of heat treatment (normal temperature) to 12 (rc, from 12 〇 after 110 seconds gradually warmed to 135 ° c after '2.0. (: / sec temperature, and at the peak temperature of 18 (TC hold The results of 15 seconds were also shown in Examples 6 to 10 and Comparative Example 2 of the Table. It is apparent from the results of Comparative Examples 2 and 2 of the table that when the first metal particles are not contained, the temperature is heated at 26 ( Rc, the flux joint (joining portion) is melted, so the shear strength is 〇MP On the other hand, in Examples 1 to 10 containing the first metal particles, even if a26 (the rc is heated, the bonding strength is 0.2 MPa or more, the flux is not remelted. Further, in the present specification, the so-called flux No further melting means that the joint strength is above 〇2〇Mpa. 146300.doc 20· 201038349 [Comparative Example 3] Using the previous representative lead-free solder (Sn-3.0Ag-0.5Cu) paste, and Example 1 (4) The same method was used to measure the bonding strength of the wafer. The results are shown in Table 1. The 'reflow temperature distribution when the Cu material was bonded using the flux material' was started from the heat treatment at room temperature of (.5 seconds) (normal temperature). The temperature is raised to 140 C and then gradually warmed from 140 C to 11 〇 to 17 (rc, then heated to 170 ° C from 170 C / privately at 170 ° C, and at a peak temperature of 25 〇. (: Maintain 15 private conditions by comparison As a result of 3, it was found that the representative flux-free solder s Ag 〇 '5 € 11 'when the solder joint was heated at 260 ° C, the joint strength was 0 MPa. [Examples 11 to 20]

A solder paste was prepared by the same method as in Example 1 using a metal filler component in which the mixing ratio of the first metal particles B and the second metal particles B was changed, and further, or (10). The peak temperature of C was subjected to a reflow heat treatment (same as in Examples 1 to 1). The joint strength was measured in the same manner. The results are shown in the examples U to 2 of Table 2. According to Table 2, in Examples 11 to 20 containing the ?! metal particles B, it was revealed. c When heating, it is also the joint strength of 〇 2, and the heat resistance of the bonded state is shown. [Example 21] On a substrate including a high heat-resistant epoxy ray-breaking cloth, a f-cloth (four) non-error solder prepared in the second embodiment was mounted, and a _3-sized laminated ceramic tile electric grid was mounted. After the first 0603C, or the single-loaded parts), 4 cases of 1 (four) conditions into the (four) flow heat treatment, making samples. Next, the above-mentioned clothes were applied to the hot plate to be heated by (9) t, and the μ 146300.doc -21 - 201038349 portion of the filler was applied to the upper portion of the mounting member, and the underfill was applied and hardened at 165 ° C for 2 hours in an electric furnace. Next, the transparent molding resin was applied to the upper portion and the periphery of the mounting member to be hardened at 50 ° C for 4 hours in an electric furnace. Subsequently, after absorbing at 60 ° C and 60% RH for 40 hours, a reflow heat treatment at a peak temperature of 260 ° C was carried out under a nitrogen atmosphere. The heat treatment apparatus used a reflux simulator (MARUKOMU: SRS-1C). The temperature distribution is ramped from heat treatment (normal temperature) to 15 (TC, from 15 〇 in irc / sec. 渐 gradually warms up to 2 HTC after 1 〇〇 second, then rises from 21 (rc / sec from 21 (rc / sec) 26 〇 &lt;t, and kept at a peak temperature of 260 ° C for 15 seconds. Then, the flux was melted by reflow treatment, and the short between the electrode electrodes was visually observed. The results are shown in Table 3. As a result, Example 21 was confirmed. In the middle, the short circuit between the electrode of the part was not observed, and the heat resistance of the flux material at 2 60 C was not observed. [Comparative Example 4] In the same manner as in Example 21, the representative error-free flux Sn before the feeding was performed. Evaluation of -3.0Ag-0.5Cu. However, only when 〇6〇3 is mounted (: when the temperature distribution is different, the temperature is raised from 140C/sec from the heat treatment (normal temperature) to 140C, and 140C is passed for 1 second. Gradually warm up to 17 (Γ (: after 2 TC / sec from 2HTC to 25 〇 t, and at the peak temperature of 25 (^ hold Η seconds conditions. The results are shown in Table 3. ' From the results of Table 3 It is clear that in Comparative Example 4, the flux is melted at a very high probability, and a short circuit occurs between the electrode of the part. In Shi Xianzhong, although the melting point of the second metal particles is 138t:, the short circuit between the component electrodes does not occur. From the above results, it can be seen that the metal filler of the present invention: the non-scratch flux can be used for joining parts at low temperatures, even if After that, it is reflowed, and the 146300.doc 22·201038349 agent is not melted and flows out, and is a material excellent in heat resistance. [Example 22] The second metal ion A and the second metal ion A are mixed at a mass ratio of 丨00··186. 'As a metal filler component. Connected to (4) metal filler into (4).%, with flux (% of the quality, in the same steps as the embodiment!) to make solder paste. For printed substrates containing high heat-resistant epoxy glass cloth ^The electrode paste is coated with a solder paste, and a resistive resistor chip (hereinafter referred to as 〇41GG5R, or simply a mounted component) is mounted, and then subjected to reflow heat treatment under a nitrogen atmosphere at a pilot temperature of 160 ° C to prepare a sample. The obtained sample was embedded in epoxy resin, and the cross-section polishing was performed to observe the joint part of the mounted part'. The flux layer existing in the upper layer of the solder of the joint part of the mounting part was calculated. The number of floating particles (ie, the state in which the metal particles are separated from each other) is the total number of particles (floating particles). The results are shown in Table 4. Furthermore, the number of floating particles shown in Table * is calculated as 6 points of the ruler. The value of the floating particles in the joint portion is the average value. [Examples 23 to 24] The first metal particles A of Example 22 were used instead of the first metal particles C, and the first metal particles C were used for the same evaluation. Table 4. As is clear from the results of Fig. 4, when the average particle size 27 is called the third particle c, more floating particles in the flux layer of the upper layer of the solder at the joint portion are observed, and the average particle diameter is used. 8. When the i-th metal particles j of j μηι or the second metal particles A of the average particle diameter of 15_1 (d), it is understood that the number of floating particles generated in the flux layer is small. Thus, compared with the case of the average particle size of the metal particles used (for example, 2.7 μm), it is known that the average particle diameter is, for example, $^ 146300.doc -23-201038349 叩 and mountain μη^, which can be obtained from the burr The advantage of floating in the layer is not easy to occur. [Examples 25 to 27] The first metal particles Α and the second metal particles B were mixed at a mass ratio of 1 〇〇: 186 as a metal filler component. Next, the metal filler component 89 5 mass% and the flux (10) 0.5 mass% were mixed to prepare a flux lean in the same manner as in the example. The obtained solder paste was printed and applied on a oxidized substrate, and the adhesion was measured using an adhesion tester (manufactured by MARUKOMU Co., Ltd.) τκ-1. The results are shown in Example 25 of Table 5. # efforts to measure 5 points, the average of which is * in Table 5. Further, in place of the second metal particles, the first metal particles β or the first metal particles D were used, and a solder paste was prepared in the same manner as in Example!, and the adhesion was measured in the same manner. The results are shown in Examples % and η of Table 5, respectively. From this, it can be seen that the average particle diameter of the metal particles used is as large as the case where the average particle diameter of the metal particles is 30.2 μm, and the average particle diameter is, for example, 8.1 μl η &amp; 15.1 μηη. The advantage of the adhesion of the solder paste showing a high adhesion value. [Examples 28 and 29] The i-th metal particles 第 and the second metal particles 混合 were mixed as a metal filler component in a ratio of 1 to 100 · 186. Next, a metal paste composition of 9 〇% by mass and a flux (B) 〇% by mass were mixed, and a solder paste was prepared in the same manner as in Example i. Using the obtained solder paste, in the same manner as in Example 1 (4), a reflow heat treatment was performed at a peak temperature of 16 (rc) in a nitrogen atmosphere to prepare a Cu wafer, and the substrate was measured at room temperature and 260. (: Bonding strength at the time of heating. The results are shown in Example 28 of Table 6. 1463 〇〇.d〇c -24- 201038349 Further, the first metal particles A and the second metal particles B were mixed at a mass ratio of 100:186 as a metal filler component. A flux was prepared in the same manner as in Example 1 except that the filler component was 89.5% by mass and the flux (B) was 0.5% by mass. In the same manner as in Example 1 (4), the mixture was refluxed at a peak temperature of 160 ° C under a nitrogen atmosphere. The Cu wafer bonded substrate was prepared by heat treatment, and the joint strength at room temperature and heating at 260 ° C was measured. The results are shown in Example 29 of Table 6.

[Comparative Examples 5 and 6] Cu powder (manufactured by Futian Metal Foil Powder Co., Ltd., Cu-HWQ average particle diameter: 15 μm) and second metal particles A were mixed as a metal filler component at a mass ratio of 100:186. Then, 90% by mass of the metal filler component and 1% by mass of the flux (B) were mixed, and a solder paste was prepared in the same manner as in Example 1, and the obtained paste was used under a nitrogen atmosphere in the same manner as in Example U4). The peak temperature i6〇〇c was subjected to reflow heat treatment to prepare a Cu wafer bonded substrate, and the joint strength at normal temperature and heating at 260 ° C was measured. The results are shown in Comparative Example 5 of Table 6. Further, Cu powder (Fu Hig Metal Foil Industrial Co., Ltd. Cu HWQ 1 5 μηι) and second metal particles B were mixed at a mass ratio of 100:186 to form a metal filler component. Next, a metal paste component of 89.5 mass% and a flux (β) 〇 5 mass% were mixed, and a solder paste was prepared in the same manner as in the example i. In the same manner as in Example 1 (4), the obtained paste was subjected to reflow heat treatment at a peak temperature of 16 lapses in a nitrogen atmosphere to prepare a Cu wafer bonded substrate, and the temperature was 260 at room temperature. . Bonding strength when heated. The results are shown in Comparative Example 6 of Table 6. The combination of Example 28 and Comparative Example 5 or Example 29 of Table 6 and Comparative 146300.doc -25-201038349 and Bi-42Sn and Cu powder of the second metal are known. When the combination of Bi-42Sn and the first metal particles A of the second metal is used, the joint strength at room temperature is remarkably excellent. [Comparative Examples 7 and 8] The following evaluations were carried out in comparison with the prior art of the present inventors (JP-A-2008-183 582). Production of the third metal particles: 1.0 kg of Ag particles (purity of 99% by mass or more), 2 particles of Bi particles (purity of 99% by mass or more), 1.5 kg of Cu particles (purity of 99% by mass or more), and 20.0 kg of In particles (purity) 99% by mass or more), Sn particles of 3.5 kg (purity of 99°/mass or more) (ie, target constituent elements, Ag: 1 〇 mass%, Bi: 2 〇 mass%, Cu. 15 mass%, In: 20 mass%) And Sn: 35 mass%) placed in graphite crucible at 99 volumes. /. In the above atmosphere, it is melted by heating to MOOt by a high frequency induction heating device. Next, the molten metal is introduced into the spray chamber of the helium atmosphere from the tip end of the crucible, and then helium gas is discharged from a gas nozzle provided near the tip end of the crucible (purity of 99% by volume or more, oxygen concentration of less than 1% by volume, and pressure of 2.5 MPa). The atomization is performed to produce the third metal particles. The cooling rate at this time was 260 (TC/sec.) The obtained third metal particles were observed by a scanning electron microscope (manufactured by Hitachi, Ltd.: s_27〇〇), and were found to be spherical. The airflow classifier (TCM5N manufactured by Nissin Engineering Co., Ltd.) was classified at a setting of 5 μηΐ, and the large particle fraction was recovered, and then classified again at a setting of 15 μm to recover a small particle fraction. The laser diffraction particle diameter was recovered. The third metal particles recovered were measured by the distribution of 敎I (HEL〇s &amp; R〇D〇s), and the average diameter was found to be 55 μηη. The third metal thus obtained was 146300.doc •26· 201038349 'Confirmed The low-melting-point particles were used as a sample, and differential scanning calorimetry was performed. The results were at 66 ° C, 87 t, and 38 (the endothermic peak of TC, which had a plurality of melting points in the "seven and seven regions". Next, the mass ratio was 100: 186. The second metal particles A and the third metal particles B were used as the metal filler component, and then the metal filler component 88.4 and the flux were 1.6% by mass, and a solder paste was prepared in the same manner as in Example i. The same as in the example i (4). Use the resulting cream in the atmosphere

The reflow heat treatment was carried out at a peak temperature of 16 〇t to prepare a Cu wafer substrate, and the joint strength at normal temperature and 260 t heating was measured. The results are shown in Comparative Example 7 of Table 7. Further, a cu powder (CU-HWQ 15 μmη, manufactured by Fukuda Metal Foil Co., Ltd.) and a third metal particle were mixed as a metal filler in an amount of 100 to 186. Then, the metal filler component 88 7 mass% and the flux (Β) ιι. 3 mass% were mixed, and the same (4) was produced as in the case of the real thing (4), which was the same as the example ι (4), under a nitrogen atmosphere, at a peak temperature (10). . c, a reflow heat treatment was performed to prepare a Cu wafer bonded substrate, and the bonding strength at room temperature and 26 〇 (&gt;c heating was measured. The results are shown in Comparative Example 8 of Table 7. According to Examples 28 and 29 and Comparative Example 7, the relative When the metal filler in which the third metal particles are mixed is used in place of the second metal particles, it is found that the bonding strength under the service is low. Further, comparing Comparative Example 7 and Comparative Example 8, the bonding strength is displayed. The lower value is approximately the same joint strength. That is, when the third metal particles are used, it is confirmed that the combination with the second metal particles A and the combination with the Cu powder exhibits low joint strength. 146300.doc • 27- 201038349 [Table i] Reflow heat treatment peak temperature Metal filler composition (mass ratio) Bonding strength (MPa) First metal particle A Second metal particle A Normal temperature 260 〇 C Example 1 160 ° C 100 300 15.4 0.35 Example 2 160. 100 186 12.4 0.72 Example 3 160. 100 122 10.2 0.97 Example 4 160 ° C 100 82 3.4 0.78 Example 5 160 ° C 100 54 2.4 0.48 Example 6 180 ° C 100 300 15.9 0.34 Example 7 180 ° C 100 186 13.2 1.1 Example 8 180 ° C 100 122 9.8 1.7 Example 9 180 ° C 100 82 7.7 1.1 Example 10 180 ° C 100 54 3.4 0.8 Comparative Example 1 160 ° C 0 100 38.2 0 Comparative Example 2 180. 0 100 44.3 0 Comparative Example 3 250 ° C Sn-3.0Ag-0.5Cu 26.4 0 [Table 2] Reflow heat treatment peak temperature Metal filler composition (mass ratio) Bonding strength (MPa) First metal particle B Second metal particle B Normal temperature 260 〇 C Example 11 160 ° C 100 300 14 0.5 Example 12 160 ° C 100 186 12.4 0.9 Example 13 160 ° C 100 122 6.7 1.2 Example 14 160 ° C 100 82 3.0 0.9 Example 15 160 ° C 100 54 2.8 1.1 Example 16 180 ° C 100 300 17.1 0.7 146300.doc -28- 201038349 Example 17 180 ° C 100 186 14.9 1.0 Example 18 180 ° C 100 122 7.4 0.9 Example 19 180 ° C 100 82 4.8 1.0 Example 20 180°C 100 54 4.5 1.3 [Table 3] Number of occurrences of short circuit between parts and the total number of occurrences Example 21 0/45 0% Comparative Example 4 17/83 20.5%

[Table 4] First metal particles (mass ratio) Second metal particles (mass ratio) Number of floating particles (s) First metal particles A First metal particles B First metal particles C Second metal particles A Example 22 100 0 0 186 7 Example 23 0 100 0 34 Example 24 0 0 100 878 [Table 5] First metal particle (mass ratio) Second metal particle (mass ratio) Adhesion (gf) First metal particle A First Metal particles B First metal particles D Second metal particles B Example 25 100 0 0 186 148 Example 26 0 100 0 160 Example 27 0 0 100 91 146300.doc -29- 201038349 [Table 6] Reflow heat treatment peak temperature Metal filler composition (mass ratio) Bonding strength (MPa) First metal particle A Cu powder Second metal particle A Second metal particle B Normal temperature 260. . Example 28 160 ° C 100 0 186 0 13.5 0.86 Example 29 160 ° C 100 0 0 186 26.8 0.65 Comparative Example 5 160 ° C 0 100 186 0 4.3 0.63 Comparative Example 6 160 ° C 0 100 0 186 12.4 1.3 [Table 7] Reflow heat treatment peak temperature Metal filler composition (mass ratio) Bonding strength CMPa) First metal particle A Cu powder Third metal particle normal temperature 260 〇 C Comparative Example 7 160 ° C 100 0 186 3.82 1.74 Comparative Example 8 160 ° C 0 100 186 3.48 1.51 [Industrial Applicability] The metal filler of the present invention and the lead-free solder containing the same can be applied to applications in which a plurality of heat treatments are received in the subsequent step (for example, in an electronic device such as a component-embedded substrate or a package) The solder material used, for example, a conductive adhesive, and low temperature mounting is possible. 146300.doc -30-

Claims (1)

201038349 VII. Patent application scope: L A metal filler comprising a mixture of a first metal particle and a second metal particle, '(1) The first metal particle contains the highest quality ratio of the main metal component as a main component~, Further, the ruthenium and the Cu alloy particles are further contained; and the second metal particles are contained in an amount of 4 〇 to 7 〇 mass%, and the metal selected from the group consisting of Ag Cu, In, and Sn The mass % of the B i alloy particles; and the amount of the second metal particles is 40 to 300 parts by mass relative to the ith (9) parts by mass of the i-th metal particles. 2. The metal filler according to the above aspect, wherein the second metal particles contain Sn. 3. The metal filler according to claim 1 or 2, wherein the average particle diameter of the second metal particles and the second metal particles are in the range of 5 to 2 S μη. 4. 〇 5. The metal filler according to claim 1 or 2. The second metal particles further contain one or more metals selected from the group consisting of Ag and Bi. The metal filler according to claim 1 or 2, wherein the foregoing second metal particles comprise Ag 5 to 15 mass. /〇, Bi 2 to 8 mass%, (: u 49-81 mass%, /❶, In 2 to 8 mass%, and Sn 10 to 20 mass%, and the first metal particles are described in differential scanning calorimetry (Dsc) ), having a temperature of 230 to 300. (: at least one exothermic peak observed in the range, and at least one endothermic peak observed in the range of 480 to 530 ° C. 6. A lead-free solder containing the request item A metal filler of 1 or 2. 7. A connection structure comprising a first electronic component, a second electronic component, 146300.doc 201038349, and a solder joint portion joining the first electronic component and the second electronic component, wherein the solder bonding The part is formed by subjecting the lead-free solder of claim 6 to reflow heat treatment. 8. A component mounting substrate having a substrate and a connection structure as claimed in claim 7 mounted on the substrate. 146300.doc 201038349 IV (1) The representative representative of the case is: (none) (2) The symbolic symbol of the representative figure is simple: 5. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: (none) 146 300.doc -2-