TW201538759A - Copper powder - Google Patents

Abstract

This invention provides a novel copper powder capable of suppressing the generation of gas during the process of baking the paste and further suppressing the swelling or cracking of the cured paste containing the copper powder. The copper powder contains a carbon content of 20 to 60 ppm, and less than 60 % of copper-carbon ratio 1 defined by the formula (PC1*100/PCu1) wherein PC1 represents an average peak strength of carbon detected by Energy Dispersion type X ray splitting method in the voids within the particle and PCu1 represents an average peak strength of copper within the same voids.

Description

銅粉 Copper powder

本發明係關於一種可使用來作為各種用途所使用的導電材料之銅粉，例如於電路的形成或可使用於陶瓷電容器的外部電極之形成之導電性膏劑，可使用來作為導電填充劑之銅粉。 BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a copper powder which can be used as a conductive material for various purposes, for example, in the formation of a circuit or a conductive paste which can be used for forming an external electrode of a ceramic capacitor, which can be used as a conductive filler copper. powder.

作為形成電子元件等電極或電路之方法，將作為導電性材料的銅粉分散於膏劑之導電膏劑印刷於基板後，使該膏劑經過燒成或熟化並硬化而形成電路之方法已為人所知。 As a method of forming an electrode or an electric circuit such as an electronic component, a method in which a conductive paste in which a copper powder as a conductive material is dispersed in a paste is printed on a substrate, and the paste is fired or cured and hardened to form a circuit is known. .

此種導電膏劑係由樹脂系黏結劑與溶劑所構成之媒液(vehicle)中分散有導電填充劑之流動性組成物，廣泛被使用於電路的形成或陶瓷電容器的外部電極之形成等。 Such a conductive paste is a fluid composition in which a conductive filler is dispersed in a vehicle composed of a resin-based binder and a solvent, and is widely used for formation of a circuit or formation of an external electrode of a ceramic capacitor.

於此種導電膏劑中，係有：存在有以樹脂的硬化來加壓黏著導電性填充劑並確保導通之樹脂硬化型、及以煅燒來揮發有機成分並燒結導電性填充劑而確保導通之煅燒型。 In the conductive paste, there is a resin-cured type in which a conductive filler is pressure-bonded by curing of a resin to ensure conduction, and an organic component is volatilized by firing to sinter the conductive filler to ensure conduction. type.

前者的樹脂硬化型導電膏劑，一般而言，為含有由金屬粉末所構成之導電填充劑、及由環氧樹脂等 熱硬化性樹脂所構成之有機黏結劑之膏劑狀組成物，且藉由加熱而使熱硬化型樹脂與導電填充劑一起硬化收縮，然後經由樹脂而使導電填充劑彼此間被壓黏，成為接觸狀態，並確保導通性者。此種樹脂硬化型導電性膏劑可在100℃至頂多200℃之較低溫的區域進行處理，且熱損傷較少，故可使用於印刷配線基板或不耐熱的樹脂基板等。 The resin-curable conductive paste of the former is generally a conductive filler composed of a metal powder, and an epoxy resin or the like. A paste-like composition of an organic binder composed of a thermosetting resin, and a thermosetting resin and a conductive filler are hardened and shrunk together by heating, and then the conductive filler is pressure-bonded to each other via a resin to become a contact. State and ensure continuity. Such a resin-curable conductive paste can be treated in a relatively low temperature region of from 100 ° C to at most 200 ° C and has less thermal damage, so that it can be used for a printed wiring board or a heat-resistant resin substrate or the like.

另一方面。後者的燒成型導電膏劑為使由金屬粉末所構成之導電填充劑與玻璃粉料(glass frit)分散於有機媒液而成之膏劑狀組成物，以500至900℃進行燒成，以使有機媒液揮發，進一步藉由燒結導電填充劑可確保導通性者。此時，玻璃粉料具有使此導電膜接著於基板之作用，有機媒液係作用為用以使金屬粉末及玻璃粉料印刷之有機液體介質。 on the other hand. The latter fire-formed conductive paste is a paste-like composition obtained by dispersing a conductive filler composed of a metal powder and a glass frit in an organic vehicle, and firing at 500 to 900 ° C to make The organic vehicle liquid is volatilized, and the conductivity is further ensured by sintering the conductive filler. At this time, the glass frit has a function of causing the conductive film to adhere to the substrate, and the organic vehicle serves as an organic liquid medium for printing the metal powder and the glass powder.

燒成型導電膏劑由於燒成溫度高，故無法使用於印刷配線基板或樹脂材料中，但因為燒結後金屬一體化，故可實現低阻抗化，例如使用於積層陶瓷電容器的外部電極等。 Since the baking paste has a high firing temperature, it cannot be used in a printed wiring board or a resin material. However, since the metal is integrated after sintering, it is possible to achieve low resistance, for example, an external electrode used for a multilayer ceramic capacitor.

作為樹脂硬化型導電膏劑及高溫燒成型導電膏劑之任一者中，以往大多採用銅粉導電填充劑。銅粉不僅便宜，而且難以產生遷移、耐銲接性優異，故使用銅粉的導電膏劑漸普及化起來。 In any of the resin-curable conductive paste and the high-temperature fired conductive paste, a copper powder conductive filler has been conventionally used. Copper powder is not only inexpensive, but also difficult to cause migration and excellent solder resistance, so conductive paste using copper powder is becoming more and more popular.

作為此種銅粉的製造方法，已知有：藉還原劑由含有銅鹽的溶液等析出之濕式還原法、使銅鹽加熱氣化並在氣相中進行還原之氣相還原法、使熔融的銅塊在 惰性氣體或水等冷媒中進行急冷而粉末化之噴霧法等。 As a method for producing such a copper powder, a wet reduction method in which a reducing agent is precipitated from a solution containing a copper salt or the like, a vapor phase reduction method in which a copper salt is heated and vaporized, and reduction in a gas phase is known. Molten copper in the A spray method in which a refrigerant such as an inert gas or water is rapidly cooled and powdered.

在此等方法中噴霧法係較一般廣泛使用的濕式還原法，更具有可減小所得之銅粉中之雜質的殘留濃度，以及減少所得之銅粉的粒子表面至內部之細孔之優點。因此，利用噴霧法所製造的銅粉，當使用於導電膏劑的導電材料時，具有可減少膏劑硬化時氣體的產生量，以及可大幅抑制氧化的進行之優點。由此種觀點來看，已揭示各種例如利用噴霧法所製造的銅粉(專利文獻1至5)。 In these methods, the spray method is more effective than the wet reduction method widely used, and has the advantages of reducing the residual concentration of impurities in the obtained copper powder and reducing the pores of the obtained copper powder to the inner pores. . Therefore, the copper powder produced by the spray method has an advantage of reducing the amount of gas generated when the paste is cured and suppressing the progress of oxidation when it is used for a conductive material of a conductive paste. From such a viewpoint, various kinds of copper powders produced by, for example, a spray method have been disclosed (Patent Documents 1 to 5).

銅粉中的碳已知成為膏劑硬化時產生氣體的原因，故已揭示各種著眼於存在銅粉中的碳之銅粉的發明。 The carbon in the copper powder is known to cause gas generation during the hardening of the paste, and thus various inventions have been disclosed which focus on the copper powder of carbon present in the copper powder.

例如特許文獻6中，揭示一種低碳銅粒子，其特徵雖為降低碳含量者，卻仍為微粒且粒度分佈整齊之銅粒子，而碳的含量未達0.01重量%，且磷的含量未達0.01重量%，變動係數CV值為10至35%，於表面的一部份具有非曲面部之略球狀。 For example, in Patent Document 6, a low-carbon copper particle is disclosed, which is characterized in that it is a copper particle having a fine particle size distribution while reducing the carbon content, and the carbon content is less than 0.01% by weight, and the phosphorus content is not up to 0.01% by weight, the coefficient of variation CV is 10 to 35%, and a part of the surface has a slightly spherical shape of a non-curved portion.

專利文献7中，同樣地揭示了一種低碳銅粒子，其特徵雖為降低碳含量者，卻仍為微粒且粒度分佈整齊之銅粒子，該碳的含量未達0.01重量%，且含有100至1000ppm之磷，D90與D50之比例D90/D50為1.3至2.5，且一次粒子的平均粒徑D為0.1至4μm。 Patent Document 7 similarly discloses a low carbon copper particle which is characterized in that it is a copper particle having a fine particle size distribution while reducing the carbon content, and the carbon content is less than 0.01% by weight and contains 100%. The phosphorus of 1000 ppm, the ratio of D90 to D50 is D90/D50 of 1.3 to 2.5, and the average particle diameter D of the primary particles is 0.1 to 4 μm.

[專利文獻] [Patent Literature]

[專利文獻1]日本特開2012-67327號公報 [Patent Document 1] Japanese Patent Laid-Open Publication No. 2012-67327

[專利文獻2]日本特開2012-21193號公報 [Patent Document 2] Japanese Patent Laid-Open Publication No. 2012-21193

[專利文獻3]日本特開2011-6740號公報 [Patent Document 3] Japanese Patent Laid-Open Publication No. 2011-6740

[專利文獻4]日本特開2011-6739號公報 [Patent Document 4] Japanese Patent Laid-Open Publication No. 2011-6739

[專利文獻5]日本特開2010-196105號公報 [Patent Document 5] Japanese Patent Laid-Open Publication No. 2010-196105

[專利文獻6]日本特開2012-233222號公報 [Patent Document 6] Japanese Laid-Open Patent Publication No. 2012-233222

[專利文獻7]日本特開2012-117146號公報 [Patent Document 7] Japanese Patent Laid-Open Publication No. 2012-117146

如上述般，由噴霧法所製造的銅粉，已知使用作為導電膏劑的導電材料時，可抑制燒成膏劑時氣體的產生量至較低。然而，即使欲使用由噴霧法所製造的銅粉，亦有時膏劑燒成時會產生膨脹或破裂。 As described above, when the copper powder produced by the spray method is known to use a conductive material as a conductive paste, the amount of gas generated when the paste is fired can be suppressed to be low. However, even if a copper powder produced by a spray method is to be used, there is a case where the paste is swelled or broken when it is fired.

因此，本發明欲提供一種可更有效地抑制膏劑燒成時之產生氣體，並可更進一步抑制膨脹或破裂之新穎的銅粉。 Accordingly, the present invention is intended to provide a novel copper powder which can more effectively suppress the generation of gas when the paste is fired, and can further suppress expansion or cracking.

有鑑於此課題，本發明提出一種銅粉，其係銅粉的碳含量為20至60ppm，並且於X射線能量散佈光譜法(EDX測定)中相對於在粒子內部的空隙(void)內所測出之銅的平均譜峰強度(P_Cu1)，在該空隙(void)內所測出之碳的平均譜峰強度(P_C1)之碳銅比例1(P_C1×100/P_Cu1)未達60%。 In view of this problem, the present invention provides a copper powder having a carbon content of 20 to 60 ppm and measured in an X-ray energy dispersive spectroscopy (EDX measurement) relative to a void inside a particle. The average peak intensity of copper (P _Cu1 ), the carbon peak ratio 1 (P _C1 × 100 / P _Cu1 ) of the average peak intensity (P _C1 ) of carbon measured in the void (void) 60%.

藉由本發明所提出的銅粉，可更有效地抑 制膏劑燒成時之氣體產生，並可更進一步抑制膨脹或破裂。 By the copper powder proposed by the invention, it can be more effectively suppressed The gas generated when the paste is fired is generated, and the expansion or cracking can be further suppressed.

第1圖係為概念地說明碳銅比例1及2，示意性地顯示於粒子內部具有空隙(void)之銅粉粒子之剖面圖。 Fig. 1 is a cross-sectional view schematically showing copper-carbon ratios 1 and 2, and schematically showing copper powder particles having voids inside the particles.

其次，根據實施的形態例來說明本發明。惟，本發明並不受限於下列所說明的實施形態。 Next, the present invention will be described based on an embodiment of the embodiment. However, the invention is not limited to the embodiments described below.

本發明之實施形態的一例之銅粉，係含有具備空隙(void)且碳於空隙(void)內不偏析的銅粉粒子之銅粉(以下稱為「本銅粉」)。 The copper powder of an example of the embodiment of the present invention is a copper powder (hereinafter referred to as "the present copper powder") containing copper powder particles having voids and carbon which is not segregated in voids.

(空隙) (void)

本銅粉係含有於粒子內部具備空隙(void)的銅粉粒子之銅粉。本銅粉係於粒子內部具備空隙(void)的銅粉粒子(以下，稱為「銅粒子A」)為占全銅粉粒子的1至30個數%左右，其中以2個數%以上或20個數%以下，尤其是3個數%以上或15個數%以下為較佳。 The copper powder is a copper powder containing copper powder particles having voids inside the particles. The copper powder is a copper powder particle having a void in the inside of the particle (hereinafter referred to as "copper particle A"), and is about 1 to 30% of the total copper powder particles, of which 2% or more or It is preferably 20% or less, particularly 3% or more or 15% or less.

將空隙(void)控制成如上述般之粒子個數頻率，可抑制來自孔隙內部的揮發成分所造成之粒子本身的爆裂(popcorn)現象，並且可降低在燒結導電膏劑時因急劇的收縮所造成之龜裂不良。 Controlling the void to the frequency of the number of particles as described above suppresses the popcorn phenomenon of the particles themselves caused by the volatile components inside the pores, and can reduce the sharp shrinkage caused by sintering the conductive paste. The crack is bad.

此外，上述銅粒子A的個數%可由電子顯微鏡照片來測量。具體而言，於電子顯微鏡照片中任意選擇100個銅粒子，並觀察各個銅粒子的剖面，計算具有0.2μm以上的 空隙之銅粒子A的個數，藉由算出前述100個銅粒子中之銅粒子A的比率，亦即銅粒子A的個數頻率(%)來求出。惟，並不限制於100個。 Further, the number of the above-mentioned copper particles A can be measured by an electron micrograph. Specifically, 100 copper particles are arbitrarily selected in an electron microscope photograph, and the cross section of each copper particle is observed, and it is calculated to have 0.2 μm or more. The number of copper particles A in the voids is obtained by calculating the ratio of the copper particles A in the above-mentioned 100 copper particles, that is, the number (%) of the number of copper particles A. However, it is not limited to 100.

其中，本銅粉較佳係以含有於粒子內部具備粒子的大小比例較大的空隙(void)之銅粉粒子。 Among them, the copper powder is preferably a copper powder particle containing voids having a large proportion of particles in the inside of the particles.

由緩和燒結粒子時的爆裂，降低急劇的體積收縮之觀點來看，較佳為含有於粒子內部具備空隙剖面的銅粉粒子(以下稱為「銅粒子B」)之銅粉，該空隙剖面係於粒子剖面之剖面積的30%以上且50%以下之剖面積。 It is preferable to contain copper powder containing copper powder particles (hereinafter referred to as "copper particles B") having a void profile in the inside of the particles from the viewpoint of the bursting of the sintered particles and the reduction of the abrupt volume shrinkage. The cross-sectional area of 30% or more and 50% or less of the sectional area of the particle cross section.

其中，「銅粒子B」係以銅粉粒子整體中之2個數%以上，其中以3個數%以上或20個數%以下，尤其是4個數%以上或10個數%以下的比率佔有之銅粉為進一步更佳。 Here, the "copper particle B" is a ratio of two or more of the total copper powder particles, and a ratio of three to several hundred or more, more than 20 to several hundred, or less, particularly, four or more and ten or less. The copper powder possessed is further better.

此外，上述銅粒子B的個數%可由電子顯微鏡照片來測量。具體而言，於電子顯微鏡照片中任意選擇100個銅粒子，並使用圖像分析軟體而求得粒子剖面積與空隙剖面積之比率，計算該比率為30%以上且50%以下之銅粒子B的個數，藉由算出前述100個銅粒子中之銅粒子B的比率，亦即銅粒子B的個數頻率(%)來求出。惟，並不限定於100個。 Further, the number of the above copper particles B can be measured by an electron micrograph. Specifically, 100 copper particles are arbitrarily selected in an electron microscope photograph, and the ratio of the particle cross-sectional area to the void cross-sectional area is obtained by using an image analysis software, and the copper particles B having a ratio of 30% or more and 50% or less are calculated. The number of the copper particles B is calculated by calculating the ratio of the copper particles B in the above-mentioned 100 copper particles, that is, the number (%) of the copper particles B. However, it is not limited to 100.

如此般，為製造含有將空隙占有率控制在既定的範圍內之銅粒子A或B之銅粉，以例如噴霧法，特別是水噴霧法或氣體噴霧法來進行微粒化較佳。其中，以於使用感應爐而使其熔融後藉噴霧法來進行微粉化者較佳。惟，本銅粉的製造方法並不限定於此等製造方法。 In the same manner, in order to produce copper powder containing copper particles A or B which control the void occupancy rate within a predetermined range, it is preferred to carry out microparticulation by, for example, a spray method, in particular, a water spray method or a gas spray method. Among them, it is preferred that the powder is melted by using an induction furnace and then micronized by a spray method. However, the method for producing the copper powder is not limited to such a production method.

(碳含量) (carbon content)

本銅粉之碳含量係以20ppm至60ppm為較佳，其中，以45ppm以下，尤其是35ppm以下為較佳。 The carbon content of the copper powder is preferably from 20 ppm to 60 ppm, and more preferably 45 ppm or less, particularly preferably 35 ppm or less.

本銅粉所含有之碳可想定為例如起因於脫氧劑的碳。惟，並不限定於此。 The carbon contained in the copper powder may be, for example, carbon derived from a deoxidizer. However, it is not limited to this.

所含有的碳含量高於60ppm時，氣體產生的影響變顯著。又，低於20ppm時，於銅熔液中容易殘留氧，且粒子的氧含量會上升，故作為導電性材料較不佳。 When the carbon content contained is higher than 60 ppm, the influence of gas generation becomes remarkable. Moreover, when it is less than 20 ppm, oxygen is likely to remain in the copper melt, and the oxygen content of the particles increases, so that it is less preferable as a conductive material.

相對於此，若為20ppm至60ppm左右的碳含量，使本銅粉來製作導電膏劑時，可有效地抑制在膏劑燒成時之氣體產生。 On the other hand, when the carbon powder is about 20 ppm to 60 ppm, when the copper powder is used to produce a conductive paste, gas generation during firing of the paste can be effectively suppressed.

此外，碳含量可利用加熱爐燃燒-紅外線吸收法來進行測定。 Further, the carbon content can be measured by a furnace combustion-infrared absorption method.

(空隙內碳含量) (carbon content in the void)

關於本銅粉係於X射線能量散佈光譜法(EDX測定)中相對於在粒子內部的空隙(void)內所測出之銅的平均譜峰強度(P_Cu1)，以該空隙(void)內所測出之碳的平均譜峰強度(P_C1)之銅炭素比例1(P_C1×100/P_Cu1)未達60%為較佳。 The copper powder is in the X-ray energy dispersive spectroscopy (EDX measurement) with respect to the average peak intensity (P _Cu1 ) of copper measured in a void inside the particle, in the void (void) It is preferred that the measured carbon peak ratio (P _C1 × 100 / P _Cu1 ) of the average peak intensity (P _C1 ) of the carbon is less than 60%.

在此的「在粒子內部之空隙(void)內所測出之銅的平均譜峰強度(P_Cu1)」及「在該空隙(void)內所測出之碳的平均譜峰強度(P_C1)」均為具有空隙的銅粉粒子之平均值。碳銅比例1(P_C1×100/P_Cu1)亦為具有空隙的銅粉粒子之平均值。 Here, "the average peak intensity of copper (P _Cu1 ) measured in the void inside the particle" and the average peak intensity of carbon measured in the void (P _{C1 )} )) are average values of copper powder particles having voids. The carbon-copper ratio 1 (P _C1 × 100 / P _Cu1 ) is also an average value of the copper powder particles having voids.

此外，於本發明中所測定之X射線能量散佈光譜法(EDX測定)之各譜峰測定條件係由使加速電壓設為10kV之 二次電子像所得到。 Further, each of the peak measurement conditions of the X-ray energy dispersive spectroscopy (EDX measurement) measured in the present invention is such that the acceleration voltage is set to 10 kV. Obtained from the secondary electron image.

又，銅的譜峰係藉由處理於K α線的8.040keV及L α線的0.930keV顯現之特性X射線之能量而求得，而碳的譜峰係藉由處理於K α線的0.277keV顯現特性X射線之能量而求得。 Further, the peak of copper is obtained by processing the energy of the characteristic X-rays at 0.040 keV of the Kα line and 0.930 keV of the L α line, and the peak of the carbon is 0.277 processed by the K α line. keV is obtained by exhibiting the energy of characteristic X-rays.

若碳於空隙(void)內偏析，於進行粒子燒結時會局部產生二氧化碳氣體，成為燒成膜膨脹或破裂的原因。因此，為免殘留於粒子內部的碳偏析而使其分散，可得知能更有效地抑制二氧化碳氣體的產生，且能抑膨脹或破裂。 When carbon segregates in a void, carbon dioxide gas is locally generated when the particles are sintered, which causes expansion or cracking of the fired film. Therefore, in order to prevent segregation of carbon remaining inside the particles and disperse them, it is known that the generation of carbon dioxide gas can be more effectively suppressed, and expansion or cracking can be suppressed.

由此觀點來看，本銅粉的碳銅比例1(P_C1×100/P_Cu1)係以未達60%為較佳，其中，以50%以下，尤其是25%以下為更佳。 From this point of view, the carbon-copper ratio 1 (P _C1 × 100 / P _Cu1 ) of the present copper powder is preferably less than 60%, and more preferably 50% or less, particularly preferably 25% or less.

以使本銅粉的碳銅比例1(P_C1×100/P_Cu1)成為未達60%的方式，為以免碳於空隙(void)內偏析而使其分散，可列舉例如縮小脫氧劑的粒徑、或提高熔解溫度、或提高攪拌速度等而提高脫氧劑的分散性之方法。惟，並不限定於此等方法。 In the case where the carbon-copper ratio 1 (P _C1 × 100 / P _Cu1 ) of the present copper powder is less than 60%, the carbon is segregated in the void to be dispersed, and for example, the particles of the deoxidizer are reduced. A method of increasing the dispersibility of a deoxidizing agent by increasing the melting temperature or increasing the stirring speed. However, it is not limited to these methods.

(空隙外碳含量) (outside void carbon content)

關於本銅粉係於X射線能量散佈光譜法(EDX測定)中，相對於在粒子內部的空隙(void)外所測出之銅的平均譜峰強度(P_Cu2)，在該空隙(void)外所測出之碳的平均譜峰強度(P_C2)之銅碳比例2(P_C2×100/P_Cu2)為10至40%較佳，其中，以13%以上或37%以下，其中，尤其以15以上35%以下為 更佳。 The present copper powder is in the X-ray energy dispersive spectroscopy (EDX measurement), and the average peak intensity (P _Cu2 ) of copper measured outside the void (void) inside the particle, in the void (void) the average intensity peak (P _C2) of the measured the carbon to carbon ratio of Cu _{2 (P C2 × 100 / P} Cu2) is preferably 10 to 40%, wherein at least 13% or 37% or less, wherein, In particular, it is more preferably 15 or more and 35% or less.

在此的「在粒子內部的空隙(void)外所測出之銅的平均譜峰強度(P_Cu2)」及「在該空隙(void)外所測出之銅的平均譜峰強度(P_C2)」均為具有空隙的銅粉粒子之平均值。碳銅比例2(P_C2×100/P_Cu2)亦為具有空隙的銅粉粒子之平均值。 Here, the average peak intensity (P _Cu2 ) of copper measured outside the void inside the particle and the average peak intensity of copper measured outside the void (P _{C2 )} )) are average values of copper powder particles having voids. The carbon-copper ratio 2 (P _C2 × 100 / P _Cu2 ) is also an average value of the copper powder particles having voids.

(空隙內外碳含量比例) (proportion of carbon content inside and outside the void)

相對於前述碳銅比例2(P_C2×100/P_Cu2)，前述碳銅比例1(P_C1×100/P_Cu1)之比例較佳為1.0至2.0。 The ratio of the carbon-copper ratio 1 (P _C1 × 100 / P _Cu1 ) is preferably 1.0 to 2.0 with respect to the carbon-copper ratio 2 (P _C2 × 100 / P _Cu2 ).

與上述同樣地，若為免碳於空隙(void)內偏析而使其分散，可抑制膨脹或破裂。由此觀點來看，相對於在粒子內部的該空隙(void)外所測出之銅的譜峰強度(P_Cu2)，在該空隙(void)外所測出之碳的譜峰強度(P_C2)之碳銅比例2(P_C2×100/P_Cu2)係以1.0至2.0為較佳，其中，以1.5以下，其中，尤其是1.3以下為更佳。 Similarly to the above, if carbon is segregated in a void to be dispersed, swelling or cracking can be suppressed. From this point of view, the intensity of the peak of the carbon measured outside the void (Poid) relative to the peak intensity (P _Cu2 ) of copper measured outside the void inside the particle (P) _C2) to carbon ratio of Cu _{2 (P C2 × 100 / P} Cu2) based preferably 1.0 to 2.0, wherein 1.5 or less, wherein, in particular, is more preferably 1.3 or less.

為免碳於空隙(void)內偏析使其分散，如上述般，可列舉例如縮小脫氧劑的粒徑、提高熔解溫度、或提高攪拌速度等而提高脫氧劑的分散性之方法。 In order to prevent the carbon from being segregated and dispersed in the void, as described above, for example, a method of reducing the particle diameter of the deoxidizing agent, increasing the melting temperature, or increasing the stirring speed, and the like, and improving the dispersibility of the deoxidizing agent can be mentioned.

(D50) (D50)

關於本銅粉，由空隙(void)的安定形成及膏劑的分散性、或塗佈膏劑時的細微加工性之觀點來看，藉由D50亦即雷射繞射散射式粒徑分佈測定法測定而得之以體積基準粒度分佈之D50以1.5μm至8.0μm為較佳，其中，以1.8μm以上或5.0μm以下，其中，尤其是2.0μm以上或4.0μm以下為更佳。 The present copper powder is determined by D50, that is, laser diffraction scattering particle size distribution measurement, from the viewpoint of stability of void formation and dispersibility of a paste, or fine workability at the time of applying a paste. The D50 of the volume-based particle size distribution is preferably 1.5 μm to 8.0 μm, and more preferably 1.8 μm or more or 5.0 μm or less, and particularly preferably 2.0 μm or more or 4.0 μm or less.

(D10) (D10)

由同樣的觀點來看，藉由本銅粉的D10亦即雷射繞射散射式粒徑分佈測定裝置測定之體積累積粒徑D10較佳為0.5μm至5.0μm。 From the same viewpoint, the volume cumulative particle diameter D10 measured by the D10 of the present copper powder, that is, the laser diffraction scattering type particle size distribution measuring apparatus is preferably from 0.5 μm to 5.0 μm.

若本銅粉的D10為0.5μm以上，於燒成時銅粉就不會過度收縮，故可保持燒成膜中之玻璃的分散性。另一方面，若本銅粉的D10為5.0μm以下，則燒結不進行而可防止燒成膜多孔化，以得到空隙少之緻密的燒成膜，且可保持焼成膜中之玻璃的分散性。 When the D10 of the present copper powder is 0.5 μm or more, the copper powder does not excessively shrink during firing, so that the dispersibility of the glass in the fired film can be maintained. On the other hand, when the D10 of the present copper powder is 5.0 μm or less, sintering does not proceed, and the sintered film can be prevented from being porous, so that a dense fired film having few voids can be obtained, and the dispersibility of the glass in the ruthenium film formation can be maintained. .

由此觀點來看，本銅粉的D10係以0.5μm至5.0μm為較佳，其中，以0.8μm以上或4.0μm以下，其中，以1.0μm以上或3.5μm以下為更佳。 From this point of view, the D10 of the present copper powder is preferably 0.5 μm to 5.0 μm, more preferably 0.8 μm or more or 4.0 μm or less, and more preferably 1.0 μm or more or 3.5 μm or less.

(D90) (D90)

利用本銅粉的D90，亦即雷射繞射散射式粒徑分佈測定裝置所測定之體積累積粒徑D90較佳為2.0μm至20.0μm。 The volume cumulative particle diameter D90 measured by the D90 of the present copper powder, that is, the laser diffraction scattering type particle size distribution measuring apparatus is preferably from 2.0 μm to 20.0 μm.

若本銅粉的D90為2.0μm以上，於燒成時銅粉不會過度收縮，故可保持燒成膜中之玻璃的分散性。另一方面，若本銅粉的D90為20.0μm以下，則燒結不進行而可防止燒成膜多孔化，以得到緻密的燒成膜，，且可保持燒結膜中之玻璃的分散性。 When the D90 of the present copper powder is 2.0 μm or more, the copper powder does not excessively shrink during firing, so that the dispersibility of the glass in the fired film can be maintained. On the other hand, when the D90 of the present copper powder is 20.0 μm or less, sintering does not proceed, and the sintered film can be prevented from being porous, so that a dense fired film can be obtained, and the dispersibility of the glass in the sintered film can be maintained.

由此觀點來看，本銅粉的D90係以2.0μm至20.0μm為較佳，其中，以3.0μm以上或15.0μm以下，其中以4.0μm以上或10.0μm以下為更佳。 From this point of view, the D90 of the present copper powder is preferably 2.0 μm to 20.0 μm, more preferably 3.0 μm or more or 15.0 μm or less, and more preferably 4.0 μm or more or 10.0 μm or less.

(製造方法) (Production method)

說明本銅粉的製造方法之一例。 An example of a method for producing the copper powder will be described.

使用熔解爐而使為作為原料的銅形成熔液後，將粒徑細的碳材料作為脫氧劑添加於熔液中，並且以比較高的攪拌速度使脫氧劑充分分散地進行攪拌，然後藉噴霧法進行微粒化而製造銅粉為較佳。惟，並不限制於此種製造方法。 After forming a molten metal as a raw material by using a melting furnace, a carbon material having a small particle diameter is added as a deoxidizing agent to the molten metal, and the deoxidizing agent is sufficiently dispersed and stirred at a relatively high stirring speed, and then sprayed. It is preferred to carry out micronization to produce copper powder. However, it is not limited to this manufacturing method.

若銅粉中的氧濃度高，可能使電特性變差，故必須於噴霧時減少氧量。因此，通常藉噴霧法進行銅粉微粒化時，在進行噴霧之前，會進行添加脫氧劑。然而，由於脫氧劑中之碳殘留，會與水或氧等反應而成為二氧化碳氣體而產生，推測此乃成為膨脹或破裂的原因。又，若於空隙(void)內碳偏析，偏析的碳會聚集而氣體化於燒成膜內形成氣泡而存在，故認為因此成為膨脹或破裂的原因。 If the oxygen concentration in the copper powder is high, the electrical characteristics may be deteriorated, so it is necessary to reduce the amount of oxygen at the time of spraying. Therefore, when the copper powder is usually atomized by a spray method, a deoxidizer is added before the spraying. However, since the carbon in the deoxidizer remains, it reacts with water or oxygen to cause carbon dioxide gas, which is presumed to be a cause of swelling or cracking. In addition, when carbon segregates in a void, segregated carbon aggregates and gasizes in the fired film to form bubbles, which is considered to be a cause of expansion or cracking.

所以，為免碳於空隙(void)內偏析，可縮小脫氧劑的粒徑而容易分散，結果可抑制於空隙(void)內碳偏析，並可抑制燒成時之氣體發生。藉此，可得到更緊密的銅膏劑燒成膜。 Therefore, in order to prevent segregation of carbon in the void, the particle diameter of the deoxidizer can be reduced and the dispersion can be easily performed. As a result, segregation of carbon in the void can be suppressed, and generation of gas at the time of firing can be suppressed. Thereby, a more compact copper paste fired film can be obtained.

為了提高脫氧劑的分散性，認為除了縮小脫氧劑的粒徑以外，還可提高熔解溫度或提高攪拌速度。 In order to increase the dispersibility of the deoxidizer, it is considered that in addition to reducing the particle diameter of the deoxidizer, the melting temperature or the stirring speed can be increased.

作為使用於本銅粉製造之熔解爐，以具備攪拌功能的熔解爐，尤其是使用感應爐為較佳。 As a melting furnace used for the production of the present copper powder, it is preferable to use a melting furnace having a stirring function, in particular, an induction furnace.

使用感應爐而進行熔液化時，藉由使銅熔液的每單位重量之投入電力量(kW/kg)設為0.1至2.0kW/kg，熔液藉電磁感應更有效率地自然流動並攪拌，捲入脫氧劑，銅熔液 中的氧與脫氧劑會更容易有效率地進行反應，故會於銅粉粒子內產生較大的空隙(void)。藉此，殘留於粒子內部的脫氧劑(碳)會被降低。因此，使用感應爐進行製造時，可更進一步獲得本發明之效果。 When the amount of electric power per unit weight (kW/kg) of the copper melt is set to 0.1 to 2.0 kW/kg when the melt is liquefied by the induction furnace, the molten metal flows and stirs more efficiently by electromagnetic induction. , entrapped in deoxidizer, copper melt The oxygen and the deoxidizer in the reaction are more easily and efficiently reacted, so that a large void is generated in the copper powder particles. Thereby, the deoxidizer (carbon) remaining inside the particles is lowered. Therefore, the effect of the present invention can be further obtained when manufacturing using an induction furnace.

又，即使使用燃氣爐，藉由機械性地攪拌熔液可得到與感應爐同樣的效果。此時的攪拌方法較佳係使用石墨棒於10至15分鐘內一次攪拌30次。惟，若為反應爐，爐的特性上，即使不刻意地攪拌，熔液仍會流動並被攪拌，故可謂反應爐能更有效地使脫氧劑進行反應。 Further, even if a gas furnace is used, the same effect as that of the induction furnace can be obtained by mechanically stirring the melt. The stirring method at this time is preferably carried out by using a graphite rod for 30 times in 10 to 15 minutes. However, if it is a reaction furnace, the characteristics of the furnace, even if not intentionally stirred, the melt will flow and be stirred, so that the reaction furnace can more effectively react the deoxidizer.

又，將感應爐與熔液攪拌併用而組裝熔解爐亦為有效。 Further, it is also effective to assemble the melting furnace by stirring the induction furnace and the melt.

熔解的溫度，亦即熔液溫度係以1150至1700℃為較佳，其中，以1200℃以上，尤其是1380℃以上為進一步更佳。 The melting temperature, that is, the melt temperature is preferably 1150 to 1700 ° C, and more preferably 1200 ° C or higher, especially 1380 ° C or higher.

雖熔解溫度係高者能有効率地消粍脫氧劑(碳)，但過高時，會有因爐材質造成的缺陷，故設為1700℃以下較佳。 Although the melting temperature is high, the deoxidizing agent (carbon) can be efficiently removed. However, if it is too high, there is a defect due to the material of the furnace, so it is preferably 1700 ° C or less.

於進行噴霧之前，作為加入於熔液的脫氧劑，可列舉木炭、穎殼、焦炭等。 Before the spraying, examples of the deoxidizing agent added to the melt include charcoal, hull, coke, and the like.

然後，脫氧劑係為提高其分散性，以粒徑低者為較佳。若為木碳，以調整至粒徑100至500μm者為較佳，尤其以調整至150μm以下者為更佳。此粒徑可利用轉子旋轉式粉砕機等粉砕機或標準篩網等篩網過濾器進行調整。 Then, the deoxidizer is preferably used to improve the dispersibility, and the particle size is preferably low. In the case of wood carbon, it is preferably adjusted to a particle diameter of 100 to 500 μm, and particularly preferably adjusted to 150 μm or less. The particle size can be adjusted by a sieve filter such as a rotary pulverizer or a standard sieve.

在此係脫氧劑之粒徑為較小者，在有效率地與氧反應上為有利，惟未達100μm的粒徑因粒子之重量非常輕，故容易在爐內產生揚起，反而難以處理。然而，未達100μm的木炭係藉由與樹脂混合而成形為顆粒狀並固化再使用亦可迴避上述的問題。 In this case, the particle size of the deoxidizer is small, and it is advantageous in efficiently reacting with oxygen. However, the particle size of less than 100 μm is very light due to the weight of the particles, so it is easy to rise in the furnace, but it is difficult to handle. . However, charcoal which is less than 100 μm can be prevented from being agglomerated by being mixed with a resin to form pellets and solidified and reused.

作為噴霧法係有氣體噴霧法與水噴霧法。其中，若謀求粒子形狀均整化，以氣體噴霧法為較佳，若謀求粒子細微化，則以水噴霧法為較佳。 As the spray method, there are a gas spray method and a water spray method. Among them, in order to achieve uniform particle shape, a gas spray method is preferred, and if the particles are made fine, a water spray method is preferred.

例如，若藉由噴霧法，可得到5至30μm左右的銅粉，若藉由水噴霧法，可得到1μm至8μm左右的銅粉。又，噴霧法之中，藉高壓噴霧法所製造者為較佳。藉由此種高壓噴霧法所得之銅粉係粒子更均整或更細微而較佳。 For example, copper powder of about 5 to 30 μm can be obtained by a spray method, and copper powder of about 1 μm to 8 μm can be obtained by a water spray method. Further, among the spray methods, those produced by a high pressure spray method are preferred. The copper powder particles obtained by such a high pressure spray method are more uniform or finer and more preferable.

順帶一提，所謂高壓噴霧法係指於水噴霧法中以50MPa至150MPa左右的水壓力進行噴霧之方法，於氣體噴霧法中以1.5MPa至3MPa左右的氣體壓力進行噴霧之方法。 Incidentally, the high-pressure spray method is a method of spraying in a water spray method at a water pressure of about 50 MPa to 150 MPa, and spraying in a gas spray method at a gas pressure of about 1.5 MPa to 3 MPa.

又，噴霧後亦可進行還原處理。藉由此還原處理可進一步降低易進行氧化的銅粉之表面的氧濃度。 Moreover, the reduction treatment can also be carried out after spraying. By this reduction treatment, the oxygen concentration on the surface of the copper powder which is easily oxidized can be further reduced.

就上述還原處理而言，由作業性的觀點來看，以氣體之還原為較佳。 In the above reduction treatment, it is preferred to reduce the gas from the viewpoint of workability.

此還原處理用氣體並無特別限定，可列舉例如氫氣、氨氣、丁烷氣等。 The gas for the reduction treatment is not particularly limited, and examples thereof include hydrogen gas, ammonia gas, and butane gas.

又，藉由噴霧進行微粒化後，可視需要而予以分級。 Further, after atomization by spraying, it can be classified as needed.

此分級係以使目標的粒度成為中心之方式來使用適當的分級裝置，可藉由從所得之銅粉分離出粗粉及微粉而容易實施。 This classification is carried out by using an appropriate classification device in such a manner that the particle size of the target is centered, and can be easily carried out by separating the coarse powder and the fine powder from the obtained copper powder.

<文字的說明> <Description of text>

於本說明書中，表現為「X至Y」(X、Y為任意的數字)之時，只要沒有特別的聲明，亦包含「X以上至Y以下」之意、以及「較佳為較X大」或「較佳為較Y小」之意。 In the present specification, the expression "X to Y" (where X and Y are arbitrary numbers) includes the meaning of "X or more to Y or less" and "better than X" unless otherwise stated. Or "preferably smaller than Y".

又，表現為「X以上」(X為任意的數字)或「Y以下」(Y為任意的數字)之時，亦包含「較佳為大於X」或「較佳為未達Y」之含意。 In addition, the meaning of "better than X" or "preferably not up to Y" is also included in the case of "X" or above (X is an arbitrary number) or "Y" (Y is an arbitrary number). .

(實施例) (Example)

以下，根據下列實施例及比較例而詳述本發明。 Hereinafter, the present invention will be described in detail based on the following examples and comparative examples.

<樣本的調製：實施例、比較例> <Modulation of sample: Example, comparative example>

使用燃氣爐或感應爐將電解銅(銅純度：Cu99.95%)加熱至表1所示之溫度而形成熔液，並將以標準篩網調整至100μm以上、500μm以下的木炭粉添加於熔液作為脫氧劑。 The electrolytic copper (copper purity: Cu 99.95%) is heated to a temperature shown in Table 1 by a gas furnace or an induction furnace to form a molten metal, and charcoal powder adjusted to a size of 100 μm or more and 500 μm or less by a standard sieve is added thereto. The melt acts as a deoxidizer.

其次，於水噴霧裝置中之漏斗(tundish)中注入上述熔液100kg(保持溫度1300℃)，一邊使從漏斗底部的噴嘴(口徑5mm)滴下熔液(流量5kg/min)，一邊從圓錐型的噴嘴(口徑26mm)之噴射孔使水成為逆圓錐狀的水流形狀的方式對上述熔液進行噴射式噴射(水壓100MPa、水量350L/min)而進行水噴霧，藉此製造銅粉。 Next, 100 kg of the melt (holding temperature: 1300 ° C) was poured into a funnel (tundish) in a water spray device, and the melt (flow rate: 5 kg/min) was dropped from a nozzle (caliber: 5 mm) at the bottom of the funnel. The injection hole of the nozzle (both diameter: 26 mm) was spray-sprayed (water pressure: 100 MPa, water amount: 350 L/min) so that the water became a shape of a reverse cone-shaped water flow, and water spray was performed to produce copper powder.

其次，將所得之銅粉以分級裝置(日清工程股份有限公司製「Turbo Classifier(商品名)TC-25(型號)」進行分級而得到銅粉(樣本)。 Next, the obtained copper powder was classified by a classification apparatus (Turbo Classifier (trade name) TC-25 (model) manufactured by Nissin Engineering Co., Ltd.) to obtain copper powder (sample).

<銅粉(樣本)的評估> <Evaluation of copper powder (sample)>

對於實施例及比較例所得之銅粉，以下述所示之方法評估各種特性。 For the copper powders obtained in the examples and the comparative examples, various characteristics were evaluated by the methods shown below.

(1)粒徑分佈 (1) Particle size distribution

將銅粉(樣本)0.2g置入於純水100ml中照射超音波並使其分散3分鐘後，以粒徑分佈測定裝置(日機裝股份有限公司製「Microtrac(商品名)MT3000(型號)」)測定體積累積粒徑D10、D50及D90。 0.2 g of copper powder (sample) was placed in 100 ml of pure water, and the ultrasonic wave was irradiated and dispersed for 3 minutes. The particle size distribution measuring apparatus (Microtrac (trade name) MT3000 (model) manufactured by Nikkiso Co., Ltd.) 》) The volume cumulative particle diameters D10, D50 and D90 were measured.

(2)碳(C)含量 (2) Carbon (C) content

使用碳分析裝置(堀場製作所股份有限公司製EMIA-221V2)並依照JIS Z 2615：2009(金屬材料的碳定量方法通則)進行碳分析。 A carbon analysis device (EMIA-221V2 manufactured by Horiba, Ltd.) was used and carbon analysis was carried out in accordance with JIS Z 2615:2009 (General Rules for Carbon Determination of Metallic Materials).

(3)void產生率及剖面積占有率 (3) void production rate and cross-sectional area occupancy rate

使用掃描型電子顯微鏡(SEM)來拍攝剖面的照片，將剖面中的空隙之剖面積(稱為「void剖面積」)以圖像分析軟體(Mountech股份有限公司製、MAC-VIEW)進行計測，計測各粒子的孔隙剖面積並算出10個於粒子內部具有空隙(void)之銅粉粒子的平均值。 A photograph of the cross section was taken by a scanning electron microscope (SEM), and the cross-sectional area of the void in the cross section (referred to as "void cross-sectional area") was measured by an image analysis software (manufactured by Mountech Co., Ltd., MAC-VIEW). The pore cross-sectional area of each particle was measured, and the average value of 10 copper powder particles having a void inside the particle was calculated.

又，計測空隙(void)剖面積占有粒子剖面積的30%以上、50%以下之粒子「銅粒子B」於全部銅粉粒子中所占有的比率。 Further, the void area is measured to occupy a ratio of the particles "copper particles B" of 30% or more and 50% or less of the particle cross-sectional area to all the copper powder particles.

(4)空隙(void)內外碳量、銅量 (4) The amount of carbon inside and outside the void (void)

使用掃描型電子顯微鏡(SEM)，並以20個於粒子內部具有空隙(void)之銅粉粒子為對象，以X射線能量散佈光譜法(EDX測定)測定在粒子內部的空隙(void)內所測出之銅的平均譜峰強度(P_Cu1)、與在該空隙(void)內所測出之碳的平均譜峰強度(P_C1)，算出碳銅比例1(P_C1×100/P_Cu1)。 A scanning electron microscope (SEM) was used to measure the voids inside the particles by X-ray energy dispersive spectroscopy (EDX measurement) for 20 copper powder particles having voids in the particles. The average peak intensity (P _Cu1 ) of the measured copper and the average peak intensity (P _C1 ) of the carbon measured in the void (void) were calculated to calculate the ratio of carbon to copper 1 (P _C1 × 100 / P _{Cu1 )} ).

又，同樣地，以20個於粒子內部具有空隙(void)之銅粉粒子為對象，以X射線能量散佈光譜法(EDX測定)測定在粒子內部的空隙(void)外所測出之銅的平均譜峰強度(P_Cu2)、與在該空隙(void)外所測出之碳的平均譜峰強度(P_C2)，算出碳銅比例2(P_C2×100/P_Cu2)。 In the same manner, 20 copper particles having voids in the inside of the particles were used, and the copper measured outside the voids in the particles was measured by X-ray energy dispersive spectroscopy (EDX measurement). The average peak intensity (P _Cu2 ) and the average peak intensity (P _C2 ) of the carbon measured outside the void were calculated to calculate the carbon-copper ratio 2 (P _C2 × 100 / P _Cu2 ).

再者，算出碳銅比例1對碳銅比例2之比例作為「空隙內外碳量比例」。 Furthermore, the ratio of the ratio of carbon to copper 1 to the ratio of carbon to copper 2 was calculated as "the ratio of the amount of carbon inside and outside the void".

(5)碳酸氣體產生評估 (5) Assessment of carbon dioxide production

使用熱分析-質譜儀(TG-MS)將粉末在含有50ppm的氧之惰性氣體環境中從常溫升溫至1000℃，測定此時所產生的CO₂氣體量。 The powder was heated from a normal temperature to 1000 ° C in an inert gas atmosphere containing 50 ppm of oxygen using a thermal analysis-mass spectrometer (TG-MS), and the amount of CO ₂ gas generated at this time was measured.

氣體產生量係作為在600至900℃的溫度範圍之譜峰面積，亦即600至900℃區域的各溫度之積分值，在表中以「TG-MSCO₂產生譜峰面積」表示。 The gas generation amount is an integral value of the peak area in the temperature range of 600 to 900 ° C, that is, the temperature in the range of 600 to 900 ° C, and is expressed by "TG-MSCO ₂ generation peak area" in the table.

(6)燒成膜評估 (6) Burnt film evaluation

將銅粉7g加入於溶劑(丙烯酸樹脂+萜品醇)2.5g而形成膏劑狀，然後於氧化鋁基板上塗佈成乾燥後膜厚65μm，在大氣中以150℃加熱乾燥10分鐘後，在氮氣環 境以90℃/分鐘的升溫速度加熱至845℃，並在845℃保持20分鐘後進行燒成，將燒結後的膜之狀態以掃描型電子顯微鏡(SEM)以倍率250倍觀察10區域。 7 g of copper powder was added to a solvent (acrylic resin + terpineol) to form a paste, and then coated on an alumina substrate to have a film thickness of 65 μm after drying, and dried by heating at 150 ° C for 10 minutes in the air. Nitrogen ring The temperature was raised to 845 ° C at a temperature elevation rate of 90 ° C /min, and the temperature was maintained at 845 ° C for 20 minutes, and then fired, and the state of the film after sintering was observed by a scanning electron microscope (SEM) at a magnification of 250 times in the 10 region.

然後，以下列的判定標準進行燒成膜外觀評估。 Then, the appearance of the fired film was evaluated by the following criteria.

C：燒成膜的表面有龜裂、或膨脹存在4個以上(不良)。 C: There are cracks or swelling on the surface of the fired film, and there are four or more (defective).

B：燒成膜的表面有裂痕，且膨脹存在1至3個(可使用)。 B: The surface of the fired film is cracked, and there are 1 to 3 swellings (usable).

A：燒成膜的表面無裂痕，且膨脹存在1至3個(良好)。 A: The surface of the fired film was free from cracks, and there were 1 to 3 (good) swelling.

AA：燒成膜的表面無裂痕，且無膨脹(最佳)。 AA: The surface of the fired film has no cracks and no swelling (best).

表1中的「通用木炭」係表示粒徑較500μm大的木炭，「微粒木炭」係表示粒徑為100μm以上且未達500μm的粉砕木炭，在「攪拌」的項目中之「有」係表示於燃氣爐中以10分鐘至15分鐘為1次的頻率以手動攪拌。 The "universal charcoal" in Table 1 indicates charcoal having a particle size larger than 500 μm, and the "microparticle charcoal" indicates that the powder has a particle size of 100 μm or more and less than 500 μm, and the "yield" in the "stirring" item indicates The mixture was manually stirred in a gas furnace at a frequency of 10 minutes to 15 minutes.

(考察) (examine)

由上述實施例及至今的發明人所進行試驗之結果來看，若銅粉所含有的碳含量為20至60ppm，並且於X射線能量散佈光譜法(EDX測定)中，相對於在該空隙(void)內所測出之銅的平均譜峰強度(P_Cu1)，在粒子內部的空隙(void)內所測出之碳的平均譜峰強度(P_C1)之碳銅比例1(P_C1×100/P_Cu1)未達60%時，得知可抑制燒成膏劑時的氣體產生，並可更進一步抑制膨脹或龜裂。 From the results of experiments conducted by the above examples and the inventors of the present invention, if the copper powder contains a carbon content of 20 to 60 ppm and is in the X-ray energy dispersive spectroscopy (EDX measurement), relative to the void ( The average peak intensity of copper measured in void) (P _Cu1 ), the carbon peak ratio of the average peak intensity (P _C1 ) of carbon measured in the void inside the particle (P _C1 × When 100/P _Cu1 ) is less than 60%, it is known that gas generation at the time of baking the paste can be suppressed, and expansion or cracking can be further suppressed.

此外，上述實施例所得之任一個銅粉之孔隙剖面積係占有粒子剖面積的30至50%之銅粒子(銅粒子B)的比率為銅粉粒子整體的4至20個數%。 Further, the ratio of the pore cross-sectional area of any of the copper powders obtained in the above examples to the copper particles (copper particles B) occupying 30 to 50% of the cross-sectional area of the particles is 4 to 20% by number of the entire copper powder particles.

Claims (7)

一種銅粉，其係銅粉的碳含量為20至60ppm，並且於X射線能量散佈光譜法(EDX測定)中，相對於在粒子內部的空隙(void)內所測出之銅的平均譜峰強度(P_Cu1)，在粒子內部的空隙(void)內所測出之碳的平均譜峰強度(P_C1)之碳銅比例1(P_C1×100/P_Cu1)未達60%。 A copper powder having a carbon content of 20 to 60 ppm and an average peak of copper measured in a void inside a particle in an X-ray energy dispersive spectroscopy (EDX measurement) The strength (P _Cu1 ), the carbon peak ratio 1 (P _C1 × 100 / P _Cu1 ) of the average peak intensity (P _C1 ) of carbon measured in the void inside the particle was less than 60%. 如申請專利範圍第1項所述之銅粉，其係於X射線能量散佈光譜法(EDX測定)中，相對於在粒子內部的空隙(void)外所測出之銅的平均譜峰強度(P_Cu2)，在粒子內部的空隙(void)外所測出之碳的平均譜峰強度(P_C2)之碳銅比例2(P_C2×100/P_Cu2)為10至40%。 The copper powder according to claim 1, which is obtained by X-ray energy dispersive spectroscopy (EDX measurement), and the average peak intensity of copper measured outside the void (void) inside the particle ( P _Cu2 ), the carbon-to-copper ratio 2 (P _C2 × 100 / P _Cu2 ) of the average peak intensity (P _C2 ) of carbon measured outside the void inside the particle is 10 to 40%. 如申請專利範圍第1項或第2項所述之銅粉，其中，相對於前述碳銅比例2(P_C2×100/P_Cu2)，前述碳銅比例1(P_C1×100/P_Cu1)之比例為1.0至2.0。 The copper powder according to claim 1 or 2, wherein the carbon-copper ratio 1 (P _C1 × 100 / P _Cu1 ) is relative to the carbon-copper ratio 2 (P _C2 × 100 / P _Cu2 ) The ratio is 1.0 to 2.0. 如申請專利範圍第1項至第3項中任一項所述之銅粉，其係藉雷射繞射散射式粒徑分佈測定法測定而得之以體積基準粒度分佈之D50為1.5μm至8.0μm。 The copper powder according to any one of claims 1 to 3, which is obtained by a laser diffraction scattering particle size distribution measurement, and has a D50 of a volume basis particle size distribution of 1.5 μm to 8.0 μm. 如申請專利範圍第1項至第4項中任一項所述之銅粉，其係藉由水噴霧法或氣體噴霧法所製造者。 The copper powder according to any one of claims 1 to 4, which is produced by a water spray method or a gas spray method. 一種銅粉，其係將如申請專利範圍第1項至第5項中任一項所述之銅粉粒子進行形狀加工處理而成者。 A copper powder obtained by subjecting copper powder particles according to any one of claims 1 to 5 to shape processing. 一種導電膏劑，其係含有如申請專利範圍第1項至第6項中任一項所述之銅粉。 A conductive paste comprising the copper powder according to any one of claims 1 to 6.