WO2020238142A1 - 一种表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺 - Google Patents

一种表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺 Download PDF

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WO2020238142A1
WO2020238142A1 PCT/CN2019/123827 CN2019123827W WO2020238142A1 WO 2020238142 A1 WO2020238142 A1 WO 2020238142A1 CN 2019123827 W CN2019123827 W CN 2019123827W WO 2020238142 A1 WO2020238142 A1 WO 2020238142A1
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copper
low
sintering
copper particles
paste
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PCT/CN2019/123827
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English (en)
French (fr)
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张卫红
刘旭
敖日格力
叶怀宇
张国旗
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深圳第三代半导体研究院
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Publication of WO2020238142A1 publication Critical patent/WO2020238142A1/zh

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1003—Use of special medium during sintering, e.g. sintering aid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H01L21/56—Encapsulations, e.g. encapsulation layers, coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
    • H01L23/29—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the material, e.g. carbon

Definitions

  • the invention relates to a copper particle, a low-temperature sintered copper paste, a sintering process using the same, and a sintering process using the same, which are especially used in the field of semiconductor packaging materials and whose surface is protected against oxidation.
  • Non-Patent Documents 1-3 the oxidation of the copper surface is one of the main factors hindering the reduction of the sintering temperature. Moreover, as the size of copper particles is further reduced, the surface energy of the copper increases, and the chance of metal atoms being fused increases. The oxidation tendency is more aggravated, so it is necessary to reduce the sintering temperature of copper particles by reducing the oxidation of the copper surface.
  • Non-Patent Document 1 Jang E-J, Hyun S, Lee H-J, Park Y-B, J. Electron Material 2009; 38:1598
  • Non-Patent Document 2 Suga T.ECS Transaction 2006; 3(6):155
  • Non-Patent Document 3 Tan CS, Chen KN, Fan A, Reif R.J. Electron Material 2004; 33: 1005
  • copper is generally susceptible to oxidation even at room temperature.
  • an oxide film is formed on the surface in a short time, and the oxidation is spread from the surface to the Continuously internally.
  • the copper particles have a smaller particle size, such as a nano-scale particle size, the surface area thereof is relatively increased, and the thickness of the oxide film formed on the surface thereof tends to increase.
  • copper particles with an oxide film on the surface are used in copper paste, only partial sintering between the copper particles can be achieved, and a thin copper oxide layer remains at the particle boundary, and it is difficult especially at low temperatures.
  • the mutual melting and/or diffusion of copper particles is achieved, resulting in low sintering efficiency, and it is difficult to obtain a sintered product layer with excellent bonding strength and compactness.
  • a copper particle whose surface is protected against oxidation is provided, wherein the surface of the copper particles is modified by using an organic solderable preservative (OSP).
  • OSP organic solderable preservative
  • the present invention also provides a low-temperature sintered copper paste, which contains the above-mentioned copper particles and flux.
  • a low-temperature sintered copper paste contains the above-mentioned copper particles and flux.
  • the present invention also provides a low-temperature sintering copper paste sintering process, which uses the above-mentioned low-temperature sintering copper paste of the present invention.
  • Fig. 1(a) shows the copper particles before the OSP film protection
  • Fig. 1(b) shows the copper particles after the OSP film protection.
  • Fig. 2 is a view showing a state where coated copper particles and flux are mixed.
  • FIG. 1 is a schematic diagram showing copper particles before (a) and after (b) protection by an OSP film.
  • the present invention there is also provided a low-temperature sintered copper paste and a sintering process using the low-temperature sintered copper paste, wherein the low-temperature sintered copper paste contains the aforementioned copper particles whose surfaces are protected against oxidation.
  • the copper particles of the present invention can be produced by, for example, an atomization method, a template method, a chemical reduction method, a mechanical ball milling method, a vacuum deposition method, and the like.
  • copper precursor salts such as copper nitrate, copper sulfate, etc.
  • template agents such as PEG600, etc.
  • reducing agents such as ethylene glycol, glycerol, glucose and other polyols
  • Ascorbic acid, etc. surfactants
  • CAB cetyltrimethylammonium bromide
  • copper particles can also be obtained commercially.
  • the purity of the copper particles is usually 99.9% or more, and may be 99.99% or more.
  • the content of impurities such as Cl and S in the copper particles is preferably as small as possible, for example, 0.1% or less.
  • the oxygen concentration in the copper particles is preferably 0.5% by mass or less. This is because if the oxygen concentration in the copper particles is greater than 0.5% by mass, the degree of oxidation of the copper particles becomes obvious. Even if the surface of the copper particles is modified with OSP described later, the dispersibility in the copper paste deteriorates, making the copper The printability of the paste deteriorates, and it is not easy to exert the corrosion inhibition effect of OSP during the sintering process of the copper paste, and a sintered structure with high shear strength cannot be obtained.
  • the copper particles of the present invention preferably have an average particle diameter (D50) of 0.01 ⁇ m to 10 ⁇ m, more preferably 0.1 ⁇ m to 5 ⁇ m, and even more preferably 1 ⁇ m to 2 ⁇ m.
  • D50 average particle diameter
  • the copper particles tend to agglomerate and excessively fuse and are easily oxidized.
  • it is not easy to form a uniform thickness of the organic solderability protective agent described later on the surface.
  • the average particle size of the copper particles is greater than 10 ⁇ m, the copper particles tend to be easily deposited during the preparation of the copper paste, and a uniform sintered structure cannot be obtained during sintering.
  • the copper particles of the present invention can be copper particles within one size range, or a mixture of copper particles with multiple size ranges, that is, a mixture of copper particles with bimodal or multi-sealed distribution in the particle size distribution. , Preferably has a bimodal distribution.
  • the "average particle size” refers to the use of scanning transmission electron microscope (STEM) and energy dispersive X-ray analysis (EDX) and other means, and the measurement of more than 10 randomly selected particles The arithmetic mean of their measured values when the equivalent circle diameter (Heywood diameter) is measured.
  • the copper particles in the present invention preferably have a surface roughness Ra of 0.01-1.5 ⁇ m.
  • a surface roughness Ra of 0.01-1.5 ⁇ m.
  • Forming a surface with a surface roughness Ra in the above range by microetching the surface of the copper particles makes it easy to form the OSP film described below.
  • the thickness of the microetching also directly affects the film formation speed of the OSP film described below.
  • the surface roughness Ra is less than 0.01 ⁇ m, it is sometimes difficult to form a firm OSP film on the surface of the copper particles, and the OSP is easy to be separated from the surface of the copper particles when the copper paste is prepared.
  • the surface roughness Ra is greater than 1.5 ⁇ m, sometimes the OSP formed on the surface of the copper particles is too deep.
  • the copper particles in the present invention can be used for surface cleaning and surface roughness control through the following processes: degreasing ⁇ secondary water washing ⁇ micro-etching ⁇ secondary water washing ⁇ pickling ⁇ DI water washing ⁇ drying.
  • Micro-etching can be performed by immersing copper particles in, for example, aqua regia, ferric chloride solution or the like.
  • Pickling can be carried out using hydrochloric acid, nitric acid, sulfuric acid, etc.
  • Copper particles of the present invention may have 2-10m 2 / g, preferably 4-6m 2 / g specific surface area.
  • the specific surface area can be measured by the BET method, for example.
  • the shape of the copper particles of the present invention is not particularly limited, and may be in the form of particles, flakes, random shapes, or the like.
  • the surface of the copper particles in the present invention is modified and covered with an organic solderable protective agent (OSP) film.
  • OSP organic solderable protective agent
  • OSP is a protective film used on the surface of copper pads in the semiconductor packaging industry to improve its solderability.
  • a specific OSP protection is designed for the copper particles, which can further remove oxides on the copper surface and slow down the oxidation of copper. It will decompose and leave the copper at high temperatures (around 200°C). Surface, thereby promoting the mutual diffusion of copper atoms during the sintering process.
  • benzotriazole (BTA), imidazole (IM), benzimidazole (BIM), etc. can be used. These can be used alone or in combination of two or more.
  • the OSP material used in the present invention does not contain sulfur element and halogen element.
  • the OSP coated on the surface of copper particles has an increased possibility of oxidation due to its increased surface area, it is sometimes necessary to add a certain amount of low-melting anti-OSP oxidation substances (such as diphenyl-p-phenylenediamine (DPPD)) to the film. .
  • DPPD diphenyl-p-phenylenediamine
  • the coverage rate of the organic solderable protective agent on the surface of the copper particles is not particularly limited, but in order to ensure the antioxidant protection of the copper particles, it is 40% or more, preferably 70% or more, and more preferably 90% relative to the surface of the copper particles. Above, 100% is particularly preferable.
  • the coverage rate can be qualitatively confirmed using, for example, a transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), or the like.
  • the upper limit may be 100 nm or less, preferably 50 nm or less, more preferably 40 nm or less, and the lower limit may be 1 nm or more, preferably 10 nm or more, and more preferably 20 nm or more.
  • the thickness is too large, it is difficult to expose the copper particles during low-temperature sintering, which hinders the diffusion of atoms between the copper particles during sintering.
  • the thickness is too small, it may not be able to effectively protect the copper particles from oxidation and corrosion.
  • the OSP copper protection needs to be resistant to repeated reflow soldering before packaging, and the high temperature stability of the OSP protection layer is required. Therefore, the OSP protection layer requires a certain thickness, but at low temperatures In sintering applications, OSP should not be too thick, otherwise the sintering temperature and time will be prolonged.
  • the said thickness can be calculated
  • the method of forming the organic solderable protective agent on the surface of the copper particles is not particularly limited. For example, it can be formed using electroplating, dipping, sol-gel, CVD, PVD, or the like.
  • the time for forming the OSP film on the surface of the copper particles varies depending on the particle size, the formation method, and the like, and can be appropriately adjusted to form the above-mentioned thickness.
  • the low-temperature sintered copper paste of the present invention contains the above-mentioned copper particles whose surfaces are protected against oxidation.
  • the low-temperature sintered copper paste of the present invention also contains high-link resin, flux, and optional organic solvents, hydrogenating agents, curing agents, tackifiers and other additives.
  • the low-temperature sintered copper paste of the present invention contains 10-90% by mass of high-linkage resin, may contain 30-80% by mass of high-linkage resin, and may also contain 40-60% by mass of high-linkage resin.
  • the low-temperature sintered copper paste of the present invention uses a high-link resin, which usually has a curing temperature of about 200°C (for example, 160-220°C).
  • the presence of high link resin can reduce the deposition of copper particles, provide shrinkage after curing, and more importantly, provide pressure during sintering.
  • the curing shrinkage pressure from the resin is obtained, so that the copper paste is under a certain pressure, which helps As the sintering efficiency is improved, the sintering temperature is further reduced and the sintering porosity is reduced.
  • a high-link resin epoxy resin, phenol resin, polyimide resin, silicone resin, etc. are mentioned, for example.
  • the low-temperature sintered copper paste of the present invention contains 1-10% by mass of flux.
  • the oxide on the copper surface can be removed in time before and during the sintering process and the oxygen-free cleanliness of the copper surface can be improved to ensure sufficient wetting of the solder and copper And combination, increase the inter-diffusion of copper atoms at the copper particle interface, prevent the re-formation of oxides before and after the welding operation, and reduce the inclusion of foreign substances. Otherwise, solder wetting problems may occur due to the low surface energy of copper oxide.
  • rosin-based resins for example, rosin-based resins, carboxylic acids (such as citric acid, adipic acid, cinnamic acid, etc.), amines (such as tertiary amines) and solvents (such as containing water and polyols such as Diol or glycerin polar solvent) system.
  • Fig. 2 is a view showing a state where coated copper particles and flux are mixed.
  • the low-temperature sintered copper paste of the present invention may further contain additives such as organic solvents, hydrogenating agents, curing agents, and thickening agents as other components. These additives are 0.01-5 parts by mass relative to 100 parts by mass of the low-temperature sintered copper paste, and may be 0.1-4 parts by mass or 1-2 parts by mass.
  • organic solvents that can be used in the present invention include acetone and ethanol.
  • the hydrogenating agent reduces the oxide on the surface of the copper particles into a non-oxidized state.
  • hydrogenating agents that can be used in the present invention include boron hydride and its derivatives.
  • the sintering temperature can be significantly lowered compared with the conventional copper particles, and the sintering between the copper particles can be achieved at about 200°C, and the same or more than the previous Dense structure.
  • Sintering can be performed in an atmospheric atmosphere, an inactive atmosphere, or a vacuum atmosphere. When heating and sintering in a vacuum atmosphere, the voids and pores of the sintered body are greatly reduced, which is preferable.
  • the inventors found that the formic acid-enhanced nitrogen sintering atmosphere is more beneficial to the corrosion inhibition of OSP, which is more preferable.
  • the present invention also provides a low-temperature sintered copper paste sintering process, which uses the above-mentioned low-temperature sintered copper paste of the present invention, and can realize the solder joint between the substrate and the chip at a low temperature of, for example, about 200°C.
  • the low-temperature sintered copper paste of the present invention is coated on a substrate (such as a semiconductor substrate such as a Si substrate, an ITO substrate, etc.) by screen printing, and then a chip is placed on the copper paste, and it is maintained at about 80-100°C.
  • Copper particles with an average particle diameter of 0.1 ⁇ m were selected to have a surface roughness Ra of 0.03 ⁇ m on the surface, and a uniform OSP film (film thickness 10 nm) using benzotriazole (BTA) was formed on the surface.
  • the obtained copper paste was coated on the silicon substrate by the screen printing method, the chip was placed on the coated copper paste, and the volatile components were removed by keeping it at about 100°C for 1 hour, and then applying 10MPa Under a nitrogen atmosphere, heating and sintering and curing were performed at 220°C for 2 hours under a nitrogen atmosphere to obtain a substrate and chip joint.
  • Copper particles with an average particle diameter of 0.1 ⁇ m were selected to have a surface roughness Ra of 0.03 ⁇ m on the surface, and a uniform OSP film (film thickness 10 nm) using imidazole (IM) was formed on the surface.
  • Example 2 Except for this, a copper paste was produced in the same manner as in Example 1, and a bonded body of a substrate and a chip was obtained.
  • Copper particles with an average particle diameter of 15 ⁇ m were selected to have a surface roughness Ra of 1.2 ⁇ m on the surface, and a uniform OSP film (film thickness 10 nm) using benzotriazole (BTA) was formed on the surface.
  • Example 2 Otherwise, a copper paste was produced in the same manner as in Example 1, and a bonded body of a substrate and a chip was obtained.
  • Copper particles with an average particle diameter of 10 ⁇ m were selected to have a surface roughness Ra of 1.5 ⁇ m on the surface, and a uniform OSP film (film thickness 80 nm) using benzotriazole (BTA) was formed on the surface.
  • Example 2 Otherwise, a copper paste was produced in the same manner as in Example 1, and a bonded body of a substrate and a chip was obtained.
  • Copper particles with an average particle size of 9.5 ⁇ m were selected to have a surface roughness Ra of 1.0 ⁇ m on the surface, and a uniform OSP film (film thickness 120 nm) using benzotriazole (BTA) was formed on the surface.
  • Example 2 Otherwise, a copper paste was produced in the same manner as in Example 1, and a bonded body of a substrate and a chip was obtained.
  • a bonded body of a substrate and a chip was obtained in the same manner as in Example 1, except that no pressure was applied from the outside to the sintering target.
  • a bonded body of a substrate and a chip was obtained in the same manner as in Example 3 except that no external pressure was applied to the sintering target.
  • a bonded body of a substrate and a chip was obtained in the same manner as in Example 1, except that the copper particles were not subjected to OSP treatment and the pressure during sintering was set to 20 MPa.
  • the chip shear strength of the bonded bodies of Examples 1-9 and Comparative Example 1-2 was measured to evaluate the bonding strength of the bonded bodies.
  • the joined body was pressed in the horizontal direction under the conditions of a measurement speed of 5 mm/min and a measurement height of 10 ⁇ m.
  • a joined body having a shear strength of more than 20 MPa is judged to be able to achieve good low-temperature sintering. The measurement results are shown in Table 1.
  • a transmission electron microscope (STEM) measures the area ratio of voids in these measurement points, and uses the average value as the porosity. In addition, in the present invention, a porosity of 15% or less is considered acceptable.
  • STEM transmission electron microscope
  • Examples 1-9) the shear strength and porosity of the obtained joined body were significantly improved, and it is considered that reliable low-temperature sintering was achieved.
  • Example 1 the comparison between Example 1 and Example 2, it can be seen that selecting BTA as a corrosion inhibitor has a better effect and obtains higher shear strength. It is believed that the reason is that BTA is more sensitive to temperature. It can be seen from Example 3 that when heating and sintering in a vacuum atmosphere, the voids and pores of the resulting bonded body (sintered body) are greatly reduced. In addition, it can be seen that even when Example 3 is changed to pressureless sintering (Example 9), satisfactory shear strength and porosity are obtained.
  • Example 4 when the sintering atmosphere is formic acid nitrogen, even if the sintering is performed under the conditions of a lower temperature and a lower applied pressure, the resulting bonded body has good shear strength and porosity.
  • the average particle size was slightly larger (Example 5: 15 ⁇ m)
  • the surface roughness Ra was slightly larger (Example 6: 1.5 ⁇ m)
  • the OSP protective layer was thicker (Example 7: In the case of 120nm)
  • the resulting bonded body achieved a certain decrease in shear strength and a certain increase in porosity, it was still within an acceptable range.
  • the resulting bonded body obtained acceptable levels of shear strength and porosity.
  • the low-temperature sintered copper paste according to the present invention can be used, for example, as a raw material for copper wiring required for printing in electronic products.

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Abstract

一种表面进行抗氧化保护的铜颗粒（1、3）、低温烧结铜膏及使用其的烧结工艺，其中，利用有机可焊接保护剂对铜颗粒（1、3）的表面进行修饰，该有机可焊接保护剂为苯并三氮唑、咪唑、苯并咪唑中的至少一种。

Description

一种表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺 技术领域
本发明涉及一种特别是用于半导体封装材料领域的、表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺及使用其的烧结工艺。
背景技术
新一代的用于电车、航空、和其他工业的功率模组需要高功率和高服役温度。在过去10年证明了宽禁带半导体可以耐300℃以上的高运行温度。然而，传统封装材料，比如锡基的焊料和导电胶，限制在200℃以下工作。研究人员一直在寻找各种办法获得高温和高功率情况下的高可靠性。在过去的探索中，人们发现银或者铜的烧结是有前景的方法。出于成本的考虑，烧结铜是代替银烧结的一个近几年一直在尝试的技术。但是烧结铜的相对高的烧结温度还在困扰着半导体封装业界。与银相比，铜虽然具有较高表面能，但其较易氧化，从而表面生成难溶且较低表面能的氧化物。
目前，铜表面的氧化是阻碍烧结温度降低的主要原因之一(非专利文献1-3)，而且，随着铜颗粒尺寸的进一步降低，铜表面能增加，金属原子互融机会增大，但氧化倾向更为加剧，所以，通过减少铜表面氧化从而降低铜颗粒烧结温度是很有必要的。
现有技术文献
非专利文献1：Jang E-J,Hyun S,Lee H-J,Park Y-B,J.Electron Material 2009；38:1598
非专利文献2：Suga T.ECS Transaction 2006；3(6):155
非专利文献3：Tan CS,Chen KN,Fan A,Reif R.J.Electron Material 2004；33:1005
发明内容
发明所要解决的课题
如上所述，与银相比，铜通常即使在室温下也容易被氧化，当制备成颗粒状的分散体时，在其表面上短时间内就形成了氧化物膜，并且氧化从其表面到内部连续进行。尤其在铜颗粒具有较小粒径例如纳米级粒径时，其表面积相对增加，并且具有形成于其表面上的氧化物膜的厚度倾向于增加。在将这种表面具有氧化物膜的铜颗粒用于铜膏时，只能实现铜颗粒之间的部分烧结且在颗粒边界残残留有薄的铜氧化物层，而且，特别是在低温下难以实现铜颗粒之间的彼此熔融和/或扩散，从而导致烧结效率低，并且难以得到有优异的接合强度和致密性的烧结产物层。
用于解决课题的手段
在本发明中，为了降低铜颗粒的表面氧化，提供一种表面经抗氧化保护的铜颗粒，其中，利用有机可焊接保护剂(OSP，Organic Solderability Preservatives)对铜颗粒的表面进行修饰，以对铜颗粒表面进行抗氧化性保护。
本发明还提供一种低温烧结铜膏，该低温烧结铜膏包含上述的铜颗粒和助焊剂。通过使用这样的低温烧结铜膏，能够在低温(例如约180-250℃)实现铜颗粒的烧结，获得低温烧结体且得到致密结构的封装结构，并且能够以无压烧结实现铜颗粒的低温烧结。
另外，本发明还提供一种低温烧结铜膏的烧结工艺，其使用了上述本发明的低温烧结铜膏。
附图说明
图1(a)是示出OSP膜保护前的铜颗粒，图1(b)是示出OSP膜保护后的铜颗粒。
图2是示出将包覆的铜颗粒与助焊剂混合的状态的图。
附图标记说明
1,3…铜颗粒
2...OSP膜
4…助焊剂
具体实施方式
以下，对本发明实施方式进行说明。但是，本发明不以任何方式限定于以下的实施方式。在本发明的目的范围内进行适当的变更，也能够实施本发明。
在本发明中，为了降低铜颗粒的表面氧化问题，提供一种表面经抗氧化保护的铜颗粒，其中，利用有机可焊接保护(OSP，Organic Solderability Preservatives)对铜颗粒的表面进行修饰。图1是示出OSP膜保护前(a)和后(b)的铜颗粒的示意图。
在本发明中，还提供一种低温烧结铜膏及使用其的烧结工艺，其中该低温烧结铜膏包含上述的表面经抗氧化保护的铜颗粒。
以下，对本发明的铜颗粒、低温烧结铜及使用其的烧结工艺进行详细说明。
1.铜颗粒
本发明的铜颗粒可通过例如雾化法、模板法、化学还原法、机械球磨法、真空沉积法等来制造。例如，在模板法的情况下，可将铜的前体盐(例如硝酸铜、硫酸铜等)、模板剂(例如PEG600等)、还原剂(例如乙二醇、丙三醇、葡萄糖等多元醇，抗坏血酸等)、表面活性剂(例如十六烷基三甲基溴化铵(CTAB))等在溶液中在加热的状态下进行自组装来获得铜颗粒。另外，铜颗粒也可以通过市售获得。铜颗粒的纯度通常为99.9％以上，可以 为99.99％以上。铜颗粒中Cl、S等杂质的含量优选尽可能少，例如为0.1％以下。另外，铜颗粒中的氧浓度优选为0.5质量％以下。这是因为，如果铜颗粒中的氧浓度大于0.5质量％，则铜颗粒的氧化程度变得明显，即使在其表面进行了后述的OSP修饰，在铜膏中的分散性变差，使得铜膏的印刷性变差，而且在铜膏的烧结过程中不易发挥OSP的缓蚀作用，得不到剪切强度高的烧结结构。
本发明的铜颗粒优选具有0.01μm～10μm、更优选0.1μm～5μm、进一步优选1μm～2μm的平均粒径(D50)。当铜颗粒的平均粒径小于0.01μm时，铜颗粒之间倾向于团聚和过度熔合而容易被氧化，同时也不容易在表面形成一定厚度的均匀的后述的有机可焊性保护剂。当铜颗粒的平均粒径大于10μm时，铜颗粒倾向于在制备铜膏时容易沉积，在烧结时得不到均匀的烧结结构。另外，本发明的铜颗粒可以是一种尺寸范围内的铜颗粒，也可以是多种尺寸范围的铜颗粒的混合物，即可以是在粒度分布中具有双峰或多封分布的铜颗粒的混合物，优选具有双峰分布。予以说明，在本发明中，除非另外说明，“平均粒径”是指使用扫描型透射电子显微镜(STEM)和能量分散型X射线分析(EDX)等手段并且对随机选择的10个以上的粒子的圆当量直径(Heywood直径)进行测定时它们的测定值的算术平均值。
本发明中的铜颗粒优选具有0.01-1.5μm的表面粗糙度Ra。通过对铜颗粒表面进行微蚀形成上述范围的表面粗糙度Ra的表面，使得容易形成下述的OSP膜。另外，微蚀的厚度也直接影响下述的OSP膜的成膜速度。当表面粗糙度Ra小于0.01μm时，有时不易在铜颗粒表面形成牢固的OSP膜，OSP在制备铜膏时容易从铜颗粒表面脱离。当表面粗糙度Ra大于1.5μm，有时形成于铜颗粒表面的OSP过深，即使在高温情况下OSP也不易完全分解而离开铜表面。因此，为了形成稳定的OSP膜，优选将铜颗粒表面的表面粗糙度Ra控制在上述范围内。例如，本发明中的铜颗粒可通过如下工艺来进行表面清洗和表面粗糙度控制：除油→二级水洗→微蚀→二级水洗→酸洗→DI水洗→干燥。微蚀可通过将铜颗粒浸渍在例如王水、三氯化铁溶液等中进行。酸洗可使用盐酸、硝酸、硫酸等进行。
本发明的铜颗粒可具有2-10m 2/g、优选4-6m 2/g的比表面积。予以说明，比表面积例如可通过BET法来测定。另外，对于本发明的铜颗粒的形状不特别限定，可以为粒子状、片状、无规则形状等。
2.有机可焊接保护剂
本发明中的铜颗粒的表面用有机可焊接保护剂(OSP)膜进行修饰而被覆盖。OSP是用在半导体封装界中铜焊盘表面提高其可焊接的保护膜。在本发明中，根据铜颗粒烧结的特殊性质，为铜颗粒设计了特定OSP的保护，可进一步除去铜表面的氧化物，减缓铜氧化，在高温情况下(200℃左右)会分解而离开铜表面，从而促进烧结过程中铜原子之间的相互扩散。
作为可用于本发明中的OSP，可使用苯并三氮唑(BTA)、咪唑(IM)、苯并咪唑(BIM)等。它们可以单独使用一种，或混合两种以上使用。予以说明，用于本发明的OSP材料中不含有硫元素和卤素元素。另外，由于涂在铜颗粒表面的OSP因其表面积增加而氧化可能性增强，因此，有时需要在膜中添加一定量的低熔点抗OSP氧化物质(比如二苯基对苯二胺(DPPD))。
有机可焊接保护剂在铜颗粒表面的被覆率没有特别限制，但为了确保对铜颗粒的抗氧化保护作用，相对于铜颗粒的表面为40％以上，优选为70％以上，更优选为90％以上，特别优选为100％。被覆率例如可使用透射型电子显微镜(TEM)、X射线光电子光谱法(XPS)等来定性地确认。
对于有机可焊接保护剂的厚度而言，作为上限，可以为100nm以下，优选为50nm以下，更优选为40nm以下，作为下限，可以为1nm以上、优选为10nm以上，更优选为20nm以上。当厚度过大时，在低温烧结不易使铜颗粒露出，阻碍烧结期间铜颗粒之间的原子扩散。当厚度过小时，有可能无法对铜颗粒有效的抗氧化保护和缓蚀。特别地，在本发明中，为了降低铜烧结温度，在封装前OSP铜保护需要耐反复的回流焊接，要求OSP保护层的高温稳定性，因此，OSP保护层要求有一定的厚度，而在低温烧结应用中，OSP不宜太厚，否则，烧结温度和时间都会拖长。予以说明，可从利用扫描型电子显微镜(SEM)或透射型电子显微镜(TEM)的图像分析来求出上述厚度。
有机可焊接保护剂在铜颗粒的表面的形成方法没有特别限定，例如可以使用电镀、浸渍法、溶胶凝胶法、CVD法、PVD法等形成。在铜颗粒表面形成OSP膜的时间因颗粒尺寸、形成方法等的大小而异，可以以形成上述厚度的方式进行适当调整。
以下，对本发明的低温烧结铜膏进行说明。
本发明的低温烧结铜膏包含上述的表面经抗氧化保护的铜颗粒。此外，本发明的低温烧结铜膏还包含高链接树脂、助焊剂、以及任选的有机溶剂、氢化剂、固化剂、增粘剂等添加剂。
本发明的低温烧结铜膏含有10-90质量％的高链接树脂，可以含有30-80质量％的高链接树脂，也可以含有40-60质量％的高链接树脂。本发明的低温烧结铜膏使用高链接树脂，该高链接树脂通常具有200℃左右(例如160-220℃)的固化温度。高链接树脂的存在可减少铜颗粒的沉积，在固化后提供收缩，更重要的是提供烧结时的压力，在烧结时获得来自树脂固化收缩压力，使铜膏整体处于一定压力下，从而有助于烧结效率的提升，进一步降低烧结温度并使得烧结孔隙减小。通过使用高链接树脂，在烧结时有时不需要从外部对烧结对象施予压力也能实现烧结。作为具体的高链接树脂，例如可举出环氧树脂、酚醛树脂、聚酰亚胺树脂、有机硅树脂等。
本发明的低温烧结铜膏含有1-10质量％的助焊剂。在本发明的低温烧结铜膏含有助焊剂的情况下，在进行烧结前和过程中能够及时清除铜的表面的氧化物和提升铜表面的无氧的清洁性以保证焊锡与铜的充分润湿和结合，增加铜颗粒界面铜原子互扩散，防止在焊接操作之前和之后重新形成氧化物，和减少外来物质的夹杂。否则，有可能出现因氧化铜存在的低表面能而导致的焊锡沾润问题。作为可用于本发明的助焊剂，例如可举出松香系树脂、基于羧酸(例如柠檬酸、己二酸、肉桂酸等)、胺(例如叔胺)和溶剂(例如含有水和多元醇如二醇或甘油的极性溶剂)的体系等。图2是示出将包覆的铜颗粒与助焊剂混合的状态的图。
在不影响本发明效果的范围内，本发明的低温烧结铜膏还可以进一步包含有机溶剂、氢化剂、固化剂、增粘剂等添加剂作为其它成分。这些添加剂相对于低温烧结铜膏100质量份计为0.01-5质量份，可以为0.1-4质量份或1-2质量份。作为可用于本发明的有机溶剂，可举出丙酮、乙醇等。氢化剂具有使铜颗粒表面上的氧化物还原而成为非氧化状态。作为可用于本发明的氢化剂，例如可举出氢化硼及其衍生物等。
如上述，通过将本发明中的铜颗粒用于铜膏，与以往的铜颗粒相比能显著降低烧结温度，在200℃左右就能实现铜颗粒之间的烧结，获得与以往同等或以上的致密结构。烧结可以在大气气氛、非活性气氛或真空气氛中进行。在真空气氛中加热烧结时，烧结体的空洞和孔隙会大幅减少，因而优选。另外，本发明人发现，甲酸强化的氮气的烧结氛围会更有益于OSP的缓蚀性，因而更优选。
另外，本发明还提供一种低温烧结铜膏的烧结工艺，其使用了上述本发明的低温烧结铜膏，能够在例如200℃左右的低温下实现基板和芯片的焊接接合。例如，将本发明的低温烧结铜膏通过丝网印刷等涂覆在基板(例如Si基板、ITO基板等半导体基板)上，其后在铜膏上放置芯片，通过在80-100℃左右下保持1-2小时以除去挥发成分并使得助焊剂等成分分解溢出，然后在例如施加0-20MPa的压力在例如180-250℃下进行加热，烧结固化，从而将基板和芯片有效地接合。通常，在烧结时施加压力，有助于烧结体的空隙减少，但压力过大时，反应物不易逸出，容易引起空洞的增大和空隙的增加的问题，不利于获得致密可靠的烧结体结构，而适当的压力和真空加热环境有利于抑制上述问题的发生。
实施例
对于铜颗粒，按照以下的表面清洗、蚀刻、成膜顺序，形成表面具有OSP膜的铜颗粒：除油→二级水洗→微蚀→二级水洗→酸洗→DI水洗→成膜风干→DI水洗→干燥。
实施例1
选择平均粒径为0.1μm的铜颗粒，使其表面具有0.03μm的表面粗糙度Ra，在其表面形成利用苯并三氮唑(BTA)的均匀的OSP膜(膜厚10nm)。
将包覆有OSP膜的铜颗粒50质量份、作为高链接树脂的环氧树脂35质量份、作为助焊剂的松香树脂5质量份、作为有机溶剂的丙酮5质量份、固化剂3质量份、增粘剂2质量份混合，得到铜膏。此时，环氧树脂将铜颗粒包裹。
接着，利用丝网印刷法将得到的铜膏涂覆到硅基板上，在经涂覆的铜膏上设置芯片，通过在约100℃的环境下保持1小时以除去挥发成分，然后在施加10MPa的压力、在氮气氛下、在220℃进行加热和烧结固化2小时，得到基板与芯片的接合体。
实施例2
选择平均粒径为0.1μm的铜颗粒，使其表面具有0.03μm的表面粗糙度Ra，在其表面形成利用咪唑(IM)的均匀的OSP膜(膜厚10nm)。
除此以外，与实施例1同样地制作了铜膏，得到了基板与芯片的接合体。
实施例3
选择平均粒径为8μm的铜颗粒，使其表面具有0.5μm的表面粗糙度Ra，在其表面形成利用苯并三氮唑(BTA)的均匀的OSP膜(膜厚100nm)；将烧结气氛设为真空。除此以外，与实施例1同样地制作了铜膏，得到了基板与芯片的接合体。
实施例4
选择平均粒径为4μm的铜颗粒，使其表面具有0.25μm的表面粗糙度Ra，在其表面形成利用咪唑(IM)的均匀的OSP膜(膜厚50nm)；将烧结气氛设为含甲酸的氮气氛(甲酸：5vol％)、将烧结时的施加压力设为5MPa，将烧结温度设为180℃。除此以外，与实施例1同样地制作了铜膏，得到了基板与芯片的接合体。
实施例5
选择平均粒径为15μm的铜颗粒，使其表面具有1.2μm的表面粗糙度Ra，在其表面形成利用苯并三氮唑(BTA)的均匀的OSP膜(膜厚10nm)。
以外，与实施例1同样地制作了铜膏，得到了基板与芯片的接合体。
实施例6
选择平均粒径为10μm的铜颗粒，使其表面具有1.5μm的表面粗糙度Ra，在其表面形成利用苯并三氮唑(BTA)的均匀的OSP膜(膜厚80nm)。
以外，与实施例1同样地制作了铜膏，得到了基板与芯片的接合体。
实施例7
选择平均粒径为9.5μm的铜颗粒，使其表面具有1.0μm的表面粗糙度Ra，在其表面形成利用苯并三氮唑(BTA)的均匀的OSP膜(膜厚120nm)。
以外，与实施例1同样地制作了铜膏，得到了基板与芯片的接合体。
实施例8
除了不对烧结对象从外部施加压力以外，与实施例1同样地得到了基板与芯片的接合体。
实施例9
除了不对烧结对象从外部施加压力以外，与实施例3同样地得到了基板与芯片的接合体。
比较例1
除了没有对铜颗粒进行OSP处理，将烧结时的压力设为20MPa以外，与实施例1同样地得到了基板与芯片的接合体。
比较例2
除了在制备铜膏时没有使用助焊剂，将烧结时的压力设为20MPa以外，与实施例1同样地得到了基板与芯片的接合体。
[性能测试]
1.芯片剪切强度
使用安装有测力传感器的万能型黏结强度试验机，对实施例1-9和比较例1-2的接合体的芯片剪切强度进行测定，以评价接合体的结合强度。在测定速度5mm/min、测定高度10μm的条件下将接合体在水平方向上按压。予以说明，在本发明中，将剪切强度超过20MPa的接合体判定为能实现良好的低温烧结。将测定结果示于表1。
2.空隙率
将进行了芯片剪切强度测定的实施例1-9和比较例1-2的接合体的接合部位进行打磨抛光，对经抛光的平面上随机选择5个1μm×1μm的测定点，利用扫描型透射电子显微镜(STEM)测定这些测定点中的空孔的面积比率，并将其平均值作为空隙率。予以说明，在本发明中，认为空隙率为15％以下的情形是可接受的。将测定结果示于表1。
表1
Figure PCTCN2019123827-appb-000001
Figure PCTCN2019123827-appb-000002
如上述表1所示，在使用没有进行OSP表面修饰的比较例1、和在没有使用助焊剂的比较例2中，即使提高了烧结时的烧结压力，得到的接合体的剪切强度低，空隙率较高，因此认为没有实现良好的低温烧结。
与此相对，在本发明(实施例1-9)的情况下，得到的接合体的剪切强度和空隙率显著改善，认为都实现了可靠的低温烧结。另外，从实施例1和实施例2的对比可知，选择BTA作为缓蚀剂效果更好，获得较高的剪切强度。认为其原因在于BTA对温度更敏感。由实施例3可知，在真空气氛中加热烧结时，得到的接合体(烧结体)的空洞和孔隙会大幅减少。另外可知，即使在将实施例3改变为无压烧结的情况下(实施例9)，也得到了令人满意的剪切强度和空隙率。由实施例4可知，将烧结气氛设为含甲酸氮气时，即使在较低温度和较低的施加压力的条件下进行烧结，得到的接合体也获得了良好的剪切强度和空隙率。在实施例5、6、7中，使用了平均粒径稍大(实施例5:15μm)、表面粗糙度Ra稍大(实施例6:1.5μm)或OSP保护层较厚(实施例7:120nm)的情况下，虽然得到的接合体都实现了剪切强度的一定程度的下降及空隙率的一定程度的上升，但仍在可接受的范围内。另外，即 使在氮气气氛下进行了无压烧结的情况下(实施例8)，得到的接合体也获得了可接受程度的剪切强度和空隙率。
产业的可利用性
本发明所涉及的低温烧结铜膏例如能够在电子产品中用作印刷所需的铜配线等的原料。

Claims (11)

  1. 一种表面经抗氧化保护的铜颗粒，其中，利用有机可焊接保护剂对铜颗粒的表面进行修饰，其中，该有机可焊接保护剂为苯并三氮唑、咪唑、苯并咪唑中的至少一种。
  2. 权利要求1所述的铜颗粒，其中，该有机可焊接保护剂为苯并三氮唑。
  3. 权利要求1或2所述的铜颗粒，其具有0.01μm～10μm的平均粒径和0.01-1.5μm的表面粗糙度Ra。
  4. 权利要求1至3中任一项所述的铜颗粒，其中，表面修饰的有机可焊性保护剂的厚度为1-100nm。
  5. 一种低温烧结铜膏，其由权利要求1至4的任一项所述的铜颗粒、高链接树脂、助焊剂以及任选的添加剂构成。
  6. 权利要求5所述的低温烧结铜膏，其中，高链接树脂为环氧树脂。
  7. 权利要求5或6所述的低温烧结铜膏，其中，上述铜膏加工为预制低温烧结铜膜的形式。
  8. 一种低温烧结铜膏的烧结工艺，其包括：将权利要求5-7中任一项的低温烧结铜膏涂覆在基板与被连接对象之间，在180-250℃下进行加热，烧结固化。
  9. 权利要求8所述的烧结工艺，其中，在真空气氛或非活性气体气氛下进行加热。
  10. 权利要求9所述的烧结工艺，其中，上述非活性气体为包含甲酸的氮气。
  11. 权利要求8-10中任一项所述的烧结工艺，其中，在施加0-20MPa的压力下进行加热。
PCT/CN2019/123827 2019-05-29 2019-12-06 一种表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺 WO2020238142A1 (zh)

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CN110211934B (zh) * 2019-05-29 2021-07-20 深圳第三代半导体研究院 一种抗氧化保护的铜颗粒、烧结铜膏及使用其的烧结工艺
CN111266568A (zh) * 2020-02-18 2020-06-12 深圳第三代半导体研究院 一种咪唑基团修饰的微纳米颗粒膏体及其制备方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101139716A (zh) * 2007-10-25 2008-03-12 金川集团有限公司 一种防止铜粉氧化的方法
CN104508759A (zh) * 2012-05-18 2015-04-08 材料概念有限公司 导电性糊剂、布线形成方法及电子部件、硅太阳能电池
CN104810247A (zh) * 2014-01-24 2015-07-29 英飞凌科技股份有限公司 用于使用印刷工艺在半导体基体上生产铜层的方法
JP2016145404A (ja) * 2015-02-09 2016-08-12 Ｄｏｗａエレクトロニクス株式会社 導電性ペースト用銅粉およびその製造方法
CN107221512A (zh) * 2017-06-20 2017-09-29 广东工业大学 一种互连工艺
CN107214333A (zh) * 2017-06-20 2017-09-29 广东工业大学 一种互连材料及其制备方法
CN110211934A (zh) * 2019-05-29 2019-09-06 深圳第三代半导体研究院 一种表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101139716A (zh) * 2007-10-25 2008-03-12 金川集团有限公司 一种防止铜粉氧化的方法
CN104508759A (zh) * 2012-05-18 2015-04-08 材料概念有限公司 导电性糊剂、布线形成方法及电子部件、硅太阳能电池
CN104810247A (zh) * 2014-01-24 2015-07-29 英飞凌科技股份有限公司 用于使用印刷工艺在半导体基体上生产铜层的方法
JP2016145404A (ja) * 2015-02-09 2016-08-12 Ｄｏｗａエレクトロニクス株式会社 導電性ペースト用銅粉およびその製造方法
CN107221512A (zh) * 2017-06-20 2017-09-29 广东工业大学 一种互连工艺
CN107214333A (zh) * 2017-06-20 2017-09-29 广东工业大学 一种互连材料及其制备方法
CN110211934A (zh) * 2019-05-29 2019-09-06 深圳第三代半导体研究院 一种表面进行抗氧化保护的铜颗粒、低温烧结铜膏及使用其的烧结工艺

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