CN111015008A - High-temperature service lead-free solder and preparation method thereof - Google Patents
High-temperature service lead-free solder and preparation method thereof Download PDFInfo
- Publication number
- CN111015008A CN111015008A CN201911377107.7A CN201911377107A CN111015008A CN 111015008 A CN111015008 A CN 111015008A CN 201911377107 A CN201911377107 A CN 201911377107A CN 111015008 A CN111015008 A CN 111015008A
- Authority
- CN
- China
- Prior art keywords
- lead
- free solder
- nano
- temperature service
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/26—Selection of soldering or welding materials proper with the principal constituent melting at less than 400 degrees C
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/40—Making wire or rods for soldering or welding
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Electric Connection Of Electric Components To Printed Circuits (AREA)
Abstract
The invention relates to the technical field of lead-free solder alloy and electronic packaging interconnection, in particular to a high-temperature service lead-free solder and a preparation method thereof. The lead-free solder is prepared from the following raw materials in parts by weight of 1: (5-20). The invention provides a high-temperature service solder, which can improve the high-temperature service and surface gloss performance of a welding spot obtained by the solder through reflow soldering by adding nano metal powder, such as nano copper powder, nano copper alloy powder and the like and controlling the particle size and the like, and when the solder is subjected to reflow soldering for the second time or even under higher temperature conditions, such as the temperature of more than 260 ℃, the welding spot is still solid and can not be melted and damaged, thus being applicable to multiple times of soldering of electronic packaging.
Description
Technical Field
The invention relates to the technical field of lead-free solder alloy and electronic packaging interconnection, in particular to a high-temperature service lead-free solder and a preparation method thereof.
Background
In modern electronic assembly processes, such as the production and assembly processes of semiconductor chips, it is often necessary to attach some devices or modules, such as soldering with high temperature solder (melting point higher than 240 degrees), so as to prevent the corresponding semiconductor components (e.g. cpu, memory, etc.) from being damaged by melting of internal solder joints during the subsequent assembly and soldering processes. The high temperature solders commonly used today are alloys containing a large amount of lead (e.g., Sn5Pb95, Sn10Pb90, melting point about 280 degrees), or tin-antimony alloys (Sn95Sb5, Sn90Sb10, melting point about 238 and 245 degrees). The tin-lead alloy has a proper melting point, but a lead-free process cannot be realized. Tin-antimony alloys also face the toxicity problem of metallic antimony. Meanwhile, the high-temperature alloy is used, the temperature is required to be increased to be higher than the melting point of the alloy during welding, the temperature is greatly higher than the heat-resistant temperature of a common PCB material, and certain damage is caused to devices. It is currently an important need to use lead-free alloys as solder for electronic packaging.
In addition, in the current packaging process, multiple times of welding are often needed, and in the subsequent welding process, the situation that the welded device is damaged due to the fact that a welding point is melted when the welded device is heated is often caused. To avoid this, solder assembly of different stages of devices/assemblies using different melting point temperatures of solder is required. The process is complicated and the cost is wasted.
Disclosure of Invention
In order to solve the problems, the invention provides a lead-free solder for high-temperature service, and the lead-free solder is prepared from raw materials of nano metal powder and tin-silver-copper alloy powder in a weight ratio of 1: (5-20).
As a preferable technical scheme of the invention, the nano metal powder comprises nano copper powder, and the particle size is 5-50 nm.
As a preferred technical solution of the present invention, the nano metal powder further includes nano copper alloy powder, and the weight ratio of the nano copper alloy powder to the nano copper powder is 1: (3-5).
As a preferable technical scheme of the invention, the particle size of the nano-copper alloy powder is 50-100 nm.
As a preferable technical scheme of the invention, the weight percentage of copper in the nano copper alloy powder is more than 50 wt%.
As a preferable technical scheme of the invention, the nano-copper alloy powder is binary nano-copper alloy and/or ternary nano-copper alloy.
The second aspect of the invention provides a preparation method of the lead-free solder for high-temperature service, which comprises the following steps: and mixing the raw materials for preparing the lead-free solder to obtain the lead-free solder.
The invention provides a construction process of the lead-free solder with high-temperature service, which comprises the following steps: the solder joints are formed by reflow soldering.
The fourth aspect of the invention provides a welding spot obtained by the construction process of the lead-free solder with high-temperature service.
The fifth aspect of the invention provides an application of the high-temperature service lead-free solder, which is applied to the field of electronic packaging.
Compared with the prior art, the invention has the following beneficial effects: the invention provides a high-temperature service solder, which can improve the high-temperature service and surface gloss performance of a welding spot obtained by the solder through reflow soldering by adding nano metal powder, such as nano copper powder, nano copper alloy powder and the like and controlling the particle size and the like, and when the solder is subjected to reflow soldering for the second time or even under higher temperature conditions, such as the temperature of more than 260 ℃, the welding spot is still solid and can not be melted and damaged, thus being applicable to multiple times of soldering of electronic packaging.
Detailed Description
The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.
The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.
When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.
The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.
In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.
The present invention is illustrated by the following specific embodiments, but is not limited to the specific examples given below.
The invention provides a lead-free solder in high-temperature service, which is prepared from the following raw materials in parts by weight: (5-20).
In a preferred embodiment, the raw materials for preparing the lead-free solder comprise nano metal powder and tin-silver-copper alloy powder, wherein the weight ratio of the nano metal powder to the tin-silver-copper alloy powder is 1: 9.
tin-silver-copper alloy powder
The tin-silver-copper alloy (Sn-Ag-Cu alloy) is added with Cu on the basis of the Sn-Ag alloy, can slightly reduce the melting point of the Sn-Ag alloy while maintaining the good performance of the Sn-Ag alloy, and can reduce the dissolution of Cu in a welded material after the Cu is added, thereby being an important development direction for replacing a lead-containing solder at present. The melting point is generally 217-230 ℃.
In one embodiment, the tin-silver-copper alloy powder of the present invention is selected from one or more of sn96.5ag3.0cu0.5, sn99ag0.3cu0.7, sn98.5ag1cu0.5, sn95.5ag4.0cu0.5; further, the Sn-Ag-Cu alloy powder is Sn96.5Ag3.0Cu0.5 and/or Sn99Ag0.3Cu0.7.
In the case of a tin-silver-copper alloy powder, the number indicates the weight percentage of each element in the alloy, and for example, sn96.5ag3.0cu0.5 indicates that the content of Sn is 96.5 wt%, the content of Ag is 3.0 wt%, and the content of Cu is 0.5 wt%.
Preferably, the particle size of the tin-silver-copper alloy powder is 5-25 μm; furthermore, the particle size of the tin-silver-copper alloy powder is 5-15 mu m.
The particle size is the size of the particles, and when a certain physical property or physical behavior of the measured particles is most similar to a homogeneous sphere (or combination) with a certain diameter, the diameter (or combination) of the sphere is taken as the equivalent particle size (or particle size distribution) of the measured particles, and the particle size of the tin-silver-copper alloy powder is obtained by testing according to a method well known to those skilled in the art, such as GB _ T29089-2012.
The tin-silver-copper alloy powder can be purchased or manufactured by self. In one embodiment, the tin-silver-copper alloy powder disclosed by the invention is Sn99Ag0.3Cu0.7, which is purchased from Highai New Material science and technology Limited in Shenzhen, with a particle size of 5-15 μm.
Nano metal powder
In one embodiment, the nano metal powder comprises nano copper powder, and the particle size is 5-50 nm; furthermore, the particle size of the nano copper powder is 20 nm.
The nano copper powder is purple brown or purple black powder, is pure copper powder, and has a copper content of more than 99 wt%.
The particle size of the nano metal powder is obtained according to methods well known in the art, such as STM, SEM, SPM, X-ray diffraction, UV, Raman spectrum and X-ray small angle scattering method.
The applicant finds that, when nano-copper powder is added and the particle size and weight ratio of the nano-copper powder and the tin-silver copper alloy powder are controlled, the nano-copper powder can be melted at the melting temperature of the tin-silver copper alloy powder, so that the components of the formed welding spot comprise the copper powder and the tin-silver copper alloy powder, and the high melting temperature of the copper is beneficial to improving the melting temperature of the welding spot, so that the welding spot can be kept solid at the second reflow soldering or even higher temperature, but the nano-copper and the tin are easy to melt, Silver and the like easily form intermetallic compounds, and influence the mechanical properties and the glossiness of the welding spot.
Preferably, the nano-copper powder of the present invention is purchased from nanotechnology limited, Changhu, Suzhou (particle size 20 nm).
More preferably, the nano metal powder further comprises nano copper alloy powder, and the weight ratio of the nano copper alloy powder to the nano copper powder is 1: (0.4-0.6); further, the weight ratio of the nano copper alloy powder to the nano copper powder is 1: 0.5.
further preferably, the particle size of the nano copper alloy powder is 50-100 nm; furthermore, the particle size of the nano copper alloy powder is 80 nm.
The nano copper alloy powder with the particle size of 50-100 nm can be purchased or manufactured by self, such as a mechanical crushing method, a gas phase synthesis method, a liquid phase synthesis method and the like, and the nano copper alloy powder with the particle size of 50-100 nm is obtained through mechanical crushing, such as a high-energy ball milling method.
Still more preferably, the weight percentage of copper in the nano copper alloy powder is more than 50 wt%.
In a preferred embodiment, the nano copper alloy powder is selected from binary nano copper alloy and/or ternary nano copper alloy.
As examples of the binary nano copper alloy powder, there are, but not limited to, nano copper zinc alloy powder, nano copper nickel alloy powder, nano copper tin alloy powder;
examples of ternary nano-copper alloy powders include, but are not limited to, nano-copper tin phosphorus alloy powders, nano-copper tin zinc alloy powders, and nano-copper tin nickel alloy powders.
In a more preferred embodiment, the nano copper alloy powder of the present invention is a nano copper tin phosphorus alloy powder.
In a further preferred embodiment, the nano copper-tin-phosphorus alloy powder is CuSn4Zn 3; furthermore, the CuSn4Zn3 has the mark of QSn4-3, and is purchased from special alloy Co., Ltd (the particle size is 80nm) of Jiangsu Jingding.
The weight percentage of each component in CuSn4Zn3 with the mark of QSn4-3 is 3.5-4.5 wt% of tin (Sn), 2.7-3.3 wt% of zinc (Zn) and the balance of copper (Cu), wherein the total content of impurities is less than or equal to 0.2 wt%.
The applicant finds that the high-temperature service performance of the welding spot can be further improved by adding the nano-copper alloy powder and the nano-copper powder as the nano-metal powder, particularly the nano-copper alloy powder with the copper content of more than 50 wt%, and simultaneously, the smooth and glossy welding spot can be promoted to be formed, and the mechanical property of the welding spot can be improved, which is probably because, by adding the nano-copper alloy powder, particularly the nano-copper tin zinc alloy powder with a certain particle size, when reflow soldering is carried out, the zinc and the tin in the nano-copper tin zinc alloy powder can be well dissolved in the tin silver copper alloy powder, so that the dispersion of the nano-metal powder in the tin silver copper alloy powder is also facilitated, the fluidity of the molten nano-metal powder in the tin zinc alloy is improved in the reflow soldering process, the high-temperature service performance and the smoothness and the gloss degree of the welding spot are promoted, while the use of the nano-copper alloy powder with higher copper content is also beneficial to promote the melting of the nano-copper powder and, thereby further increasing the high-temperature service performance.
However, the applicant has unexpectedly found that when the nano copper-tin-phosphorus alloy powder is added, the smoothness and the gloss of the welding spot are affected, and even white spots appear, which is probably caused by that the content of intermetallic compounds in the welding spot is too large and the formed crystal grains are relatively coarse due to the addition of the copper-tin-phosphorus alloy powder. On the contrary, when the nano copper-tin-zinc alloy is added, the surface of the welding spot has good luster, and no white spots are generated, which can be because the added nano copper-tin-zinc alloy has good compatibility and fluidity, so that the dispersion of the nano copper powder and the nano copper-tin-zinc alloy is promoted, and in the welding spot, the copper can form a refined intermetallic compound with tin, silver and the like, so that a higher melting area and a melting process of the welding spot are promoted, the welding spot can keep a solid state at a second reflow soldering even at a higher temperature, and the welding spot has better high-temperature service performance and smoothness and luster performance of the welding spot.
The second aspect of the present invention provides a method for preparing the lead-free solder for high temperature service, which comprises the following steps: and mixing the raw materials for preparing the lead-free solder to obtain the lead-free solder.
The third aspect of the invention provides a construction process of the lead-free solder for high-temperature service, which comprises the following steps: the solder joints are formed by reflow soldering.
In a preferred embodiment, the reflow soldering of the present invention includes preheating, soldering, and cooling.
In a preferred embodiment, the preheating is carried out at a rate of 3-5 ℃/s until the temperature is 140-150 ℃/s, and then at a rate of 1-3 ℃/s until the temperature is 190-210 ℃.
In a preferred embodiment, the welding is carried out by raising the temperature to 230-240 ℃ at a rate of 5-6 ℃/s and keeping the temperature for 1-2 min.
In a preferred embodiment, the cooling is carried out at a rate of 8-10 ℃/s to 170-150 ℃.
The applicant finds that the condition of solder reflow soldering needs to be controlled, and the obtained solder joint has good high-temperature service performance, smooth surface and luster, and particularly, the temperature rise rate and the heat preservation time of soldering and the cooling rate need to be controlled within a proper range, so that when the temperature rise rate and the heat preservation time of the soldering are controlled within a proper range, nano metal powder in the solder can be melted at the melting temperature of tin-silver-copper alloy powder to form a soldering head together with the tin-silver-copper alloy, and by controlling the reasonable heat preservation time, the solder can be promoted to wet a PCT board to form a certain intermetallic compound such as copper-tin, copper-silver and the like, so as to promote the high-temperature service performance, and when the temperature rise rate of the soldering is too high or the heat preservation time is too long, coarse intermetallic compound is easily caused, so as to affect the mechanical property and the luster of the solder joint, and when the temperature rise rate of the soldering is, the solder can not be fully wetted, and even false soldering is caused, so that the use and the luster of the welding spot are influenced.
The applicant finds that the cooling speed is controlled, particularly the cooling speed is higher, the mechanical property of the welding flux is improved, brittle fracture is prevented, probably because the addition of the nano metal powder, particularly the nano copper powder and the nano copper alloy powder, coarse crystal grains and intermetallic compounds are easily formed, the mechanical property is reduced, the glossiness is reduced, the control of the payment cooling speed is beneficial to refining the sizes of the crystal grains and the intermetallic compounds, fine crystals are uniformly distributed in a welding spot, and the mechanical property and the glossiness of the welding spot are improved.
In a preferred embodiment, the lead-free solder of the present invention is mixed with a flux and then reflowed to form a solder joint.
The welding spot is a connecting substance which has electric conduction, heat conduction and mechanical strength between the electronic component and the substrate on which the electronic component is arranged.
In a preferred embodiment, the soldering flux of the invention accounts for 10-20 wt% of the lead-free solder; further, the soldering flux of the invention accounts for 15 wt% of the lead-free solder.
The soldering flux is a chemical substance which can help and promote the welding process in the welding process, and has the functions of protection and prevention of oxidation reaction. Fluxes can be divided into solids, liquids and gases. The method mainly comprises the aspects of auxiliary heat conduction, oxide removal, surface tension reduction of welded materials, oil stain removal of the surfaces of the welded materials, welding area increase, reoxidation prevention and the like. The soldering flux of the present invention is well known in the art, and is not limited in particular, for example, the formulations of the soldering fluxes in CN201310401137.3, CN201310401128.4, and CN201410720716.9 of the applicant can be used.
The fourth aspect of the invention provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
In a preferred embodiment, the weight percentage of copper in the solder joint of the present invention is 4 to 10 wt%.
The applicant unexpectedly finds that the high-temperature service performance and the use stability are good only by controlling the content of the added nano metal powder and the content of the tin-silver-copper alloy powder and the construction process and controlling the weight percentage of copper in a welding spot to be 4-10 wt%, when the added nano metal powder is too little, or the particle size is too large, the heating rate of welding is too low and the like, the content of copper in the welding spot is too low, the high-temperature service performance is reduced, and when the nano metal powder is too much, or the particle size is too small, and the heating rate of welding is too large, the weight percentage of copper is too much, the intermetallic compounds generated by copper, silver, tin and the like are too much, the size is large, the mechanical property of the welding spot is not facilitated, and the use stability is influenced.
The fifth aspect of the invention provides the application of the high-temperature service lead-free solder, which is applied to the field of electronic packaging.
Examples
The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.
Example 1
The embodiment 1 of the invention provides a lead-free solder for high-temperature service, and the lead-free solder is prepared from the following raw materials in parts by weight of 1: 9; the tin-silver-copper alloy powder is Sn99Ag0.3Cu0.7 which is purchased from Shenzhen, Haizhesheng New materials science and technology Limited company (the particle size is 5-15 μm); the nano-metal powder is nano-copper powder and is purchased from Suzhou Changhu nanotechnology Co., Ltd (the particle size is 20 nm).
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the lead-free solder is obtained by mixing the raw materials for preparing the lead-free solder.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, which comprises the following steps:
premixing: mixing the lead-free solder and the soldering flux to obtain soldering paste;
and (3) reflow soldering: preheating, welding and cooling the soldering paste to obtain a welding spot, wherein the preheating is to heat to 150 ℃/s at the speed of 4 ℃/s and then to 200 ℃ at the speed of 2 ℃/s; the welding is to heat up to 240 ℃ at the speed of 5 ℃/s and keep the temperature for 1.5 min; the cooling was carried out at a rate of 9 ℃/s to 150 ℃.
The soldering flux accounts for 15 wt% of the lead-free solder; the soldering flux is the soldering flux disclosed in CN 201310401137.3.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 2
The embodiment 2 of the invention provides a lead-free solder for high-temperature service, and the lead-free solder is prepared from the following raw materials in parts by weight of 1: 5; the tin-silver-copper alloy powder is Sn99Ag0.3Cu0.7 which is purchased from Shenzhen, Haizhesheng New materials science and technology Limited company (the particle size is 5-15 μm); the nano metal powder is nano copper powder and nano copper-tin-phosphorus alloy powder, and the weight ratio is 1: 0.4, the nano copper powder is purchased from Suzhou Changhu nanometer technology Co Ltd (the particle size is 20nm), the nano copper-tin-phosphorus alloy powder is CuSn4Zn3, the mark is QSn4-3, and the nano copper powder is purchased from Jiangsu Huandin Special alloy Co Ltd (the particle size is 80 nm).
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the lead-free solder is obtained by mixing the raw materials for preparing the lead-free solder.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, which comprises the following steps:
premixing: mixing the lead-free solder and the soldering flux to obtain soldering paste;
and (3) reflow soldering: preheating, welding and cooling the soldering paste to obtain a welding spot, wherein the preheating is to heat to 150 ℃/s at the speed of 4 ℃/s and then to 200 ℃ at the speed of 2 ℃/s; the welding is to heat up to 240 ℃ at the speed of 5 ℃/s and keep the temperature for 1.5 min; the cooling was carried out at a rate of 9 ℃/s to 150 ℃.
The soldering flux accounts for 15 wt% of the lead-free solder; the soldering flux is the soldering flux disclosed in CN 201310401137.3.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 3
The embodiment 1 of the invention provides a lead-free solder for high-temperature service, and the lead-free solder is prepared from the following raw materials in parts by weight of 1: 20; the tin-silver-copper alloy powder is Sn99Ag0.3Cu0.7 which is purchased from Shenzhen, Haizhesheng New materials science and technology Limited company (the particle size is 5-15 μm); the nano metal powder is nano copper powder and nano copper-tin-phosphorus alloy powder, and the weight ratio is 1: 0.6, the nano copper powder is purchased from Suzhou Changhu nanometer technology Co Ltd (the particle size is 20nm), the nano copper-tin-phosphorus alloy powder is CuSn4Zn3, the mark is QSn4-3, and the nano copper powder is purchased from Jiangsu Huandin Special alloy Co Ltd (the particle size is 80 nm).
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the lead-free solder is obtained by mixing the raw materials for preparing the lead-free solder.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, which comprises the following steps:
premixing: mixing the lead-free solder and the soldering flux to obtain soldering paste;
and (3) reflow soldering: preheating, welding and cooling the soldering paste to obtain a welding spot, wherein the preheating is to heat to 150 ℃/s at the speed of 4 ℃/s and then to 200 ℃ at the speed of 2 ℃/s; the welding is to heat up to 240 ℃ at the speed of 5 ℃/s and keep the temperature for 1.5 min; the cooling was carried out at a rate of 9 ℃/s to 150 ℃.
The soldering flux accounts for 15 wt% of the lead-free solder; the soldering flux is the soldering flux disclosed in CN 201310401137.3.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 4
The embodiment 4 of the invention provides a lead-free solder for high-temperature service, and the lead-free solder is prepared from the following raw materials in parts by weight of 1: 9; the tin-silver-copper alloy powder is Sn99Ag0.3Cu0.7 which is purchased from Shenzhen, Haizhesheng New materials science and technology Limited company (the particle size is 5-15 μm); the nano metal powder is nano copper powder and nano copper-tin-phosphorus alloy powder, and the weight ratio is 1: 0.5, the nano copper powder is purchased from Suzhou Changhu nanometer technology Co Ltd (the particle size is 20nm), the nano copper-tin-phosphorus alloy powder is CuSn4Zn3, the mark is QSn4-3, and the nano copper powder is purchased from Jiangsu Huandin Special alloy Co Ltd (the particle size is 80 nm).
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the lead-free solder is obtained by mixing the raw materials for preparing the lead-free solder.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, which comprises the following steps:
premixing: mixing the lead-free solder and the soldering flux to obtain soldering paste;
and (3) reflow soldering: preheating, welding and cooling the soldering paste to obtain a welding spot, wherein the preheating is to heat to 150 ℃/s at the speed of 4 ℃/s and then to 200 ℃ at the speed of 2 ℃/s; the welding is to heat up to 240 ℃ at the speed of 5 ℃/s and keep the temperature for 1.5 min; the cooling was carried out at a rate of 9 ℃/s to 150 ℃.
The soldering flux accounts for 15 wt% of the lead-free solder; the soldering flux is the soldering flux disclosed in CN 201310401137.3.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 5
The embodiment 5 of the invention provides a lead-free solder in high-temperature service, which is different from the embodiment 1 in the specific implementation mode that the tin-silver-copper alloy powder is Sn99Ag0.3Cu0.7 which is purchased from Haizheng New Material science and technology Limited in Shenzhen (particle size is 25-45 μm).
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 6
Embodiment 6 of the present invention provides a lead-free solder for high temperature service, which is similar to embodiment 1 in specific implementation manner, and is different in that the weight ratio of the nano metal powder to the tin-silver-copper alloy powder is 1: 2.
the embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 7
Embodiment 7 of the present invention provides a lead-free solder for high temperature service, which is similar to embodiment 1 in specific implementation manner, and is different from embodiment 1 in that the raw material for preparing the lead-free solder does not include nano metal powder.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 8
Embodiment 8 of the present invention provides a lead-free solder used at high temperature, and the specific implementation manner is the same as that in embodiment 1, except that the particle size of the nano copper powder is 100 nm.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 9
Embodiment 9 of the present invention provides a lead-free solder used at high temperature, which is similar to embodiment 4 in specific implementation, and is different from that in embodiment 4 in that CuSn4Zn3, the trademark is QSn4-3, and the particle size is 40 nm.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 10
The embodiment 10 of the invention provides a lead-free solder serving at a high temperature, which is different from the embodiment 4 in the specific implementation mode that CuSn4Zn3 is provided with the mark of QSn4-3, and the grain diameter is 0.2 mu m.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 11
Embodiment 11 of the present invention provides a lead-free solder for high temperature service, which is similar to embodiment 4, except that CuSn4Zn3 is replaced by CuSn4Zn3 with a mark of QSn4-3, and is available from special alloy ltd (particle size 80 nm).
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 12
Embodiment 12 of the present invention provides a lead-free solder used at a high temperature, which is similar to embodiment 4, and is different in that the nano metal powder is nano copper powder and nano copper-tin-phosphorus alloy powder, and the weight ratio is 1: 2.
the embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 13
Embodiment 13 of the present invention provides a lead-free solder for high temperature service, and the specific implementation manner is the same as that of embodiment 4.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, which is the same as that in the embodiment 1, and is different from that in the embodiment 1 in that the welding is carried out by raising the temperature to 240 ℃ at the speed of 2 ℃/s and preserving the temperature for 1.5 min.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 14
Example 14 of the present invention provides a lead-free solder for high temperature service, and the specific implementation manner is the same as example 4.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The embodiment also provides a construction process of the lead-free solder for high-temperature service, which is the same as that in the embodiment 1, and is characterized in that the welding is carried out by raising the temperature to 240 ℃ at the speed of 5 ℃/s and keeping the temperature for 4 min.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Example 15
Example 15 of the present invention provides a lead-free solder for high temperature service, and the specific implementation manner is the same as example 4.
The embodiment also provides a preparation method of the lead-free solder for high-temperature service, and the specific implementation mode is the same as that of the embodiment 1.
The present embodiment further provides a construction process of the lead-free solder in high temperature service, which is similar to that of embodiment 1, except that the cooling is performed at a rate of 5 ℃/s to 150 ℃.
The example also provides a welding spot obtained according to the construction process of the lead-free solder in high-temperature service.
Evaluation of Performance
1. The physical state of the second reflow soldering: the solder joints provided in examples 1 to 15 were heated to 240 ℃, 250 ℃, 260 ℃, 265 ℃ and kept warm for 5min, and the physical state of the solder joints was observed and rated as 1-5, wherein 1 is solid, 2 is slightly liquefied, 3 is partially liquefied, 4 is obviously liquefied, and 5 is completely liquefied, and the results are shown in table 1.
2. Sensory evaluation of solder joints: performing sensory evaluation on the glossiness of the welding spots provided by the embodiments 1-15, and evaluating the glossiness to be 1-4 grades, wherein the glossiness of the welding spots is obvious on the 1 grade; grade 2 is generally glossy; the 3 grade is darker luster; the level 4 was matt and the results are shown in table 1, and in addition, the surface of the solder joint provided in example 11 was found to be white speckled.
3. The copper content of the welding spot: the solder joints provided in examples 1 to 15 were evaluated for copper weight percent according to ICP-MS and rated as 1 to 3 grades based on copper weight percent, where 1 grade was less than 4 wt% copper, 2 grade was greater than or equal to 4 wt% copper, less than or equal to 10 wt% copper, and 3 grade was greater than 10 wt% copper, and the results are shown in Table 1.
Table 1 performance characterization test
The test results in table 1 show that the solder joint formed by reflow soldering of the high-temperature service lead-free solder provided by the invention has good high-temperature service performance, can be subjected to second reflow soldering at even higher temperature, such as no melting at 260 ℃ or higher, and still maintains a solid state, and by controlling the conditions of the nano metal powder, the construction process and the like, the high-temperature service performance of the solder joint is improved, meanwhile, the surface gloss and smoothness of the solder joint can be ensured, the mechanical properties of the solder joint are improved, the situations of brittle fracture or insufficient soldering and the like are prevented, and the use stability of the solder joint is improved.
The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Also, where numerical ranges are used in the claims, subranges therein are included, and variations in these ranges are also to be construed as possible being covered by the appended claims.
Claims (10)
1. The lead-free solder for high-temperature service is characterized in that the lead-free solder is prepared from raw materials including nano metal powder and tin-silver-copper alloy powder in a weight ratio of 1: (5-20).
2. The lead-free solder used at high temperature according to claim 1, wherein the nano metal powder comprises nano copper powder, and the particle size is 5-50 nm.
3. The lead-free solder for high-temperature service according to claim 2, wherein the nano metal powder further comprises nano copper alloy powder, and the weight ratio of the nano copper alloy powder to the nano copper powder is 1: (3-5).
4. The lead-free solder for high-temperature service according to claim 3, wherein the particle size of the nano-copper alloy powder is 50-100 nm.
5. The high-temperature service lead-free solder as claimed in claim 3, wherein the weight percentage of copper in the nano-copper alloy powder is more than 50 wt%.
6. The lead-free solder for high-temperature service according to any one of claims 3 to 5, wherein the nano copper alloy powder is a binary nano copper alloy and/or a ternary nano copper alloy.
7. The preparation method of the lead-free solder serving at high temperature according to any one of claims 1 to 6, characterized by comprising the following steps: and mixing the raw materials for preparing the lead-free solder to obtain the lead-free solder.
8. The construction process of the high-temperature service lead-free solder according to any one of claims 1 to 6, characterized by comprising the following steps: the solder joints are formed by reflow soldering.
9. A solder joint, which is obtained by the construction process of the high-temperature service lead-free solder according to claim 8.
10. The application of the high-temperature service lead-free solder according to any one of claims 1 to 6, which is applied to the field of electronic packaging.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911377107.7A CN111015008B (en) | 2019-12-27 | 2019-12-27 | High-temperature service lead-free solder and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911377107.7A CN111015008B (en) | 2019-12-27 | 2019-12-27 | High-temperature service lead-free solder and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111015008A true CN111015008A (en) | 2020-04-17 |
| CN111015008B CN111015008B (en) | 2021-12-07 |
Family
ID=70194661
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911377107.7A Active CN111015008B (en) | 2019-12-27 | 2019-12-27 | High-temperature service lead-free solder and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111015008B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113977130A (en) * | 2021-11-24 | 2022-01-28 | 广东中实金属有限公司 | High-temperature-resistant soldering paste capable of being sintered at low temperature under no pressure and preparation method and use method thereof |
| CN114434040A (en) * | 2021-01-15 | 2022-05-06 | 重庆理工大学 | Dissimilar material interconnected zinc alloy mixed solder powder and connecting method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1657225A (en) * | 2004-12-09 | 2005-08-24 | 中国电子科技集团公司第十四研究所 | Ultra particle leadless brazing filler metal and its manufacturing method |
| US20120272790A1 (en) * | 2008-08-11 | 2012-11-01 | Samsung Electro-Mechanics Co., Ltd. | Alloy nanoparticles of sn-cu-ag, preparation method thereof and ink or paste using the alloy nanoparticles |
| CN104741821A (en) * | 2015-04-17 | 2015-07-01 | 哈尔滨工业大学 | Micro-nano copper particle filled Sn based soldering paste for high-temperature packaging of electronic module and preparation method of soldering paste |
| CN104759725A (en) * | 2015-04-17 | 2015-07-08 | 哈尔滨工业大学 | Method for achieving electronic building brick high-temperature packaging by filling Sn-based solder with micro-nano metallic particles |
| WO2019027261A1 (en) * | 2017-08-01 | 2019-02-07 | 서울시립대학교 산학협력단 | Lead-free solder alloy composition and preparation method therefor |
-
2019
- 2019-12-27 CN CN201911377107.7A patent/CN111015008B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1657225A (en) * | 2004-12-09 | 2005-08-24 | 中国电子科技集团公司第十四研究所 | Ultra particle leadless brazing filler metal and its manufacturing method |
| US20120272790A1 (en) * | 2008-08-11 | 2012-11-01 | Samsung Electro-Mechanics Co., Ltd. | Alloy nanoparticles of sn-cu-ag, preparation method thereof and ink or paste using the alloy nanoparticles |
| CN104741821A (en) * | 2015-04-17 | 2015-07-01 | 哈尔滨工业大学 | Micro-nano copper particle filled Sn based soldering paste for high-temperature packaging of electronic module and preparation method of soldering paste |
| CN104759725A (en) * | 2015-04-17 | 2015-07-08 | 哈尔滨工业大学 | Method for achieving electronic building brick high-temperature packaging by filling Sn-based solder with micro-nano metallic particles |
| WO2019027261A1 (en) * | 2017-08-01 | 2019-02-07 | 서울시립대학교 산학협력단 | Lead-free solder alloy composition and preparation method therefor |
Non-Patent Citations (2)
| Title |
|---|
| 汪源: "纳米Ag3Sn、Cu6Sn5颗粒对Sn基无铅焊料性能影响研究", 《中国优秀硕士学位论文全文数据库工程科技I辑》 * |
| 辛瞳等: "SAC305-纳米铜复合焊膏微观组织及力学性能研究", 《焊接学报》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114434040A (en) * | 2021-01-15 | 2022-05-06 | 重庆理工大学 | Dissimilar material interconnected zinc alloy mixed solder powder and connecting method |
| CN113977130A (en) * | 2021-11-24 | 2022-01-28 | 广东中实金属有限公司 | High-temperature-resistant soldering paste capable of being sintered at low temperature under no pressure and preparation method and use method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111015008B (en) | 2021-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6842500B2 (en) | Lead-free solder paste and its manufacturing method | |
| Zhang et al. | Development of Sn–Zn lead-free solders bearing alloying elements | |
| JP4613823B2 (en) | Solder paste and printed circuit board | |
| KR101160860B1 (en) | Cream solder and method of soldering electronic part | |
| US10376994B2 (en) | Soldering material based on Sn Ag and Cu | |
| JP4770733B2 (en) | Solder and mounted products using it | |
| WO2009131178A1 (en) | Lead-free solder alloy suppressed in occurrence of shrinkage cavity | |
| EP3715040B1 (en) | Solder alloy, solder paste, solder ball, resin cored solder, and solder joint | |
| JPWO2009051255A1 (en) | Solder joint | |
| TW201410374A (en) | Solder alloy, solder paste, and electronic circuit board | |
| JP5206779B2 (en) | Pb-free solder alloy based on Zn | |
| TWI401132B (en) | Pb-free solder alloy | |
| CN111015008B (en) | High-temperature service lead-free solder and preparation method thereof | |
| WO2007014529A1 (en) | A low melting point lead-free solder alloy | |
| CN110125571A (en) | A kind of high intensity low-temperature lead-free solder and its solder(ing) paste | |
| JP4462721B2 (en) | Solder alloys and solder balls | |
| JP2011062736A (en) | Lead-free high-temperature solder material | |
| CN113677477B (en) | Solder alloy, solder paste, solder preform, solder ball, wire-like solder, cored solder, solder joint, electronic circuit board, and multilayer electronic circuit board | |
| JP3991788B2 (en) | Solder and mounted product using it | |
| EP1980355A1 (en) | Lead-free solder alloy | |
| JP5093373B2 (en) | Pb-free solder paste | |
| WO2007014530A1 (en) | Lead-free sn-ag-cu-ni-al system solder alloy | |
| JP5408589B2 (en) | Solder alloy and manufacturing method thereof | |
| JP5080946B2 (en) | Lead-free solder alloy for manual soldering | |
| GB2413565A (en) | Lead-free, bismuth-free solder alloy powders and a method of production thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |