KR20160080014A - Bi-coated lead-free solder ball, and method for preparing thereof using electroless plating - Google Patents
Bi-coated lead-free solder ball, and method for preparing thereof using electroless plating Download PDFInfo
- Publication number
- KR20160080014A KR20160080014A KR1020140192737A KR20140192737A KR20160080014A KR 20160080014 A KR20160080014 A KR 20160080014A KR 1020140192737 A KR1020140192737 A KR 1020140192737A KR 20140192737 A KR20140192737 A KR 20140192737A KR 20160080014 A KR20160080014 A KR 20160080014A
- Authority
- KR
- South Korea
- Prior art keywords
- solder ball
- tin
- electroless plating
- silver
- copper
- Prior art date
Links
Images
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
- B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
- B23K35/0222—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in soldering, brazing
- B23K35/0233—Sheets, foils
- B23K35/0238—Sheets, foils layered
-
- 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
- B23K35/262—Sn as the principal constituent
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/54—Contact plating, i.e. electroless electrochemical plating
Abstract
Description
The present invention relates to a Bi-coated lead-free solder ball coated with Bi (bismuth) using an electroless plating method and a manufacturing method thereof.
Lead-free solder having Sn-x (0 to 4.0 wt%) Ag-y (0 to 0.9 wt%) Cu composition, that is, a solder having a composition of Sn-3.0Ag-0.5Cu (hereinafter referred to as SAC305) The reflow soldering process used can have problems causing warpage in the chip, package or substrate, thereby reducing the reliability of the chip or package.
The main reason for such a bending phenomenon is that the reflow process is performed at an excessively high peak temperature such as 240 ° C. or higher. In this case, the degree of warpage of the chip, package or substrate itself made of a different material having different thermal expansion coefficients Lt; / RTI > increases in proportion to the peak temperature. This bending phenomenon is easily observed not only in solder paste use but also in reflow soldering process using solder balls. Therefore, it is necessary to lower the melting point of the solder balls used to solve the bending problem.
Reflow soldering may be possible at a temperature of 200 ° C or less in the case of a typical low melting point lead-free solder (Sn-58 (wt%) Bi) having a melting point of 138 ° C. However, Sn- There is a great problem indicating low mechanical reliability. Therefore, solder balls having the above composition are rarely used.
Korean Patent No. 10-0431090 discloses a high melting point solder which contains Sn as a main component and contains at least one element selected from the group consisting of Ag, Cu, Bi and Zn and other inevitable substances within 20 wt% (For example, Sn-3.5Ag or Sn-0.75Cu-based) is formed using a lead-free soldering alloy and a low melting point solder having a melting point lower than that of the high melting point solder is added to the Bi content of 5 to 77 wt% (For example, Sn-58Bi, Sn-20Bi) is formed by using a Sn-based lead-free soldering alloy containing Sn-58Bi and Sn- have.
However, in the above-mentioned patent, a binary composition composed of any one element selected from Ag, Cu, Bi, and Zn is used as the main component of Sn as a core composition, and Bi is contained as a skin plating layer. However, And an alloy composition of Sn and Bi.
Therefore, in order to perform low temperature reflow soldering, a solder ball composed of a ternary composition of Sn-x (0 to 4.0 wt%) Ag-y (0 to 0.9 wt%) Cu is used as a core composition, I have not been using the technology I used.
Korean Patent No. 10-105555 discloses a metal or plastic core; A first metal layer formed on the surface of the core; A second metal layer formed on the surface of the first metal layer, the second metal layer including a different kind of metal from the first metal layer; And a second solder layer formed on the surface of the second metal layer and containing Sn-Cu or Sn-Ag, and a second solder layer containing Sn-Ag or Sn-Cu different from the first solder layer, Based Sn-Ag-Cu-based solder layer.
In this patent, in order to provide a metal or plastic core solder ball having excellent thermal fatigue characteristics by suppressing the formation of intermetallic compounds between a metal layer and a solder layer, a multilayer metal layer is formed on the metal or plastic core, and Sn- Based solder layer. However, a specific composition of the Sn-Ag-Cu ternary solder layer and a technique of forming a plating layer on the surface of the Sn-Ag-Cu ternary solder layer have not been proposed.
The eutectic point of the Sn-Bi binary alloy is 138 ° C which is much lower than the melting point of SAC305 (Sn-3.0Ag-0.5Cu) solder ball which is 217 ° C. From this, the Sn-3.0Ag-0.5Cu solder ball It can be seen that soldering is possible at a temperature significantly lower than the general reflow temperature of 250 ° C. Accordingly, in the present invention, a solder ball capable of low temperature soldering is proposed by plating a Bi layer on the surface of a SAC305 solder ball by electroless plating.
In the present invention, by coating the pure Bi composition alone instead of the Sn-58Bi composition used as the coating layer in the prior art, the coating composition can be maintained more easily on the Sn component-based solder ball and the coating composition can be maintained more easily And how to do it.
Accordingly, an object of the present invention is to provide a tin-silver-copper lead-free solder ball which can be soldered at 200 ° C or lower by forming a Bi layer using an electroless plating method.
The tin-silver-copper lead-free solder ball having the Bi coating layer according to the present invention is formed by applying Sn-58Bi process to the surface portion of the solder ball while the Bi coating layer and Sn as the solder ball component are mutually diffused during the heating process for reflow soldering. And this layer is melted at a temperature of 138 占 폚 or higher and soldered to a pad of a connection pad, so that it has a characteristic of being bonded at a low temperature of 200 占 폚 or lower.
The Bi-coated lead-free solder balls according to the present invention may include tin-silver-copper (Sn-Ag-Cu) solder balls; And a Bi coating layer formed on the surface of the solder ball.
The tin-silver-copper (Sn-Ag-Cu) solder balls are more specifically Sn-x (0-4.0 wt%) Ag-y (0-00.9 wt%) Cu composition.
The Bi coating layer is preferably formed by electroless plating.
The average thickness of the Bi coating layer is preferably 5 to 15 mu m.
According to the present invention, during the heating process for reflow soldering, the Bi coating layer and Sn as a solder ball component are mutually diffused within a short period of time, and an alloy layer of Sn-58Bi process composition is instantly formed on the surface of the solder ball.
The Sn-58Bi layer is melted at a temperature of 138 ° C or higher and soldered to the connection pad portion, so that bonding can be performed at a low temperature of 200 ° C or lower.
Thus, the Bi-coated tin-silver-copper lead-free solder ball is characterized by being solderable below 200 < 0 > C.
The Bi-coated lead-free solder balls according to the present invention may also be manufactured by a method comprising the steps of: preparing a plating solution; and immersing the tin-silver-copper solder balls in the plating solution to form a tin- Bi coating layer on the substrate.
The plating solution may include sodium citrate (C 6 H 5 Na 3 O 7 2H 2 O), ethylenediaminetetraacetic acid (EDTA), Bi precursor And ammonia water.
The sodium citrate (C 6 H 5 Na 3 O 7 2H 2 O) is preferably contained in an amount of 0.1 to 1.0 mole.
The ethylenediaminetetraacetic acid (EDTA) is preferably contained in an amount of 0.01 to 0.2 mol.
The electroless plating is preferably carried out at a pH of 7.5 to 9.0 by titrating the plating solution with ammonia water.
It is preferable that the Bi precursor is contained in an amount of 0.02 to 0.1 mole in the entire plating solution.
The electroless plating is preferably performed at a temperature of 50 to 70 DEG C for 5 to 60 minutes.
According to the present invention, a bismuth (Bi) coating layer is formed on the surface of a tin-silver-copper lead-free solder ball using an electroless plating method to form a tin-silver- The ball can be manufactured. By lowering the soldering temperature of the solder ball as in the present invention, it is possible to solve the warpage problem in the package and the substrate using the Bi-coated tin-silver-copper lead-free solder ball of the present invention.
1 is a schematic diagram illustrating a process of forming a liquid layer by mutual diffusion of Sn in a Bi coating layer and a solder ball component,
Figure 2 shows the outline of nine Bi coated solder ball samples (Table 1) prepared according to Preparation Example 1
FIG. 3 is a cross-sectional optical microscope and SEM photographs of a solder ball coated with a Bi layer on a SAC solder ball as a sample of
4 is a cross-sectional EDS element mapping profile of a Bi-coated solder ball as a sample in
5 shows the results of analysis using a differential scanning thermal analyzer (DSC) of a Bi-coated solder ball as a sample in
Fig. 6 shows the result of applying a flux to a solder ball coated with Bi as a sample in
7 is a graph of the thickness of the coated Bi layer according to the coating time of the Bi-coated solder balls prepared according to Production Example 2. [
Hereinafter, the present invention will be described in more detail.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a,""an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.
The present invention relates to a Bi-coated lead-free solder ball capable of lowering the reflow process temperature of a solder ball to solve warping problems occurring in devices and parts materials and a method of manufacturing the same.
The Bi-coated lead-free solder balls according to the present invention are solder balls made of tin-silver-copper (Sn-Ag-Cu); And a Bi coating layer formed on the surface of the solder ball.
1, the solder balls formed on the copper pads are lead-free solder balls made of tin-silver-copper (Sn-Ag-Cu), specifically Sn-x (0 to 4.0 wt%) Ag-y (0 to 0.9 wt%) Cu composition, typically a Sn-3.0Ag-0.5Cu (SAC305) composition.
The Bi coating layer in the present invention is preferably formed by electroless plating. The Bi precursor material used for forming the Bi coating layer is BiCl 3 , but is not limited thereto.
The Bi coating layer may be formed through an electroless plating process triggered by the following reaction formula.
Each positive reduction potential shows the possibility of electroless plating using Sn or Sn 2 + as a reducing agent.
The thickness of the Bi coating layer formed on the surface of the solder ball of the present invention can be adjusted according to the plating time in which the tin-silver-copper (Sn-Ag-Cu) solder ball is immersed in the Bi coating solution to perform electroless plating. , It is more preferable that the average thickness of the Bi coating layer is in the range of 5 to 15 占 퐉 to form a sufficient molten layer.
A solder ball having a Bi coating layer formed by an electroless plating method according to the present invention is as shown in FIG. 1, and has a tin-silver-copper (Sn-Ag-Cu) solder ball and a Bi coating layer formed on the surface thereof Structure.
According to the present invention, during the heating process for reflow soldering, the Bi coating layer and Sn, which is a solder ball component, are mutually diffused within a short period of time to instantaneously form a Sn-Bi alloy layer having a low melting point on the surface of the solder ball.
Further, since the Sn-Bi alloy layer is melted at a temperature of 138 ° C or higher and soldered to the connection pad portion, bonding can be performed at a low temperature of 200 ° C or lower.
Therefore, the Bi-coated lead-free solder ball of the present invention produced as described above has an advantage of soldering at 200 ° C or less. This can effectively reduce the reflow process temperature of 240 DEG C or more, which was a main cause of the warpage of the conventional chip, package, or substrate, and thus can prevent the deflection problem in the chip, the package or the substrate.
The Bi-coated tin-silver-copper lead-free solder ball according to the present invention is manufactured by preparing a Bi plating solution and immersing the tin-silver-copper solder ball in the plating solution to form the tin- And forming a Bi coating layer on the solder ball surface.
The plating solution is prepared by mixing sodium citrate (C 6 H 5 Na 3 O 7 2H 2 O), ethylenediaminetetraacetic acid (EDTA), and Bi precursor (BiCl 3 ) to distilled water at a predetermined concentration, . It may dissolve while heating at 50 to 60 ° C for smooth dissolution. Then, the mixed solution is cooled to room temperature, and the pH of the solution is adjusted to 7.5 to 9 using an aqueous ammonia solution.
The plating solution of
Also, a tin-silver-copper solder ball is immersed in the plating solution to form a Bi coating layer on the surface of the tin-silver-copper solder ball by electroless plating.
The Sn-3.0Ag-0.5Cu (SAC305) solder balls are dropped into the plating solution while heating the plating solution to a temperature of about 50-70 DEG C and stirring continuously before immersing the solder balls in the plating solution. Then, after holding for a specific time, the solder ball is extracted from the solution, washed, and then dried in a vacuum chamber to produce a Bi-coated tin-silver-copper lead-free solder ball.
It is preferable that the electroless plating time is set in inverse proportion to the addition amount of the Bi precursor to be incorporated, that is, BiCl 3 . BiCl 3 Is preferably contained in an amount of 0.02 to 0.1 mole, and the electroless plating time is preferably 5 to 60 minutes.
The electroless plating may be performed at a temperature of 50 to 70 캜.
Hereinafter, preferred embodiments of the present invention will be described in detail. The following examples are intended to illustrate the present invention, but the scope of the present invention should not be construed as being limited by these examples. In the following examples, specific compounds are exemplified. However, it is apparent to those skilled in the art that equivalents of these compounds can be used in similar amounts.
Manufacturing example 1: Table 1 Manufacturing example
30 mL of distilled water was poured into a 50 mL beaker and sodium citrate (C 6 H 5 Na 3 O 7 2H 2 O, Sigma-Aldrich), ethylenediaminetetraacetic acid (EDTA, C 10 H 16 N 2 O 8 , Sigma-Aldrich), and BiCl 3 (Sigma-Aldrich) were added to the beaker, and the mixture was heated to 60 ° C and completely dissolved while being stirred for 30 minutes. The concentrations of the sodium citrate and EDTA were varied as shown in the following Table 1, and the concentration of BiCl 3 was fixed to 0.08 mol. After cooling from room temperature to room temperature, the pH of the solution was adjusted to 8.75 using an aqueous ammonia solution.
Then, the beaker was heated to 50 DEG C again, and when the temperature of the solution was 50 DEG C, the solution was stirred at 130 rpm and 0.1 g of Sn-3.0Ag-0.5Cu (SAC305) Solution. Then, after stirring and reacting for 30 minutes, the solder balls were collected, washed and dried in a vacuum chamber for one day.
Manufacturing example 2: Secondary manufacturing
0.27 g of SAC305 solder balls were plated at a plating solution temperature of 55 [deg.] C. That is, 0.27 g of SAC305 solder balls were charged into the
Experimental Example One : Solder Check ball structure
FIG. 2 shows the outline of nine Bi-coated solder ball samples (Table 1) prepared according to Preparation Example 1, and it can be seen that the sphericity of the
Fig. 3 is a cross-sectional optical microscope photograph and SEM cross-sectional photograph of a solder ball coated with a Bi layer on a SAC solder ball as a sample of
The average thickness of the Bi layer measured in
Experimental Example 2 : EDS analysis
The line profile results for the EDS element components in the cross-sectional images of the Bi-coated solder balls prepared according to
4, it can be more clearly seen that the Bi layer is coated on the surface of the SAC305 which is the solder ball of the
Experimental Example 3: DSC analysis
Figure 5 shows the analysis results of the Bi-coated solder balls according to
Referring to FIG. 5, two endothermic reactions occur, one at 136.86 ° C (near the eutectic point of the Sn-Bi binary system composition) and the other at 196.20 ° C. In addition, no peak can be observed at 271.5 ° C near the melting point of Bi because the produced Bi layer was alloyed with Sn, which is a solder ball component during heating.
From these results, the solder balls of
Experimental Example 4 : Soldering Whether or not
The results are shown in FIG. 6, in which the flux was applied to a Bi-coated solder ball prepared according to
Experimental Example 5: Manufacturing example According to 2 Bi Coquettish Confirm thickness change pattern
FIG. 7 is a graph showing the thickness of the coated Bi layer according to the coating time of the Bi-coated solder ball prepared according to Preparation Example 2. Referring to FIG. 7, as the coating time increases, the thickness increases linearly .
Claims (12)
Wherein the Bi-coated lead-free solder ball comprises a Bi coating layer on the tin-silver-copper (Sn-Ag-Cu) solder ball surface.
Wherein the tin-silver-copper (Sn-Ag-Cu) solder ball is Sn-x (0-4.0 wt%) Ag-y (0-0.9 wt%) Cu composition.
Wherein the Bi coating layer is formed by electroless plating.
Wherein the Bi coating layer has an average thickness of 5 to 15 占 퐉.
Tin (Sn) of the tin-silver-copper (Sn-Ag-Cu) solder ball and bismuth (Bi) of the Bi coating layer are mutually diffused during heating for reflow soldering to form a Sn- Bi-coated lead-free solder ball.
Wherein said Bi-coated lead free solder balls are capable of soldering below 200 < 0 > C.
And immersing the tin-silver-copper solder balls in the plating solution to form a Bi coating layer on the surface of the tin-silver-copper solder ball by electroless plating to form a Bi-coated lead-free solder ball.
Wherein the plating solution comprises sodium citrate (C 6 H 5 Na 3 O 7 2H 2 O), ethylenediaminetetraacetic acid (EDTA), BiCl 3 , and aqueous ammonia.
Wherein said sodium citrate (C 6 H 5 Na 3 O 7 2H 2 O) is contained in an amount of 0.1 to 1.0 mol.
Wherein said ethylenediaminetetraacetic acid (EDTA) is contained in an amount of 0.01 to 0.2 mol.
Wherein the electroless plating solution is plated at a pH of 7.5 to 9.0.
Wherein the electroless plating is performed at a temperature of 50 to 70 DEG C for 5 to 60 minutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020140192737A KR20160080014A (en) | 2014-12-29 | 2014-12-29 | Bi-coated lead-free solder ball, and method for preparing thereof using electroless plating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020140192737A KR20160080014A (en) | 2014-12-29 | 2014-12-29 | Bi-coated lead-free solder ball, and method for preparing thereof using electroless plating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR20160080014A true KR20160080014A (en) | 2016-07-07 |
Family
ID=56499794
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020140192737A KR20160080014A (en) | 2014-12-29 | 2014-12-29 | Bi-coated lead-free solder ball, and method for preparing thereof using electroless plating |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR20160080014A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117712035A (en) * | 2024-02-06 | 2024-03-15 | 苏州锐杰微科技集团有限公司 | Composite welding spot low-temperature interconnection method for solving substrate warpage problem |
| CN117712035B (en) * | 2024-02-06 | 2024-04-30 | 苏州锐杰微科技集团有限公司 | Composite welding spot low-temperature interconnection method for solving substrate warpage problem |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100431090B1 (en) | 2001-06-20 | 2004-05-12 | 정재필 | Lead free solder plated with low-melting-pointed alloy |
| KR101085525B1 (en) | 2010-01-08 | 2011-11-23 | 덕산하이메탈(주) | core solder balls, method of manufacturing core solder balls and electronic parts including the same |
-
2014
- 2014-12-29 KR KR1020140192737A patent/KR20160080014A/en not_active Application Discontinuation
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100431090B1 (en) | 2001-06-20 | 2004-05-12 | 정재필 | Lead free solder plated with low-melting-pointed alloy |
| KR101085525B1 (en) | 2010-01-08 | 2011-11-23 | 덕산하이메탈(주) | core solder balls, method of manufacturing core solder balls and electronic parts including the same |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117712035A (en) * | 2024-02-06 | 2024-03-15 | 苏州锐杰微科技集团有限公司 | Composite welding spot low-temperature interconnection method for solving substrate warpage problem |
| CN117712035B (en) * | 2024-02-06 | 2024-04-30 | 苏州锐杰微科技集团有限公司 | Composite welding spot low-temperature interconnection method for solving substrate warpage problem |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101738841B1 (en) | HIGH-TEMPERATURE SOLDER JOINT COMPRISING Bi-Sn-BASED HIGH-TEMPERATURE SOLDER ALLOY | |
| KR20140025406A (en) | Lead-free solder ball | |
| EP1088615A2 (en) | Sn-Ag-Cu solder and surface treatment and parts mounting methods using the same | |
| KR20200036948A (en) | Solder alloys, solder pastes, solder balls, resin embedded solders and solder joints | |
| CN101374630B (en) | Solder alloy, solder ball and solder joint using same | |
| JPWO2013132942A1 (en) | Bonding method, bonded structure and manufacturing method thereof | |
| KR101165426B1 (en) | Pb-free solder alloy | |
| JP5784109B2 (en) | Lead-free solder alloy | |
| JP2010029868A (en) | Lead-free solder paste, electronic circuit board using the same, and method for manufacturing the same | |
| JP4282482B2 (en) | Solder alloys and solder joints | |
| KR20130014913A (en) | Composite for lead-free solder sn-ag-cu-in-bi alloy having low melting point | |
| TWI781050B (en) | Lead-free and antimony-free solder alloys, solder balls, and solder joints | |
| Sun et al. | Intermetallic compound formation in Sn-Co-Cu, Sn-Ag-Cu and eutectic Sn-Cu solder joints on electroless Ni (P) immersion Au surface finish after reflow soldering | |
| EP3707285B1 (en) | Low-silver tin based alternative solder alloy to standard sac alloys for high reliability applications | |
| KR20160080014A (en) | Bi-coated lead-free solder ball, and method for preparing thereof using electroless plating | |
| CN103476540A (en) | Solder alloy | |
| JP2022026896A (en) | Solder alloy and molding solder | |
| JP2004082212A (en) | Tin-silver-based lead-free solder | |
| JP6267427B2 (en) | Soldering method and mounting board | |
| KR100431090B1 (en) | Lead free solder plated with low-melting-pointed alloy | |
| Koon et al. | Study on IMC morphology and impact to solder joint performance for different halogen free (HF) flux in semiconductor application | |
| Hasan | Effect of alloying on mechanical and electrical properties of zinc-based high temperature solders | |
| JP4364234B2 (en) | Electrical / electronic equipment with solder joints | |
| KR20150037426A (en) | Lead-free solder paste | |
| KR20110097329A (en) | Sn-ag-ce ternary pb-free solder alloy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E601 | Decision to refuse application |