Solder paste and mount structure

A solder paste and flux technology, applied in the direction of soldering medium, soldering equipment, electric solid device, etc., can solve problems such as difficulty in disposal, and achieve the effect of excellent coating workability, excellent moisture resistance and insulation, and anti-bleeding effect.

Active Publication Date: 2019-08-06
PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, if solder powder is added at a high ratio, it becomes highly viscous and handling becomes very difficult
Even if a solvent is added like a cream solder paste, a non-reactive solvent will hinder the curing reaction between the epoxy resin and the curing agent and act as a plasticizer, so it is not preferable.

Method used

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  • Solder paste and mount structure
  • Solder paste and mount structure
  • Solder paste and mount structure

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0106] Examples and comparative examples of the present invention are shown below. Embodiments of the following examples and comparative examples of the present invention are merely illustrations and do not limit the present invention at all. In Examples and Comparative Examples, "parts" and "%" are based on weight unless otherwise mentioned.

[0107]

[0108] First, the base epoxy resin, rubber-modified epoxy resin, reactive diluent, organic acid, and curing agent were weighed in proportions to account for the parts by weight listed in Table 1 below in the solder paste, and placed Each component was kneaded in a planetary mixer, and was uniformly dispersed in an epoxy resin, and the fluxes of Examples 1-6 and Comparative Examples 1-4 were prepared. As the base epoxy resin, bisphenol F-type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., jER806) was used. As the rubber-modified epoxy resin, a polybutadiene-modified epoxy resin (manufactured by Nagase ChemteX, R-1...

Embodiment 2

[0135] Example 2 was excellent in printability similarly to Example 1. The adhesiveness at room temperature was excellent at 18 Kg / chip, but the adhesiveness at 160° C. was slightly improved at 7 Kg / chip, so it was at a usable level, and it was set to △. Bleeding was not observed in the epoxy resin cured product after reflow. Moisture-resistant insulation is also a volume resistivity of 1×10 8 Ω·cm or more is excellent. From the above evaluation results, the judgment of △ is one item, so it was set to △ as the comprehensive judgment. However, the evaluation results of this Example 2 can be judged to be at a sufficiently usable level and to have slightly excellent characteristics.

[0136] In Examples 3 to 5, 42Sn-58Bi (shown as SB in the table) was used as the type of solder powder, and the solder ratios shown in Table 1 above were respectively set. In addition, regarding the parts by weight of the basic epoxy resin in the flux, the type and parts by weight of the rubber-m...

Embodiment 6

[0137] In Example 6, the composition of the flux was the same as in Example 1, and the type of solder powder was 42Sn-57Bi-1.0Ag (shown as SBA in the table). The evaluation results of Example 6 are shown in Table 1 above.

[0138] In Comparative Example 1, DME-100 (1,4-cyclohexanedimethanol diglycidyl ether (structural formula of Compound 6 shown below)) manufactured by Nippon Chemical Co., Ltd. was used as the reactive diluent in the flux. 3 parts by weight. The reactive diluent has a viscosity of not less than 50 mPa·s and not more than 100 mPa·s, and the total amount of chlorine contained in the reactive diluent is 5% by weight. The reactive diluent has slightly weak cyclic rings in the backbone. Therefore, the room-temperature adhesiveness of the epoxy cured product in Comparative Example 1 was weakened. In addition, since there are very many chlorine ions, deterioration in moisture resistance and insulation is likely to occur.

[0139] [chemical 6]

[0140]

[014...

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Abstract

Provided herein is a solder paste having low viscosity and easy coatability, and that provides high reinforcement for electronic components while satisfying both high room-temperature adhesion and high repairability, and forming a cured product of excellent properties, for example, high insulation against humidity. Amount structure including an electronic component mounted with the solder paste isalso provided. The solder paste contains a solder powder and a flux. The flux contains an epoxy resin, a reactive diluent, a curing agent, an organic acid, and a rubber modified epoxy resin. The reactive diluent contains a compound having two or more epoxy groups, and has a viscosity of 150 mPa*s or more and 700 mPa*s or less. The reactive diluent has a total chlorine content of 0.5 weight % or less, and is contained in a proportion of 5 weight % or more and 45 weight % or less with respect to a total weight of the flux.

Description

technical field [0001] The present invention mainly relates to a solder paste used when soldering semiconductor components, electronic components, etc. to a circuit board, and particularly relates to a solder paste and a mounting structure in which an epoxy resin is included in a flux component. Background technique [0002] In recent years, miniaturization and higher functionality of mobile devices such as mobile phones and PDAs (Personal Digital Assistants) have been promoted. Mounting structures such as BGA (Ball Grid Array) and CSP (Chip Scale Package) are often used as mounting techniques that can cope with this. Mobile equipment is easily exposed to mechanical loads such as drop shocks. For QFP (Quad Flat Package), the lead part absorbs the shock. However, for BGAs and CSPs that do not have lead wires for shock mitigation, it is becoming more and more important to ensure reliability against shocks. [0003] The melting point of Pb eutectic solder, which is a typical...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K35/36B23K35/362B23K101/42
CPCB23K35/362B23K35/3612B23K35/262C22C13/02B23K35/025H05K3/3489H05K2201/10977H05K3/3436H01L23/49816H01L2224/81193H01L2224/1339H01L2224/13294H01L24/16H01L24/13H01L2224/8192H01L2224/131H01L2224/13391H01L24/98H01L2224/16227H01L2224/133H01L2224/81594H01L2224/816H01L2224/8169H01L2224/81691H01L2224/1132H01L2224/11332H01L24/81H01L2224/81815H01L2224/81862H01L2224/81905H01L2224/81444H01L2224/1601H01L24/11H01L2224/8121C08L63/00C08G59/42C08G59/5073H05K3/3485H01L2924/0665H01L2924/014H01L2924/095H01L2924/0715H01L2924/00014H01L2924/00012H05K1/181H05K3/3457H05K3/3494B23K2101/40B23K2101/42H01L2224/16501H01L2924/069H01L2924/01083H01L2924/01047H01L2924/01049H01L2924/0105H05K2201/10636H05K2201/10734
Inventor 日野裕久大桥直伦铃木康宽松野行壮
Owner PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
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