TW550301B - Lead-free solder - Google Patents

Abstract

This invention discloses a lead-free solder alloy of Sn-Zn-Al-Ag, which is composed of 7-10 wt% Zn, up to 0.5 wt% Al, up to 4.0 wt% Ag, and the balance Sn; and a lead-free solder alloy of Sn-Zn-Al-Ag-Ga, which is composed of 7-10 wt% Zn, up to 0.5 wt% Al, up to 4.0 wt% Ag, up to 4.0 wt% Ga; and the balance Sn. The lead-free solder alloys of the present invention have better tensile strength and elongation than the conventional Sn-Pb solder alloys. In addition, the lead-free solder alloys of the present invention have a melting point lower than 200 DEG C, which is close to 183.5 DEG C of the eutectic Sn-Pb alloy.

Description

550301

FIELD OF THE INVENTION The present invention relates to a quaternary lead-free solder alloy " 0 a type of error-free solder, especially Sn-Zn-Ag-A1 gold and 8] 1-2111§1 Bu (^ 5 yuan lead-free solder combination Ming Ming Background We already know that the people in the class have gold, and they are wrong with the human body; t, ::;:;! T The main ingredient is wrong—Sikkim ’s wrong silver is thick θ; Therefore R & D benefits

The second engraved person is not = New Zealand 1 eutectic alloy: 2:83 5 5 its :, the point is too high, about 221. . ^ The increase in the cost of equipment and costs, and because of the "much higher". Therefore, tolerant. Miscellaneous dreams * Due to the damage to electronic components to Wen Yi-° Xi patent literature attempts to tin-silver eutectic The alloy is mainly three =, quaternary and pentad alloy systems, adding a small amount of other alloy components, QCU, Zn, Bi, ln and Sb, to reduce the melting point of the tin-silver eutectic alloy, but its melting point is still high. At 200 t. Although adding a large amount of "and dagger" can reduce the melting point of the alloy, it makes the cost significantly higher, for example: 'USP 5,52 7,62 9 (1 9 9 6); Sn-Ag-Zn-Bi, USP 5,993,7 PRICE

(,! 9 99); Sn-Ag-Bi-In, USP 5,958,333 (1 99 9), USP ^ 843,37 1 (1 998), USP 5,658,52 8 (1 997);

Sn-Ag-Bi-Cu-In, USP 5,918,795 (1999); Sn-Ag-In-Bi-Sb, USP 5,733,501 (1998); Sn ~ Ag-Zn-In-Bi, USP 5,762,866 (1998).

Page 5 550301 V. Description of the invention (2) Summary of the invention One objective of Mao Ming is to provide a lead-free tin-zinc-based solder alloy. ^ It has 忐 which is comparable to or better than traditional lead-tin eutectic alloys. Mechanical properties, such as tensile strength and elongation; low cost; and lower than the melting point of 200 earthworms, or even lower than the melting point of lead-tin eutectic alloy (183 · 5 it), without causing IC component components damage. Another object of the present invention is to provide a lead-free tin-zinc-based solder alloy 'which has a high wetting ability. In order to achieve the above-mentioned object of the present invention, the error-free solder in the factory according to the present invention is basically composed of 7.0--10% by weight zinc,-catty 4; two 2/0 silver / 0-01-0 · 5% by weight of aluminum and the rest are composed of tin. Compared with the lead-free solder of the present invention, the mirror further contains 0.1-4.0% by weight of spoon iridium ', that is, 7-1.0-10% by weight 0 / 〇 zinc, 〇 14.0 by weight 0.0b 0.5% by weight The inscription is 0.04% by weight of 4.0% by weight of gallium and its thickness. It is preferred that the group is tin. The lead-free solder of the present invention contains 0.25 to 0.05. / t Gallium. ≪:!: / 〇 Preferred 'Lead-free solder of the present invention contains 0.25 to 0.5 hectare silver. To Liqin

DETAILED DESCRIPTION OF THE INVENTION The present invention discloses an improved lead-free solder, which contains zinc and more than tin, and is characterized in that the solder further includes aluminum of 0 ^ weight. The inventor of this case found that the Sn_Zn-Ag solder man

Page 6 550301

A 1 improves the wetting properties of solder alloys. The improved lead-free solder of the present invention preferably further includes 0.1 to 40% by weight of gallium. The gallium (Ga) alloy element is mainly to reduce the melting temperature of the alloy (Ga's melting point is 29.8 ° C). Because Ga is solid-soluble in Sn, Zn, Ag, and the addition of a small amount of Ga will not form a compound. In addition, Ga also has other properties, such as low vapor pressure, high heat and electrical conductivity, 'wettable', most metals and oxides, which is very suitable for application in the electronics fabrication industry [D · L. Smith and HJ CauU, All〇ys of Gallium with Powdered Metals as Possible Replacement for Dental Amalgam, M J. Amer. Dent. Assoc, vol. 53, pp315-324, 1956; SK

Bhattacharya and D. F. Baldwin, " Gallium Alloy

Breakthrough for Via-filling Application, " Adv · Packaging Sept. pp · 6 64, 2000]. The lead-free solder of the present invention is mainly composed of Sn-Zn-Ag-A1 and Sn-Zn-Ag-Al-Ga systems. The composition of lead-free solder contains at least 75% by weight of Sn, Zn 7.0-1〇.〇wt%, Ag 0 · 1-4.0 wt%, A1 0 · 01-0 · 5 wt%, and Ga 0-4 · 0 wt% ° Ga mainly dissolves in Sn base,

Ag and Zn form compounds of AgZri3 and AgsZn8. Adding Ga can not only maintain the elongation of the Sn-9Zn eutectic alloy, but also increase the tensile strength by about 18%. Compared with the traditional 63Sn-37Pb eutectic alloy, the lead-free solder alloy according to a preferred embodiment of the present invention has a tensile strength that is about 68% higher than that of the 63Sn ~ 37pb alloy, and its elongation can be higher than 63Sn-37Pb. Alloy about 400 / 〇

Page 7 550301

about.

The present invention can be further understood, and their scope is only. For illustrative purposes, the examples are used instead of limiting the present invention.

Sn — 9 wt% Zn eutectic is fully supplied to H and Zn, and the prepared sheep will be inserted into the preparation a using a pure 9 9 * 99%, such as, ^. Zi of all kinds of pure metal particles, Qiu About 30 coupons, which started to enter the 'flame seal stone' with a mixture of oxygen and gas ::, ⑽f into the official atmosphere of Shiyang. Quartz flesh ^ Q is 4 Shi Yangguan, filled with Ar gas after evacuating. Gu, Tian Tianzhong a Shi Lai, outer diameter 10 positions. The sealed quartz tube was placed in a furnace oven, heated to 80 ° C, and cooled at a rate of t / min. Office, Rensi Kobe's back furnace is cold, which heats up

Desrion: E8—82 test method The alloy cast key is made into a tensile test bar by using a Zhuo lathe. mm and Table II _ e dl_ter) 4 „m. The application rate is 〇9 mm / min (〇 table reach rate: "% alloy on the maximum tensile strength is 78% and Shenchang sheep is 41. 3 / G. The melting point of the alloy is 98.3%. Example 1

The preparation and test methods of Sn-8 · 55% Zη-l. (NAg-zA1 solder alloy tensile test piece are the same as those of the comparative example. The results show that a small amount of aluminum %) Makes it significantly increase the wetting ability on copper substrates. The experimental results show that Sn-8.55% Zn-l% Ag-zAl based solder alloys are heated to 25 0 ° C and organic flux in DMAHC1 Under fluxing, it is about 0075 ^ 20mN, which is about 550301 more than the wetting force of Sn-9Zn eutectic solder alloy (~ 0.41N).

To double. In terms of wetting time, the wetting time of S η-8 · 55% Zn η-1% A g-z A1 solder alloy is about 0 · Π 1 second, which is also longer than that of Sn_Zn eutectic solder alloy. Wetting time (~; [· 32 seconds) is much better. Example 2 ^ Sn—8.55% Zn—0.45% A1-0 · 5% Ag-0 · 25% Ga alloy stretched sheet was prepared and tested in the same manner as the comparative example. The results show that the maximum resistance, the strength (UTS) is 80 · 4 MPa, the tensile strength is 63Sn- 37Pb higher than about $ 46%, the elongation is 43.6%, and the elongation is higher than 63Sn-37Pb j The alloy is about 16%. The melting point of the alloy is 195 · 55, which is very close to 63 _

The melting point of Sn-37 Pb alloy (183.5). Example 3

The preparation and test methods of Sn-8 · 55% Zn-0.45% Al1-0.5% Ag-0,5% Ga alloy tensile test pieces are the same as those of the comparative example. The results show that the maximum tensile strength (UTS) is 92 · 5 MPa, its tensile strength is about 68% higher than that of 63Sn-37Pb alloy, its elongation is 42.2%, and its elongation is higher than that of 63311-37? 1) alloy. About 12%. The melting point of the alloy is 194.7 t :. The procedures of Examples 2 and 3 were repeated to obtain the stress-strain curve of Sn-8 · 55Zη-0. 45A1-0 · 5Ag-yGa solder alloy as shown in Fig. 1. Fig. 1 also shows the stress-strain curve of the 63Sn-37Pb alloy of Comparative Example. Example 4

Sn-8.55% Zn_0-45% A1-0.25% Ag ~~ 0,5% Ga alloy tensile 550301 V. Description of the invention (6) The preparation and test methods are the same as those of the comparative example. The results show #: the maximum resistance I is 82.1 MPa, and its tensile strength is about 49% higher than that of 63Sn_ 37Pb alloys, and spoons, and the elongation is 5 to 7 〇 /, Gan μ e + everyone ... 7 reverse + Ma Yi. (/ 〇, its elongation is higher than 6 3811-3 7 ~ 5 a gold about 40%. The melting point of the alloy is 195. 0 9 ° C. Example 5

The preparation and test methods of Zn-0.45% A1_1% Ag_〇5% tensile test specimens with alloys are the same as those of the comparative examples. The results show: maximum tensile strength. (UTS) is 86 · 8 MPa, and its tensile strength is about 58% higher than that of 63Sn_37Pb alloy. The melting point of the alloy is 194.1 ° c. Repeat the steps of Examples 4 and 5 to obtain the stress-strain curve of Sn 8 · 〇 · 4 5Al-xAg-0 · 5Ga solder alloy as shown in FIG. 2. Figure 2 shows the stress-strain curve of 63Sn-37Pb alloy of Comparative Example. The mechanical properties of the tin alloy with -8.55Zn_0.45A1_xAg-yGa in other embodiments of the present invention are shown in FIGS. 3 and 4. dry

550301 Brief description of the diagram Figure 1 shows the stress-strain curve of the Sn-8. Alloy and the conventional 63Sn-37Pb solder alloy of the present invention. 'Figure 2 shows the stress-strain curve of the Sn-8. 55Znm / UiAgU (iana alloy and the conventional 63Sn-37Pb solder alloy of the present invention. Figure 3 shows the Sn-8 of the present invention. XAg-y (ia # ^ ^ The tensile strength of gold, in which the rhombus is 0.5% by weight Ga, the distance shape, Yi Shidan / 〇Ga, the triangle is 2.0% by weight Ga, and the χ shape is 3.0% by weight Gawidely Figure 4 Shows the elongation of the Sn-8. 55Zn-0.45M_xAg_yGa solder gold of the present invention, whose diamond shape is 0.5% by weight Ga, distance ^ h, triangle is 2_0% by weight Ga, and X shape is 30% by weight. % To. 垔 里 /.

Page 11

Claims (1)

550301 Amendment 90129748 1. A lead-free solder consisting of 7.0-10.0% by weight zinc, 0.1-4.0% by weight silver, 0.01-0.5% by weight aluminum and the rest tin. 2. A lead-free solder consisting of 7.0 -10.0% by weight zinc, 0.1-4.0% by weight silver, 0.01-0. 5% by weight aluminum, 0.1-4. 0% by weight gallium, and the rest is tin composition. 3. For example, the solder in the scope of patent application No. 2 contains 0.25-0. 5 wt% of gallium. 4. The solder as claimed in the scope of the patent application, which contains 0.25-0. 5 wt% of silver. 5. The solder as claimed in the scope of patent application No. 2, which contains 0.25-0. 5 wt% of silver. 6. The solder according to item 3 of the scope of patent application, which contains 0.2 to 0.5% by weight of silver. 7. An improved lead-free solder comprising 7.0-10.0% by weight zinc, 0.1-4.0% by weight silver, and 75% by weight or more tin, characterized in that the solder further includes an inscription of 0.01-0.5% by weight. 8. If the solder of the scope of patent application No. 7 is characterized by the solder ckull313Amend01.ptc Page 12 2003.06.24.012 550301 Case No. 90129748 Amendment VI. The scope of patent application further includes 0.1-4.0% by weight of gallium 9. If the solder of the scope of patent application No. 8 is included, the fresh tin includes 0 25-0. 5 wt% gallium. mi ckull313Amend01.ptc Page 13 2003.06.24.013