TWI602929B - Solder composition - Google Patents

Description

Solder composition

The present invention relates to a solder composition, and more particularly to a solder composition suitable for use in forming solder balls having a sphere diameter of 0.05 mm to 0.1 mm.

The general consumer's impression of the quality of consumer electronics is important, depending on whether the consumer electronics are durable. When a consumer electronic product is impacted, or used for a long period of time at different performance levels, after repeated high temperature and low cycle, if there is no damage or failure, it can often be brought to life due to durability. The impression of good quality. Whether a consumer electronics product withstands shock and temperature is important, depending on the package used and the quality of the solder used to encapsulate it. There are many ways to package electronic components. For example, one of them is the Wafer Level Chip Scale Package (WLCSP). Wafer-level wafer size packaging is a technology that uses solder balls formed by solder for packaging. The quality of the solder used in this packaging method has a great influence on the quality of the package.

In general, the properties such as the drop strength and the tensile strength of the solder are better, and the solder joint formed by the solder can obtain a large shear force in the Ball Shear Test. The point can often be better in the Thermal Cycling Test (TCT), that is, it has better resistance to temperature aging; and the ductility of the solder can be maintained fairly, or after the solder is soldered. The formed solder joint can be broken from the solder portion in the push ball test, and the brittle fracture (hereinafter referred to as the boundary metal break, IMC Crack) is generated in the non-intermetallic compound (IMC). In addition to its better performance in the temperature cycling test, the solder joints also perform well in the Drop Test.

The solder used in the early solder balls was a tin-silver-copper alloy (Sn-Ag-Cu, SAC) numbered 105 to 405. The first digit of the number represents the amount of silver, and the last two digits represent the amount of copper. For example, SAC 105 means that the solder contains 1 wt% silver, and 0.5 wt% copper, and the balance tin. With such a SAC solder, as the amount of silver used is increased from 1 wt% to 4 wt%, the mechanical properties such as hardness, tensile strength and tensile strength of the solder are also increased. However, in order to further increase the packaging strength of electronic components, a series of SACNB solders in which nickel (Ni) and bismuth (Bi) are added to the SAC alloy solder have been introduced as the packaging of the electronic components is intensive and the degree of precision and heat generation are improved.

This kind of SACNB solder has better lodging strength and tensile strength than SAC solder. However, when this kind of SACNB solder is used in WLCSP package, the solder joint formed in the push ball test is often because If the mechanical strength is too high and brittle fracture of the self-bounding metal is likely to occur, or RDL fracture or Pad Peeling occurs during the temperature cycle test, it is judged to be poorly packaged, and it cannot be improved by detection.

It is an object of the present invention to provide a solder composition that overcomes at least one of the disadvantages of the prior art.

The solder composition contains 3 to 4 wt% of silver, 0.5 to 1 wt% of copper, 0.04 to 0.07 wt% of nickel, and 2.5 to 3.5 wt% of rhodium, based on 100 wt% of the total weight of the solder composition. 0.2 to 1.5 wt% of indium, and the balance of tin.

The solder composition can have better properties such as lodging strength and tensile strength because it contains an appropriate amount of 3-4% by weight of silver, and can make the solder joint formed by the solder composition in the temperature cycle test. Better performance. If a low-silver-containing solder composition has a silver content of less than 3% by weight, the low-silver-containing solder composition may have poor properties such as a drop strength and a tensile strength, and the low silver content cannot be used. The solder joint formed by the solder composition is better in the temperature cycle test. If a high silver content solder composition has a silver content of more than 4% by weight, the high silver content solder composition will be coarsened by the Ag ₃ Sn boundary metal formed by tin and silver, so that the high silver content solder The solder joint formed by the composition will cause breakage of the self-bounding metal portion in the push ball test, and cannot pass the push ball test.

The solder composition has better mechanical properties because it contains an appropriate amount of 0.5 to 1% by weight of copper. If a low copper content solder composition contains less than 0.5% by weight of copper, the mechanical properties of the low copper content solder composition will be poor and will not meet the requirements for use. For example, if a copper composition having a high copper content has a copper content of more than 1%, the formed solder ball will be in a slurry state with poor fluidity upon melting, and there is a problem that the wettability is poor.

The solder composition can effectively reduce the thickness of the metal portion of the solder joint formed by the solder composition because it contains an appropriate amount of 0.04 to 0.07 wt% of nickel, thereby avoiding the self-border of the solder joint during the push ball test. The case where the metal part is broken. If the nickel composition of a low nickel content solder composition is less than 0.04% by weight, the thickness of the boundary metal formed by the solder composition formed by the low nickel content of the solder composition cannot be effectively suppressed. If the nickel composition of the high nickel content solder composition is higher than 0.07 wt%, the solder joint formed by the high nickel content solder composition will easily appear as a self-bounding metal part or self due to segregation of nickel. The case where the pad/substrate is broken.

The solder composition has a suitable property of reducing strength and tensile strength because it contains an appropriate amount of 2.5 to 3.5 wt% of antimony, and has good wettability to the copper substrate, and is formed by the solder composition. The solder joints will not have too thick metal parts. If a low-ruthenium-containing solder composition has a niobium content of less than 2.5% by weight, the low-ruthenium-containing solder composition may have poor properties such as a drop strength and a tensile strength, except that the low niobium content cannot be obtained. In addition to the better performance of the solder joint formed by the solder composition in the temperature cycle test, the solder composition having a low niobium content is also inferior to the wettability of the copper substrate. For example, a high-yield solder composition having a cerium content of more than 3.5% by weight, the properties such as the strength of the drop and the tensile strength will be too strong, so that the solder joint formed by the high-yield solder composition is In the push ball test, it is easy to cause breakage of the self-bounding metal portion, and the wettability of the high-ruth-containing solder composition with respect to the copper substrate is also inferior. Preferably, the solder composition comprises 3% by weight of bismuth, which has the best wet performance for the copper substrate and can optimally reduce the thickness of the boundary metal portion of the solder joint.

In general, if the solder composition has a higher drop strength and tensile strength, the solder joint formed by the solder ball made of the solder composition can perform better in the temperature cycle test, but In the ball test, the more easily the self-bounding metal part is broken, and the better the ductility of the solder composition, the solder joint formed by the solder ball made of the solder composition is in the push ball test. It is less likely to break the self-bounding metal part, and it is easy to break from the solder part and pass the push ball test.

The solder composition of the present invention contains 0.2 to 1.5% by weight of indium, and has a relatively large lattice boundary due to the formation of a large number of lattice boundaries and a good flexibility and ductility of indium compared to a conventional solder composition not containing indium. The solder composition can improve the yield of the solder joint formed by the solder composition through the push ball test while maintaining or increasing the drop strength and the tensile strength.

For example, if the indium content of the solder composition having a low indium content is less than 0.2% by weight, the solder joint formed by the solder composition having the low indium content may still be unable to pass the push ball test; for example, a high indium content If the amount of indium contained in the solder composition is more than 1.5% by weight, the solder composition having a high indium content will be too strong due to the strength of the drop and the mechanical strength, and the test may not be performed by the push ball test. Preferably, the solder composition comprises 1 wt% of indium, which has a higher tensile strength and a lower tensile strength while having a higher push test yield.

The solder composition of the present invention may further comprise an antioxidant component selected from the group consisting of ruthenium greater than 0 and less than 0.02 wt%, gallium greater than 0 and less than 0.003 wt%, and both combination. The solder composition, if it contains the above-mentioned appropriate amount of the antioxidant component, will be less susceptible to oxidation, so that the solder joint formed by the solder composition is not easily aged due to oxidation, and an appropriate amount of the antioxidant component can also be improved. The advantage of the wettability of the solder composition.

The solder composition of the present invention may further comprise a platinum group component greater than 0 wt% but less than 0.05 wt%, the platinum group component being selected from the group consisting of palladium, platinum, and combinations of the foregoing. The solder composition, if it contains the above-mentioned appropriate amount of the platinum group component, can withstand more temperature cycling tests in the temperature cycle test by the solder joint formed by the solder composition. If the amount of the platinum group component used is increased to more than 0.05% by weight, the ability of the solder joint formed of the solder composition to withstand the number of temperature cycles can not be further increased as expected, resulting in an increase in cost.

The solder composition has the effect of containing an appropriate amount of silver, copper, nickel, bismuth, indium and tin, which can promote or improve the properties of the lodging strength and the tensile strength as compared with the conventional solder composition. The solder joint formed by the solder composition maintains a good or better performance in the temperature cycle test, and the solder joint has a higher yield in the push ball test and has better shear strength.

"Embodiment 1"

One embodiment 1 of the solder composition of the present invention comprises 3 wt% silver, 0.5 wt% copper, 0.05 wt% nickel, 2.5 wt% bismuth, 0.2 wt% indium, and the balance tin. The following test was conducted on this Example 1 to understand the properties of the Example 1, and the test results are recorded in Table 1.

Hardness Test

The measured Vickers hardness (Vickers-Hardness, HV) was recorded in Table 1 using a Vickers hardness tester purchased from Taiwan Nakazawa Co., Ltd., model number FM-100e.

"Stretching test"

Tested with a universal tensile tester. The mechanical properties such as measured drop strength, tensile strength and elongation were recorded in Table 1.

Push Ball Test

The test is conducted in accordance with the AEC Q100-010-Q003 standard test method, which is summarized as follows: A copper substrate (pad) is provided. An opening of 270 μm in diameter is opened in the pad. A solder ball made of Example 1 and having a diameter of 250 μm was placed in the opening, and the solder ball was soldered back to the copper substrate to form a solder joint, and the model was purchased from a company. The Dage-4000 push-pull machine performs a push ball test on the solder joint. According to JESD22-B117B in the JEDEC specification, the contact height of the pusher and the solder joint (pushing height) cannot be higher than 25% of the height of the reflow ball (preferably 10%), and the pusher must not touch the pad. Anti-mite layer. The sample has a movement rate of 350 μm/s relative to the pusher and provides a thrust of 2 kg. The number of different test results obtained by pushing the ball test and the average shear force that the solder joint can withstand are recorded in Table 1.         <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Push ball test results</td></tr><tr><td><img wi ="85" he="38" file="IMG-2/Draw/02_image001.gif" img-format="jpg"></img></td><td> Location/Method </td>< Td> cross-section solder residue </td><td> test result</td></tr><tr><td> Mode1 </td><td> ductile fracture from solder site</td><td > 100% </td><td> Pass </td></tr><tr><td> Mode2 </td><td> Brittle fracture from solder joints</td><td> 100% </ Td><td> Pass </td></tr><tr><td> Mode3 </td><td> Fracture from solder and intermetallic parts</td><td> less than 25% </td> <td> Failure </td></tr><tr><td> Mode4 </td><td> Pad (Copper Substrate) </td><td> 0% </td><td> Failure < /td></tr></TBODY></TABLE>

The reflowing is started from room temperature and rises to the peak temperature when the temperature is uniform inside and outside. The peak temperature of the profile of the reflow is about 245±5° C., and the heating time is maintained at the peak temperature. (Peak time) is about 40 to 60 seconds.

"Bearing Ball Hardness Test"

The welding ball was formed as described in the above-mentioned push ball test, and welded to the copper substrate to form a package portion (PKG portion), and covered with a mold having a groove having a shape matching the PKG portion. In the PKG portion, a resin is injected between the PKG portion and the mold to be embedded, and the PKG portion is fixed by a resin. Then, the mold is separated and the PKG portion is cut, and the PKG portion is polished by a grinder until the PKG portion is polished. About two-thirds of the remaining spheres were subjected to the hardness test as described above, and the results are reported in Table 1.

Embodiments 2 to 9

Examples 2 to 9 are similar to this Example 1, except that the ingredients contained in the respective examples are changed, or the proportions of the respective components are changed. The components actually used in the respective examples, as well as the actual ratios of the components, are shown in Tables 1 and 2. Examples 1 to 3 differ from each other in that the amount of indium used differs. The main difference between Examples 4 and 7 is also that the amount of indium used is different, but the amount of silver used is increased to 4% by weight, wherein Examples 6 and 7 respectively further contain 0.05% by weight and 0.1% by weight of palladium, and Example 8 further Including 0.02 wt% of ruthenium and 0.003 wt% of gallium, Example 9 further comprises 0.1 wt% of ruthenium, and 0.01 wt% of gallium.

Comparative Examples 1 to 3

Comparative Examples 1 to 3 are the existing SACNB solders mentioned in the prior art. The amounts of the respective components of tin, silver, copper, nickel, and ruthenium of Comparative Examples 1 to 3 are shown in Table 3.

Comparative Examples 4 to 7

Comparative Examples 4 to 7 are similar to Example 1, except that the components contained in the respective comparative examples are changed, or the proportions of the respective components are changed. The amount of indium used in Comparative Example 4 was 0.1 wt% and less than 0.2 wt%, and the amount of indium used in Comparative Example 5 was 2 wt% and more than 1.5 wt%, and the use of Comparative Example 6 and Comparative Example 7 was used. The amount is 2% by weight and less than 2.5% by weight. The amounts of the components of Comparative Examples 1 to 4 are reported in Table 4.

Discussion and Description

From the comparison of Examples 1 to 9 and Comparative Examples 1 to 3, it was found that when the solder composition contained 0.2 to 1.5% by weight of indium, no failure of Mode3 to Mode4 occurred in the push ball test after repeated reflowing. In the case, in Comparative Examples 1 to 3, since an appropriate amount of indium element was not added, Mode 3 and 4 failure occurred in the push ball test. From the comparison of Example 4 and Comparative Example 2, it was found that when the solder composition was added with 0.5 wt% of indium, although the mechanical properties related to the stretching of Example 4 were similar to those of Comparative Example 2, the welding formed in Example 4 was used. In the push ball test, the unexpectedly tolerable shear force is greatly improved, and the average hardness of the upper edge of the boundary metal is also improved, and there is no possibility that the ball cannot be tested by pushing the ball. From the comparison of Example 4 and Example 5, it can also be found that when the addition amount of indium is increased from 0.5 wt% to 1 wt%, the solder joint formed in Example 5 can withstand the shear force in the push ball test and The hardness of the upper edge of the boundary metal can be further improved, and it is advantageous to increase the amount of indium used in an appropriate amount range, wherein the amount of indium added is 1 wt% of Example 5, and the addition amount of indium is 0.5 wt%. In Example 4, the effect of the lift was most remarkable, and the effect was similar to that of Example 6 in which the amount of indium added was 1.5 wt% and palladium was contained.

From the comparison between Example 4 and Comparative Examples 4 and 5, it can be found that when the addition amount of indium is less than 0.2% by weight or more than 1.5% by weight, the solder joint formed by the comparative examples 4 and 5 will still be unable to be obtained. The situation by pushing the ball test.

From the comparison of Examples 2 and 3 with Comparative Examples 6 and 7, it can be found that when the amount of niobium added is less than 2.5 parts by weight, the solder joints formed by the solder balls prepared in Comparative Examples 6 and 7 can withstand The shear force will drop and it will not meet the usage requirements.

Further, by performing the temperature cycle tests as described below for Examples 1 to 5 and Examples 6 and 7, the results obtained are as follows: Examples 1 to 5 can withstand about 1000 to 2000 temperature cycles, including The number of temperature cycles that can be withstood by Example 6 of 0.05 wt% of palladium is further increased to about 2,000 times or more, but the number of temperature cycle tests that can be withstood by Example 7 containing 0.1 wt% of palladium is again reduced to 2000. Below. Therefore, it can be found from the comparison in Examples 1 to 7 that the appropriate addition of palladium can contribute to the improvement of the solder joint performance in the temperature cycle test, but when the amount of palladium added exceeds 0.05 wt%, for example, 0.1 wt%, It is impossible to increase the number of temperature cycle tests that the solder joint can withstand, but only increases the production cost. Therefore, it has been confirmed that the addition of excess palladium element cannot effectively increase the number of temperature cycle tests.

"Temperature Cycle Test"

The test was carried out in accordance with the IPC-9701 specification. The test is summarized as follows: The electronic component is soldered on the copper substrate by using Examples 1 to 7 to obtain a test object, and the specification of the test article conforms to the standard plate specification of JESD22-B111. The test object is placed in an environment where the temperature can be cyclically changed, and the number of temperature cycles experienced by the test article is recorded when the message of the test article is detected to be invalid. Among them, there are four stages in each cycle, each of which lasts for 15 minutes, which is the heating phase, the high temperature staying phase, the cooling phase, and the low temperature staying phase. The temperature during the high temperature dwell phase was set to 125 °C. The temperature in the low temperature residence phase was set to -40 °C.

Wetness Test

100 g of each of the solder balls prepared in Examples 8 and 9 and two aluminum discs were prepared. The solder balls prepared in Examples 8 and 9 were placed in the corresponding aluminum pans, placed in the oven together with the aluminum pan, and baked at 240 ° C for 10 minutes, and then taken out for observation. The solder balls prepared in Example 9 in which a large amount of germanium and gallium were added were observed by naked eyes or under a microscope after baking, and the appearance of the spheres did not diffuse and dissolve each other. After the solder balls prepared in Example 8 in which an appropriate amount of bismuth and gallium were added were baked, the spheres were diffused and miscible with each other on the aluminum pan without the aid of the flux. Therefore, from the comparison of Examples 8 and 9, it can be understood that the addition of an appropriate amount of bismuth and gallium has an effect of improving the wettability in addition to the improvement of the antioxidant ability.

In summary, the solder composition of the present invention has the effect of containing an appropriate amount of silver, copper, nickel, antimony, indium and tin, which can promote the solder while maintaining or improving the properties of the tensile strength and the tensile strength. The solder joint formed by the composition maintains a good or better performance in the temperature cycling test, and the solder joint has a higher yield in the push ball test and has a better shear strength.

The above is only the embodiment of the present invention, and the scope of the present invention is not limited thereto. The simple equivalent changes and modifications made by the content of the patent application and the contents of the patent specification of the present invention are still the patents of the present invention. Covered by the scope.

no. <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Table 1 </td><td> Example 1 </td><td> Example 2 </td><td> Example 3 </td><td> Example 4 </td><td> Example 5 </td></tr><tr><td> Alloy Composition </td ><td> Weight percentage</td><td> Ag </td><td> 3 </td><td> 3 </td><td> 3 </td><td> 4 </td> <td> 4 </td></tr><tr><td> Cu </td><td> 0.5 </td><td> 0.5 </td><td> 0.5 </td><td> 0.5 </td><td> 0.5 </td></tr><tr><td> Ni </td><td> 0.05 </td><td> 0.05 </td><td> 0.05 </ Td><td> 0.05 </td><td> 0.05 </td></tr><tr><td> Bi </td><td> 2.5 </td><td> 3.5 </td>< Td> 3 </td><td> 3 </td><td> 3 </td></tr><tr><td> In </td><td> 0.2 </td><td> 0.5 </td><td> 0.9 </td><td> 0.5 </td><td> 1 </td></tr><tr><td> Ge </td><td></td> <td></td><td></td><td></td><td></td></tr><tr><td> Ga </td><td></td> <td></td><td></td><td></td><td></td></tr><tr><td> Pd </td><td></td> <td></td><td></td><td></td><td></td></tr><tr><td> Sn </td><td> balance </ Td><td> margin </td><td> margin </td><td> margin </td><td> margin </td></tr><tr><td> Mechanical properties</td><td> Hardness</td><td> HV </td><td> 24.6 </td><td> 25.6 </td><td> 26.3 </td><td> 26.03 </td><td> 26.2 </td></tr><tr><td> Falling strength</td><td> Mpa </td><td> 49 </td><td> 51 </ Td><td> 53 </td><td> 53 </td><td> 52 </td></tr><tr><td> tensile strength</td><td> Mpa </td ><td> 78 </td><td> 81 </td><td> 89 </td><td> 89 </td><td> 85 </td></tr><tr><td > Extension rate</td><td> % </td><td> 14 </td><td> 13 </td><td> 10 </td><td> 18 </td><td> 18 </td></tr><tr><td> Push ball test <copper substrate> </td><td> reflow once</td><td> average thickness of IMC (μm) </td>< Td> 2.07 </td><td> 2.33 </td><td> 2.53 </td><td> 2.4 </td><td> 2.2 </td></tr><tr><td> Mode1 </td><td> % </td><td> 100 </td><td> 100 </td><td> 100 </td><td> 100 </td><td> 100 </ Td></tr><tr><td> Mode2 </td><td> % </td><td></td><td></td><td></td><td>< /td><td></td></tr><tr><td> Mode3 </td><td> % </td><td></td><td></td><td> </td><td></td><td></td></tr><tr><td> Mode4 </td><td> % </td><td></td><td ></td><td></td><td></td><td></td></tr><tr><td> reflow Three times</td><td> IMC average thickness (μm) </td><td> 3.33 </td><td> 3.83 </td><td> 3.86 </td><td> 3.53 </td> <td> 3.41 </td></tr><tr><td> Mode1 </td><td> % </td><td> 100 </td><td> 100 </td><td> 100 </td><td> 100 </td><td> 100 </td></tr><tr><td> Mode2 </td><td> % </td><td></td ><td></td><td></td><td></td><td></td></tr><tr><td> Mode3 </td><td> % </ Td><td></td><td></td><td></td><td></td><td></td></tr><tr><td> Mode4 </ Td><td> % </td><td></td><td></td><td></td><td></td><td></td></tr>< Tr><td> ball shear average (g) (reflow once) </td><td> 325.38 </td><td> 332.7 </td><td> 343.48 </td><td> 408.8 < /td><td> 430.53 </td></tr><tr><td> ball shear average (g) (reflow three times) </td><td> 311.4 </td><td> 296.12 /td><td> 298.48 </td><td> 384.2 </td><td> 411.9 </td></tr><tr><td> Solder Ball Hardness Test</td><td> Interface IMC Upper edge average hardness (Hv) (reflow once) </td><td> 42.6 </td><td> 43.6 </td><td> 39.7 </td><td> 44.4 </td><td > 48.4 </td></tr><tr><td> Interface IMC upper edge average hardness (Hv) (reflow three times) </td><td> 45. 7 </td><td> 45.6 </td><td> 44.5 </td><td> 45.7 </td><td> 49.6 </td></tr></TBODY></TABLE>< TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Table 2 </td><td> Example 6 </td><td> Example 7 </td><td> Example 8 </td><td> Example 9 </td></tr><tr><td> Alloy Composition</td><td> Weight Percentage</td>< Td> Ag </td><td> 4 </td><td> 3 </td><td> 4 </td><td> 4 </td></tr><tr><td> Cu </td><td> 0.5 </td><td> 0.5 </td><td> 0.5 </td><td> 0.5 </td></tr><tr><td> Ni </td ><td> 0.05 </td><td> 0.05 </td><td> 0.05 </td><td> 0.05 </td></tr><tr><td> Bi </td><td > 3 </td><td> 3 </td><td> 3 </td><td> 3 </td></tr><tr><td> In </td><td> 1.5 < /td><td> 0.2 </td><td> 1.5 </td><td> 1.5 </td></tr><tr><td> Ge </td><td></td>< Td></td><td> 0.02 </td><td> 0.1 </td></tr><tr><td> Ga </td><td></td><td></td ><td> 0.003 </td><td> 0.01 </td></tr><tr><td> Pd </td><td> 0.05 </td><td> 0.1 </td><td ></td><td></td></tr><tr><td> Sn </td><td> balance </td><td> balance </td><td> balance </td><td> balance</td></tr><tr><td> mechanical </td><td> Hardness</td><td> HV </td><td> 26.5 </td><td> 24.8 </td><td> 26.45 </td><td> 26.5 </ Td></tr><tr><td> drop strength</td><td> Mpa </td><td> 53 </td><td> 56 </td><td> 54 </td> <td> 55 </td></tr><tr><td> Tensile strength</td><td> Mpa </td><td> 88 </td><td> 91 </td>< Td> 90 </td><td> 91 </td></tr><tr><td> Extension rate</td><td> % </td><td> 16 </td><td> 16 </td><td> 12 </td><td> 11 </td></tr><tr><td> Push ball test <copper substrate> </td><td> reflow once </ Td><td> IMC average thickness (μm) </td><td> 2.13 </td><td> 1.99 </td><td> 2.58 </td><td> 2.6 </td></tr ><tr><td> Mode1 </td><td> % </td><td> 100 </td><td> 100 </td><td> 100 </td><td> 100 </ Td></tr><tr><td> Mode2 </td><td> % </td><td></td><td></td><td></td><td>< /td></tr><tr><td> Mode3 </td><td> % </td><td></td><td></td><td></td><td> </td></tr><tr><td> Mode4 </td><td> % </td><td></td><td></td><td></td><td ></td></tr><tr><td> Reflow three times</td><td> IMC average thickness (μm) </td><td> 3.81 </td><td> 3.11 </td ><td> 3.32 </td><td> 3.56 </td></tr><tr><td> Mod E1 </td><td> % </td><td> 100 </td><td> 100 </td><td> 100 </td><td> 100 </td></tr>< Tr><td> Mode2 </td><td> % </td><td></td><td></td><td></td><td></td></tr> <tr><td> Mode3 </td><td> % </td><td></td><td></td><td></td><td></td></tr ><tr><td> Mode4 </td><td> % </td><td></td><td></td><td></td><td></td></ Tr><tr><td> ball shear average (g) (reflow once) </td><td> 433.15 </td><td> 333.1 </td><td> 442.3 </td><td > 441.6 </td></tr><tr><td> ball shear average (g) (reflow three times) </td><td> 416.5 </td><td> 315.7 </td><td > 418.8 </td><td> 419.6 </td></tr><tr><td> Solder Ball Hardness Test</td><td> Average IMC Upper Edge Hardness (Hv) (Reflow Once) < /td><td> 48.6 </td><td> 43.1 </td><td> 44.8 </td><td> 43.9 </td></tr><tr><td> Interface IMC upper edge average Hardness (Hv) (reflow three times) </td><td> 49.9 </td><td> 46.8 </td><td> 47.9 </td><td> 47.3 </td></tr>< /TBODY></TABLE><TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Table 3 </td><td> Comparative Example 1 </ Td><td> Comparative Example 2 </td><td> Comparative Example 3 </td></tr><tr><td> Alloy Composition</td><td> Weight Percentage</td><td> Ag </td><td> 3 </td><td> 4 </td><td> 4.5 </td></tr ><tr><td> Cu </td><td> 0.5 </td><td> 0.5 </td><td> 0.5 </td></tr><tr><td> Ni </td ><td> 0.05 </td><td> 0.05 </td><td> 0.05 </td></tr><tr><td> Bi </td><td> 4 </td><td > 3 </td><td> 2 </td></tr><tr><td> In </td><td></td><td></td><td></td> </tr><tr><td> Ge </td><td></td><td></td><td></td></tr><tr><td> Ga </td ><td></td><td></td><td></td></tr><tr><td> Pd </td><td></td><td></td ><td></td></tr><tr><td> Sn </td><td> balance </td><td> balance </td><td> balance </td> </tr><tr><td> Mechanical properties</td><td> Hardness</td><td> HV </td><td> 24.22 </td><td> 25.41 </td><td > 25.6 </td></tr><tr><td> Falling strength</td><td> Mpa </td><td> 48 </td><td> 53 </td><td> 61 </td></tr><tr><td> Tensile strength</td><td> Mpa </td><td> 77 </td><td> 89 </td><td> 88 < /td></tr><tr><td> Extension rate</td><td> % </td><td> 15 </td><td> 19 </td><td> 10 </td ></tr><tr><td> Push ball test <copper substrate> </td><td> reflow once</td><td> average thickness of IMC Degree (μm) </td><td> 2.5 </td><td> 2.41 </td><td> 2.7 </td></tr><tr><td> Mode1 </td><td> % </td><td> 100 </td><td> 100 </td><td> 95 </td></tr><tr><td> Mode2 </td><td> % </ Td><td></td><td></td><td></td></tr><tr><td> Mode3 </td><td> % </td><td>< /td><td></td><td> 5 </td></tr><tr><td> Mode4 </td><td> % </td><td></td><td ></td><td></td></tr><tr><td> Reflow three times</td><td> IMC average thickness (μm) </td><td> 3.91 </td> <td> 3.83 </td><td> 3.17 </td></tr><tr><td> Mode1 </td><td> % </td><td> 90 </td><td> 90 </td><td> 90 </td></tr><tr><td> Mode2 </td><td> % </td><td></td><td></td> <td></td></tr><tr><td> Mode3 </td><td> % </td><td> 5 </td><td> 5 </td><td> 5 </td></tr><tr><td> Mode4 </td><td> % </td><td> 5 </td><td> 5 </td><td> 5 </td ></tr><tr><td> ball shear average (g) (reflow once) </td><td> 455.3 </td><td> 379.77 </td><td> 390.6 </td ></tr><tr><td> ball shear average (g) (reflow three times) </td><td> 431.2 </td><td> 346.26 </td><td> 375.8 </td ></tr><tr><td> Solder Ball Hardness Test</td><td> Interface IMC Upper Edge Hardness (Hv) (reflow once) </td><td> 42.7 </td><td> 42.9 </td><td> 41.5 </td></tr><tr><td> Interface IMC Upper edge average hardness (Hv) (reflow three times) </td><td> 42.9 </td><td> 43.2 </td><td> 43.6 </td></tr></TBODY></ TABLE><TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> Table 4 </td><td> Comparative Example 4 </td><td> Comparative Example 5 </td><td> Comparative Example 6 </td><td> Comparative Example 7 </td></tr><tr><td> Alloy Composition</td><td> Weight Percentage </ Td><td> Ag </td><td> 4 </td><td> 4 </td><td> 3 </td><td> 3 </td></tr><tr>< Td> Cu </td><td> 0.5 </td><td> 0.5 </td><td> 0.8 </td><td> 0.8 </td></tr><tr><td> Ni </td><td> 0.05 </td><td> 0.05 </td><td> 0.05 </td><td> 0.05 </td></tr><tr><td> Bi </td ><td> 3 </td><td> 3 </td><td> 2 </td><td> 2 </td></tr><tr><td> In </td><td > 0.1 </td><td> 2 </td><td> 0.5 </td><td> 0.9 </td></tr><tr><td> Ge </td><td> </ Td><td></td><td></td><td></td></tr><tr><td> Ga </td><td> </td><td></ Td><td></td><td></td></tr><tr><td> Pd </td><td> </td><td></td><td></ Td><td></td></tr><tr><td> Sn </td><td> balance </td><td> balance </td><td> balance </td><td> balance </td></tr><tr><td > Mechanical properties</td><td> Hardness</td><td> HV </td><td> 25.48 </td><td> 26.77 </td><td> 26.4 </td><td> 27.27 </td></tr><tr><td> Falling strength</td><td> Mpa </td><td> 52 </td><td> 63 </td><td> 45 < /td><td> 39 </td></tr><tr><td> Tensile strength</td><td> Mpa </td><td> 88 </td><td> 97 </ Td><td> 74 </td><td> 67 </td></tr><tr><td> Extension rate</td><td> % </td><td> 18 </td> <td> 8 </td><td> 15 </td><td> 18 </td></tr><tr><td> Push ball test <copper substrate> </td><td> reflow Once </td><td> IMC average thickness (μm) </td><td> 2.35 </td><td> 2.3 </td><td> 2.8 </td><td> 2.5 </td> </tr><tr><td> Mode1 </td><td> % </td><td> 100 </td><td> 90 </td><td> 100 </td><td> 100 </td></tr><tr><td> Mode2 </td><td> % </td><td> </td><td></td><td></td>< Td></td></tr><tr><td> Mode3 </td><td> % </td><td> </td><td> 10 </td><td></td ><td></td></tr><tr><td> Mode4 </td><td> % </td><td> </td><td></td><td></ Td><td></td></tr><tr><td> reflow three </td><td> IMC average thickness (μm) </td><td> 3.78 </td><td> 3.53 </td><td> 3.1 </td><td> 3.83 </td>< /tr><tr><td> Mode1 </td><td> % </td><td> 90 </td><td> 85 </td><td> 100 </td><td> 85 </td></tr><tr><td> Mode2 </td><td> % </td><td> </td><td></td><td></td><td ></td></tr><tr><td> Mode3 </td><td> % </td><td> 5 </td><td> 10 </td><td></td ><td> 10 </td></tr><tr><td> Mode4 </td><td> % </td><td> 5 </td><td> 5 </td><td ></td><td> 5 </td></tr><tr><td> ball shear average (g) (reflow once) </td><td> 381.3 </td><td> 441 </td><td> 282.32 </td><td> 269.85 </td></tr><tr><td> ball shear average (g) (reflow three times) </td><td> 348.6 </td><td> 423.5 </td><td> 252.25 </td><td> 266.69 </td></tr><tr><td> Solder Ball Hardness Test</td><td> Interface IMC upper edge average hardness (Hv) (reflow once) </td><td> 43.2 </td><td> 40.5 </td><td> 40.5 </td><td> 40.1 </td> </tr><tr><td> Average hardness (Hv) of the upper edge of the interface IMC (reflow three times) </td><td> 43.8 </td><td> 46.3 </td><td> 41.9 </ Td><td> 41.8 </td></tr></TBODY></TABLE>

no.

:no

Claims (3)

A solder composition comprising: 3 to 4 wt% of silver; 0.5 to 1 wt% of copper; 0.04 to 0.07 wt% of nickel; 2.5 ～ based on the total weight of the solder composition: 100% by weight 3.5 wt% of bismuth; 0.2 to 1.5 wt% of indium; and the balance of tin. The solder composition of claim 1, wherein the solder composition further comprises cerium greater than 0 and less than 0.02 wt%, gallium greater than 0 and less than 0.003 wt%, or a combination of the two. The solder composition of claim 1, wherein the solder composition further comprises more than 0 wt% but less than 0.05 wt% of a platinum group component selected from palladium, platinum, or both The combination.