JP2014096198A - Method of bonding window pane for automobiles and feeding terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that, in the case where a lead-free solder alloy is used, since a bond strength of a feeding terminal is not sufficient and a cooling/heating cycle test or a salt water spray test cannot be passed, it is restricted originally to use the lead-free solder alloy for vehicle glass.SOLUTION: When heating and bonding a window pane for automobiles and a feeding terminal via a sintered body of silver paste and a lead-free solder alloy, the method includes: a first step of disposing the lead-free solder alloy on the silver paste and then performing heating deposition; a second step of heating and depositing a lead-free solder alloy of the same composition as the lead-free solder alloy to the feeding terminal of the window pane for automobiles; and a third step of further heating and bonding the window pane for automobiles and the feeding terminal via the lead-free solder alloy.

Description

  The present invention relates to a method for joining a metallic terminal called a power feeding terminal to an automobile window glass.

  In recent years, attempts have been made to impart various characteristics using window glass for vehicles. For example, there is an antifogging element called a defogger or a glass antenna. Commercialized using its electrical characteristics. With respect to the defogger, by passing an electric current, fogging is removed by the heat and a field of view is secured. Further, a glass antenna is used for a radio, a TV, and the like by converting a radio wave picked up by the antenna into a current. Since glass used for vehicles does not flow current, it is a general system that current flows between a defogger and a glass antenna via a power supply terminal. Furthermore, in order to improve the antiglare performance, many glasses on which a ceramic having a black color or a color tone close thereto (hereinafter referred to as a black ceramic) is applied to a part of the glass are on the market.

  Conventionally, the feeder terminal and the defogger or glass antenna are connected by solder containing lead. However, lead is a highly toxic environmental pollutant, and in addition to adverse effects on human health, adverse effects and pollution on the environment, especially the ecosystem, are regarded as problems. Therefore, there is a strong social demand not to use lead as much as possible. Many industries, including the consumer electronics industry, have already used low-lead or lead-free solder for various soldering applications. Such a movement is similar to the solder for the vehicle, and the movement to make the solder for the vehicle lead-free is rapidly spreading.

  However, it is very difficult to satisfy the characteristics conventionally required with low-lead or lead-free solder in the application of vehicle glass. This is mainly because household appliances are used indoors, whereas glass for vehicles is used outdoors, so it must withstand a poor environment. In addition, safety issues are extremely important, and are required to pass, so they must pass a severe test. For this reason, for example, the customer is required to pass a cooling / heating cycle test or a salt spray test, but it cannot be easily passed. Furthermore, there is also a circumstance that the characteristics for the black ceramics described above must be taken into account.

  Patent Document 1 discloses a lead-free silver-containing conductive coating composition, a silver-containing conductive coating, a method for producing a silver-containing conductive coating, and a coated support, which can be used particularly for a rear window (backlight) of an automobile. The body is disclosed.

  Further, Patent Document 2 discloses a glazing having an electrical terminal including an adhesive and, optionally, solder, for buildings, equipment or vehicles, particularly for automobiles.

  Patent Document 3 discloses a glass panel for a vehicle that pays attention to the generation of stress in glass after soldering with a lead-free solder alloy.

Further, Patent Document 4 discloses a heat generating glass and a method for manufacturing the same by reliably joining the fillers of the resin-based conductive adhesive to improve the reliability of conduction.
Patent Document 5 discloses a lead-free bulk metallic glass solder of high strength and high reliability formed from an alloy having a deep eutectic melting point having an asymmetric liquefaction curve.

  Furthermore, Patent Document 6 discloses a lead-free solder composition containing tin, indium, silver and bismuth and a method and apparatus for joining to automobile glass using two types of solder.

JP-A-7-105723 Japanese translation of PCT publication No. 2003-521093 JP-T-2006-523917 JP 2009-199746 A Special table 2009-509767 gazette Special table 2009-504411

  In the conventional joining by lead solder, solder is attached only to the power supply terminal of the automobile window glass, and the automobile window glass and the power supply terminal are joined using a sintered body of silver paste and a flux. This method is advantageous in that it is simple and low in cost.

  In recent years, lead-free solder alloys have been used mainly due to environmental problems. Lead-free solder alloys have also been studied by soldering only the power supply terminals, which is almost the same as the conventional method. In this method, cracks in the solder hardly occur, but cracks tend to occur frequently at the interface between the solder and the sintered silver paste or the interface between the silver paste sintered and the black ceramic. For this reason, the use of lead-free solder alloys has been strongly demanded by customers, but it has been able to cope only with various limited conditions. In particular, this problem is remarkable in the window glass for automobiles coated with black ceramics.

  The method described in Patent Document 1 has the advantage that solder wetting due to migration can be dealt with even with a lead-free solder alloy, but little attention is paid to the bonding strength of the power supply terminals.

  In the article described in Patent Document 2, the role is clearly divided by the adhesive and the solder, and the bonding strength is not assigned to the solder. For this reason, when an adhesive is not used, it cannot be applied as it is.

  In the article described in Patent Document 3, a mechanical stress relaxation component is shown, which is presumed to lead to an increase in bonding strength. However, the concept for the cold cycle test and the salt spray test is not shown.

  In the method described in Patent Document 4, the characteristics of the lead-free solder alloy can be improved by controlling the structure of the lead-free solder alloy, but the concept for the cold cycle test and the salt spray test is not shown.

  Although the concept described in Patent Document 5 takes into account thermal circulation and temperature difference, it is specialized for bulk metal solder (BMG) and is not suitable for applications in so-called ordinary lead-free solder alloys. It is difficult.

    Although the composition and method described in Patent Document 6 are epoch-making in that two types of solder are used, the concept for the cold cycle test and the salt spray test is not shown. Further, in the two types of solder, for example, the upper layer solder is said to have a lower melting temperature than the lower layer solder, and there are some which are difficult to manage during manufacture.

  As described above, in the prior art, when a lead-free solder alloy is used, the joining strength of the power supply terminal is not sufficient, and it has not been possible to pass a cooling / heating cycle or a salt spray test. For this reason, in the glass for vehicles, there was a restriction | limiting naturally to using a lead-free solder alloy. The present invention has been made in view of the above-described problems, and an object of the present invention is to increase the bonding strength of a power supply terminal made of a lead-free solder alloy, particularly in the case of an automotive window glass coated with black ceramics.

  In the present invention, when a window glass for an automobile and a power supply terminal are heat-bonded with a silver paste sintered body and a lead-free solder alloy, the lead-free solder alloy is heat-welded on the silver paste sintered body to form a first lead-free solder. A first step of forming a solder alloy layer, a second step of forming a second lead-free solder alloy layer by heat-welding a lead-free solder alloy having the same composition as the lead-free solder alloy to the power supply terminal, and a first lead-free solder alloy layer This is a method of joining a window glass for an automobile and its power supply terminal comprising a third step in which a solder alloy and a second lead-free solder alloy are heated and joined.

  Further, the present invention is a method for joining the above-described automotive window glass and its power supply terminal, wherein the lead-free solder alloy in the first step has a thickness of 0.2 mm to 3 mm.

  Moreover, this invention is the joining method of the above-mentioned window glass for motor vehicles and the electric power feeding terminal whose quantity of lead-free solder alloy in the 1st step is 0.01g or more and 0.6g or less per electric power feeding terminal seat of an electric power feeding terminal. is there.

  Further, the present invention is a method for joining the above-described automotive window glass and its power supply terminal, wherein the heat welding temperature of the lead-free solder alloy in the first step is not lower than the melting point and not higher than the melting point + 300 ° C.

  Further, the present invention is a method for joining the above-described automotive window glass and its power supply terminal, wherein the lead-free solder alloy is heat-welded in the first step using ultrasonic waves.

  Further, the present invention is a method for joining the above-described automotive window glass and its power supply terminal, wherein the lead-free solder alloy in the second step has a thickness of 0.5 mm or more and 5 mm or less.

  The present invention is also the above-described method for joining an automotive window glass and its power supply terminal, wherein the amount of lead-free solder alloy in the second step is 0.04 g or more and 1 g or less per power supply terminal seat of the power supply terminal.

  The present invention also provides the above-described automotive window glass in which the weight ratio of the amount of lead-free lead-free solder alloy alloy formed in the first step to the amount of lead-free lead-free solder alloy alloy formed in the second step is 0.1-1. And a method of joining the power supply terminals.

  Moreover, this invention is a joining method of the above-mentioned window glass for motor vehicles and its electric power supply terminal whose joining temperature in a 3rd step is more than melting | fusing point and below melting | fusing point +300 degreeC.

  Moreover, the window glass for automobiles has a black ceramic, and the above-mentioned automobile window glass and its power supply terminal are bonded to each other by sintering a silver paste sintered body on the black ceramic.

  Moreover, this invention is a joining method of the above-mentioned window glass for motor vehicles whose lead-free solder alloy is In-Ag-Sn type solder, and its electric power feeding terminal.

  Furthermore, the present invention is a method for joining the above-described automotive window glass and its power supply terminal, wherein the lead-free solder alloy is Sn-Ag-Cu solder.

  The present invention is characterized in that a lead-free solder alloy is deposited in advance on a silver paste sintered body, and the lead-free solder alloy is heated and welded to the silver paste. A large bonding strength can be obtained by performing the heat welding in the first step.

  In this case, lead-free solder alloy with the same composition is also used for power supply terminals for automobile window glass. That is, it is characterized in that two types of lead-free solder alloys are not fused to bond the solders together, but are joined using the same lead-free solder alloy. It is quite difficult to successfully fuse two types of lead-free solder alloys, and an interface may occur between the two types of lead-free solder alloys. When such an interface occurs, a problem of heat shrinkage occurs on the interface, or salt water enters.

  ADVANTAGE OF THE INVENTION According to this invention, even when joining using the window glass for motor vehicles and a metallic material, especially a metallic terminal called a power feeding terminal, and a lead-free solder alloy, joining strength can be raised. In particular, even after a cold cycle test or a salt spray test, it is possible to sufficiently maintain the joining strength of the power supply terminal using the lead-free solder alloy.

It is a cross-sectional conceptual diagram which shows the state which joined the electric power feeding terminal to glass by the method of this invention. It is a cross-sectional conceptual diagram which shows the state which joined the electric power feeding terminal to the glass by the method of a prior art. It is a conceptual diagram of this invention which shows a mode that the lead-free solder alloy is heat-welded on the sintered body of the silver paste set | placed on the black ceramics in the 1st step. In a 3rd step, it is a conceptual diagram of this invention which shows a mode that the electric power feeding terminal for window glass for motor vehicles, and the window glass for motor vehicles are heat-joined. It is a conceptual diagram of this invention which shows a mode that the heat melting of the lead-free solder alloy made to adhere on a silver paste is made using an ultrasonic wave. It is a conceptual diagram which shows a mode that when a lead-free solder alloy is provided on the sintered body of a silver paste in a 1st step, a thread-like solder is heated with a soldering iron and it is made the molten solder.

  A mode for carrying out the present invention will be described below.

  The present invention provides a first step of heat-welding a lead-free solder alloy on a silver paste sintered body in the case where the window glass for an automobile and its power supply terminal are heat-bonded by a silver paste sintered body and a lead-free solder alloy, From the second step of heat-welding a lead-free solder alloy having the same composition as the lead-free solder alloy to the power supply terminal of the window glass for automobiles, and further from the third step of heat-joining the window glass for automobile and the power supply terminal with the lead-free solder alloy described above. It is the joining method of the window glass for motor vehicles and the electric power feeding terminal which become.

  FIG. 2 is a conceptual cross-sectional view showing a state in which a power feeding terminal is joined to glass by a conventional method. The glass 1, the black ceramic 2, the silver paste sintered body 3 and the power supply terminal 6 are joined by solder 5.

  FIG. 1 is a conceptual cross-sectional view showing a state where a power supply terminal is bonded to glass by the method of the present invention. A black ceramic 2 is arranged on the glass 1. The black ceramic 2 is applied to the glass 1 and then dried. The silver paste is also applied on the black ceramic 2 and then dried. Further, it is common that sintering and strengthening of black ceramics and silver paste are simultaneously performed in a glass strengthening furnace.

  On the silver paste sintered body 3, the lead-free solder alloy layer 4 applied in the first step and the lead-free solder alloy layer 5 applied in the second step coexist. Further, the power supply terminal 6 is on the lead-free solder alloy layer 5 applied in the second step. The power supply terminal 6 is often made of brass, but the material is not limited. Although the general shape of the power supply terminal 6 is shown in FIG. 1, the shape of the power supply terminal is many and is not limited to this shape. Further, when the power supply terminal 6 is viewed in large size, the power supply terminal 6 is composed of a connection portion 10 with an external power supply element and a power supply terminal seat 11 attached to glass. In general, the power supply terminal 11 has two seats, but there may be one or three or more.

  FIG. 3 shows a state in which lead-free solder alloys 4 and 5 are heated and welded by a soldering iron (heater) 7 on a silver paste sintered body placed on a black ceramic in the first step. It is a conceptual diagram of this invention.

  FIG. 4 is a conceptual diagram of the present invention showing how the power supply terminal for an automobile window glass and the automobile window glass are heated and joined in the third step. The lead-free solder alloy heat-welded in the first step and the second step is heated and bonded at a temperature not lower than the melting point and not higher than the melting point + 300 ° C. for not less than 3 seconds and not more than 30 seconds by the heater 9 or the like, and then blown with air. Or left to cool to room temperature.

  In the present invention, it is desirable that the thickness of the lead-free solder alloy in the first step is 0.2 mm or more and 3 mm or less. If the thickness is less than 0.2 mm, a problem that good bonding strength cannot be obtained occurs. On the other hand, when it exceeds 3 mm, the problem which looks worse arises. More preferably, the thickness is 0.3 mm to 2 mm, and still more preferably 0.4 mm to 1.5 mm. In addition, about lead-free solder alloy, it does not necessarily become a uniform thickness in all, but since the area differs somewhat, it is better to interpret the above-mentioned value as an average value.

  In the present invention, it is desirable that the amount of the lead-free solder alloy in the first step is 0.01 g or more and 0.6 g or less per one feeding terminal seat of the feeding terminal. If it is less than 0.01 g, a problem that good bonding strength cannot be obtained occurs. On the other hand, if it exceeds 0.6 g, the problem of poor appearance occurs. Preferably they are 0.02g or more and 0.44g or less, More preferably, they are 0.03g or more and 0.3g or less.

  In the present invention, it is desirable that the heat welding temperature of the lead-free solder alloy in the first step is not lower than the melting point and not higher than the melting point + 300 ° C. If the temperature is lower than the melting point, a problem that the lead-free solder alloy does not melt occurs. On the other hand, when the melting point exceeds + 300 ° C., fine cracks or the like are generated on the glass, resulting in a problem that good bonding strength cannot be obtained. Furthermore, since time is required for cooling, the problem that production efficiency falls arises. More preferably, it is melting | fusing point +10 degreeC or more and melting | fusing point +290 degrees C or less, More preferably, it is melting | fusing point +20 degreeC or more and melting | fusing point +280 degrees C or less. Here, the melting point is measured by a general differential thermal analyzer.

  Further, in the present invention, as shown in FIG. 5, it is desirable that the lead-free solder alloy is heat-welded in the first step using ultrasonic waves. The effect of the present invention can be further enhanced by using ultrasonic waves. In addition, it is desirable that the application time of ultrasonic waves be 0.5 seconds or more and 20 seconds or less. If it is less than 0.5 seconds, a problem that good adhesive strength cannot be obtained occurs. On the other hand, if it exceeds 20 seconds, the characteristics of the silver paste change, and it may not be possible to join the lead-free solder alloy. More preferably, they are 1 second or more and 15 seconds or less, More preferably, they are 2 seconds or more and 10 seconds or less.

  In the present invention, it is desirable that the lead-free solder alloy in the second step has a thickness of 0.5 mm or more and 5 mm or less. If the thickness is less than 0.5 mm, a problem that good bonding strength cannot be obtained occurs. On the other hand, when it exceeds 5 mm, the problem which looks worse arises. More preferably, it is 0.8 mm or more and 4 mm or less, More preferably, it is 1 mm or more and 3 mm or less.

  In the present invention, it is desirable that the amount of the lead-free solder alloy in the second step is 0.04 g or more and 1 g or less per one feeding terminal seat of the feeding terminal. If it is less than 0.04 g, a problem that good bonding strength cannot be obtained occurs. On the other hand, if it exceeds 1 g, the problem of poor appearance occurs. Preferably they are 0.1g or more and 0.8g or less, More preferably, they are 0.2g or more and 0.6g or less.

  In the present invention, the ratio of the amount of lead-free solder alloy in the first step to the amount of lead-free solder alloy in the second step is preferably 0.1-1. Even if the ratio between the amount of lead-free solder alloy in the first step and the amount of lead-free solder alloy in the second step is smaller than 0.1 or larger than 1, sufficient bonding strength cannot be obtained. Preferably they are 0.1 or more and 0.9 or less, More preferably, they are 0.2 or more and 0.8 or less.

  In the present invention, the bonding temperature in the third step is desirably a melting point or higher and a melting point + 300 ° C. If the temperature is lower than the melting point, a problem that the lead-free solder alloy does not melt occurs. On the other hand, when the melting point exceeds + 300 ° C., fine cracks or the like are generated on the glass, resulting in a problem that good bonding strength cannot be obtained. Furthermore, since time is required for cooling, the problem that production efficiency falls arises. More preferably, it is melting | fusing point +10 degreeC or more and melting | fusing point +290 degrees C or less, More preferably, it is melting | fusing point +20 degreeC or more and melting | fusing point +280 degrees C or less.

  In the present invention, the window glass for automobiles has black ceramics, and is particularly useful when a sintered body of silver paste is heat-welded on the black ceramics. Conventionally, automotive window glass coated with black ceramics has a large temperature difference between where black ceramics are coated and where black ceramics are not coated. The terminal bonding strength tended to decrease. In particular, when a lead-free solder alloy was used, this problem of joint strength was remarkable, but by using the method of the present invention, it could be greatly improved.

In the present invention, the lead-free solder alloy is preferably In—Ag—Sn solder. Furthermore, a desirable composition is described below. In-Ag-Sn solder composed of 26 wt% to 56 wt% In, 5 wt% or less Ag, and 39 wt% to 74 wt% Sn. . If In is less than 26%, the Young's modulus increases, and the glass may be cracked. On the other hand, if In exceeds 56%, the adhesive strength of the lead-free solder alloy decreases due to residual internal stress due to the phase change of In ₃ Sn / In ₃ Sn + InSn ₄ and the occurrence of cracks even at a temperature change near room temperature. More preferably, it is 28 to 54 weight%. More preferably, it is 31 to 51 weight%. The amount of Ag added in the present invention is preferably 0.1 to 5% by mass. By adding Ag, an effect excellent in improving the mechanical strength of the lead-free solder alloy is exhibited. Further, in the glass for vehicles, a silver paste is screen-printed-dried-fired to form defogger heat wires and antenna wires, and the power supply terminals that contact the silver wires and the vehicle body are connected by a lead-free solder alloy. At this time, in order to prevent silver wire corrosion (so-called silver erosion) by the lead-free solder alloy, it is effective to add Ag to the lead-free solder alloy. However, if it is less than 0.1%, these effects are low, and if it exceeds 5%, coarse Ag ₃ Sn is precipitated, which causes a decrease in strength and fatigue strength. Preferably they are 0.5 weight% or more and 3 weight% or less, More preferably, they are 0.8 weight% or more and 2 weight% or less. Further, if Sn is less than 39% by weight, there arises a problem that characteristics as a lead-free solder alloy are lowered. On the other hand, when it exceeds 74% by weight, there arises a problem that the bonding strength is lowered. More preferably, it is 42 to 54 weight%, More preferably, it is 45 to 52 weight%.

  Further, the melting point is preferably 90 ° C. or higher and 200 ° C. or lower. A lead-free solder alloy of less than 90 ° C. cannot be easily obtained. On the other hand, when it exceeds 200 ° C., there arises a problem that the bonding strength is lowered. More preferably, it is 95 degreeC or more and 180 degrees C or less, More preferably, it is 100 degreeC or more and 160 degrees C or less. However, it is not necessarily limited to these conditions.

Furthermore, in the present invention, it is desirable that the lead-free solder alloy is Sn—Ag—Cu solder. Furthermore, a desirable composition is described below. Sn—Ag— composed of 94 wt% or more and 97 wt% or less of Sn, 2 wt% or more and 5 wt% or less of Ag, or 0.5 wt% or more and 2 wt% or less of Cu. Cu solder. When Sn is less than 94% by weight, there arises a problem that basic characteristics as a lead-free solder alloy are deteriorated. On the other hand, if it exceeds 97% by weight, there arises a problem that the bonding strength becomes weak. More preferably, they are 94.5 weight% or more and 96.5 weight% or less. Further, when Ag is less than 2% by weight, there arises a problem that the bond strength between the silver paste and the sintered body is weakened. On the other hand, if it exceeds 5% by weight, there will be a problem that fine cracks are generated on the surface of the lead-free solder alloy and the mechanical properties are lowered. More preferably, it is 2.2 to 4.5 weight%, More preferably, it is 2.5 to 3.8 weight%. Further, when Cu is less than 0.5% by weight, the bonding of the Ag ₃ Sn intermetallic compound becomes weak, and there arises a problem that the bonding strength decreases with time. On the other hand, if it exceeds 2% by weight, the lead-free solder alloy becomes hard and brittle, which causes a problem that the bonding strength is lowered. More preferably, they are 0.7 weight% or more and 1.8 weight% or less, More preferably, they are 0.8 weight% or more and 1.7 weight% or less.

  Moreover, as melting | fusing point, 180 degreeC or more and 280 degrees C or less are desirable. In the case of Sn-Ag-Cu solder having a temperature of less than 180 ° C, a problem of bonding strength occurs. On the other hand, if it exceeds 280 ° C., a problem occurs in uniformity as a lead-free solder alloy, and utilization as a lead-free solder alloy decreases. More preferably, it is 190 degreeC or more and 270 degrees C or less, More preferably, it is 200 degreeC or more and 250 degrees C or less. However, it is not necessarily limited to these conditions.

  Hereinafter, the present invention will be described in detail by way of examples. Here, the cold cycle test, the salt spray test, and the adhesive strength test refer to the following tests. The details will be described below.

[Cool cycle test]
A thermal cycle test according to JIS C2807 was performed. That is, 20 ° C. (3 minutes) → −30 ° C. (30 minutes) → 20 ° C. (3 minutes) → 85 ° C. (30 minutes) → 20 ° C. (3 minutes) The bonding strength was measured. In JIS C2807, the high temperature side temperature is the same as 85 ° C., but the low temperature side temperature is −25 ° C., which is looser than our test.

[Salt spray test]
A salt spray test according to JIS Z2371 was conducted. That is, a 5% NaCl aqueous solution was continuously sprayed at a spraying pressure of 0.1 MPa for 100 hours in an atmosphere at 35 ° C., and the bonding strength after the test was measured.

[Joint strength test]
This was performed according to JIS C62137. The connecting portion of the power supply terminal was bent so as to be perpendicular to the terminal seat, and the connecting portion was subjected to a tensile test with a push-pull gauge. In addition, the thing which does not peel at 80N was determined to be good adhesive strength.
[Example 1]

  First, the black ceramics manufactured by Okuno Seiyaku Kogyo Co., Ltd. are applied to a glass sample and then dried once. Thereafter, a silver paste manufactured by Fukuda Metal Foil Powder Co., Ltd. is applied on the black ceramics, and the glass is dried. Reinforcement treatment was performed in a reinforced furnace. In this way, a tempered glass sample similar to a commercially available automobile window glass provided with a sintered body of silver paste was prepared.

  As a first step, a general flux (NJ1 manufactured by Nippon Filler Metals) was thinly spread on the sintered body of the silver paste. Thereafter, about 0.3 g of a lead-free solder alloy (manufactured by NanoJoin Co., Ltd.) having a diameter of 1.6 mm manufactured in a thread shape was melted on the silver paste sintered body so as to have a thickness of about 1.5 mm. At this time, as shown in FIG. 6, the thread-shaped lead-free solder alloy 12 is a lead-free solder alloy 13 in a molten state at the tip of the soldering iron 7. The composition of the lead-free solder alloy used here was 51% by weight of In, 1% by weight of Ag, 48% by weight of Sn, and its melting point was 115 ° C. The melting point was measured according to JIS Z3198-1, and was measured using a differential type differential thermal balance TG8120 manufactured by Rigaku Corporation. Further, the lead-free solder alloy was heated for about 5 seconds on the sintered body of the silver paste, and was deposited on the sintered body of the silver paste. The temperature of the soldering iron was adjusted so that the lead-free solder alloy temperature was a predetermined temperature.

  Next, as a second step, flux was applied to the terminal seat surface of the power feeding terminal turned upside down. Thereafter, while dissolving about 0.4 g of the above-described thread-shaped lead-free solder alloy with a soldering iron, 0.8 g in total was deposited on the two bearing surfaces per terminal so that the thickness was about 2 mm. Therefore, the total amount of lead-free solder alloy in the first step and the second step is about 0.70 g, and the ratio of the amount of lead-free solder alloy in the first step to the amount of lead-free solder alloy in the second step is 0.8. there were.

  Furthermore, as a third step, the lead-free solder alloy heat-welded in the first step and the second step was combined, the terminal and the glass were fixed with clips, and soldering was performed by applying a Steinel heater. At this time, the heater was adjusted so that the lead-free solder alloy temperature was about 160 ° C.

  The initial bonding strength of the five power supply terminals thus heat-bonded was measured. As a result, it was confirmed that all values exceeding 80N required in the market were exceeded.

  Then, after the thermal cycle test (100 cycles), the results of examining the joint strength exceeded all the values of 80N required in the market. Moreover, the joint strength after the salt spray test (after 100 hours) was also carried out. As a result, it exceeded all 80N values required in the market.

As a result, it was confirmed that even when a lead-free solder alloy was used, it exceeded the value of 80N required in the market.
[Example 2]

  A tempered glass sample almost the same as in Example 1 was prepared. As a first step, a general flux (NJ1 manufactured by Nippon Filler Metals) was thinly spread on the sintered body of the silver paste. Thereafter, about 0.03 g of a lead-free solder alloy (manufactured by NanoJoin Co., Ltd.) having a diameter of 1.6 mm produced in a thread shape was melted so as to have a thickness of about 0.4 mm on the sintered silver paste. The composition of the lead-free solder alloy used here is 95.2% by weight of Sn, 3.8% by weight of Ag, 1% by weight of Cu, and its melting point is 215 ° C.

  Next, as a second step, flux was applied to the terminal seat surface of the power feeding terminal turned upside down. Then, while melting the above lead-free solder alloy with a soldering iron, about 0.2 g was deposited on one seating surface per terminal so that the thickness was about 1 mm. Accordingly, the total amount of lead-free solder alloy in the first step and the second step is about 0.23 g, and the ratio of the amount of lead-free solder alloy in the first step and the amount of lead-free solder alloy in the second step is 0.2. there were.

  Furthermore, as a third step, the lead-free solder alloy heat-welded in the first step and the second step was combined, the terminal and the glass were fixed with clips, and soldering was performed by applying a Steinel heater. At this time, the heater was adjusted so that the solder temperature was about 230 ° C.

  The initial bonding strength of the five power supply terminals thus heat-bonded was measured. As a result, it was confirmed that it exceeded all 80N values required in the market.

  Then, after the thermal cycle test (100 cycles), the results of examining the joint strength exceeded all the values of 80N required in the market. Moreover, the joint strength after the salt spray test (after 100 hours) was also carried out. As a result, it exceeded all 80N values required in the market.

As a result, it was confirmed that even when a lead-free solder alloy was used, it exceeded the value of 80N required in the market.
[Example 3]

  A tempered glass sample almost the same as in Example 1 was prepared. As a first step, a general flux (NJ1 manufactured by Nippon Filler Metals) was thinly spread on the sintered body of the silver paste. Thereafter, about 0.3 g of a lead-free solder alloy (manufactured by NanoJoin Co., Ltd.) having a diameter of 1.6 mm manufactured in a thread shape was melted on the silver paste sintered body so as to have a thickness of about 1.5 mm. At that time, an ultrasonic heater manufactured by Eishin Industry Co., Ltd. was operated for about 2 seconds. The composition of the lead-free solder alloy used here was 51% by weight of In, 1% by weight of Ag, 48% by weight of Sn, and its melting point was 115 ° C.

  Next, as a second step, flux was applied to the terminal seat surface of the power feeding terminal turned upside down. Thereafter, about 0.6 g of the aforementioned lead-free solder alloy was piled up with a soldering iron so that the thickness was about 3 mm. Therefore, the total amount of lead-free solder alloy in the first step and the second step is about 0.9 g, and the ratio of the amount of lead-free solder alloy in the first step to the amount of lead-free solder alloy in the second step is 0.5. there were. The conditions other than those described above were the same as in Example 1.

  The initial bonding strength of the five power supply terminals thus heat-bonded was measured. As a result, it was confirmed that it exceeded all 80N values required in the market.

  Then, after the thermal cycle test (100 cycles), the results of examining the joint strength exceeded all the values of 80N required in the market. Moreover, the joint strength after the salt spray test (after 100 hours) was also carried out. As a result, it exceeded all 80N values required in the market.

As a result, it was confirmed that even when a lead-free solder alloy was used, it exceeded the value of 80N required in the market. Since the bonding strength was measured with a push-pull gauge, a clear strength difference could not be measured, but it seemed stronger than the bonding strength in Example 1 and Example 2. Therefore, the push-pull gauge was set to 200N, and the initial strength, as well as the joint strength after the cooling / heating cycle test (100 cycles) and after the salt spray test (100 hours) were measured. It was over.
[Comparative Example 1]

  A glass sample prepared under substantially the same conditions as in Example 1 was prepared. As for the lead-free solder alloy, a lead-free solder alloy having 25 wt% In, 1 wt% Ag, 74 wt% Sn, and a melting point of 115 ° C. was used. The same soldering iron as in Example 1 was used. Moreover, it performed by what is called the conventional method of performing only by Step 2 without dividing Step 1 and Step 2. At this time, the amount of the lead-free solder alloy was about 0.55 g. Other conditions were the same as in Example 1.

  The initial bonding strength of the five power supply terminals thus heat-bonded was measured. As a result, it was confirmed that it exceeded all 80N values required in the market.

After that, after the thermal cycle test (100 cycles) was conducted and the bonding strength was examined. As a result, 2 samples out of 5 samples were 80 N or less compared to 80 N of the value required in the market. It was. Moreover, the joint strength after the salt spray test (after 100 hours) was also carried out. As a result, 3 samples out of 5 samples were 80 N or less compared to 80 N, which is the value required in the market.
[Comparative Example 2]

  A glass sample prepared under substantially the same conditions as in Example 2 was prepared. As for the lead-free solder alloy, a lead-free solder alloy having 95% by weight of Sn, 1% by weight of Ag, 4% by weight of Cu and a melting point of 216 ° C. was used. Moreover, it performed by what is called the conventional method of performing only by Step 2 without dividing Step 1 and Step 2. At this time, the amount of lead-free solder alloy was about 0.43 g. Other conditions were the same as in Example 2.

  The initial bonding strength of the five power supply terminals thus heat-bonded was measured. As a result, one sample out of five samples was 80 N or less with respect to 80 N which is a value required in the market.

After that, after the thermal cycle test (100 cycles), the bonding strength was examined. As a result, 4 samples out of 5 samples were 80 N or less compared to 80 N of the value required in the market. It was. Moreover, the joint strength after the salt spray test (after 100 hours) was also carried out. As a result, 4 samples out of 5 samples were 80 N or less compared to 80 N, which is the value required in the market.

DESCRIPTION OF SYMBOLS 1 Automotive window glass 2 Black ceramics 3 Silver paste sintered body 4 Lead-free solder alloy applied in the first step 5 Lead-free solder alloy applied in the second step 6 Feeding terminal 7 Heater (soldering iron)
8 Ultrasonic heater (ultrasonic soldering iron)
9 Heater 10 Connection portion 11 with external power supply element 11 Glass-attached power supply terminal seat 12 Thread-like lead-free solder alloy 13 Lead-free solder alloy in molten state

Claims (12)

In a method of heating and joining a power supply terminal to a conductive wire of an automotive window glass with a silver paste sintered body and a lead-free solder alloy, a first step of heat-welding the lead-free solder alloy onto the silver paste sintered body, the lead-free It consists of a second step in which a lead-free solder alloy having the same composition as the solder alloy is heat-welded to the power supply terminal of the automotive window glass, and a third step in which the automotive window glass and the power supply terminal are heat-bonded with the lead-free solder alloy. A method for joining an automotive window glass and a power supply terminal. The method for joining an automotive window glass and its power supply terminal according to claim 1, wherein the lead-free solder alloy in the first step has a thickness of 0.2 mm or more and 3 mm or less. The amount of the lead-free solder alloy in the first step is 0.01 g or more and 0.6 g or less per one feeding terminal seat of the feeding terminal, and the window glass for an automobile according to claim 1 or 2, A method of joining the power supply terminals. 4. The window glass for an automobile according to claim 1, wherein the heat welding temperature of the lead-free solder alloy in the first step is not lower than the melting point and not higher than the melting point + 300 ° C. 5. Joining method. The method for joining an automotive window glass and its power supply terminal according to any one of claims 1 to 4, wherein the lead-free solder alloy is heat-welded in the first step using ultrasonic waves. . The automotive window glass according to any one of claims 1 to 5, wherein the lead-free solder alloy in the second step has a thickness of 0.5 mm or more and 5 mm or less. How to join the power supply terminals. 7. The automobile according to claim 1, wherein the amount of the lead-free solder alloy in the second step is 0.04 g or more and 1 g or less per one feeding terminal seat of the feeding terminal. Joining method for window glass and its power supply terminal. The automobile according to any one of claims 1 to 7, wherein the ratio of the amount of lead-free solder alloy in the first step to the amount of lead-free solder alloy in the second step is 0.1-1. Joining method for window glass and its power supply terminal. 9. The method for joining an automotive window glass and its power supply terminal according to claim 1, wherein the joining temperature in the third step is not lower than the melting point and not higher than the melting point + 300 ° C. 9. The window glass for automobiles has black ceramics, and a sintered body of silver paste is heat-welded on the black ceramics. Method of automobile window glass and its power supply terminal. The lead-free solder alloy is an In-Ag-Sn solder, and the method for joining an automotive window glass and its power supply terminal according to any one of claims 1 to 10. The lead-free solder alloy is Sn-Ag-Cu solder, and the method for joining an automotive window glass and its power supply terminal according to any one of claims 1 to 10.

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