TWI511827B - Active soft solder filler composition - Google Patents

Description

Active solder filler composition

The present invention is an active solder filler which can be directly bonded in an atmosphere and can be bonded to a metal having a low wettability.

Sputtering mainly uses the principle of glow discharge in vacuum to impact the plasma on the surface of the target at high speed. The atoms of the target are ejected and then ejected on the surface of the substrate to form a film. The method can be applied to plastics. The etching and coating of metal, glass, cloth or composite materials have the advantages of high quality, good adhesion and excellent process stability.

During a typical sputtering operation, a current is formed on the target side to form a negative electrode. In the sputtering vacuum chamber, an inert gas ion excited with a positive charge collides with the target, and the target is collided. The material is bombarded into atomic particles and splashed onto the substrate. Since this process causes the target to generate a large amount of heat, in order to cool the target, the backing plate joined to the target is usually cooled by means of water cooling. If the bonding strength between the target and the backing plate is not good, or the thermal conductivity of the interface is poor, the target temperature will rise rapidly during the sputtering operation, causing problems such as desoldering, melting, or overheating of the device.

The bonding of the target and the backing plate requires not only strength, thermal conductivity, temperature resistance, etc., but also the operational convenience and cost of the heavy-duty joint recovered by the back sheet. In consideration of the bonding temperature and the requirements of the operating temperature and thermal conductivity, indium is usually used as a bonding material for the target and the back sheet. In the bonding application of most metal targets, since indium can produce good wettability with the metal target during melting, the bonding can be smoothly completed.

Recently, however, the joining of ceramics and metals has attracted attention from all walks of life. Because the composite members made of ceramics and metals can fully exploit their respective performance advantages, they can also make up for the shortcomings of their own material properties. Focus on research direction, but due to the different ways of linking the ceramics and the metal itself, the physical and chemical properties of the two are greatly different, which makes the two joints difficult to process. Since the ceramic target is a material having low wettability, the ceramic surface is usually capable of reacting with a metal to bond, and it is often necessary to apply a metallization treatment to the ceramic surface to be joined. The main methods of ceramic metallization include vacuum coating methods such as evaporation and sputtering, thin film processes such as chemical vapor deposition, ion implantation or electroless plating, or thick film processes using sintered metal powder or coated active brazing filler. Wait. After the metallization, the indium is used for bonding, but such a process requires a high cost and a cumbersome process.

In Japanese Patent Laid-Open Publication No. I321159, a solder alloy is provided for bonding a target to a backing plate made of copper or a copper alloy, characterized by comprising zinc containing 3-9% by weight, and the remainder The composition is composed of tin and unavoidable impurities. However, in this technical feature, only a solderable target which is easy to wet can be used, and a target having a low wettability such as a ceramic material or the like is not mentioned.

In Taiwan Patent Publication No. 201026741, it is disclosed that a surface of a ceramic sputtering target is subjected to a pure chromium or chromium alloy plating treatment to form an interface layer, and then the interface between the solder layer of the backing plate and the target is formed. The layer is soft soldered, and finally the interface layer is annealed so that the interface layer and the soft solder layer can be easily joined. The invention provides a joint joining method with low joint wettability, but in this technical feature, an interface layer needs to be plated on the surface of the target to facilitate soldering, which not only requires high cost in the coating process but also makes the joint The procedures are complicated, and more procedures such as annealing are performed, and the bonding interface of the multilayer metal also affects the bonding performance.

In this way, it is necessary to develop new technologies to overcome the above shortcomings. The inventor will target It is placed on a target with low wettability, such as ceramics, aluminum, aluminum alloy, etc. In view of the problems of increasing cost and complicated process in the previous method, after the research and experiment, the active soldering is finally produced. A filler and a method of joining the target to the backing plate using the filler.

The main object of the present invention is to provide an active soldering filler which can directly bond a target with low wettability to a backing plate by using an active solder filler, without coating the surface of the target. .

A secondary object of the present invention is to provide an active solder filler, which can be directly engaged by the worker without any protective equipment.

Another object of the present invention is to provide an active soldering filler which has excellent wettability and is suitable for bonding a target having low wettability to a backing plate, which simplifies the processing step and can save processing time and cost.

Another object of the present invention is to provide an active soldering filler, wherein when the target is bonded to the backing plate, a low temperature operating temperature is used, and in addition to being safe to operate, the problem of interface thermal stress can be solved. Increase the joint strength.

Another object of the present invention is to provide an active soldering filler, wherein one of the metal substrate materials is zinc, the ductility is better than that of general lead-free solder, and the bonding temperature is also low, and the target and the backing plate can also be reduced. The problem of thermal stress makes the joint strength stronger.

The present invention provides an active soldering filler which can directly join a target having a low wettability and a back sheet in an atmospheric environment, and includes an active material having a composition of titanium plus rare earth element or magnesium; a metal substrate; It is a tin-zinc alloy and contains a specific amount of niobium, indium. , silver, copper. The active bonding temperature of the active solder filler is between 150 ° C and 200 ° C, between the low temperature solder and the high temperature solder. The operating temperature is low in the lead-free solder, so the thermal stress at the joint interface can be reduced. The bonding operation temperature needs to be above 150 ° C, otherwise the target will be separated from the backing plate during the sputtering operation. When the active solder filler is manufactured, the temperature is 200 ° C or less, which is lower than the temperature required for the general commercial lead-free solder, and is more convenient, faster, and safer to manufacture.

The active soldering filler developed by the present invention has a technical breakthrough in the joining operation of a target which is difficult to wet so as to have low wettability which is difficult to bond, and can be directly bonded by the active element contained in the solder. The low wettability target and the back sheet save cost and time, and can also improve the bonding effect. Moreover, in the active solder filler, the metal substrate is mainly tin-zinc alloy, and the ductility of the solder reduces heat. The problem of stress.

10‧‧‧Active soft solder filler

20‧‧‧First joint

21‧‧‧First joint

30‧‧‧Second joint

21‧‧‧Second joint

1 is a schematic view showing the bonding of the joint of the present invention to the active solder filler; and FIG. 2 is a schematic view showing the use of the active solder filler of the present invention.

In order to provide a better understanding and understanding of the structural features and the achievable effects of the present invention, the preferred embodiments and the detailed description are as follows: The present invention is a kind of "active soft" The composition of the solder filler uses the active solder filler to directly join the target and the back sheet having low wettability in an atmospheric environment without requiring protective equipment.

Please refer to FIG. 1 and Table 1 respectively, which is a structural schematic diagram and an alloy composition table of a preferred first embodiment of the present invention; as shown in the figure, one of the active soft solder fills of the present invention The material 10 includes: an active material and a metal substrate; wherein the active material is titanium and a rare earth element selected from the group consisting of La, La, Pr, and Nd), giant (Pm), strontium (Sm), europium (Eu), strontium (Gd), strontium (Tb), strontium (Dy), strontium (Ho), strontium (Er), strontium (Tm), sputum ( Yb), 镏 (Lu), 钇 (y), 钪 (Sc), and any combination of the above. And the metal substrate is mainly composed of a tin-zinc alloy.

Furthermore, the active solder filler 10 has a main bonding temperature of 150 ° C to 200 ° C, and further includes an additive selected from one of bismuth, indium, silver, and copper or the above. Any combination, at least with the following proportional combinations of the list 1:

The active solder filler 10 can directly bond a first bonding material 20 and a second bonding material 30 in an atmospheric environment because the active solder filler 10 has an active element titanium and a rare earth element, respectively, and the first The surfaces of the bond 20 and the second bond 30 react to form a bond, and the first bond 20 and the active solder filler 10 create a first joint surface 21, and the second bond 30 and the active solder filler 10 are produced. The second joint surface 31 is formed.

The first bonding material 20 is selected from one of a metal and a ceramic; the second bonding material 30 is selected from one of a metal and a ceramic.

In the first embodiment, the active solder filler 10 is capable of directly bonding the first bond 20 and the second bond 30. Because of the application of the active metal method, the active metal method adds active elements to the general metal solder to promote the metal. It can react and wet with targets with low wettability such as ceramics to facilitate the bonding operation. However, the solder alloy obtained by using the active metal method has a bonding temperature of 800 ° C to 1000 ° C, and has problems such as thermal stress and high temperature process. The present invention develops active softness by adding active element titanium and trace rare earth elements. The solder packing 10 can be directly joined at 150 ° C to 200 ° C. This temperature range has the best performance and can be adjusted by the operator according to the needs of the operation.

Among them, because the rare earth element has a relatively high affinity, under the atmosphere, the active soldering filler can wet the target with low wettability such as ceramic, and can directly combine the target and the back plate without using a flux. According to the experimental results, the bonding operation temperature needs to be higher than 150 ° C, so that the target can be bonded to the back plate without being separated during the sputtering operation.

As shown in Fig. 2, in the first embodiment of the active solder filler of the present invention, a method of joining a target having a low wettability and a backing plate in an atmospheric environment is as follows:

Step S40: Prepare the filler alloy and the active element in a predetermined weight percentage in advance, melt it in a vacuum arc melting furnace, evacuate to a temperature of 10 ^-2 to 10 ^-3 torr or more, and pass argon gas as a protective atmosphere. Afterwards, the active solder filler 10 is obtained;

Step S42: Before joining, the surfaces of the first and second joints 20 and 30 are ground with sandpaper, and then placed in acetone to be ultrasonically oscillated to remove surface oil stains.

Step S44: causing the active solder filler 10 to wet with the first and second joints 20 and 30 in a mechanically activated manner.

Step S46: When the active solder filler 10 can be completely wetted and uniformly coated on the surface of the bonding material, the first and second bonding materials 20 and 30 are superposed on each other, and the air holes are discharged by friction and the active soldering is performed. The surface oxide of the filler 10 is broken, and the bonding effect is improved to achieve close bonding.

In the first embodiment, the rare earth element is used as the active element of the active metal method. However, since the rare earth element has low yield and high price, and is concentrated in a few countries, the raw material is difficult to grasp, so the present invention simultaneously develops the activity of adding the active element magnesium. A solder filler, as in the second embodiment. Please refer to FIG. 1 and Table 2, which are schematic structural diagrams and alloy composition tables according to another preferred embodiment of the present invention. The active solder filler 10 of the present invention comprises an active material and a metal substrate. Wherein the active material is magnesium or a magnesium alloy, and the metal substrate is mainly composed of a tin-zinc alloy.

The active solder filler 10 has a main bonding temperature of 150 ° C to 200 ° C, and further includes an additive selected from one of yttrium, indium, silver, and copper, or any combination thereof. At least there are several ratio combinations in the following list:

The active solder filler 10 is capable of directly bonding a first bond 20 and a second bond 30 in an atmospheric environment because of active activity in the active solder fill filler 10. The elemental magnesium reacts with the surfaces of the first conjugate 20 and the second conjugate 30, respectively, to form a bond, and the first conjugate 20 and the active solder filler 10 create a first joint surface 21, and the second conjugate 30 A second joint surface 31 is created with the active solder filler 10.

The first bonding material 20 is selected from one of a metal and a ceramic; the second bonding material 30 is selected from one of a metal and a ceramic.

In the first embodiment, the active solder filler 10 is capable of directly bonding the first bond 20 and the second bond 30. Because of the application of the active metal method, the active metal method adds active elements to the general metal solder to promote the metal. It can react and wet with targets with low wettability such as ceramics to facilitate the bonding operation. The solder alloy obtained by using the active metal method has a bonding temperature of 800 ° C to 1000 ° C, and has problems such as thermal stress and high temperature process. The present invention develops an active solder filler containing active element magnesium, which can be used not only Significantly reduce the cost, and also promote the wettability of the surface of the target with low wettability, and is excellent in the joining operation, comparable to the active solder filler with the active element titanium and trace rare earth elements.

As shown in Fig. 2, a second embodiment of the active solder filler of the present invention is a method of joining a target having a low wettability to a backing plate in an atmospheric environment: as follows:

Step S40: Prepare the filler alloy and the active element in a predetermined weight percentage in advance, melt it in a vacuum arc melting furnace, evacuate to a temperature of 10 ^-2 to 10 ^-3 torr or more, and pass argon gas as a protective atmosphere. Afterwards, the active solder filler 10 is obtained;

Step S42: Before joining, the surfaces of the first and second joints 20 and 30 are ground with sandpaper, and then placed in acetone to be ultrasonically oscillated to remove surface oil stains.

Step S44: causing the active solder filler 10 to wet with the first and second joints 20 and 30 in a mechanically activated manner.

Step S46: when the active solder filler 10 can be completely wetted and uniformly coated on the surface of the bonding material, and then the first and second bonding materials 20 and 30 are superposed on each other, using friction The pores are discharged and the surface oxide of the active solder filler 10 is broken, and the bonding effect is improved to achieve close bonding.

In summary, the present invention is an active solder filler and a method for bonding a target and a back sheet by using the active solder filler, which is an active element added to the active solder filler to improve the wettability of the surface of the target. The bonding operation can be directly completed without the metal layer being plated on the surface of the target. The advantages and effects are listed as follows:

1. The active soldering filler developed by the invention can directly join the target and the backing plate with low wettability in the atmospheric environment, without special protection device, and is convenient and convenient to use, and also saves cost and Simplified the process.

2. The main bonding temperature is between 150 ° C and 200 ° C, which is between the normal low temperature solder temperature and the high temperature solder temperature, which can reduce the problem of thermal stress, and the temperature range does not fall outside the previous operating range. Therefore, it can be directly operated by the original equipment during processing without adding new equipment.

3. The target having low wettability and the back sheet can be joined. The important technical feature of the active solder fill filler of the present invention is to add a certain proportion of active elements to the metal substrate to make the surface of the joint to be joined. The reaction is such that a bond is formed, so that the target having low wettability and the back sheet can be effectively joined in the atmosphere, and the flux is not required, thereby saving cost and steps.

4. The active solder filler of the present invention, wherein the metal substrate is a tin-zinc alloy, which is softer than a general solder, so that the problem of thermal stress can be reduced, and the joint strength can be further improved.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

10‧‧‧Active soft solder filler

20‧‧‧First joint

21‧‧‧First joint

30‧‧‧Second joint

31‧‧‧Second joint

Claims (3)

A composition of an active solder filler comprising: an active selected from the group consisting of titanium and a rare earth element; and a metal substrate comprising a tin-zinc alloy, and an additive being ruthenium, in the active solder filler The weight percentage ranges from 0.1 wt% to 10 wt%. The composition of the active solder filler according to claim 1, wherein the rare earth element is selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), cerium (Nd), and giant (Pm). , Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu , 钇 (y), 钪 (Sc), and any combination of the above. A composition of an active solder filler comprising: an active selected from the group consisting of magnesium; and a metal substrate comprising a tin-zinc alloy, and an additive being ruthenium, the weight percentage of the active solder filler It is between 0.1% by weight and 10% by weight.