Solder strip for tinning nickel-plated surface of device

Abstract

The utility model belongs to the technical field of metal material welding, and particularly discloses a solder strip for tinning the nickel-plated surface of a device, which comprises a material strip layer and a soldering flux layer, the soldering flux layer is laid on one side face of the material belt layer, and a plurality of air holes are formed in the material belt layer. The air holes are formed in the material belt layer, so that the interaction force of the welding flux of the material belt layer on the liquid level of the welding flux in the welding process can be reduced, the tin shrinkage degree at a welding spot is effectively reduced, the probability of tin shrinkage on a plane after welding is reduced, and the welding quality is improved; moreover, the air holes can increase the mode that the soldering flux exhausts gas outwards in the welding process, waste gas generated in the welding process can be better exhausted, the generation probability of welding spot air holes is effectively reduced, generation of welding spot air holes in the welding face is reduced, and therefore welding spots are smoother after the nickel plating surface of the device is tinned.

Description

Technical Field

[0001] This utility model relates to the field of metal material welding technology, and in particular to a solder strip for tinning the nickel-plated surface of a device. Background Technology

[0002] Currently, to avoid reliability issues with solder joints in irregularly shaped devices due to poor soldering, tinning is required for the nickel-plated surfaces of these devices. Given the vacuum soldering requirements of these devices, direct soldering of nickel-plated joints is not permitted; tinning is necessary. Tinning is a surface treatment process involving mixing tin powder, oil, and other impurities, melting the mixture, and then applying it to a metal surface via spraying or coating. For irregularly shaped device encapsulation, tinning methods generally include manual soldering, solder pots, and reflow soldering. Due to the unique characteristics of solder joints in irregularly shaped devices, printed solder paste is unsuitable; therefore, pre-formed solder pads are typically used for tinning. When using pre-formed solder pads for reflow soldering of tin-lead alloys on nickel-plated surfaces, the result is uneven solder joint distribution, excessive porosity, or solder shrinkage. Utility Model Content

[0003] The purpose of this invention is to provide a solder strip for tinning nickel-plated surfaces of devices, in order to solve the technical problems caused by uneven solder joint distribution, excessive porosity, or tin shrinkage when using pre-formed solder sheets to reflow solder tin-lead alloys onto nickel-plated surfaces in the prior art.

[0004] To achieve the above objectives, this utility model provides a solder strip for tinning nickel-plated surfaces of devices, comprising: a strip layer and a flux layer; the flux layer is laid on one side of the strip layer, and the strip layer is provided with multiple vent holes.

[0005] Preferably, the strip layer is a tin-lead alloy layer, and the tin-lead alloy layer is one of Sn63Pb37, Sn60Pb40, and Sn62Pb36Ag2.

[0006] Preferably, the thickness of the strip layer is 0.1 mm to 0.2 mm.

[0007] Preferably, the plurality of vent holes are divided into multiple groups of vent holes; each group of vent holes has at least two vent holes, and all the vent holes in each group of vent holes are arranged sequentially along a first straight line direction, wherein the first straight line direction has an angle with the length direction of the material strip layer, and the plurality of vent holes are distributed sequentially along the length direction of the material strip layer.

[0008] Preferably, the angle between the first straight direction and the length direction of the strip layer is 45 degrees.

[0009] Preferably, the plurality of pore groups are distributed sequentially along the length of the material strip layer, and the distance between two adjacent pore groups is 2 mm to 3 mm.

[0010] Preferably, the distance between two adjacent vents in the same group of vents is 0.5 mm to 2 mm.

[0011] Preferably, the shape of the vent hole is cylindrical, square, triangular, or hexagonal.

[0012] Preferably, the equivalent diameter of the vent is 0.05 mm to 0.2 mm.

[0013] The solder strip for tinning nickel-plated surfaces of devices provided by this utility model has the following advantages: processing vent holes on the strip layer can reduce the interaction force between the solder surface during the soldering process, effectively reducing the degree of solder shrinkage at the solder joint, reducing the probability of solder shrinkage on the surface after soldering, and improving the soldering quality; moreover, the vent holes can also increase the way flux releases gas during soldering, allowing the waste gas generated during soldering to be discharged better, effectively reducing the probability of solder joint porosity formation, reducing the formation of solder joint porosity on the soldering surface, thereby achieving a smoother solder joint after tinning nickel-plated surfaces of devices.

[0014] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the solder strip with cylindrical holes for tinning the nickel-plated surface of the device according to an embodiment of the present invention;

[0016] Figure 2 This is a cross-sectional schematic diagram of the solder strip used for tinning the nickel-plated surface of the device according to an embodiment of the present invention;

[0017] Figure 3 This is a top view structural schematic diagram of the solder strip used for tinning the nickel-plated surface of the device according to an embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of the structure of the solder strip with triangular prism holes for tinning the nickel-plated surface of the device according to an embodiment of the present invention;

[0019] Figure 5 This is a schematic diagram of the structure of the solder strip with hexagonal columnar holes for tinning the nickel-plated surface of the device according to an embodiment of the present invention.

[0020] In the diagram, 100 represents the strip layer; 200 represents the flux layer; 300 represents the vent hole; and 400 represents the vent group. Detailed Implementation

[0021] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0022] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0025] Please refer to the following: Figures 1 to 5 The solder strip for tinning the nickel-plated surface of the device provided in this embodiment will now be described.

[0026] like Figure 1 and Figure 3 As shown in the figure, the solder strip for tinning the nickel-plated surface of the device according to this utility model embodiment includes: a strip layer and a flux layer; the flux layer is laid on one side of the strip layer, and the strip layer is provided with multiple vent holes. That is, processing vent holes on the strip layer can reduce the interaction force between the solder surfaces during the soldering process, effectively reducing the degree of solder shrinkage at the solder joints, reducing the probability of solder shrinkage on the surface after soldering, and improving the soldering quality; moreover, the vent holes can also increase the way the flux releases gas during soldering, allowing the waste gas generated during soldering to be better discharged, effectively reducing the probability of solder joint porosity formation, reducing the formation of solder joint porosity on the soldering surface, thereby achieving a smoother solder joint after tinning the nickel-plated surface of the device.

[0027] It should be noted that, in this embodiment of the utility model, the strip layer is a tin-lead alloy layer, and the tin-lead alloy layer is one of Sn63Pb37, Sn60Pb40, and Sn62Pb36Ag2.

[0028] During manufacturing, one of the tin-lead alloys selected from Sn63Pb37, Sn60Pb40, and Sn62Pb36Ag2 can be processed to a thickness of 0.1 mm to 0.2 mm using equipment such as a rolling mill, resulting in a strip layer thickness B of 0.1 mm to 0.2 mm. Then, ventilation holes are machined on the surface of the strip layer using equipment such as a laser cutter, marking machine, or die-cutting fixture. Finally, a layer of flux is applied to one side of the perforated strip layer to form a flux layer, thus completing the manufacturing process. The flux layer can be applied to the surface of the strip layer using methods such as printing, dipping, or spraying to form a solder strip with a flux layer.

[0029] It is understood that, in use, the solder strip of this utility model can be cut into any or specific shape and closely attached to the surface of irregularly shaped nickel-plated devices for reflow soldering and tinning.

[0030] In some embodiments of this utility model, the plurality of vent holes are divided into multiple groups of vent holes; each group of vent holes has at least two vent holes, and all the vent holes in each group of vent holes are arranged sequentially along a first straight line direction, wherein the first straight line direction K has an angle with the length direction L of the strip layer, and the plurality of vent hole groups are distributed sequentially along the length direction of the strip layer. That is, the plurality of vent holes in the same group are arranged sequentially along the first straight line direction to facilitate regular processing of the strip layer and make it convenient to use; moreover, in order to adapt to the welding process, the angle A between the first straight line direction and the length direction of the strip layer is 45 degrees so that the vent holes can discharge gas and reduce the interaction force of the solder surface during the welding process.

[0031] Ideally, in order to achieve better exhaust performance, the distance C between two adjacent sets of air holes is 2 mm to 3 mm, and the distance D between two adjacent air holes in the same set of air holes is 0.5 mm to 2 mm.

[0032] It should be noted that the shape of the vent hole can be cylindrical, square, triangular, or hexagonal. That is, the shape of the vent hole can be a variety of regular shapes to allow for selection based on the specific welding conditions, thereby better reducing the interaction forces between the solder surfaces during the welding process and further minimizing the probability of porosity at the solder joint. Optimally, the equivalent diameter R of the vent hole is between 0.05 mm and 0.2 mm.

[0033] The tin-lead alloy layer is one of Sn63Pb37, Sn60Pb40, and Sn62Pb36Ag2, with Sn62Pb36Ag2 alloy used as the strip layer for illustration:

[0034] (Example 1)

[0035] In this embodiment, Sn62Pb36Ag2 alloy solder strip is selected as the nickel-plated surface of the device for tin plating, and the following steps are performed (mm is millimeters):

[0036] Sn62Pb36Ag2 alloy was processed into a 0.2mm thick strip layer. A marking machine was used to penetrate the strip layer to create cylindrical holes with a diameter R of 0.2mm, a spacing D of 2mm between adjacent holes, and a linear spacing C of 3mm between adjacent holes. A layer of flux was then applied to the surface of the perforated strip layer to form a solder strip. The strip was then cut into two sizes: 20*10*0.2mm and 10*10*0.2mm. The solder strips of both sizes were then attached tightly to the nickel-plated surface of the device groove. The mounted devices were then placed in a reflow oven for soldering and tinning. The solder joints of both sizes were observed to be smooth with only a few pores, meeting the requirements for tinning.

[0037] (Example 2)

[0038] In this embodiment, Sn62Pb36Ag2 alloy solder strip is selected as the nickel-plated surface of the device for tin plating, and the following steps are performed:

[0039] Sn62Pb36Ag2 alloy was processed into a 0.1mm thick strip layer. A marking machine was used to penetrate the strip layer to create cylindrical holes with a diameter R of 0.05mm, a spacing D of 0.5mm between adjacent holes, and a linear spacing C of 2mm between adjacent holes. A layer of flux was then applied to the surface of the perforated strip layer to form a solder strip. The strip was then cut into two sizes: 20*10*0.1mm and 10*10*0.1mm. The solder strips of both sizes were then attached tightly to the nickel-plated back of the device groove. The mounted devices were then placed in a reflow oven for soldering and tinning. The solder joints of both sizes were observed to be smooth with only a few pores, meeting the requirements for tinning.

[0040] (Example 3)

[0041] In this embodiment, Sn62Pb36Ag2 alloy solder strip is selected as the nickel-plated surface of the device for tin plating, and the following steps are performed:

[0042] Sn62Pb36Ag2 alloy was processed into a 0.1mm thick strip layer. A marking machine was used to penetrate the strip layer to create triangular prism holes with a diameter R of 0.08mm, a spacing D of 1mm between adjacent holes, and a linear spacing C of 2mm between adjacent holes. A layer of flux was then applied to the surface of the perforated strip layer to form a solder strip. The strip was then cut into 20*10*0.1mm pieces. The solder strips of this size were then attached tightly to the nickel-plated back of the device groove. The mounted devices were then placed in a reflow oven for soldering and tinning. It was observed that the solder joints of this size were smooth with only a few pores, meeting the requirements for tinning.

[0043] (Example 4)

[0044] In this embodiment, Sn62Pb36Ag2 alloy solder strip is selected as the nickel-plated surface of the device for tin plating, and the following steps are performed:

[0045] Sn62Pb36Ag2 alloy was processed into a 0.1mm thick strip layer. A marking machine was used to penetrate the strip layer to create square prism holes with a diameter R of 0.08mm, a spacing D of 1mm between adjacent holes, and a linear spacing C of 2mm between adjacent holes. A layer of flux was then applied to the surface of the perforated strip layer to form a solder strip. The strip was then cut into 20*10*0.1mm pieces. The solder strips of this size were then attached tightly to the nickel-plated back of the device groove. The mounted devices were then placed in a reflow oven for soldering and tinning. It was observed that the solder joints of this size were smooth with only a few pores, meeting the requirements for tinning.

[0046] (Example 5)

[0047] In this embodiment, Sn62Pb36Ag2 alloy solder strip is selected as the nickel-plated surface of the device for tin plating, and the following steps are performed:

[0048] Sn62Pb36Ag2 alloy was processed into a 0.1mm thick solder strip. A marking machine was used to penetrate the strip layer to create hexagonal prism holes with a diameter R of 0.08mm, a spacing D of 1mm between adjacent holes, and a linear spacing C of 2mm between adjacent holes. A layer of flux was then applied to the surface of the perforated strip layer to form the solder strip. The strip was then cut into 20*10*0.1mm pieces. The solder strips of this size were then attached tightly to the nickel-plated back of the device groove. The mounted devices were then placed in a reflow oven for soldering and tinning. It was observed that the solder joints of this size were smooth with only a few pores, meeting the requirements for tinning.

[0049] (Comparative Example 1)

[0050] This comparative example uses Sn62Pb36Ag2 alloy solder strip as the nickel-plated surface of the device for tin plating. Other alloys such as Sn63Pb37 and Sn60Pb40 also exhibit similar characteristics, and the following steps are followed:

[0051] Sn62Pb36Ag2 alloy was processed into a 0.2mm thick solder strip. A layer of flux was applied to the surface of the solder strip, and then it was cut into 20*10*0.2mm sizes. The solder strip of this size was then attached tightly to the nickel-plated surface of the device groove. The mounted device was then placed in a reflow oven for soldering and tinning. It was observed that the solder joints of this size were uneven, with many pores and solder shrinkage, which did not meet the requirements for tinning.

[0052] (Comparative Example 2)

[0053] This comparative example uses Sn62Pb36Ag2 alloy solder strip to tin-plat the nickel-plated surface of the device, and includes the following steps:

[0054] Sn62Pb36Ag2 alloy was processed into a 0.1mm thick solder strip. A layer of flux was applied to the surface of the solder strip, and then it was cut into 20*10*0.1mm sizes. The solder strip of this size was then placed tightly against the nickel-plated surface of the device groove. The mounted device was then placed in a reflow oven for soldering and tinning. It was observed that the solder joints of this size were uneven, with many pores and solder shrinkage, which did not meet the requirements for tinning.

[0055] The experimental results of the above embodiments are shown in Table 1.

[0056] Table 1 Comparison of data between the embodiments and comparative embodiments.

[0057]

[0058]

[0059] In summary, processing vent holes on the strip layer can reduce the interaction force between the solder surface during the soldering process, effectively reducing the degree of solder shrinkage at the solder joint, decreasing the probability of solder shrinkage on the surface after soldering, and improving the soldering quality. Moreover, vent holes can also increase the way flux releases gas during soldering, allowing the waste gas generated during soldering to be discharged more effectively, effectively reducing the probability of solder joint porosity formation, and reducing the formation of solder joint porosity on the soldering surface, thereby achieving a smoother solder joint after tinning on the nickel-plated surface of the device.

[0060] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.

Claims

1. A solder strip for tinning nickel-plated surfaces of devices, characterized in that, include: The material strip layer and the flux layer are provided; the flux layer is laid on one side of the material strip layer, and the material strip layer is provided with multiple vent holes.

2. The solder strip for tinning the nickel-plated surface of a device according to claim 1, characterized in that, The strip layer is a tin-lead alloy layer, and the tin-lead alloy layer is one of Sn63Pb37, Sn60Pb40, and Sn62Pb36Ag2.

3. The solder strip for tinning the nickel-plated surface of a device according to claim 2, characterized in that, The thickness of the strip layer is 0.1 mm to 0.2 mm.

4. The solder strip for tinning the nickel-plated surface of a device according to claim 1, characterized in that, The plurality of vent holes are divided into multiple groups of vent holes; each group of vent holes has at least two vent holes, and all the vent holes in each group of vent holes are arranged sequentially along a first straight line direction, wherein the first straight line direction has an angle with the length direction of the material strip layer, and the plurality of vent holes are distributed sequentially along the length direction of the material strip layer.

5. The solder strip for tinning the nickel-plated surface of a device according to claim 4, characterized in that, The angle between the first straight line direction and the length direction of the strip layer is 45 degrees.

6. The solder strip for tinning the nickel-plated surface of a device according to claim 4, characterized in that, Multiple groups of air holes are distributed sequentially along the length of the strip layer, and the distance between two adjacent groups of air holes is 2 mm to 3 mm.

7. The solder strip for tinning nickel-plated surfaces of devices according to claim 6, characterized in that, The distance between two adjacent vents in the same vent group is 0.5 mm to 2 mm.

8. The solder strip for tinning nickel-plated surfaces of devices according to claim 1, characterized in that, The shape of the vent hole is cylindrical, square, triangular, or hexagonal.

9. The solder strip for tinning nickel-plated surfaces of devices according to claim 8, characterized in that, The equivalent diameter of the vent is 0.05 mm to 0.2 mm.

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