WO2023184788A1 - Welding method, welding structure of elastic electric contact terminal, and electronic device - Google Patents

Abstract

A welding method for welding a first component (400) and a second component (500) made of different metal materials, comprising: stacking a first component on a second component; adhering a first auxiliary layer (140) to the upper surface of the first component by means of an intermediate adhesive layer (150), wherein the laser absorptivity of the first auxiliary layer is greater than the laser absorptivity of the first component, the thickness of the first auxiliary layer is between 35 μm and 100 μm, and the sum of the thickness of the first component and the thickness of the first auxiliary layer is greater than or equal to 50 μm; and emitting laser that sequentially passes through the first auxiliary layer, the first component and the second component to laser weld the first component and the second component. When the welding method is used to weld the elastic electric contact terminal, the first auxiliary layer is arranged to laser weld an conductive layer with low thickness and low laser absorptivity to a heterogeneous metal, thereby reducing the cost of welding. The invention further provides a welding structure of the elastic electric contact terminal, and an electronic device.

Description

Welding method, welding structure of elastic electrical contact terminal and electronic device Technical field

The present application relates to the technical field of communication equipment, and in particular to a welding method, a welding structure of elastic electrical contact terminals, and electronic equipment.

Background technique

In communication devices, in order to prevent electronic equipment from being subject to signal interference or to eliminate static electricity inside the electronic equipment, elastic electrical contact terminals or welding shrapnel are generally used to make electrical connections between two contact surfaces that require electrical contact inside the electronic equipment.

Please refer to the Chinese patent application with publication number CN113993362A and the subject title "A grounding elastomer and electronic equipment". Elastic electrical contact terminals generally include two parts, an elastic member for buffering and rebound and an elastic member for connecting the elastic member. Flexible electrical contact terminals fixed to the base plate. Among them, in this patent application, ultrasonic welding is used to fix the welding segments to the base plate - the metal mid-plate.

However, in this patent application, the ultrasonic welding method requires the design and production of a specific ultrasonic indenter to meet the ultrasonic welding needs of the above-mentioned welding sections. The initial investment cost is high; and the service life of this ultrasonic indenter is limited, so it is difficult to use. It needs to be replaced in time after a period of time, and the cost of later maintenance is also high. It can be seen that the cost of fixing the elastic electrical contact terminals to the substrate using ultrasonic welding is relatively high.

Contents of the invention

An object of the present application is to provide a welding method suitable for welding the conductive layer of the elastic electrical contact terminal to the substrate, which has a lower cost of fixing the conductive layer on the substrate, thereby reducing the production cost of related electronic equipment.

The purpose of this application is achieved through the following technical solutions:

A welding method for welding a first component and a second component that are made of different metal materials. The thickness δ1 of the first component is less than or equal to 25 μm, including:

Stack the first component on the second component;

A first auxiliary layer is adhered to the upper surface of the first component through an intermediate glue layer. The laser absorption rate of the first auxiliary layer is greater than that of the first component; wherein the thickness δ2 of the first auxiliary layer is 35 μm. to 100 μm, the sum of the thickness δ1 of the first member and the thickness δ2 of the first auxiliary layer is greater than or equal to 50 μm;

A laser welding device is used to emit laser light so that the laser light passes through the first auxiliary layer, the first component and the second component in order to laser weld the first component and the second component.

In the welding method of this application, the thickness of the intermediate adhesive layer is h1, and 3 μm ≤ h1 ≤ 10 μm.

In the welding method of this application, 3μm≤h1≤6μm.

In the welding method of the present application, the first auxiliary layer includes a second base material and a metal coating plated on the upper surface of the second base material and used to absorb laser energy. The laser absorption rate of the metal coating is respectively Greater than the laser absorptivity of the first component and the second substrate.

In the welding method of the present application, the intermediate glue layer is one of acrylic pressure-sensitive glue, epoxy hot melt glue, polyurethane thermosetting glue, polyurethane thermoplastic glue and silicone glue.

In the welding method of the present application, before adhering the first auxiliary layer to the upper surface of the first component through the intermediate glue layer, it also includes: The lower surface of the first auxiliary layer is roughened.

In the welding method of the present application, stacking the first component on the second component specifically includes: providing a bottom glue layer on the lower surface of the first component, so that the first component It is bonded to the second component through the bottom glue layer.

In the welding method of this application, the thickness of the bottom adhesive layer is h2, and 3μm≤h2≤10μm.

In the welding method of this application, 3μm≤h2≤6μm.

In the welding method of this application, let the thickness of the middle glue layer be h1, let the thickness of the bottom glue layer be h2, h1+h2≤12 μm.

In the welding method of this application, the bottom glue layer is one of acrylic pressure-sensitive glue, epoxy hot-melt glue, polyurethane thermosetting glue, polyurethane thermoplastic glue, and silicone glue.

In the welding method of the present application, before setting the bottom glue layer on the lower surface of the first component, the method further includes: roughening the lower surface of the first component.

In the welding method of the present application, after the first auxiliary layer is adhered to the upper surface of the first component through the intermediate glue layer, it further includes: using a knife to apply The force toward the first member drives the first auxiliary layer and the first member to simultaneously recess downward until a penetrating force is formed from the upper surface of the first auxiliary layer to the lower surface of the first member. The incision is in the shape of a wedge with a width that gradually decreases from top to bottom. The first auxiliary layer is formed with a bend along the top edge of the incision, and the bend extends downward along the inner peripheral wall of the incision. , and the bent end expands to wrap the lower surface of the first member.

The purpose of this application is also achieved through the following technical solutions:

A welding structure of an elastic electrical contact terminal, including a terminal body and a substrate; the terminal body includes an elastic core and a conductive layer wrapped around the outer periphery of the elastic core, the conductive layer has an outwardly extending protrusion and forms a weld At the end of the segment, the thickness of the conductive layer is 9 μm to 25 μm; the conductive layer and the substrate are made of different metal materials; the welding segment is welded to the substrate by the above welding method, wherein, The welding section is used as the first component, and the substrate is used as the second component.

In the welding structure of the elastic electrical contact terminal of the present application, the substrate is an aluminum plate.

In the welding structure of the elastic electrical contact terminal of the present application, the conductive layer includes a first base material and a conductive coating plated on the outer surface of the first base material; wherein the first base material includes copper, and the conductive coating The anti-oxidation ability of the coating is better than that of the first substrate.

In the welding structure of the elastic electrical contact terminal of the present application, the first base material is electrolytic copper foil or rolled copper foil, and the conductive plating film is a gold layer with a thickness >10 nm or a nickel layer with a thickness >0.3 μm or a thickness greater than 0.1μm tin layer.

In the welding structure of the elastic electrical contact terminal of the present application, the first auxiliary layer includes a second base material and a metal plating film plated on the upper surface of the second base material, and the intermediate adhesive layer is provided on the second base material. Between the upper surface of a base material and the lower surface of the second base material, the second base material includes copper, and the metal plating film includes nickel.

The purpose of this application is also achieved through the following technical solutions:

An electronic device includes a display screen and a welding structure of an elastic electrical contact terminal according to any one of claims 14 to 18; the conductive layer is sandwiched between the display screen and the substrate.

The welding method proposed in this application is suitable for laser welding of first components with small thickness and low laser absorption rate.

Specifically, in the welding method of this application, since the thickness δ1 of the first component is small, in order to ensure that the first component can be welded to the second component, the laser of the first auxiliary layer that first contacts the laser in this application The larger absorption rate ensures that the first component in this application can absorb enough laser energy, so that the laser energy reaching between the first component and the second component is sufficient to form a molten pool.

In the welding method of this application, since the thickness of the first auxiliary layer is greater than or equal to 35 μm and the sum of the thicknesses of the first auxiliary layer and the first member is ≥ 50 μm, it is equivalent to thickening the first member and increasing its laser absorption. Efficient processing ensures that the first component at the micron level can form a molten pool with sufficient depth and strength between the first component and the second component during welding. In addition, when producing the first auxiliary layer, a plurality of first auxiliary layers are generally obtained in batches by cutting a larger-sized blank. In terms of the effect of laser welding, the greater the thickness of the first auxiliary layer, the The better the effect of laser welding, but the greater the thickness of the corresponding blank, the more difficult it is to cut, and the first auxiliary layer obtained after cutting is more likely to produce burrs and other defects, which is not conducive to the improvement of production efficiency. Therefore, the thickness of the first auxiliary layer is not likely to be too large. If the thickness exceeds 100 μm, the production efficiency will be too low. In addition, since the first auxiliary layer has sufficient thickness, it can also play a supporting effect on the structure of the first member and effectively prevent the first member from breaking.

In summary, it can be concluded that the welding method proposed in this application can weld a first component with a smaller thickness and a lower laser absorption rate to a second component of a heterogeneous metal through laser welding by providing a first auxiliary layer; When the welding method is applied to the welding of elastic electrical contact terminals, using laser welding instead of ultrasonic welding can reduce the cost of welding and solve the technical problem of high ultrasonic welding cost raised in the background art. For details, please refer to the second aspect of this application. Proposed welding structure of elastic electrical contact terminals.

Description of drawings

The present application will be described in further detail below with reference to the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn for the purpose of explaining the preferred embodiments only, and therefore should not be used as a basis for the present application. Scope limitations.

Figure 1 is a flow chart of the welding method proposed according to the first aspect of the embodiment of the present application.

Figure 2 is a schematic diagram of the welding of the first component and the second component in the welding method proposed according to the first aspect of the embodiment of the present application.

3 is a schematic structural diagram of the terminal body in the welding structure of the elastic electrical contact terminal proposed according to the second aspect of the embodiment of the present application.

Figure 4 is an enlarged view of point A in Figure 3.

FIG. 5 is a structural diagram when cuts and bends are formed in the welding structure of the elastic electrical contact terminal proposed according to the second aspect of the embodiment of the present application.

FIG. 6 is a structural diagram of an electronic device according to the third aspect of the embodiment of the present application.

In the picture,

100. Terminal body; 110. Elastic core; 120. Heat-resistant polymer film layer;

130. Conductive layer; 131. Welding section; 132. First base material; 133. Conductive coating; 134. Incision;

140. First auxiliary layer; 141. Second base material; 142. Metal coating; 143. Bending;

150. Middle glue layer; 160. Bottom glue layer; 170. Adhesive layer;

200. Substrate;

300. Display screen;

400. First component;

500. Second component.

Detailed ways

Preferred embodiments of the present application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are descriptive and exemplary only and should not be construed as limiting the scope of the present application.

First of all, it should be noted that the top, bottom, upward, downward and other directions mentioned in this article are defined relative to the directions in each drawing. They are relative concepts, and therefore can be defined according to their respective It changes with different positions and different practical states. Therefore, these or other terms should not be construed as limiting terms.

It should be noted that the term "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude the plural.

In addition, it should also be noted that any single technical feature described or implied in the embodiments herein, or any single technical feature shown or implied in the drawings, can still be used in these technical features (or their equivalents). Combinations continue to be made between objects) to obtain other embodiments of the application not directly mentioned herein.

It should also be understood that the terms "first", "second", etc. are used herein to describe various information, but this information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, "first" information may also be called "second" information, and similarly, "second" information may also be called "first" information.

It should be noted that in different drawings, the same reference numbers refer to the same or substantially the same components.

Referring to FIGS. 1-2 , the first aspect of the present application proposes a welding method for welding the first member 400 and the second member 500 which are made of different metal materials, wherein the thickness δ1 of the first member 400 is Between 9μm and 25μm, including:

Step S100: stack the first component 400 on the second component 500.

Step S200: adhere the first auxiliary layer 140 to the upper surface of the first component 400 through the intermediate glue layer 150. The laser absorption rate of the first auxiliary layer 140 is greater than that of the first component 400; wherein, the thickness δ2 of the first auxiliary layer 140 is Between 35 μm and 100 μm, the sum of the thickness δ1 of the first member 400 and the thickness δ2 of the second member 500 is greater than or equal to 50 μm.

Step S300: Use a laser welding device to emit laser light so that the laser light passes through the first auxiliary layer 140, the first component 400 and the second component 500 in order to laser weld the first component 400 and the second component 500.

Among them, in the welding method proposed in this application, the function of the first auxiliary layer 140 is mainly used to absorb laser energy, so that the laser energy reaching between the first component 400 and the second component 500 is sufficient; since the materials have different wavelengths, The laser absorption rate is different. Therefore, as the laser welding parameters are different, such as the wavelength of the laser welding, the material selection of the first auxiliary layer 140 will also be different.

The function of the intermediate glue layer 150 is to relatively fix the first component 400 and the first auxiliary layer 140 before laser welding, so that no misalignment occurs between the first auxiliary layer 140 and the first component 400 during laser welding. situation to ensure the progress of laser welding. In one embodiment, the area of the first member 400 is not less than 1.5mm×1.5mm, that is, the first member 400 is rectangular, and its length and width are respectively greater than or equal to 1.5mm. At this time, the middle glue layer 150 is configured as: After the intermediate adhesive layer 150 is provided, the relative peeling force at an angle of 180 degrees between the first auxiliary layer 140 and the first member 400 is greater than or equal to 500gf/25mm; more preferably, the relative peeling force is greater than or equal to 800gf/25mm to ensure that The first component 400 and the first auxiliary layer 140 are relatively fixed before laser welding.

The welding method proposed in this application is suitable for laser welding the first component 400 with a small thickness and low laser absorption rate.

However, in the existing technology, laser welding is generally suitable for welding components with large thickness or large laser absorption rate, because components with too small thickness will be directly penetrated by laser energy during laser welding, and the laser absorption rate Smaller components are difficult to weld because they are difficult to absorb laser energy; therefore, when welding some common materials, due to different laser parameters and different laser absorption rates of the materials, the materials are often required to have different thicknesses to ensure that the materials will not be Welding through; at the same time, the smaller the laser absorption rate of the material, the greater the thickness that can be used for laser welding to ensure that the material can absorb sufficient laser energy. Table 1 below lists the thickness required for laser welding of some materials:

【Table 1】

Material type	Thickness/mm	Pulse laser energy/J	Pulse width/ms
Pure copper foil	0.1	2.3	4.0
stainless steel sheet	0.29	1.21	3.7

It can be seen that generally, when the thickness of the material reaches the micron level, especially when it reaches the ten-digit micron level, laser welding processing will not be considered in the existing technology; the laser welding method proposed in this application overcomes the existing problems. Due to technical bias, laser welding is applied to the first component 400 with a thickness of micron level and a small laser absorption rate.

Specifically, in the welding method of the present application, since the thickness δ1 of the first component 400 is small, in order to ensure that the first component 400 can be welded to the second component 500, the first auxiliary device in the present application first contacts the laser. The laser absorption rate of layer 140 is relatively large, which ensures that the first component 400 in this application can absorb sufficient laser energy, so that the laser energy reaching between the first component 400 and the second component 500 is sufficient to form a molten pool.

In the welding method of the present application, since the thickness of the first auxiliary layer 140 is greater than or equal to 35 μm and the sum of the thicknesses of the first auxiliary layer 140 and the first member 400 is ≥50 μm, it is equivalent to thickening the first member 400 and The process of increasing its laser absorption rate ensures that a molten pool with sufficient depth and strength can be formed between the micron-level first component 400 and the second component 500 during welding. In addition, when the first auxiliary layer 140 is produced, a plurality of first auxiliary layers 140 are generally obtained in batches by cutting a larger-sized blank. In terms of the effect of laser welding, the thickness of the first auxiliary layer 140 The larger the thickness, the better the effect of laser welding. However, the greater the thickness of the corresponding blank, the more difficult it is to cut, and the first auxiliary layer 140 obtained after cutting is more likely to have defects such as burrs, which is not conducive to production. The efficiency is improved, so the thickness of the first auxiliary layer 140 is not likely to be too large. If the thickness exceeds 100 μm, the production efficiency will be too low. In addition, since the first auxiliary layer 140 has sufficient thickness, it can also provide a supporting effect on the structure of the first member 400 and effectively prevent the first member 400 from breaking.

In summary, it can be concluded that the welding method proposed in the first aspect of the present application can laser weld the first component 400 with a smaller thickness and lower laser absorption rate to the second component 500 of a heterogeneous metal by providing the first auxiliary layer 140 Above; when applying the welding method of this application to the welding of elastic electrical contact terminals, using laser welding instead of ultrasonic welding can reduce the cost of welding and solve the technical problem of high ultrasonic welding cost raised in the background art. For details, please Please refer to the welding structure of the elastic electrical contact terminal proposed in the second aspect of this application.

Preferably, in one embodiment, the thickness of the intermediate adhesive layer 150 is h1, and 3 μm≤h1≤10 μm. For the middle adhesive layer 150, the greater the thickness, the better the bonding effect, that is to say, the better the stability between the first auxiliary layer 140 and the first component 400 before laser welding. However, during laser welding, the thicker the middle glue layer 150, the greater the obstruction to the conduction of laser energy, resulting in worse laser welding effects; in addition, the resistance of the middle glue layer 150 after laser welding is higher, affecting the resistance of the elastic electrical contact terminals. ; Therefore, the thickness of the middle glue layer 150 should not be too large and must satisfy h1 ≤ 10 μm; however, the smaller the thickness of the middle glue layer 150, the better the connection stability between the first auxiliary layer 140 and the first component 400 before laser welding. The worse, the relative position fixing effect is limited, which is not conducive to laser welding. Therefore, the thickness of the middle adhesive layer 150 should not be too small and must satisfy h1≥3μm.

As a further preferred method, 3 μm ≤ h1 ≤ 6 μm to ensure that the intermediate adhesive layer 150 will not hinder the transmission of laser energy and affect the welding effect. As for the connection stability between the first auxiliary layer 140 and the first component 400 before laser welding, it can be further ensured through other methods; it should be noted that the description of other methods in this preferred embodiment does not limit this preferred method. The implementation of the embodiment must rely on other methods to stabilize the connection stability between the first auxiliary layer 140 and the first component 400 before laser welding. Even without other methods, the intermediate adhesive layer 150 still has a certain degree of adhesion ability to ensure laser welding. Connection stability between the first auxiliary layer 140 and the first component 400 before welding.

Among them, the first auxiliary layer 140 needs to have both good bonding effect with the intermediate adhesive layer 150 and high laser absorption rate. Optionally, the first auxiliary layer 140 can be made of silver-nickel copper, carbon steel, aluminum foil, etc. But preferably, the first auxiliary layer 140 includes a second substrate 141 and a metal coating 142 plated on the upper surface of the second substrate 141 and used to absorb laser energy. The laser absorption rate of the metal coating 142 is greater than that of the first component 400 respectively. and the laser absorption rate of the second substrate 141. Among them, the second base material 141 is used to bond with the first base material 132 through the intermediate adhesive layer 150, and the metal coating 142 is used to absorb sufficient laser energy; such an arrangement can easily achieve the guarantee and the intermediate adhesive layer at the same time. The adhesion effect between the layers 150 and the effect of being able to absorb sufficient energy of the laser energy do not need to be unduly harsh in the selection of the first auxiliary layer 140, so there is no need to repeatedly verify which material can simultaneously meet the requirements of good laser absorption rate and The requirement of being able to adhere well to the intermediate adhesive layer 150 increases the manufacturing steps of plating the metal film layer on the second substrate 141, but reduces the difficulty of material selection and can better control the cost of the product.

Optionally, the middle glue layer 150 can be one of acrylic pressure-sensitive glue, epoxy hot melt glue, polyurethane thermosetting glue, polyurethane thermoplastic glue, and silicone glue. Specifically, the cost, bonding effect, and Laser energy conduction hindrance effect and other factors are selected.

Further, in some embodiments, before adhering the first auxiliary layer 140 to the upper surface of the first member 400 through the intermediate glue layer 150 , that is, before step S200 , the method further includes: At least one of the surface and the lower surface of the first auxiliary layer 140 is roughened. Due to the small thickness of the intermediate adhesive layer 150, the bonding effect with the upper surface of the first member 400 and the lower surface of the first auxiliary layer 140 is limited. At least one surface of the lower surface of an auxiliary layer 140 is roughened, which can improve the bonding effect between the intermediate adhesive layer 150 and the roughened surface. Preferably, the upper surface of the first member 400 and the lower surface of the first auxiliary layer 140 are roughened at the same time, so that the intermediate adhesive layer 150 can achieve a better bonding effect.

Optionally, there are many methods of roughening treatment, such as using chemical reagents for etching, which are not limited here.

Further, the step S100 of stacking the first component 400 on the second component 500 specifically includes: providing a bottom glue layer 160 on the lower surface of the first component 400 to allow the first component 400 to pass through The bottom glue layer 160 is bonded to the second component 500 so that the first component 400 can be preliminarily fixed to the second component 500 before laser welding, thereby ensuring the progress of laser welding without requiring additional components like traditional laser welding. Positioning fixture. Wherein, when the conductive coating 133 is provided, the bottom glue layer 160 adheres to the lower surface of the conductive coating 133 of the first component 400 .

Preferably, in one embodiment, the thickness of the bottom glue layer 160 is h2, and 3 μm≤h2≤10 μm. The bottom glue layer 160 is similar to the middle glue layer 150 in that the bonding effect increases with the increase in thickness, but the resistance to the conduction of laser energy also increases with the increase in thickness, so the bottom glue layer 160 should also not be too large or too small, and must satisfy 3μm≤h2≤10μm.

As a further preferred method, 3 μm ≤ h2 ≤ 6 μm to ensure that the bottom adhesive layer 160 will not hinder the transmission of laser energy and affect the welding effect.

Furthermore, the sum of the thickness of the middle glue layer 150 and the thickness of the bottom glue layer 160 is h1 + h2 ≤ 12 μm to further ensure the effect of laser energy transmission.

Optionally, the bottom glue layer 160 can be one of acrylic pressure-sensitive glue, epoxy hot melt glue, polyurethane thermosetting glue, polyurethane thermoplastic glue, and silicone glue. Specifically, the cost, bonding effect, and Laser energy conduction hindrance effect and other factors are selected.

Further, in some embodiments, the method further includes: roughening the lower surface of the first component 400 before disposing the bottom glue layer 160 on the lower surface of the first component 400 .

In this embodiment, similarly, the bonding effect of the bottom glue layer 160 with limited thickness is limited. By roughening the lower surface of the first member 400, the bond between the bottom glue layer 160 and the lower surface of the first member 400 can be improved. The bonding effect between them.

Similarly, there are many methods of roughening treatment, such as using chemical reagents for etching, which are not limited here.

Further, in some embodiments, before arranging the bottom glue layer 160 on the lower surface of the first component 400, the method further includes: using a knife to apply a glue on the upper surface of the first auxiliary layer 140 toward the first auxiliary layer 140. The force of a member 400 drives the first auxiliary layer 140 and the first member 400 to recess downward at the same time until a penetrating form is formed from the upper surface of the first auxiliary layer 140 to the lower surface of the first member 400 . The cutout 134 on the surface is in the shape of a wedge with a width that gradually decreases from top to bottom. The first auxiliary layer 140 is formed with a bend 143 along the top edge of the cutout 134. The bend 143 is formed along the top edge of the cutout 134. The inner peripheral wall of the cutout 134 extends downward, and the end of the bend 143 expands to wrap the lower surface of the first member 400 , as shown in FIG. 4 .

In this embodiment, considering that the intermediate glue layer 150 cannot be too thick to affect the laser energy conduction, there is a problem of poor relative connection stability between the first auxiliary layer 140 and the first component 400 before laser welding. Through the above-mentioned folding The mutual cooperation between the bend 143 and the cutout 134 enables a lock-like structure to be formed between the first auxiliary layer 140 and the first member 400, thereby improving the stability of the connection between the first auxiliary layer 140 and the first member 400. sex.

Optionally, in some embodiments, the number of cuts 134 and bends 143 formed is multiple to form multiple lock-like structures, further improving the stability between the first auxiliary layer 140 and the first member 400 . connection stability. Multiple lock-like structures can be formed by providing multiple force-applying parts on the tool or by applying force multiple times through the tool.

Considering that the intermediate glue layer 150 cannot be too thick to affect the laser energy conduction, there is a problem of poor relative connection stability between the first auxiliary layer 140 and the first component 400 before laser welding. Furthermore, in some embodiments, It also includes: disposing a second auxiliary layer below the first component 400 .

A cutter is used to apply a predetermined force toward the first member 400 on the upper surface of the first auxiliary layer 140 to drive the first auxiliary layer 140 , the first member 400 and the second auxiliary layer to simultaneously dent downwardly until the first auxiliary layer 140 is formed. The cutout 134 extends from the upper surface to the lower surface of the second auxiliary layer. The cutout 134 is in the shape of a wedge with a gradually decreasing width from top to bottom. The first auxiliary layer 140 is formed with a bend 143 along the top edge of the cutout 134. The bend 143 is formed along the top edge of the cutout 134. The inner peripheral wall of the cutout 134 extends downward, and the end of the bend 143 expands to wrap the lower surface of the second auxiliary layer.

Therefore, in the above embodiment, through the mutual cooperation between the bends 143 and the cuts 134, a more stable locking structure can be formed between the first auxiliary layer 140, the first member 400 and the second auxiliary layer. Thereby, the connection stability between the first auxiliary layer 140 and the first member 400 is further improved.

During laser welding, in the elastic electrical contact terminal of this embodiment, during laser welding, a molten pool is formed between the second auxiliary layer and the second member 500 and fixed as a whole, which is different from the solution in which the second auxiliary layer is not provided. Compared with, firstly, the connection effect is more stable; secondly, since the thickness of the first component 400 is further increased, the laser welding effect is better; however, the solution of setting the second auxiliary layer is more difficult in production and processing. .

Referring to Figures 2 to 4, the second aspect of the present application proposes a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; the terminal body 100 includes an elastic core 110 and an elastic core wrapped around the outer circumference of the elastic core 110. The conductive layer 130 has an end that extends outward and forms a welding section 131. The thickness of the conductive layer 130 is 9 μm to 25 μm; the conductive layer 130 and the substrate 200 are made of different metal materials; Wherein, the welding section 131 is welded to the substrate 200 through the welding method proposed in the first aspect of this application, wherein the welding section 131 is used as the first component 400 and the substrate 200 is used as the Second component 500.

Specifically, when the terminal body 100 of the present application is fixed on the substrate 200 by laser welding, the first auxiliary layer 140 is first adhered to the upper surface of the welding section 131 using the intermediate adhesive layer 150, and then the welding section 131 is set on the substrate 200. Then, the laser welding device is used to emit laser light. The emitted laser light passes through the first auxiliary layer 140, the intermediate adhesive layer 150 and the welding section 131 in sequence and reaches the gap between the lower surface of the welding section 131 and the substrate 200, and the welding is performed. The segment 131 and the base plate 200 are welded respectively, so that the welding segment 131 is welded to the base plate 200 .

Among them, the above-mentioned conductive layer 130 is mainly used on the elastic electrical contact terminal as a conductive path to conductively connect the energized components that need electromagnetic shielding, elimination of signal interference or grounding, such as the display screen 300, to other components, such as the second component 500. . The thickness δ1 of the conductive layer 130 is between 9 μm and 25 μm, which meets the resilience performance requirements of the elastic core 110 and the miniaturization requirements of the terminal body 100 .

In addition, in the process of obtaining the welding structure of the elastic electrical contact terminal of the present application, the inventor of the present application thought of using laser welding to replace the existing ultrasonic welding to reduce the production cost required for welding the conductive layer 130 with a smaller thickness. Finally, it is further concluded that this embodiment also overcomes the following technical difficulties:

First, when performing laser welding, the first component 400 in this solution cannot be simply thickened to enable it to be laser welded. The reason is that this solution involves elastic electrical contact terminal products in the field of communication equipment technology. , in application, the first member 400 is a part of the conductive layer 130. If the first member 400 needs to be thickened, the conductive layer 130 must be thickened, and because the conductive layer 130 has average resilience, thickening The conductive layer 130 will then inhibit the elastic core 110 of the elastic electrical contact terminal from rebounding after being compressed, resulting in a reduction in the resilience of the elastic core 110 , thereby affecting the operation of the elastic electrical contact terminal. Moreover, the greater the thickness of the first member 400, the greater the space required for installing the elastic electrical contact terminals, which is not conducive to the miniaturization design of the elastic electrical contact terminals.

Second, when performing laser welding, the thickness of the first member 400 cannot be increased by repeatedly folding the first member 400 so that it can be laser welded. The reason is that if the first member 400 is repeatedly folded to form a larger If the thick first member 400 is to be laser welded, it must be folded at least multiple times. The multi-layered first member 400 formed after folding is not suitable for setting an adhesive layer for bonding. On the one hand, it consumes a large amount of adhesive layer, and on the other hand, it consumes a lot of adhesive layer. On the one hand, the operation is not convenient, because the multi-layer first component 400 often needs to be pressed with a customized jig to ensure that the gaps between the layers can be eliminated during the laser welding process to ensure the laser welding effect. However, the volume of this application is small Moreover, the space where the installation is located is small, and the setting of the jig is restricted; moreover, the setting of the jig correspondingly increases the cost, and the laminating process of the jig also limits the production efficiency.

Optionally, when the first auxiliary layer 140 with a laser absorption rate greater than that of the first member 400 and a thickness δ2 between 35 μm and 100 μm is adhered to the upper surface of the first member 400 through the intermediate glue layer 150 , the first auxiliary layer 140 can be bonded by pressing The first auxiliary layer 140 is pressed onto the middle adhesive layer 150 in this way. It should be noted that the lamination here is different from the lamination using multi-layer folded copper foil. The lamination here refers to the lamination process required before laser welding to produce the elastic electrical contact terminals of the present application. The lamination can be completed after the lamination is completed. The jig is removed, and during the laser welding process, the first auxiliary layer 140 and the first component 400 are fixed by the intermediate glue layer 150; and the lamination of multi-layer folded copper foil requires that the jig be kept pressed until the laser welding is completed. The fixture can be removed.

Preferably, the substrate 200 is an aluminum plate.

Preferably, in some embodiments, the conductive layer 130 includes a first base material 132 and a conductive plating film 133 plated on the lower surface of the first base material 132; wherein, the first base material 132 includes copper, and the conductive plating film 133 is The anti-oxidation ability is better than that of the first substrate 132 . The conductive coating 133 is mainly used to create an electrical connection with the substrate 200 after the welding section 131 is fixed on the substrate 200 by laser welding, so as to obtain the effects of electromagnetic shielding, elimination of signal interference, grounding, etc. and to keep it from being oxidized for a long time; the above-mentioned conductivity The anti-oxidation ability of the coating 133 is better than that of the first substrate 132. This means that under the temperature of the working environment of the elastic electrical contact terminal, the material selection of the conductive coating 133 is different as the anti-oxidation ability requirements of the working environment of the elastic electrical contact terminal are different. .

When the bottom adhesive layer 160 adheres to the conductive coating 133, the lower surface of the first component 400 is roughened, specifically: the lower surface of the conductive coating 133 is roughened.

Optionally, the first substrate 132 is rolled copper foil. Preferably, the first base material 132 is electrolytic copper foil. Compared with rolled copper foil, electrolytic copper foil has higher conductivity, and one side surface of the electrolytic copper foil has a rough burr surface, which is more conducive to adhesion with the intermediate adhesive layer 150. Together, the connection stability between the intermediate adhesive layer 150 and the first base material 132 is improved.

Optionally, the conductive coating 133 can be a gold layer with a thickness >10 nm, a nickel layer with a thickness >0.3 μm, or a tin layer with a thickness greater than 0.1 μm, to meet the conductive connection requirements between the welding section 131 and the substrate 200 .

Optionally, the first auxiliary layer 140 can be made of silver-nickel copper, carbon steel, aluminum foil, etc.; but preferably, the first auxiliary layer 140 includes the second base material 141 and is plated on the upper surface of the second base material 141 and is used to absorb The laser energy of the metal coating 142 and the laser absorption rate of the metal coating 142 are respectively greater than the laser absorption rates of the first substrate 132 and the second substrate 141. Among them, the second base material 141 is used to bond with the first base material 132 through the intermediate adhesive layer 150, and the metal coating 142 is used to absorb sufficient laser energy; such an arrangement can easily achieve the guarantee and the intermediate adhesive layer at the same time. The adhesion effect between the layers 150 and the effect of being able to absorb sufficient energy of the laser energy do not need to be unduly harsh in the selection of the first auxiliary layer 140, so there is no need to repeatedly verify which material can simultaneously meet the requirements of good laser absorption rate and The requirement of being able to adhere well to the intermediate adhesive layer 150 increases the manufacturing steps of plating the metal film layer on the second substrate 141, but reduces the difficulty of material selection and can better control the cost of the product.

The metal plating film 142 includes nickel, and the second base material 141 includes copper foil. Compared with other materials, the copper foil used as the second base material 141 of the first auxiliary layer 140 used in this preferred manner has lower strength, so even if its thickness is larger, it can be more easily formed from a larger size. Multiple first auxiliary layers 140 are cut from the large blank to ensure that the first auxiliary layer 140 with thickness δ2≥35 μm and satisfying δ1+δ2≥50 μm can be cut. In other words, the first auxiliary layer 140 of this preferred mode The processing is more convenient; moreover, the first base material 132 and the second base material 141 are made of the same material, have the same chemical properties and physical properties, and are less difficult to laser weld.

Further, in some embodiments, the terminal body 100 further includes a heat-resistant polymer film layer 120; the heat-resistant polymer film layer 120 is bonded to the outer periphery of the elastic core 110, and the conductive layer 130 includes an upper conductive portion connected in sequence, The side conductive part and the lower conductive part, the welding section 131 is formed by the lower conductive part protruding outward in a direction parallel to the lower surface of the elastic core 110; the upper conductive part is bonded to the upper surface of the heat-resistant polymer film layer 120, and the lower conductive part is bonded to the upper surface of the heat-resistant polymer film layer 120. The portion is bonded to the lower surface of the heat-resistant polymer film layer 120.

Based on the above embodiments, the elastic electrical contact terminal has a P-shaped structure as a whole, and the elastic core 110 is fully wrapped around the elastic core 110 by the heat-resistant polymer film layer 120 and the conductive layer 130, which can better protect the elastic core 110. , to prevent the right opening position of the elastic core 110 from delamination and other damage during use, and improve the service life.

Optionally, the elastic electrical contact terminal also includes an adhesive layer 170, and the heat-resistant polymer film layer 120 is bonded to the outer periphery of the elastic core 110 through the adhesive layer 170. For details, please refer to the publication number CN113993362A, the subject name is "One Chinese patent application for "Grounding Elastomer and Electronic Equipment".

In the welding structure of the elastic electrical contact terminal proposed by the present application, the conductive layer 130 and the substrate 200 are welded into one body by the welding method of the first aspect. Therefore, it has all the beneficial effects of the welding method proposed by the first aspect, which will not be discussed here. Repeat.

The welding structure of the elastic electrical contact terminal of the present application will be further described in detail below using specific examples and comparative examples. The area of the laser welding area in the following examples and comparative examples is a rectangular area of 3mm×5mm, and the solder joint size is 0.36mm/ , the solder joints are arranged in 2 rows × 4 columns or 4 rows × 4 columns. In the same row or column, the spacing between adjacent solder joints is 0.2mm. The substrate 200 is a 6063 aluminum plate. The parameters of laser welding are as follows :

The speed is 0mm/s to 60mm/s, the power is 30% to 100%, the frequency is 0KHz to 180KHz, and the Q pulse width is 15ns to 200ns.

The following examples are examples and do not limit this application.

Example 1

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 25 μm, the thickness δ2 of the first auxiliary layer 140 is 35 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 2

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 25 μm, the thickness δ2 of the first auxiliary layer 140 is 100 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 3

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 38 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 4

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 5

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 3 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 6

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 7

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 10 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Example 8

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 3 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and nickel plating layer, the thickness of the bottom adhesive layer 160 is 3 μm.

Example 9

This embodiment provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive plating film 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 3 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and a nickel plating layer, the thickness of the bottom adhesive layer 160 is 6 μm.

Comparative example 1

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 25 μm, the thickness δ2 of the first auxiliary layer 140 is 30 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Comparative example 2

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 25 μm, the thickness δ2 of the first auxiliary layer 140 is 110 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Comparative example 3

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 35 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Comparative example 4

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 1 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Comparative example 5

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 12 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, there is no bottom adhesive layer 160.

Comparative example 6

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and a nickel plating layer, the thickness of the bottom adhesive layer 160 is 1 μm.

Comparative example 7

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 6 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and a nickel plating layer, the thickness of the bottom adhesive layer 160 is 12 μm.

Comparative example 8

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 8 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and the metal coating 142 produced by the nickel plating layer, the thickness of the bottom adhesive layer 160 is 6 μm.

Comparative example 9

This comparative example provides a welding structure of an elastic electrical contact terminal, including a terminal body 100 and a substrate 200; wherein the first base material 132 is an electrolytic copper foil, the conductive coating 133 is a gold plating layer with a thickness greater than 10 nm, and the thickness of the welding section 131 is δ1 is 12 μm, the thickness δ2 of the first auxiliary layer 140 is 50 μm, the middle glue layer 150 is made of acrylic pressure-sensitive glue, the thickness h1 of the middle glue layer 150 is 3 μm, and the first auxiliary layer 140 includes a second base material made of copper foil 141 and a nickel plating layer, the thickness of the bottom adhesive layer 160 is 10 μm.

The following performance tests were performed on Examples 1 to 10 and Comparative Examples 1 to 8:

1. Tensile strength. The tensile strength refers to the maximum value of the tensile force that the terminal body 100 can withstand after it is welded and fixed to the substrate 200. When the force away from the substrate 200 is greater than the tensile strength, the terminal body 100 will peel off from the substrate 200. The tensile strength is The larger the value, the greater the welding bonding strength, which can be determined by, for example, a tensile testing device. In the welding structure of the elastic electrical contact terminal proposed in the second aspect of the present application, the sum of the tensile strength and the thickness of the first auxiliary layer 140, the thickness of the first auxiliary layer 140 and the thickness of the welding section 131, the intermediate glue layer 150 and The bottom adhesive layer 160 is all related. When the tensile strength is greater than 5N, it is considered that the tensile strength can meet the usage requirements.

2. Contact resistance. Contact resistance refers to the resistance value between the terminal body 100 and the substrate 200 after welding. The smaller the contact resistance, the better the conduction effect of the terminal body 100, that is, the better the terminal body 100's ability to ground or eliminate signal interference. This can be determined by resistance testing. In the welding structure of the elastic electrical contact terminal proposed in the second aspect of this application, the contact resistance is mainly related to the middle glue layer 150 and the bottom glue layer 160. The contact resistance is below 0.3 Ω. It is considered that the contact resistance can meet the usage requirements.

3. Auxiliary layer production efficiency. In the welding structure of the elastic electrical contact terminal proposed in the second aspect of this application, the production efficiency of the auxiliary layer is mainly limited by the thickness of the first auxiliary layer. The greater the thickness of the first auxiliary layer, the lower the production efficiency of the auxiliary layer.

4. Stability before welding. In the welding structure of the elastic electrical contact terminal proposed in the second aspect of this application, the stability before welding refers to the connection stability between the welding section 31, the first auxiliary layer 130 and the substrate 200 before laser welding. The stability before welding is mainly Limited by the thickness of the middle glue layer 150 and the bottom glue layer 160, the greater the thickness of the middle glue layer 150 and the bottom glue layer 160, the better the stability before welding. Its size is represented by levels. The larger the number of levels, the better the stability before welding.

5. Material versatility. In the welding structure of the elastic electrical contact terminal proposed in the second aspect of this application, material versatility mainly refers to the applicability of the selected middle glue layer 150 , bottom glue layer 160 and first auxiliary layer 140 to conductive layers 130 of various thicknesses. ; Among them, the middle glue layer 150 and the bottom glue layer 160 can be suitable for the production of conductive layers 130 of various thicknesses, and the thickness of the first auxiliary layer 140 needs to ensure that the corresponding conductive layer 130 can be laser welded, so the versatility of the material is important. Limited by the thickness of the first auxiliary layer 140, the smaller the thickness of the first auxiliary layer 140, the greater the thickness requirement of the conductive layer 130 that can be used for production, but the upper limit of the thickness of the conductive layer 130 is limited by the elastic terminal's resilience requirements. That is to say, the thickness of the conductive layer 130 needs to meet the requirements of less than or equal to 25 μm at the same time. Therefore, the smaller the thickness range of the conductive layer 130 that can actually be produced, the lower the material versatility; for example, the first auxiliary layer with a thickness of 35 μm is only suitable for products with a thickness of 15 μm to The first auxiliary layer with a thickness of 50 μm is suitable for the production of elastic electrical contact terminals with a conductive layer 130 having any thickness from 9 μm to 25 μm.

The test results of Examples 1 to 9 are shown in Table 2 below, and the test results of Comparative Examples 1 to 9 are shown in Table 3 below.

【Table 2】

​	Example 1	Example 2	Example 3	Example 4	Example 5
δ1/μm	25	25	12	12	12
h1/μm	6	6	6	6	3
δ2/μm	35	100	38	50	50
δ1+δ2/μm	60	125	50	62	62
h2/μm	/	/	/	/	/
h1+h2/μm	6	6	6	6	3
Tensile strength/N	7.5	15.2	5.5	8.5	9
Contact resistance/Ω	0.01	0.01	0.01	0.01	0.01
Auxiliary layer production efficiency	high	Low	medium	medium	medium
Stability before welding	Level 2	Level 2	Level 2	Level 2	Level 1
Material versatility	Low	high	medium	medium	medium

[Continued Table 2]

​	Example 6	Example 7	Example 8	Example 9
δ1/μm	12	12	12	12
h1/μm	6	10	6	6
δ2/μm	50	50	50	50
δ1+δ2/μm	62	62	62	62
h2/μm	/	/	3	6
h1+h2/μm	6	10	9	12
Tensile strength/N	8	5.2	9.1	6.9
Contact resistance/Ω	0.02	0.1	0.1	0.2
Auxiliary layer production efficiency	medium	medium	medium	medium
Stability before welding	Level 2	Level three	Level three	Level 4
Material versatility	medium	medium	medium	medium

【table 3】

​	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5
δ1/μm	25	25	12	12	12
h1/μm	6	6	6	1	12
δ2/μm	25	110	25	50	50
δ1+δ2/μm	50	135	37	62	62
h2/μm	/	/	/	/	/
h1+h2/μm	6	6	6	1	12
Tensile strength/N	3.6	15.2	1.2	9	2.8
Contact resistance/Ω	0.01	0.01	0.01	0.01	0.1
Auxiliary layer production efficiency	extremely high	extremely low	high	medium	medium
Stability before welding	Level 2	Level 2	Level 2	Level zero	Level 4
Material versatility	extremely low	extremely high	Low	medium	medium

[Continued from Table 3]

​	Comparative example 6	Comparative example 7	Comparative example 8	Comparative example 9
δ1/μm	12	12	12	12
h1/μm	6	6	8	12
δ2/μm	50	50	50	50
δ1+δ2/μm	60	62	62	62
h2/μm	1	12	6	6
h1+h2/μm	7	18	14	18
Tensile strength/N	8	0.7	2.3	1
Contact resistance/Ω	0.02	2.0	0.4	1.8
Auxiliary layer production efficiency	medium	medium	medium	medium
Stability before welding	Level 2	Level 5	Level 4	Level 5
Material versatility	medium	medium	medium	medium

Among them, regarding the values of the thickness of the first auxiliary layer 140, the middle glue layer 150 and the bottom glue layer 160, in the actual production process, since the difference is about 1 μm, it is difficult to process and the effect difference is not significant, so the first auxiliary layer 140, the middle glue layer 160 are difficult to process. The thicknesses that can be selected for the glue layer 150 and the bottom glue layer 160 are not continuous, but are single values. For example, the thickness of the first auxiliary layer 140 is generally selected at intervals of 5 μm or 10 μm. The thickness of the middle glue layer 150 and The thickness of the bottom adhesive layer 160 is generally selected at intervals of 2 μm or 3 μm.

Comparing Examples 1 to 9 and Comparative Examples 1 to 9, it can be found that:

First, regarding the thickness selection of the first auxiliary layer 140:

Comparing Example 1, Example 2, Comparative Example 1 and Comparative Example 2, it can be seen that as the thickness of the first auxiliary layer 140 increases, the production efficiency of the auxiliary layer becomes lower and the material versatility becomes higher. The production efficiency of the auxiliary layer in Example 2 has reached a low value. If the thickness of the first auxiliary layer 140 continues to increase to greater than 100 μm, as shown in Comparative Example 2, the production efficiency of the auxiliary layer is extremely low and cannot meet the production efficiency requirements of the auxiliary layer; the material of Embodiment 1 The versatility has reached a low value. If the thickness of the first auxiliary layer 140 is continued to be reduced, as shown in Comparative Example 1, the material versatility is extremely low because the thickness of the first auxiliary layer accounts for the sum of the thickness of the first auxiliary layer and the conductive layer. The proportion of the molten pool is low, so the depth of the molten pool formed is shallow and the tensile strength is also very low, which does not meet the most basic material versatility and application performance requirements.

Therefore, after comprehensively considering the production efficiency of the auxiliary layer, tensile strength reliability and material versatility, conclusion one is reached: the thickness of the first auxiliary layer 140 is preferably: 35 μm ≤ δ 2 ≤ 100 μm.

Second, regarding the sum of the thickness of the first auxiliary layer 140 and the thickness of the welding section 131:

Comparing Example 3, Example 4 and Comparative Example 3, it can be seen that in Example 3, as the sum of the thicknesses between the first auxiliary layer 140 and the welding section 131 decreases to 50 μm, the tensile force at this time is 5.5N. , quite close to 5N. Considering factors such as measurement errors, if the sum of the thicknesses between the first auxiliary layer 140 and the welding section 131 continues to decrease to less than 50 μm, as shown in Comparative Example 3, the tensile strength will not be able to meet the use requirements. , causing the formed welded structure of the elastic electrical contact terminal to easily fall off during use; in Embodiment 4, as the thickness of the first auxiliary layer 140 and the welding section 131 increases, the tensile strength is significantly improved, meeting the usage requirements.

Therefore, after considering the tensile strength reliability, conclusion 2 is obtained: the sum of the thickness of the first auxiliary layer 140 and the thickness of the welding section 131 should be greater than or equal to 50 μm.

Third, regarding the thickness selection of the intermediate adhesive layer 150:

Comparing Example 5, Example 6 and Example 7, Comparative Example 4 and Comparative Example 5, it can be seen that as the thickness of the intermediate adhesive layer 150 increases, the tensile strength gradually decreases, and the stability before welding also gradually increases. Among them, in Example 5, the stability before welding is the lowest. If the thickness of the middle adhesive layer 150 continues to decrease, as shown in Comparative Example 4, the stability before welding reaches zero level, and it is difficult to adhere the first auxiliary layer 140 to the welding section. 131; in Example 7, the tensile strength is as low as 5.2N, which is quite close to the required 5N. If the thickness of the middle adhesive layer 150 is continued to be increased, as shown in Comparative Example 5, the tensile strength cannot meet the usage requirements. In addition, as shown in Embodiment 6 and Embodiment 7, when the middle glue layer 150 is increased from 6 μm to 10 μm, although increasing the thickness of the middle glue layer 150 at this time can improve the stability before welding, the corresponding tensile strength is The decrease is large, and the increase in the thickness of the middle adhesive layer by 150 is not cost-effective.

Therefore, after comprehensively considering the tensile strength reliability and pre-welding stability, conclusion three is reached: the thickness of the intermediate adhesive layer 150 should satisfy: 3 μm ≤ h1 ≤ 10 μm, and more preferably, 3 μm ≤ h1 ≤ 6 μm.

Fourth, regarding the bottom adhesive layer 160 and its thickness selection:

As shown in Comparative Example 4, Example 8, Example 9, Comparative Example 6, Comparative Example 7 and Comparative Example 8, after setting the bottom adhesive layer 160, the stability before welding is improved, but the corresponding contact resistance also increases. increases; as the thickness of the bottom adhesive layer 160 increases, although the welding stability is further improved, the tensile strength gradually decreases and the contact resistance also gradually increases. In Embodiment 8, if the thickness of the bottom glue layer 160 is continued to be reduced, as shown in Comparative Example 6, the effect of the bottom glue layer 160 on improving welding stability is very limited, and the setting of the bottom glue layer 160 is meaningless; In Embodiment 9, the tensile strength, contact resistance and stability before welding are well balanced and can simultaneously meet the requirements of tensile strength, contact resistance and stability before welding. When the thickness of the bottom adhesive layer 160 is continued to be increased, When Example 10 was obtained, although the stability before welding was further improved, the tensile strength was further reduced and the contact resistance was further increased; when the thickness of the bottom adhesive layer 160 was continued to be increased, as shown in Comparative Example 7, although The stability before welding has been further improved, but the tensile strength and contact resistance are difficult to meet the needs of use. In addition, based on Example 9, after increasing the thickness of the middle glue layer, that is, when the sum of the thicknesses of the middle glue layer and the bottom glue layer is greater than 12 μm, as shown in Comparative Example 8, the tensile strength will be reduced. to not meet the usage requirements.

Therefore, after comprehensively considering the tensile strength reliability, contact resistance and pre-welding stability, conclusion 4 is reached: the thickness of the bottom adhesive layer 160 should satisfy: 3 μm ≤ h2 ≤ 10 μm, and more preferably, 3 μm ≤ h2 ≤ 6 μm.

Fifth, regarding the sum of the thickness of the middle glue layer 150 and the thickness of the bottom glue layer 160:

As shown in Comparative Example 9, Comparative Example 7 and Comparative Example 9, in Example 9, the tensile strength, contact resistance and pre-welding stability are well balanced, and can simultaneously satisfy the tensile strength, contact resistance and pre-welding stability. Stability requirements, at this time, whether it is to continue to increase the thickness of the middle glue layer 150 or the bottom glue layer 160, as shown in Comparative Example 7 and Comparative Example 9, although the stability before welding has been further improved Improved, but the tensile strength and contact resistance are difficult to meet the needs of use.

After comprehensively considering the tensile strength reliability, contact resistance, pre-welding stability, conclusion three and conclusion four, conclusion five is obtained: the sum of the thickness of the middle adhesive layer 150 and the thickness of the bottom adhesive layer should satisfy: h1+h2≤12μm.

Please refer to Figure 5. The third aspect of this application also proposes an electronic device, including a display screen 300 and a welding structure of elastic electrical contact terminals proposed in the second aspect of this application; the conductive layer 130 is sandwiched between the display screen 300 and the substrate 200. between.

The electronic device proposed in this application can be any electronic device that needs to avoid signal interference or eliminate internal silence of the electronic device, such as mobile phones, tablet computers, etc.; the display screen 300 and the substrate 200 refer to the two parts of the electronic device that require elastic electrical contact. structure.

In the electronic device proposed in this application, the welding section 131 of the elastic electrical contact terminal and the substrate 200 are welded by laser, so the production cost is low.

The electronic device proposed in this application includes the welding structure of the elastic electrical contact terminal proposed in the second aspect. In the welding structure of the elastic electrical contact terminal proposed in the second aspect of this application, the conductive layer 130 and the substrate 200 are connected by the first aspect. The welding method is welded into one body, so it has all the beneficial effects of the welding method proposed in the first aspect and the welding structure of the elastic electrical contact terminal proposed in the second aspect, which will not be described again here.

This specification discloses the application with reference to the accompanying drawings, and also enables any person skilled in the art to practice the application, including making and using any devices or systems, employing suitable materials and using any combined methods. The scope of the application is defined by the claimed technology, and includes other examples that occur to those skilled in the art. So long as such other examples include structural elements that are not different from the literal language of the claimed technical solution, or such other examples include equivalent structural elements that are not substantially different from the literal language of the claimed technical solution, then such other examples are It should be considered to be within the protection scope determined by the technical solution claimed in this application.

Claims (19)

1. A welding method for welding a first component and a second component that are made of different metal materials. The thickness δ1 of the first component is less than or equal to 25 μm, which is characterized by including:

   Stack the first component on the second component;

   A first auxiliary layer is adhered to the upper surface of the first component through an intermediate glue layer. The laser absorption rate of the first auxiliary layer is greater than that of the first component; wherein the thickness δ2 of the first auxiliary layer is 35 μm. to 100 μm, by cutting the blank material with a thickness corresponding to the first auxiliary layer to obtain the first auxiliary layer; the sum of the thickness δ1 of the first member and the thickness δ2 of the first auxiliary layer is greater than equal to 50μm;

   A laser welding device is used to emit laser light so that the laser light passes through the first auxiliary layer, the first component and the second component in order to laser weld the first component and the second component.
2. The welding method according to claim 1, wherein the thickness of the intermediate adhesive layer is h1, and 3 μm≤h1≤10 μm.
3. The welding method according to claim 2, characterized in that 3μm≤h1≤6μm.
4. The welding method according to claim 1, wherein the first auxiliary layer includes a second base material and a metal coating plated on the upper surface of the second base material and used to absorb laser energy, and the metal The laser absorption rate of the coating is greater than the laser absorption rate of the first component and the second substrate respectively.
5. The welding method according to claim 1, wherein the intermediate glue layer is one of acrylic pressure-sensitive glue, epoxy hot melt glue, polyurethane thermosetting glue, polyurethane thermoplastic glue and silicone glue.
6. The welding method according to claim 1, characterized in that before adhering the first auxiliary layer to the upper surface of the first component through the intermediate adhesive layer, it further includes:

   The upper surface of the first member and/or the lower surface of the first auxiliary layer is roughened.
7. The welding method according to claim 1, wherein said stacking the first component on the second component specifically includes:

   A bottom glue layer is provided on the lower surface of the first component, and the first component is bonded to the second component through the bottom glue layer.
8. The welding method according to claim 7, wherein the thickness of the bottom adhesive layer is h2, 3 μm≤h2≤10 μm.
9. The welding method according to claim 8, characterized in that 3μm≤h2≤6μm.
10. The welding method according to claim 7, wherein the thickness of the middle glue layer is h1, the thickness of the bottom glue layer is h2, and h1+h2≤12 μm.
11. The welding method according to claim 7, wherein the bottom glue layer is one of acrylic pressure-sensitive glue, epoxy hot melt glue, polyurethane thermosetting glue, polyurethane thermoplastic glue and silicone glue.
12. The welding method according to claim 7, characterized in that, before setting the bottom adhesive layer on the lower surface of the first component, it further includes:

    The lower surface of the first component is roughened.
13. The welding method according to any one of claims 1 to 12, characterized in that after adhering the first auxiliary layer to the upper surface of the first component through the intermediate adhesive layer, it further includes:

    Use a tool to apply a force toward the first member on the upper surface of the first auxiliary layer, driving the first auxiliary layer and the first member to dent downward at the same time until a layer from the first auxiliary layer is formed. The upper surface of the incision penetrates to the lower surface of the first member. The incision is in the shape of a wedge with a gradually decreasing width from top to bottom. The first auxiliary layer is formed with a bend along the top edge of the incision, so The bend extends downward along the inner peripheral wall of the cutout, and the end of the bend extends outward to wrap the lower surface of the first member.
14. A welding structure of elastic electrical contact terminals, which is characterized by including:

    Terminal body, the terminal body includes an elastic core and a conductive layer wrapped around the outer circumference of the elastic core. The conductive layer has an end that extends outward and forms a welding section. The thickness of the conductive layer is 9 μm. ~25μm; and

    A substrate, the conductive layer and the substrate are made of different metal materials;

    The welding section is welded to the substrate by the welding method according to any one of claims 1 to 13, wherein the welding section is used as the first component, and the substrate is used as the second component. member.
15. The welding structure of elastic electrical contact terminals according to claim 14, wherein the base plate is an aluminum plate.
16. The welding structure of elastic electrical contact terminals according to claim 14, wherein the conductive layer includes a first base material and a conductive coating plated on the outer surface of the first base material; wherein, the first base material The base material includes copper, and the anti-oxidation ability of the conductive coating is better than that of the first base material.
17. The welding structure of elastic electrical contact terminals according to claim 16, characterized in that the first base material is electrolytic copper foil or rolled copper foil, and the conductive coating is a gold layer with a thickness >10 nm or a thickness >0.3 μm. A nickel layer or a tin layer with a thickness greater than 0.1μm.
18. The welding structure of elastic electrical contact terminals according to claim 16, wherein the first auxiliary layer includes a second base material and a metal coating plated on the upper surface of the second base material, and the intermediate glue The layer is provided between the upper surface of the first substrate and the lower surface of the second substrate, the second substrate includes copper, and the metal plating film includes nickel.
19. An electronic device, characterized in that it includes a display screen and a welding structure of an elastic electrical contact terminal according to any one of claims 14 to 18; the conductive layer is sandwiched between the display screen and the substrate .

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