Bonding pad, bonding pad assembly and surface-mounted connector

Abstract

The embodiment of the utility model discloses a bonding pad, a bonding pad assembly and a surface-mounted connector, and relates to the technical field of bonding pads. The bonding pad is used for connecting a pin. The bonding pad comprises a bonding area, a root accumulation area and a toe accumulation area. And the root accumulation area is used for bearing root welding flux at the root of the pin. The toe accumulation area is used for bearing toe welding flux leading to the toes. Wherein the root accumulation area and the toe accumulation area are located on the two sides of the welding area respectively, and the length of the root accumulation area is smaller than that of the toe accumulation area. According to the bonding pad, the length of the root stacking area and the length of the toe stacking area can be adjusted, so that the root stacking area can keep the bonding pad length needed by product welding, meanwhile, the toe stacking area can increase the tin stacking bonding pad space needed by testing, connector pins welded normally are obviously different from abnormal pins, and the product welding quality is improved. And thus, AOI detection is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of soldering pads, in particular to a soldering pad, a soldering pad assembly and a surface mount connector. Background Art

[0002] Automated Optical Inspection (AOI) has important applications in the automotive industry in the manufacturing process of on-board electronics. It can detect welding problems in electronic modules, incorrect welding of components, connector welding quality, etc., to ensure the performance and reliability of vehicle electronic systems.

[0003] In the related art, the pad of the surface mount connector is at the bottom of the metal pin. It is not easy to see the root welding status after the pin is attached. Although there is a pad at the toe, the size is very small. At the same time, the width of the pin is close to the width of the pad, and the difference in the side tin creep imaging is not obvious. Therefore, the existing pad has the defect of low visibility of welding quality, and the welding quality cannot be clearly distinguished when using AOI inspection. Summary of the invention

[0004] In view of the above shortcomings of the prior art, the purpose of the utility model is to provide a soldering pad, which can adjust the lengths of the root stacking area and the toe stacking area so that the root stacking area can retain the pad length required for product welding while the toe stacking area increases the pad space required for testing, thereby making a clear difference between the normally welded connector pins and the abnormal pins, thereby facilitating AOI inspection.

[0005] The utility model embodiment discloses a pad for connecting pins, the pad comprising:

[0006] Welding area;

[0007] A root accumulation area for carrying the root flux at the root of the pin;

[0008] A toe accumulation area for carrying toe flux at the toe of the pin;

[0009] The root accumulation area and the toe accumulation area are respectively located on both sides of the welding area, and the length of the root accumulation area is smaller than the length of the toe accumulation area.

[0010] Furthermore, the length of the root accumulation zone is L1, the length of the toe accumulation zone is L2, and L2≥L1+0.2mm.

[0011] Further, L2=L1+0.3mm.

[0012] Furthermore, the length of the root accumulation zone is 0.3 mm, and the length of the toe accumulation zone is 0.6 mm.

[0013] The utility model also discloses a pad assembly, including the pad as described above, the pad assembly also includes a steel mesh and a green oil window, the pad is exposed from the green oil window;

[0014] The steel mesh includes a steel mesh root area and a steel mesh toe area, and the length of the steel mesh root area is smaller than the length of the steel mesh toe area, wherein the steel mesh root area is used to characterize the area between one end of the steel mesh and the projection of the root of the pin, and the steel mesh toe area is used to characterize the area between the other end of the steel mesh and the projection of the toe of the pin.

[0015] Furthermore, the length of the root area of ​​the steel mesh is 0.25 mm.

[0016] Furthermore, the length of the toe region of the steel mesh is 0.55 mm.

[0017] The embodiment of the utility model further discloses a surface mount connector, comprising the above-mentioned pad assembly, the surface mount connector further comprising pins, and the pads and the pins are connected by flux.

[0018] Furthermore, the flux is solder paste.

[0019] The soldering pad provided by the utility model has the following beneficial effects, including but not limited to:

[0020] 1) The pad can adjust the length of the root accumulation area and the toe accumulation area so that the root accumulation area can retain the pad length required for product welding while the toe accumulation area increases the pad space required for testing, so that the connector pins that are normally welded are significantly different from the abnormal pins, which is conducive to AOI inspection;

[0021] 2) The pad assembly adjusts the relative length relationship between the root area and the toe area of ​​the steel mesh to adjust the distribution of solder paste during the welding process, so as to ensure that the volume difference of the tin amount of the connector pin in the normal state and the abnormal state is obvious during AOI inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0023] Figure 1 A schematic diagram of the AOI inspection process provided for related technologies;

[0024] Figure 2 AOI inspection schematic diagram after pad welding provided for related technologies;

[0025] Figure 3 A schematic diagram of the structure of a soldering pad provided in an embodiment of the utility model;

[0026] Figure 4 A schematic diagram of the structure of a pad assembly provided by an embodiment of the utility model;

[0027] Figure 5 Another structural schematic diagram of a pad assembly provided in an embodiment of the utility model;

[0028] Figure 6 A schematic diagram of the structure of a steel mesh provided in an embodiment of the utility model;

[0029] Figure 7 A schematic diagram of a pad after welding provided in an embodiment of the utility model;

[0030] Figure 8 A schematic diagram of AOI inspection after pad welding provided in an embodiment of the utility model.

[0031] Icons: 10-soldering pad; 101-welding area; 102-root accumulation area; 103-toe accumulation area; 20-soldering pad assembly; 21-steel mesh; 211-steel mesh root area; 212-steel mesh toe; 22-green oil window; 30-pin; 31-solder paste. DETAILED DESCRIPTION

[0032] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0033] It should be noted that the illustrations provided in the following embodiments are only used to schematically illustrate the basic concept of the present invention, and thus the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0034] like Figure 1As shown, the AOI test principle in the related art is: capture through a charge coupled device (CCD) camera, and then undergo image processing (i.e., converting into the required digital signal based on information such as pixel distribution, brightness and color). These digital signals are calculated using a certain mathematical method to obtain a standard error threshold, and then the threshold obtained for each tested image is compared with the standard threshold in the system. If the comparison result is less than the standard threshold, the image passes the test, otherwise it is judged as unqualified.

[0035] like Figure 2 As shown, the reasons why AOI in the related art cannot test the pad 10 of the surface mount connector are as follows:

[0036] 1) The solder pad 10 of the surface mount connector is at the bottom of the metal pin 30. After the connection is completed, the soldering status of the root cannot be seen. Although there is a solder pad 10 at the toe, it is very small. The soldering status of the normal pin and the cold solder pin (abnormal pin) is almost the same, and there is no test feature.

[0037] 2) The width of pin 30 is close to that of pad 10, and the difference between normal pins and cold-solder pins in the side tin creep imaging is not obvious.

[0038] like Figure 3 As shown, the utility model provides a soldering pad 10 for connecting a pin 30, and the soldering pad 10 includes a soldering area 101, a root accumulation area 102, and a toe accumulation area 103. The root accumulation area 102 is used to carry the root flux at the root of the pin 30. The toe accumulation area 103 is used to carry the toe flux at the toe of the pin 30. The root accumulation area 102 and the toe accumulation area 103 are respectively located on both sides of the soldering area 101, and the length of the root accumulation area 102 is less than the length of the toe accumulation area 103.

[0039] It is worth noting that the solder paste 31 paving area at the root of the pad 10 in the related art is too large, and there is not enough tin at the toe to form the climbing arc required for the test; if the toe area of ​​the pad is too small, the solder paste 31 will accumulate, but the accumulation amount is too small, resulting in no obvious difference in the volume of tin between the normal pin and the cold solder pin, and thus it is impossible to distinguish them through the test of the accumulated solder paste volume data. In the pad 10 of this embodiment, the root accumulation area 102 can only retain the pad length required for product welding, and the toe accumulation area 103 increases the pad space required for the test, so that the connector pins with normal welding are significantly different from the abnormal pins (cold solder pins).

[0040] In this embodiment, the length of the root accumulation area 102 is L1, and the length of the toe accumulation area 103 is L2, where L2 ≥ L1 + 0.2 mm. Figure 7As shown, in one implementation of this embodiment, the longitudinal length of the pad 10 = F + connector pin length + L2. Figure 6 In the figure, T is the thickness of the connector pin, G is the solder paste thickness, L2 is the length from the toe of the connector pin to the edge of the pad (i.e., the length of the toe accumulation area 103), and L1 is the length from the root of the connector pin to the edge of the pad (i.e., the length of the root accumulation area 102).

[0041] According to the IPC standard, F = T + G, and the root tin creep shape can be roughly regarded as a quarter circle with a radius of R = F, so L1 = F = T + G. When the end (toe) of the pin creeps well, there will be a quarter arc similar to the root of the pin. In the case of a cold solder joint, the tin needs to be pushed to the end of the pad. For AOI, when the tin is pushed outward by at least 0.2mm, the cold solder joint feature is obvious and the defect can be effectively intercepted, so L2 ≥ L1 + 0.2mm.

[0042] In this embodiment, without affecting the layout of other components or test points, the pad size can be set to L2 = L1 + 0.3 mm. A pad of this size can avoid the risk of missed detection.

[0043] like Figure 4-Figure 6 As shown, an embodiment of the utility model further discloses a pad assembly 20, including the pad 10 as described above, the pad assembly 20 also includes a steel mesh and a green oil window 22, the pad 10 is exposed from the green oil window 22; the steel mesh includes a steel mesh root area 211 and a steel mesh toe area 212, the length of the steel mesh root area 211 is less than the length of the steel mesh toe area 212, wherein the steel mesh root area 211 is used to characterize the area between one end of the steel mesh and the projection of the root of the pin, and the steel mesh toe area 212 is used to characterize the area between the other end of the steel mesh and the projection of the toe of the pin.

[0044] It is worth noting that the pad assembly 20 adjusts the distribution of the solder paste 31 during the welding process by adjusting the relative length relationship between the root area 211 and the toe area 212 of the steel mesh, so as to ensure that the volume difference of the tin amount of the connector pin 30 in the normal state and the abnormal state is obvious during AOI inspection.

[0045] In one implementation of this embodiment, the length of the root accumulation area 102 can be 0.3mm, and the length of the toe accumulation area 103 can be 0.6mm; the length of the steel mesh root area 211 can be 0.25mm, and the length of the steel mesh toe area 212 can be 0.55mm. The pad assembly 20 of this size can ensure that the volume difference of the tin amount of the connector pin in the normal state and the cold solder state during AOI inspection is obvious, and can detect whether the welding is good, while avoiding the risk of missed detection. Depending on the specific implementation environment, the pad assembly 20 can also be of other sizes. This embodiment is only an example to illustrate it and does not constitute a limitation on the specific size. Figure 8The schematic diagram of AOI inspection after welding of the pad 10 provided in the embodiment of the utility model is as follows: Figure 8 As shown, the AOI imaging in this embodiment is clear, the characteristics of the cold solder pins are obvious, and the AOI can perform stable testing.

[0046] In this embodiment, a surface mount connector is also included, including the pad assembly 20 as described above, and the surface mount connector also includes a pin 30, and the pad 10 is connected to the pin 30 by flux. It can be understood that the flux in this embodiment can be solder paste 31.

[0047] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

[0048] In the description herein, many specific details, such as examples of components and / or methods, are provided to provide a complete understanding of the embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more specific details or by other devices, systems, components, methods, components, materials, parts, etc. In other cases, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of the embodiments of the present invention.

[0049] References throughout the specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described herein and shown may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0050] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0051] In addition, unless otherwise explicitly indicated, any marking arrows in the drawings should be regarded as exemplary only and not limiting. In addition, unless otherwise indicated, the term "or" used herein is generally intended to mean "and / or". In the case where the term is not clear because it is anticipated that the ability to separate or combine is provided, the combination of components or steps will also be regarded as indicated.

[0052] As used in the description herein and throughout the claims that follow, "a", "an", and "the" include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of "in" includes "in" and "on" unless otherwise indicated.

[0053] The above description of the illustrated embodiments of the present invention (including the contents in the abstract of the specification) is not intended to be an exhaustive list or to limit the present invention to the precise form disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention as will be recognized and understood by those skilled in the art. As noted, these modifications may be made to the present invention in accordance with the above description of the embodiments of the present invention, and these modifications will be within the spirit and scope of the present invention.

[0054] Systems and methods have been generally described herein as details that are helpful for understanding the present invention. In addition, various specific details have been given to provide an overall understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the embodiments of the present invention can be practiced without one or more specific details, or practiced using other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusion with various aspects of the embodiments of the present invention.

Claims

1. A pad for connecting a pin, characterized in that: include: Welding area; A root accumulation area for carrying the root flux at the root of the pin; A toe accumulation area for carrying toe flux at the toe of the pin; The root accumulation area and the toe accumulation area are respectively located on two sides of the welding area, and the length of the root accumulation area is smaller than the length of the toe accumulation area.

2. The pad according to claim 1, characterized in that The length of the root accumulation zone is L1, the length of the toe accumulation zone is L2, and L2≥L1+0.2mm.

3. The pad according to claim 2, characterized in that: L2=L1+0.3mm.

4. The pad according to claim 3, characterized in that: The length of the root accumulation zone is 0.3 mm, and the length of the toe accumulation zone is 0.6 mm.

5. A pad assembly, comprising the pad according to any one of claims 1 to 4, characterized in that: The pad assembly also includes a steel mesh and a green oil window, and the pad is exposed from the green oil window; The steel mesh includes a steel mesh root area and a steel mesh toe area, the length of the steel mesh root area is smaller than the length of the steel mesh toe area, wherein the steel mesh root area is used to characterize the area between one end of the steel mesh and the projection of the root of the pin, and the steel mesh toe area is used to characterize the area between the other end of the steel mesh and the projection of the toe of the pin.

6. The pad assembly according to claim 5, characterized in that: The length of the root zone of the steel mesh is 0.25 mm.

7. The pad assembly according to claim 6, characterized in that: The length of the steel mesh toe area is 0.55 mm.

8. A surface mount connector, comprising a pad assembly as claimed in any one of claims 5 to 7, characterized in that: The surface mount connector also includes pins, and the pads are connected to the pins using flux.

9. The surface mount connector according to claim 8, characterized in that: The flux is solder paste.

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