Electroplating clamp

Abstract

The utility model discloses an electroplating clamp and relates to the technical field of electroplating. The electroplating clamp comprises two clamping pieces and an elastic assembly, the two clamping pieces are symmetrically arranged along a plane perpendicular to the first direction; a plurality of clamping parts arranged in the second direction are arranged at one end of each clamping piece, and the faces, facing each other, of the clamping parts of the two clamping pieces are clamping faces; the plurality of clamping parts can be independently deformed in the first direction; an included angle is formed between the second direction and the first direction; the elastic assembly is arranged on the two clamping pieces; the elastic assemblies can drive the multiple clamping parts on the corresponding clamping pieces to deform in the direction of the other clamping piece. The electroplating clamp is used for ensuring that the contact area between the clamp and a substrate is uniform, and the electroplating quality is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to electroplating technical field especially relates to a kind of electroplating clamps. BACKGROUND

[0002] Warpage refers to the planar deformation of glass substrate caused by uneven stress distribution during manufacturing, which is manifested as bending or twisting of edge or center region. Warpage of large-size glass square during manufacturing is a common and difficult-to-avoid problem, which is the result of combined action of material properties, process stress and size effect.

[0003] In the prior art, flat clamps or simple point contact clamps are usually used to clamp the substrate during electroplating. Once the substrate has warpage problem, the conventional clamps cannot dynamically adjust the clamping force or contact mode according to the warpage mode of the substrate, cannot effectively compensate for warpage, and lead to uneven current distribution. When local current density is too high, it will cause overplating (such as burning, thick plating layer), and when local current density is too low, it will cause underplating (such as thin plating layer or no plating), which leads to poor overall electroplating uniformity and affects product performance.

[0004] Therefore, there is an urgent need for an electroplating clamp to solve the above technical problems. SUMMARY

[0005] The utility model aims at providing an electroplating clamp for ensuring uniform contact area between the clamp and the substrate and ensuring electroplating quality.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides an electroplating clamp, which comprises two clamping pieces and an elastic assembly. The two clamping pieces are symmetrically arranged along a plane perpendicular to a first direction. One end of each clamping piece is provided with a plurality of clamping portions arranged along a second direction. The faces of the clamping portions of the two clamping pieces facing each other are clamping faces. Each clamping portion can independently deform in the first direction. The second direction forms an angle with the first direction. The elastic assembly is arranged between the two clamping pieces. The elastic assembly can drive the clamping portions on the corresponding clamping piece to deform towards the other clamping piece.

[0008] In some embodiments, the clamping portion comprises a plurality of clamping sub-portions spaced apart along the second direction.

[0009] The plurality of clamping portions are arranged at intervals in the second direction on the same clamping piece; a gap between two adjacent clamping portions is a first gap, and a gap between two adjacent clamping sub-portions on the same clamping portion is a second gap; in a third direction, the size of the first gap is greater than the size of the second gap; the first direction, the second direction, and the third direction are arranged at angles with each other.

[0010] In some embodiments, the number of elastic components is two, and the two elastic components are respectively arranged on the clamping portions of the two clamping pieces and located on the side of the clamping surfaces away from the clamping portions.

[0011] In some embodiments, the clamping piece further comprises a fixed portion, the two clamping pieces are detachably connected through the fixed portion, a connecting portion is used for connecting the fixed portion and the clamping portion, the connecting portion and the clamping portion are arranged at an angle, in the first direction, the fixed portions of the two clamping pieces are arranged in abutment, a gap between the two connecting portions is a third gap, a gap between the two clamping portions is a fourth gap, and the size of the third gap is greater than the size of the fourth gap.

[0012] In some embodiments, the fixed portion, the connecting portion, and the clamping portion are integrally formed.

[0013] In some embodiments, the connecting portion is an elastic structure.

[0014] In some embodiments, the elastic component comprises an air bag arranged in abutment on the side of the clamping surface away from the clamping portion.

[0015] In some embodiments, the outer surface of the clamping piece is provided with a cladding layer.

[0016] In some embodiments, a plurality of electroplated contact portions are arranged one by one on the clamping surfaces of the plurality of clamping portions; and the electroplated contact portions are exposed to the cladding layer.

[0017] In some embodiments, the clamping piece further comprises a connecting portion, and the connecting portion is provided with a plurality of anchoring openings.

[0018] The utility model discloses the beneficial effects of:

[0019] The utility model provides a kind of electroplating fixture, by setting two clamping pieces along the plane perpendicular to first direction symmetry, and multiple clamping portions along second direction are arranged in one end of clamping piece, wherein the face of the clamping portion of two clamping pieces towards each other is clamping face, and multiple clamping portions are set as being able to individually deform in first direction;In addition, elastic assembly is also set on clamping piece, and the elastic assembly can drive multiple clamping portions on corresponding clamping piece, and the direction of multiple clamping portions on another clamping piece is deformed.This makes that elastic assembly can provide clamping force (i.e. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the structure diagram of a kind of electroplating fixture provided by the utility model specific embodiment;

[0021] Figure 2 It is Figure 1 The sectional view structure diagram along A-A direction shown in structure;

[0022] Figure 3 It is the structure diagram of a kind of clamping piece provided by the utility model specific embodiment;

[0023] Figure 4 It is Figure 3 The enlarged structure diagram of region B in the structure shown;

[0024] Figure 5 It is the structure diagram of another view of a kind of clamping piece provided by the utility model specific embodiment.

[0025] In the figure:

[0026] 1, clamping piece;11, clamping portion;111, clamping face;112, clamping sub-department;113, electroplating contact portion;12, fixed part;13, connecting portion;131, anchoring aperture;2, elastic assembly;21, air bag;3, cladding layer;

[0027] D1, first gap;D2, second gap;D3, third gap;D4, fourth gap;

[0028] X1, first direction; X2, second direction; X3, third direction. DETAILED DESCRIPTION

[0029] The utility model will be described in further detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not limit the utility model. In addition, it should be noted that, for the convenience of description, only part of the structure related to the utility model is shown in the drawings, not all structures.

[0030] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, and the specific meaning of the above terms in the utility model can be understood according to the specific circumstances for the ordinary skilled in the art.

[0031] In the utility model, unless otherwise explicitly specified and limited, the first feature is "on" or "below" the second feature, which can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them.

[0032] In the description of the embodiment, the terms "upper", "lower", "left", "right" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in description, and have no special meaning.

[0033] In combination Figures 1 to 4 As shown in the drawings, the embodiment provides an electroplating clamp, which comprises two clamping pieces 1 and an elastic assembly 2. Wherein, the two clamping pieces 1 are symmetrically arranged along the plane perpendicular to the first direction X1, that is, the two clamping pieces 1 are symmetrically arranged along the horizontal plane. Figure 2 As an example of the viewing angle, the first direction X1 is taken as the vertical direction, and the two clamping pieces 1 are stacked in the vertical direction, and the two clamping pieces 1 are symmetrically arranged with the horizontal plane as the symmetry plane.

[0034] In combination Figure 3 , Figure 4 As shown in the drawings, one end of the clamping piece 1 is provided with a plurality of clamping parts 11 arranged along the second direction X2, for example, the clamping part 11 is in the form of a rectangular block structure, and the clamping parts 11 of the two clamping pieces 1 face each other and are clamping faces 111. In other words, taking the first clamping piece 1 as an example, the clamping part 11 is arranged on the side of the first clamping piece 1, and the clamping part 11 of the second clamping piece 1 is arranged on the side of the second clamping piece 1. Figure 2The view angle is taken as an example, the lower surface of the clamping part 11 of the upper clamping piece 1 is the clamping surface 111; the upper surface of the clamping part 11 of the lower clamping piece 1 is the clamping surface 111. When the clamping action is needed to be performed by the above-mentioned clamping device, the substrate to be clamped is located between the two clamping surfaces 111.

[0035] The above-mentioned multiple clamping parts 11 can be deformed individually in the first direction X1. The second direction X2 is arranged at an angle with the first direction X1, for example, the angle is 90°. For example, the clamping part 11 is made of conductive silicone rubber or elastomer composite material (metal nanoparticles such as gold and silver are embedded in elastomers such as polyurethane and silicone) or conductive thermoplastic elastomer, or the clamping part 11 can be a thin-walled metal spring, so that each clamping part 11 can be deformed individually and maintain high conductivity to facilitate subsequent electroplating process.

[0036] As shown in Figure 1 , Figure 2 , the above-mentioned elastic assembly 2 is arranged on the two clamping pieces 1. The elastic assembly 2 can drive the multiple clamping parts 11 on the corresponding clamping piece 1 to deform towards the other clamping piece 1. That is, as shown in the view angle, Figure 2 , the elastic assembly 2 can drive the clamping parts 11 of the upper clamping piece 1 to deform downward, and can also drive the clamping parts 11 of the lower clamping piece 1 to deform upward.

[0037] It is not difficult to understand that the number of the above-mentioned elastic assembly 2 can be one or two. When the number of the elastic assembly 2 is one, the elastic assembly 2 is in a "U" shape structure, which is clamped on the side surface of the clamping parts 11 of the two clamping pieces 1, in other words, the clamping parts 11 of the two clamping pieces 1 are located in the middle part of the "U" shape structure. By such arrangement, the installation and control of the elastic assembly 2 can be facilitated. When the number of the above-mentioned elastic assembly 2 is two, the elastic assembly 2 is, for example, in a long strip shape structure extending along the first direction X1, and the two elastic assemblies 2 are arranged on the clamping parts 11 of the two clamping pieces 1, and are located on the side of the clamping parts 11 away from the clamping surface 111 thereof, that is, as shown in the view angle, Figure 2 , one elastic assembly 2 is arranged on the upper surface of the clamping part 11 of the upper clamping piece 1, and the other elastic assembly 2 is arranged on the lower surface of the lower clamping piece 1. By such arrangement, even if one elastic assembly 2 fails during the use of the electroplating clamping device, the other elastic assembly 2 can still play an elastic role, avoiding the sudden failure of the clamping function of the entire electroplating clamping device.

[0038] The elastic assembly 2 comprises an air bag 21 arranged on the side of the clamping part 11 away from the clamping surface 111. The air bag 21 can apply force to the clamping part 11 by being inflated to drive the clamping part 11 to deform. The air bag 21 is usually made of elastic material such as silicone, which has high tensile strength and deformation capacity. Such flexibility enables it to adapt to the surface of objects of different shapes and fill the contact gap by local deformation. That is, when the substrate is warped (the surface of the substrate is uneven), the air bag 21 deforms locally (the side of the clamping part 11 in contact with the air bag 21 becomes uneven) to tightly contact the plurality of clamping parts 11 and apply adaptive force to the plurality of clamping parts 11, so that the clamping surface 111 of the plurality of clamping parts 11 can also tightly contact the outer surface of the substrate and apply adaptive clamping force according to the warping trend of the substrate. In addition, the elastic assembly 2 can also comprise a shell covering the outer surface of the air bag 21. In this way, the air bag 21 can be protected from damage, and when the air bag 21 is inflated, it can abut the inner side wall of the shell, thereby facilitating the air bag 21 to apply force to the clamping part 11. It will be appreciated that the elastic assembly 2 can also comprise other elastic materials such as flexible rubber and springs, which will not be described in detail here.

[0039] Thus, the electroplating clamp provided by the embodiment can simultaneously provide clamping force to the plurality of clamping parts 11 by arranging two clamping parts 1 symmetrically along a plane perpendicular to the first direction X1 and arranging a plurality of clamping parts 11 on one end of the clamping part 1 along the second direction X2, wherein the faces of the clamping parts 11 of the two clamping parts 1 facing each other are the clamping surfaces 111, and the plurality of clamping parts 11 are all capable of deforming individually in the first direction X1; and further arranging an elastic assembly 2 on the clamping part 1, which can drive the plurality of clamping parts 11 on the corresponding clamping part 1 to deform towards the plurality of clamping parts 11 on the other clamping part 1. In this way, the elastic assembly 2 can simultaneously provide clamping force to the plurality of clamping parts 11 (i.e., apply pressure to the clamping parts 11), and since the plurality of clamping parts 11 are all capable of deforming individually in the first direction X1, the elastic assembly 2 can dynamically adjust the clamping parts 11 according to different substrate shapes, so that the plurality of clamping parts 11 can always sufficiently contact and clamp the outer surface of the substrate according to the warping trend of the substrate clamped between the two clamping surfaces 111, ensuring that the contact area between the clamping surface 111 and the outer surface of the substrate is uniform, avoiding overplating or underplating, and thus ensuring the quality of electroplating, while also preventing the electroplating solution from leaking to non-electroplating areas. In addition, the clamping part 1 can adapt to the warping of different substrates by the above arrangement, without the need to frequently replace the clamp, thereby improving work efficiency.

[0040] In some embodiments, in combination with Figure 3 、 Figure 4As shown, the clamping part 11 includes a plurality of clamping sub-parts 112 arranged in the second direction X2, for example, in the form of long strip-shaped block structures. It is easy to understand that the plurality of clamping sub-parts 112 in each clamping part 11 can also be deformed individually in the first direction X1. On the same clamping piece 1, the plurality of clamping parts 11 are arranged in the second direction X2. The gap between the two adjacent clamping parts 11 is the first gap D1, and the gap between the two adjacent clamping sub-parts 112 on the same clamping part 11 is the second gap D2. In the third direction X3, the size of the first gap D1 is greater than the size of the second gap D2, and the first direction X1, the second direction X2 and the third direction X3 are arranged at an angle, for example, 90°, and the second direction X2 and the third direction X3 are horizontal first direction and horizontal second direction respectively. Through the above arrangement, the single clamping part 11 can be subdivided into a plurality of clamping sub-parts 112 that can be deformed individually, so that the clamping part 11 can adapt to more complex warping deformation trends, further improve the fitting accuracy of the clamping part 11 and the outer surface of the substrate, and make the clamping surface 111 of the clamping part 11 more uniform in contact with the outer surface of the substrate. At the same time, in the third direction X3, the size of the first gap D1 is set to be greater than the size of the second gap D2, that is, the size of the first gap D1 is larger, so that the clamping part 11 can be more easily deformed according to the warping of the substrate, and the size of the second gap D2 is smaller, which can ensure the structural strength of the plurality of clamping sub-parts 112 when the single clamping part 11 is subdivided into a plurality of clamping sub-parts 112, avoid the clamping sub-parts 112 from breaking and falling off, and improve the reliability of the electroplating clamp in use.

[0041] In some embodiments, as Figure 5 As shown, the clamping piece 1 also includes a fixed part 12 and a connecting part 13. The two clamping pieces 1 are detachably connected through the fixed part 12. For example, the fixed part 12 of the two clamping pieces 1 is respectively provided with a connecting through hole, and the center lines of the connecting through holes of the two clamping pieces 1 are arranged in a line, and by inserting a fixing member (such as a bolt) into the connecting through hole, the detachable connection of the two clamping pieces 1 can be achieved.

[0042] The connecting part 13 is used to connect the fixed part 12 and the clamping part 11, and the connecting part 13 and the clamping part 11 are arranged at an angle, for example, an obtuse angle. As Figure 2 As shown, in the first direction X1, the fixed parts 12 of the two clamping pieces 1 are arranged in abutment, the gap between the two connecting parts 13 is the third gap D3, and the gap between the two clamping parts 11 is the fourth gap D4, and the size of the third gap D3 is greater than the size of the fourth gap D4.

[0043] Through the above arrangement, the electroplating clamp can be conveniently clamped, avoiding the outer surface of the substrate from contacting the connecting portion 13 of the electroplating clamp when clamping the substrate, ensuring that the clamping portion 11 can smoothly apply clamping force to the substrate, and improving the reliability of the electroplating clamp in use. In addition, by avoiding the substrate from contacting the connecting portion 13, the substrate can also be prevented from being damaged.

[0044] It is easy to understand that the fixing portion 12, the connecting portion 13, and the clamping portion 11 can be integrally formed. In this way, the clamping piece 1 can be conveniently manufactured. When the three portions are integrally formed, the clamping piece 1 as a whole can be made of beryllium copper alloy or conductive rubber composite material (a rubber matrix added with conductive particles such as carbon black and metal fibers). In this way, the clamping piece 1 can have high conductivity, and the clamping portion 11 can also be elastically deformed. Of course, the fixing portion 12, the connecting portion 13, and the clamping portion 11 can also be detachable (for example, connected by bolts or clamped). In this way, the maintenance and replacement of the components can be facilitated.

[0045] In some embodiments, the connecting portion 13 can be elastically deformable. For example, the connecting portion 13 is a metal elastic sheet, or the connecting portion 13 is a wave-shaped elastic structure composed of multiple curved elastic segments. In this way, the connecting portion 13 can also be deformed in the first direction X1, so that the clamping piece 1 can also be adaptively adjusted according to the warping deformation of the substrate when clamping the substrate, further improving the fitting effect and clamping effect of the clamping portion 11 and the outer surface of the substrate.

[0046] In some embodiments, the outer surface of the clamping piece 1 is provided with a coating layer 3, which is made of, for example, fluororubber, or a composite layer of fluororubber and other materials (for example, a combination of a fluororubber inner core and a polytetrafluoroethylene outer coating layer). By providing the coating layer 3 on the outer surface of the clamping piece 1, the sealing and leakage prevention performance of the electroplating clamp can be improved, avoiding the penetration of the electroplating liquid into the clamp, and improving the chemical protection performance of the clamping piece 1, so that the clamping piece 1 can resist the corrosive components such as acid, alkali, and salt in the electroplating liquid, prolonging the service life of the clamping piece 1.

[0047] In some embodiments, the clamping surface 111 of each clamping portion 11 is provided with a corresponding electroplating contact portion 113. It is easy to understand that when a single clamping portion 11 includes multiple clamping sub-portions 112, the multiple clamping sub-portions 112 are also provided with corresponding electroplating contact portions 113. The electroplating contact portion 113 is exposed to the coating layer 3. In other words, the electroplating contact portion 113 is exposed to the outside of the clamping piece 1. Figure 5As shown in the view, in the first direction X1, the size of the electroplating contact part 113 is greater than or equal to the thickness of the single-layer cladding layer 3. By so arranging, the normal contact between the clamp 1 and the substrate can be ensured, and the smooth progress of the electroplating process can be ensured.

[0048] In some embodiments, as shown in the view, Figure 3 As shown in the view, the connecting part 13 of the clamp 1 is provided with a plurality of anchoring openings 131. By providing the anchoring openings 131, the mechanical engagement area (the anchoring structure formed by filling the anchoring openings 131 with the cladding material) can be increased when the clamp 1 is cladded with the cladding layer 3, the firmness of the cladding can be improved, and the exhaust can be facilitated, thereby ensuring the cladding quality.

[0049] The process of electroplating using the electroplating clamp is as follows: first, the substrate is placed on the electroplating clamp (i.e., between the clamping surfaces 111 of the two clamps 1), then the electroplating clamp is closed to preliminarily contact the clamping part 11 with the outer surface of the substrate, then the elastic assembly 2 is used to press the clamping part 11 of the clamp 1, so that the clamping part 11 is adaptively fitted to the outer surface of the substrate according to the warping deformation trend of the substrate, then the electroplating process is performed to electroplate the substrate, and finally, the electroplating is completed and the pressure of the elastic assembly 2 on the clamping part 11 is stopped, and the electroplating clamp is released.

[0050] In the electroplating process, the electroplating clamp is used to clamp the substrate, and the substrate is placed in the electroplating tank. The electroplating tank is provided with an electroplating solution and an anode plate. The anode plate is electrically connected to the positive electrode of the electroplating power supply, and the negative electrode of the electroplating power supply is electrically connected to the clamp 1 of the electroplating clamp. As described above, the clamp 1 has electrical conductivity, for example, is made of metal, conductive non-metal or the like. The clamping part 11 of the clamp 1 is in abutment with the electrode contact provided on the substrate through the electroplating contact part 113, so as to realize the electrical connection between the substrate and the negative electrode of the electroplating power supply. Under the action of the current, the cations in the electroplating solution are deposited and attached to the surface of the substrate, and the electroplating is completed.

[0051] In actual use, the negative electrode of the electroplating power supply is electrically connected to the clamp 1. The electrical connection mode can be selected according to the type of electroplating. For example, if only single-sided electroplating of the substrate is required, the negative electrode of the electroplating power supply is only electrically connected to one of the clamps 1 of the corresponding electroplating clamp, or only the clamp 1 on one side is provided, and the clamp 1 on the other side is cancelled; if double-sided electroplating of the substrate is required, the negative electrode of the electroplating power supply is electrically connected to both clamps 1 of the electroplating clamp.

[0052] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, various obvious changes, re-adjustments and replacements can be made without departing from the protection scope of the present application. Here, it is not necessary and also impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application claim.

Claims

1. An electroplating fixture, characterized by, The utility model relates to a kind of clamping devices, including: Two clamping pieces (1) are symmetrically arranged along the plane perpendicular to the first direction (X1);One end of the clamping piece (1) is provided with a plurality of clamping portions (11) arranged along the second direction (X2), and the surface of the clamping portion (11) of the two clamping pieces (1) facing each other is the clamping surface (111);Each of the plurality of clamping portions (11) can be deformed independently in the first direction (X1), and the second direction (X2) is arranged at an angle to the first direction (X1); A plurality of elastic components (2) are arranged on the two clamping pieces (1), and the elastic component (2) can drive the plurality of clamping portions (11) on the corresponding clamping piece (1) to deform towards the other clamping piece (1).

2. The electroplating fixture of claim 1, wherein, The clamping portion (11) includes a plurality of clamping sub-portions (112) arranged at intervals along the second direction (X2); On the same clamping piece (1), a plurality of clamping portions (11) are arranged at intervals along the second direction (X2), and the gap between the adjacent two clamping portions (11) is the first gap (D1), and the gap between the adjacent two clamping sub-portions (112) on the same clamping portion (11) is the second gap (D2); In the third direction (X3), the size of the first gap (D1) is greater than the size of the second gap (D2); The first direction (X1), the second direction (X2) and the third direction (X3) are arranged at an angle to each other.

3. The electroplating fixture of claim 1, wherein, The number of elastic components (2) is two, and the two elastic components (2) are arranged on the clamping portions (11) of the two clamping pieces (1) respectively and located on the side of the clamping portion (11) away from the clamping surface (111) of itself.

4. The electroplating fixture of claim 1, wherein, The clamping piece (1) further includes: A fixed portion (12) is arranged on the clamping piece (1), and the two clamping pieces (1) are detachably connected through the fixed portion (12); A connecting portion (13) is arranged on the clamping piece (1) and used for connecting the fixed portion (12) and the clamping portion (11), and the connecting portion (13) and the clamping portion (11) are arranged at an angle to each other; In the first direction (X1), the fixed portions (12) of the two clamping pieces (1) are arranged in close contact, the gap between the two connecting portions (13) is the third gap (D3), the gap between the two clamping portions (11) is the fourth gap (D4), and the size of the third gap (D3) is greater than the size of the fourth gap (D4).

5. The electroplating fixture of claim 4, wherein, The fixed portion (12), the connecting portion (13) and the clamping portion (11) are integrally formed.

6. The electroplating fixture of claim 4, wherein, The connecting portion (13) is an elastic structure.

7. The electroplating fixture of claim 1, wherein, The elastic component (2) includes an air bag (21), and the air bag (21) is arranged on the side of the clamping surface (111) of the clamping portion (11) away from itself.

8. The electroplating fixture of claim 1, wherein, The outer surface of the clamping piece (1) is provided with a cladding layer (3).

9. The electroplating fixture of claim 8, wherein, A plurality of electroplated contact portions (113) are arranged one by one on the clamping surface (111) of the plurality of clamping portions (11), and the electroplated contact portion (113) is exposed to the cladding layer (3).

10. The electroplating fixture of claim 8, wherein, The clamping piece (1) further comprises a connecting portion (13) provided with a plurality of anchoring openings (131).

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