Test fixture

Abstract

The utility model discloses a test fixture, relates to the technical field of steel mesh detection, the test fixture comprises a fixture body and a base, the fixture body is provided with a spacing groove and an avoiding groove, the spacing groove is used for placing the steel mesh; the avoiding groove is formed in the middle of the limiting groove, and the groove depth of the avoiding groove is larger than that of the limiting groove, so that the tension testing part of the steel mesh does not make contact with the jig body; the base is arranged on the lower portion of the jig body and used for supporting the jig body. When in use, the test fixture is placed on a platform, and the base is in contact with the platform to support the fixture body; a to-be-tested steel mesh is placed on the jig body to be subjected to tension testing, and the to-be-tested area of the steel mesh and the platform are suspended through the testing jig. Therefore, the operation steps of the steel mesh in the tension testing process can be reduced; meanwhile, the situation that the steel mesh is polluted due to the fact that the steel mesh deforms under the action of gravity and makes contact with the table top platform is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of stencil inspection, and particularly relates to a test fixture. Background Art

[0002] The stencil is an essential tooling in the processing and manufacturing of PCBA (Printed Circuit Board Assembly). Effective control of its tension value is an important prerequisite for ensuring the printing quality of the stencil. With the popularization of the frame body, more and more factories tend to adopt the combination of the frame body + mesh sheet for production, which can save storage space and procurement costs. However, for the tension test of the stencil, compared with the ordinary framed stencil test, there are problems such as complex tension test process, shortened stencil life, and poor printing during use after being contaminated. Summary of the Utility Model

[0003] The main purpose of the utility model is to propose a test fixture, aiming to reduce the operation steps of the stencil during the tension test; at the same time, to avoid the deformation of the stencil under the action of gravity and contact with the desktop platform, resulting in the stencil being contaminated.

[0004] To achieve the above purpose, the test fixture proposed by the utility model includes:

[0005] A fixture body, which is provided with a limiting groove and an avoidance groove. The limiting groove is used to place the stencil; the avoidance groove is arranged in the middle of the limiting groove, and the depth of the avoidance groove is greater than that of the limiting groove, so that the tension test part of the stencil does not contact the fixture body; and

[0006] A base, which is arranged at the lower part of the fixture body and is used to support the fixture body.

[0007] The technical solution of the utility model limits the stencil by placing it in the limiting groove of the fixture body. The avoidance groove is arranged in the middle of the limiting groove, and the area to be tested of the stencil is located above the avoidance groove. The base supports the fixture body, so that the connecting piece is suspended. In this way, when the stencil is stationary, the area to be tested is suspended relative to the fixture body, and the tension test part of the stencil does not contact the fixture body; then the tension test can be started, and after the test is completed, the stencil can be directly taken out. In this way, it is avoided that the bottom of the stencil contacts the outside, reducing the risk of the clean stencil being contaminated and damaged by the platform, thereby reducing the occurrence of poor problems in printing, improving the product quality, and ensuring the service life of the stencil.

[0008] In an embodiment, the stencil includes a mesh sheet to be tested, a frame body, and a clamping mechanism movably arranged on the frame body for clamping and fixing the mesh sheet; the frame body is placed in the limiting groove, and the avoidance groove corresponds to the clamping mechanism.

[0009] In one embodiment, the base includes a support member and a connecting member. The jig body is disposed on the upper side of the connecting member, the support member is disposed on the lower side of the connecting member, and the mesh does not contact the connecting member.

[0010] In one embodiment, a through groove is provided in the middle of the connecting member, and the avoidance groove is provided to be hollow and communicate with the through groove; the area of the through groove is smaller than that of the avoidance groove, and the area of the through groove is larger than that of the mesh.

[0011] In one embodiment, a relief notch is provided on the outer side of the connecting member, and the jig body and the support member are intermittently provided at the relief notch for a user to take / place the mesh frame body or the connecting member.

[0012] In one embodiment, a common side of the connecting member and the jig body is provided to be open so that the mesh can be inserted between the clamping mechanism and the mesh frame body through the open side.

[0013] In one embodiment, the height range of the support member is 5 mm - 25 mm.

[0014] In one embodiment, the limiting groove is provided with an upward opening, and the limiting groove and the mesh frame body are in clearance fit, and the clearance distance range is 2 mm - 6 mm.

[0015] In one embodiment, the groove depth range of the avoidance groove is 7 mm - 12 mm.

[0016] In one embodiment, the connecting member is made of a metal material.

[0017] In one embodiment, the support member and / or the jig body is made of a plastic material. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 is a schematic structural diagram of an embodiment of the test jig provided by the present invention;

[0020] Figure 2 is Figure 1 a schematic structural diagram of another perspective of the test jig in

[0021] Figure 3 isFigure 1 Structural schematic diagram of the middle test fixture from another perspective.

[0022] Explanation of the reference numerals in the attached drawings:

[0023] 100. Test fixture; 110. Connecting piece; 101. Upper side; 102. Lower side; 111. Through groove; 112. Relief notch; 120. Fixture body; 121. Limit groove; 122. Avoidance groove; 130. Support piece.

[0024] The realization, functional features and advantages of the purpose of the present utility model will be further described in conjunction with the embodiments with reference to the attached drawings. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the attached drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present utility model.

[0026] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0028] The stencil is an essential tool in the manufacturing process of PCBA (Printed Circuit Board Assembly. PCBA is the next step after PCB, which involves subjecting a blank PCB board to a series of processes, including SMT chip mounting, DIP component insertion, and testing, etc., to finally form a finished product). Effective control of its tension value is an important prerequisite for ensuring the stencil printing quality.

[0029] With the popularization of the screen frame body, more and more factories tend to adopt the combination of the screen frame body + screen sheet for production. This method can save storage space and procurement costs. However, for the tension test of the stencil, compared with the ordinary framed stencil, there are problems such as complex tension test process, shortened stencil life, and printing defects during use after being contaminated.

[0030] For the combination of the screen frame body + screen sheet, the clamping mechanism needs to support and position the screen sheet. Therefore, the screen frame body structure cannot install and disassemble the screen sheet in the state of being inverted on the desktop platform. Therefore, during the tension test, the currently adopted test method in the industry is: First, place the screen frame body upright on the desktop platform, install the screen sheet into the clamping mechanism and the screen frame body and fix it, then turn the entire screen frame body over and place it upside down on the platform, and finally use a tensiometer to test the tension value. After the test is completed, turn the screen frame body back upright, disassemble the screen sheet, and put it back into the warehouse. When testing the tension of the stencil, the bottom of the screen sheet cannot directly contact the platform and needs to be suspended. Only after suspension can the screen sheet in the center of the area to be measured deform in the vertical direction, and this deformation can be transmitted to the tensiometer to measure the true tension value. Therefore, the screen frame body needs to be placed upside down on the platform when measuring the tension. When installing the screen sheet on the screen frame body, due to the problem of structural design, it must be placed upright on the platform first. After inflating from the outside to eject the clamping mechanism, then push the screen sheet onto the clamping mechanism. After cutting off the air, the clamping mechanism drops back to fix the screen sheet. However, when the screen frame body is placed upright on the platform, the screen sheet will be contaminated and damaged.

[0031] When the screen frame body is in an inverted state, the screen sheet cannot be normally placed on the clamping mechanism (unable to support the screen sheet), so the entire test process has more steps. At the same time, when the screen frame body is directly placed upright on the platform, when installing the screen sheet, the bottom of the screen sheet will contact the platform, causing contamination and damage to the screen sheet.

[0032] Therefore, the present utility model proposes a test fixture to solve the above problems, reduce the operation steps in the process of tension testing using the screen frame body and the screen sheet; at the same time, avoid the situation where the screen sheet may contact the desktop during the installation process, resulting in contamination of the screen sheet.

[0033] Please refer to Figures 1 to 3, the test fixture 100 includes a fixture body 120 and bases (110, 130). The fixture body 120 is provided with a limiting groove 121 and an avoidance groove 122. The limiting groove 121 is used to place the stencil. In one embodiment, the stencil is a separate mesh sheet. Since there is no need to place the mesh sheet inside the mesh frame body, the operation steps can be reduced. The limiting groove 121 can be paired with other fixing parts with limiting and fixing functions to limit the mesh sheet so that the mesh sheet can be subjected to a tension test. The avoidance groove 122 is arranged in the middle of the limiting groove 121, and the groove depth of the avoidance groove 122 is greater than that of the limiting groove 121, so that the tension test part of the stencil does not contact the fixture body 120. The bases (110, 130) are arranged at the lower part of the fixture body 120 to support the fixture body 120.

[0034] The technical solution of the present utility model limits the stencil by placing it in the limiting groove 121 of the fixture body 120. The avoidance groove 122 is arranged in the middle of the limiting groove 121, and the area to be tested of the stencil is located above the avoidance groove 122. The base supports the fixture body 120, so that the connecting piece 130 is suspended. In this way, when the stencil is stationary, the area to be tested is suspended relative to the fixture body, and the tension test part of the stencil does not contact the fixture body. Subsequently, the tension test can be started directly. After the test is completed, the stencil can be directly taken out. In this way, it is avoided that the bottom of the stencil contacts the outside, reducing the risk of the clean stencil being contaminated and damaged by the platform, further reducing the occurrence of defective problems in printing, improving the product quality, and ensuring the service life of the stencil.

[0035] Without loss of generality, in one embodiment, the stencil includes a mesh sheet to be tested, a mesh frame body, and a clamping mechanism movably arranged on the mesh frame body for clamping and fixing the mesh sheet. The mesh frame body is placed in the limiting groove 121, and the avoidance groove 122 corresponds to the clamping mechanism.

[0036] The bases (110, 130) include a support piece 130 and a connecting piece 110. The fixture body 120 is arranged on the upper side 101 of the connecting piece 110, and the support piece 130 is arranged on the lower side 102 of the connecting piece 110. The mesh sheet does not contact the connecting piece 110.

[0037] That the mesh sheet does not contact the connecting piece 110 means that the mesh sheet does not contact the connecting piece 110 in the natural hanging state and does not contact the connecting piece 110 during the test process.

[0038] The main body of the screen frame is placed on the fixture body 120, and the limit groove 121 set on the fixture body 120 pre-positions the main body of the screen frame. The main body of the screen frame can be directly placed on the test fixture 100 to complete the operation of inflating and loading the mesh. The connecting member 110 is provided with a through groove 111, and the area to be tested of the mesh is located above the through groove 111. The supporting member 130 supports the connecting member 110 so that the connecting member 110 is suspended. In this way, when the mesh is stationary, the area to be tested is suspended relative to the connecting member 110; then the tension test can be started, and the mesh is directly inflated and taken out after the test is completed. Compared with before the test fixture 100 is used, the main body of the screen frame is placed on the test bracket, and a deformation area sufficient to test the real tension is left at the bottom of the mesh, so that the tension test can be completed after the main body of the screen frame is placed upright, simplifying the test process. In this way, the central opening area at the bottom of the mesh is prevented from directly contacting the platform, and the clean mesh is prevented from being contaminated and damaged by the platform, which leads to bad problems in printing, improves product quality, and ensures the service life of the mesh.

[0039] See also Figures 1 to 3 The common side of the connecting piece 110 and the fixture body 120 is set to be open, so that the mesh can be inserted between the clamping mechanism and the mesh frame body through the opening. The connecting piece 110 is a semi-enclosed frame, consisting of two long side segments and one short side segment, such as a "冂" shape. The middle of the frame is a through groove 111. The limiting groove 121 is a step formed by the inner edge of the fixture body 120. The mesh frame body is placed in the limiting groove 121 from top to bottom to avoid the movement of the mesh frame body. In order to avoid the clamping mechanism, the edges of the fixture body 120 and the through groove 111 are formed with an avoidance groove 122. The limiting groove 121 is connected to the avoidance groove 122 to avoid The groove 122 is used to avoid the clamping mechanism. After the mesh frame body is inflated, the clamping mechanism pops up downward and is located in the avoidance groove 122. The mesh is placed on the clamping mechanism from the open side of the semi-enclosed frame of the connecting member 110; the air is deflated so that the clamping mechanism clamps and fixes the mesh, and the edge of the mesh is roughly the same as the edge of the through groove 111 in projection; in other embodiments, the mesh may be located in the through groove 111 as a whole, so the avoidance groove 122 on the fixture body 120 may be eliminated. The area to be tested of the mesh is located above the through groove 111. When the mesh is stationary, the deformation due to gravity is approximately 3mm-6mm, and the deformation during the tension test is approximately 0.2mm-0.4mm. The height of the support member 130 does not need to be too high, and the thickness of the fixture body 120 and the connecting member 110 ensures that the mesh does not touch the desktop platform.

[0040] To facilitate the user to pick up and place the frame body or the connecting member 110, the connecting member 110 is provided with a relief notch 112 at the outer edge of the through slot 111. The jig body 120 and the support member 130 are discontinuously provided at the relief notch 112. On this basis, the height of the support member 130 is set to 16 mm - 24 mm, which not only ensures the suspension of the mesh sheet but also provides enough space for tools or hands to extend from the bottom of the connecting member 110 through the relief notch 112 for picking up and placing.

[0041] Please refer to Figures 1 to 3 , the projected area of the through slot 111 in the vertical direction is larger than the projected area of the area to be measured in the vertical direction. The size of the connecting member 110 is larger than the size of the frame body; the middle through slot 111 enables the central area to be measured of the mesh sheet to deform under the external force of the tensiometer, and the true tension value can be measured; relief notches 112 are left on both sides of the connecting member 110, which is convenient for personnel to hold and place the frame body.

[0042] In addition, the connecting member 110 is made of aluminum alloy with a thickness of 5 mm, which can effectively support the frame body without deformation while achieving lower weight and lower cost.

[0043] The limiting groove 121 and the frame body are in clearance fit, and the clearance distance ranges from 2 mm to 6 mm, which can enable the frame body to be easily placed in it without random movement. The depth of the limiting groove 121 is about one-third of the thickness of the frame body, which can effectively prevent the frame body from sliding out; the groove depth of the avoidance groove 122 ranges from 7 mm to 12 mm, which is enough for the clamping mechanism of the frame body to pop out; notches are left on both the left and right sides like the connecting member 110, which is convenient for personnel to pick up; the jig body 120 is made of acrylic board, which effectively reduces the tooling production cost and the overall weight.

[0044] Please refer to Figures 1 to 3 , four support members 130 are arranged at intervals. The support members 130 at the bottom of the connecting member 110 can keep a certain distance between the bottom of the mesh sheet and the desktop platform after the frame body is placed on it. The four support members 130 are fixed at the four corner positions at the bottom of the connecting member 110, playing an effective supporting role; the setting of the support members 130 can keep a distance between the bottom of the mesh sheet and the platform, preventing foreign objects on the platform from contaminating the clean mesh sheet; the support members 130 are made of acrylic material, which effectively reduces the tooling production cost and the overall weight.

[0045] Working principle: First, an operator takes the frame body and places it on the test fixture 100. Since there is already a support member 130 at the bottom of the connecting member 110 and there is a sufficiently large through slot 111 in the middle of the connecting member 110, the center of the test area of the mesh will not come into contact with the desktop platform where the test fixture 100 is placed after the mesh is installed. Therefore, the frame body can be directly placed upright in the test fixture 100. After inflating the frame body with an air pipe, the clamping mechanism pops open. Then, the mesh is pushed in from the side and placed on the clamping mechanism. After cutting off the air supply, the clamping mechanism rebounds to fix the mesh. At this time, the actual tension value of the test area of the mesh can be directly measured using a tensiometer. After the test is completed, the tensiometer is removed, the mesh is pulled out from the side after inflating with an air pipe, and the air is cut off to make the rebounding structure return. Then, the mesh can be directly put back into the warehouse. When testing the mesh, it only needs to be fixed in the limit slot 121, which can further reduce the operation of putting the mesh into the frame body.

[0046] Since the test fixture 100 has a middle through slot 111 and a bottom support member 130, compared with testing the tension of the frame body + mesh without using the test fixture 100, the operation of placing the frame body upright and then inverting it is omitted. Moreover, during the process of installing the mesh, the bottom of the mesh will not be contaminated or damaged due to contact with the platform, reducing the printing abnormality problems during the use of the stencil, improving the product quality, and extending the service life of the stencil.

[0047] The above is the solution of an embodiment of the test fixture 100 proposed by the present utility model. As an alternative, in other embodiments, the fixture body 120 and the connecting member 110 are integrally formed; or, the fixture body 120, the support member 130, and the connecting member 110 are integrally formed.

[0048] Without considering the number of uses, the material of the connecting member 110 can also be plastic. Or, under the condition of ensuring a certain structural strength and cost, the connecting member 110 is made of metal. Of course, the support member 130 and the fixture body 120 can also be made of other plastic materials, or made of metal, or non-metal materials.

[0049] When placing the frame body on the fixture body 120, a push-pull method can also be used. Without loss of generality, for example, when the opening of the limit slot 121 is the same as the opening of the semi-closed frame of the connecting member 110 and there is a stop at the upper edge of the limit slot 121, the frame body can also be pre-positioned in the limit slot 121. The clamping mechanism can be arranged in the through slot 111, which can also ensure the pop-up of the clamping mechanism and avoid interference between the frame body and the test fixture 100.

[0050] The above are only exemplary embodiments of the present utility model, and do not thus limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields is included within the patent protection scope of the present utility model.

Claims

1. A test fixture for performing tension testing on a steel mesh, characterized in that: The test fixture includes: The fixture body is provided with a limit groove and an avoidance groove, wherein the limit groove is used to place the steel mesh; the avoidance groove is arranged in the middle of the limit groove, and the groove depth of the avoidance groove is greater than that of the limit groove, so that the tension test part of the steel mesh does not contact the fixture body; and The base is arranged at the lower part of the fixture body and is used for supporting the fixture body.

2. The test fixture according to claim 1, characterized in that: The steel mesh includes a mesh to be tested and a mesh frame body, and a clamping mechanism movably arranged on the mesh frame body for clamping and fixing the mesh; The screen frame body is arranged in the limiting groove, and the avoidance groove corresponds to the clamping mechanism.

3. The test fixture as claimed in claim 2, characterized in that: The base includes a supporting member and a connecting member, the fixture body is arranged on the upper side of the connecting member, the supporting member is arranged on the lower side of the connecting member, and the mesh does not contact the connecting member.

4. The test fixture as claimed in claim 3, characterized in that: A through slot is provided in the middle of the connecting piece, and the avoidance slot is arranged to be hollow and connected to the through slot; the area of ​​the through slot is smaller than that of the avoidance slot, and the area of ​​the through slot is larger than that of the mesh.

5. The test fixture as claimed in claim 3, characterized in that: A clearance notch is provided on the outer side of the connecting piece, and the fixture body and the supporting piece are intermittently arranged at the clearance notch to allow a user to take / place the screen frame body or the connecting piece.

6. The test fixture as claimed in claim 3, characterized in that: A common side of the connecting piece and the fixture body is set to be open, so that the mesh sheet can be inserted between the clamping mechanism and the mesh frame body through the opening.

7. The test fixture as claimed in claim 3, characterized in that: The height of the support member ranges from 5 mm to 25 mm.

8. The test fixture as claimed in claim 2, characterized in that: The limiting groove is open upward, and the limiting groove and the screen frame body are clearance-matched, and the clearance distance ranges from 2mm to 6mm.

9. The test fixture according to any one of claims 1 to 8, characterized in that: The groove depth of the avoidance groove ranges from 7mm to 12mm.

10. The test fixture as claimed in claim 3, characterized in that: The connecting piece is made of metal; and / or the supporting piece and / or the fixture body is made of plastic.

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