Backflow clamp carrier and backflow clamp

Abstract

The utility model relates to the technical field of semiconductor manufacturing, and provides a reflow clamp bearing piece and a reflow clamp, and the reflow clamp bearing piece comprises a bearing body; the bearing body is provided with a bearing surface used for bearing a substrate, and the bearing surface is of a cambered surface structure with the middle protruding. Through the backflow clamp, the warping phenomenon caused by backflow of the substrate can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor manufacturing, especially relates to a reflow clamp bearing and reflow clamp. BACKGROUND

[0002] The reflow process refers to a process of connecting a substrate with other components through reflow soldering technology.

[0003] Taking AMB (active metal brazing ceramic substrate) as an example, the AMB needs to be electrically connected with a lead frame through reflow soldering, and a reflow clamp is usually used in cooperation during the reflow process. The reflow clamp is used to fix the AMB and the lead frame, so that the relative positions of the two are fixed. The existing reflow clamp only plays a role in fixing the AMB and the lead frame, and cannot effectively control the warping deformation of the two after reflowing. For example, after the AMB and the lead frame are welded, the AMB after welding will warp (for example, the AMB will be raised on both sides) due to thermal stress at the welding position.

[0004] Therefore, the utility model provides a reflow clamp bearing and reflow clamp, and the reflow clamp can improve the warping phenomenon of the substrate after reflowing. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a reflow clamp bearing and reflow clamp, and the reflow clamp can improve the warping phenomenon of the substrate after reflowing.

[0006] The utility model provides a reflow clamp bearing, which comprises a bearing body.

[0007] The bearing body is provided with a bearing surface for bearing a substrate, and the bearing surface is an arc surface structure with a raised middle part.

[0008] Optionally, the bearing surface is a spherical surface.

[0009] Optionally, the difference in height between the highest point and the lowest point of the bearing surface is not greater than 3 mm.

[0010] Optionally, the bearing body has a first side surface, and the first side surface has a boss.

[0011] Along the vertical direction of the first side surface, an end surface of the boss away from the first side surface serves as the bearing surface.

[0012] Optionally, the outer contour of the bearing surface is rectangular.

[0013] Optionally, the reflow clamp bearing further comprises a plurality of connecting parts, each of which is connected to the bearing body and arranged around the bearing surface.

[0014] Optionally, the bearing body has a rectangular plate structure.

[0015] When the outer contour of the bearing surface is rectangular, four edges of the bearing surface are parallel to four edges of the bearing body, respectively.

[0016] When the reflow clamp bearing includes a connecting portion, the connecting portion is arranged at four corners of the bearing body.

[0017] The utility model discloses still provide a kind of reflow clamp, and the reflow clamp includes the reflow clamp bearing described above.

[0018] Optionally, the reflow clamp further includes a pressing assembly, and the pressing assembly is configured to apply a force to a substrate supported on the bearing surface, so that the substrate conforms to the bearing surface.

[0019] Optionally, the reflow clamp further includes a clamp seat, and the reflow clamp bearing is mounted on the clamp seat, and the pressing assembly is detachably arranged on the clamp seat.

[0020] In this way, the reflow clamp bearing described above has a bearing surface for supporting a substrate. During reflow, the substrate conforms to the bearing surface, which is configured as a convex arc surface in the middle, so that the substrate conforms to the shape of the bearing surface during the process of conforming to the bearing surface (the edge of the substrate deforms downward). After the substrate and other components are reflow soldered, the edge of the substrate has a plurality of soldering positions. When the substrate is released to a free state, the internal stress of the soldering positions of the edge of the substrate causes the edge of the substrate to deform upward. The deformation caused by the internal stress is exactly complementary to the deformation of the substrate conforming to the bearing surface, so that the final deformation of the substrate is small, the warping phenomenon after the reflow process of the substrate is improved, and the risk of cracks or even failure of the substrate due to warping is reduced. The improvement of the warping phenomenon also benefits subsequent processes, such as improved vacuum adsorption performance in subsequent processes and improved glue overflow phenomenon, which provides a larger process window for subsequent workstations and meets the reliability requirements of power modules composed of substrates.

[0021] In addition, after the substrate completes the previous process, it usually has a certain warping phenomenon of arching in the middle and deforming the edge downward. The deformation causes the shape of the substrate to be roughly adapted to the shape of the bearing surface, so that the bearing surface is configured as an arching structure in the middle, which is also beneficial to closely conforming to the substrate. The bearing surface can accurately control the shape of the substrate during reflow soldering, so that the warping of the substrate after reflow is controllable. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a three-dimensional structure schematic view of the reflow clamp bearing of an embodiment of the utility model;

[0023] Figure 2The top view structural schematic diagram of the reflow clamp bearing of an embodiment of the utility model;

[0024] Figure 3 The cross section structural schematic diagram of the reflow clamp bearing of an embodiment of the utility model;

[0025] Figure 4 For Figure 3 The enlarged structural schematic diagram of point A of the utility model;

[0026] Figure 5 The arc structural schematic diagram of the bearing surface of an embodiment of the utility model;

[0027] Figure 6 The explosion structural schematic diagram of the reflow clamp of an embodiment of the utility model.

[0028] Figure 7 The assembly structural schematic diagram of the reflow clamp of an embodiment of the utility model;

[0029] Figure 8 The three-dimensional structural schematic diagram of the clamp seat and the reflow clamp bearing after assembly of an embodiment of the utility model;

[0030] Figure 9 The top view structural schematic diagram of the clamp seat and the reflow clamp bearing after assembly of an embodiment of the utility model;

[0031] Figure 10 The bottom view structural schematic diagram of the clamp seat and the reflow clamp bearing after assembly of an embodiment of the utility model;

[0032] Figure 11 The three-dimensional structural schematic diagram of the clamp seat, the reflow clamp bearing, the substrate and the lead frame after assembly of an embodiment of the utility model.

[0033] In the drawings:

[0034] 100-reflow clamp bearing;

[0035] 10-bearing body; 101-bearing surface; 11-first side; 12-second side; 13-boss;

[0036] 20-connection part; 21-connection table; 22-transition piece;

[0037] 200-pressing assembly; 210-first cover plate; 220-second cover plate; 230-first connecting piece; 240-second connecting piece;

[0038] 300-clamp seat; 310-hollow area; 320-stop edge; 330-first positioning protrusion; 340-second positioning protrusion;

[0039] 400 - substrate;

[0040] 500 - lead frame; 510 - connecting frame. DETAILED DESCRIPTION

[0041] The reflow clamp bearing of the utility model will be further explained in detail below in combination with the drawings and specific embodiments. The advantages and features of the utility model will be clearer according to the following description. It should be noted that the drawings are all in a very simplified form and all use non-precise proportions, only for the purpose of facilitating and clearly assisting in explaining the embodiments of the utility model.

[0042] As used in the utility model, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The term "or" is generally employed in its sense including "and / or" unless the context clearly dictates otherwise. The term "plurality" is generally employed in its sense including "at least two" unless the context clearly dictates otherwise. The term "first," "second," "third," etc. are merely used for descriptive purposes and do not necessarily imply a relative importance or an implied number of the technical features indicated. Thus, the features defined with "first," "second," "third" can explicitly or implicitly include one or at least two of the features. In addition, as used in the utility model, "mounting," "connected," "connected," one element "provided" in another element should be understood broadly, generally only indicates the existence of a connection, coupling, cooperation or transmission relationship between the two elements, and the two elements can be directly or indirectly connected, coupled, cooperated or transmitted through intermediate elements, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any direction inside, outside, above, below or one side of another element, unless the content is otherwise clearly indicated. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as they are shown in the drawings, upward or upward direction is toward the top of the corresponding drawing, and downward or downward direction is toward the bottom of the corresponding drawing.

[0043] The utility model provides a kind of reflow clamp bearing 100, comprising: bearing body 10;

[0044] The bearing surface 101 for bearing substrate is formed on the bearing body 10, and the bearing surface 101 is arc surface structure with middle part bulge.

[0045] Please refer to Figures 1 to 4As shown, in the embodiment, the carrying body 10 is a thin-walled plate structure, and the carrying body 10 has a first side surface 11 and a second side surface 12 opposite to each other, which correspond to two large surfaces of the plate structure.

[0046] The first side surface 11 corresponds to Figure 3 the upper surface of the carrying body 10, and the second side surface 12 corresponds to Figure 3 the lower surface of the carrying body 10.

[0047] Please continue to refer to Figures 1 to 4 As shown, the middle part of the first side surface 11 has a boss 13.

[0048] Along the vertical direction of the first side surface 11, the end surface of the boss 13 away from the first side surface 11 serves as the carrying surface 101. The carrying surface 101 corresponds to Figure 3 and Figure 4 the upper surface of the boss 13.

[0049] The carrying surface 101 is used for carrying the substrate, and the substrate is arranged on the carrying surface 101 in the reflow process. The carrying surface 101 is arranged as an arc-shaped structure with a raised middle part, so that the substrate also deforms when being arranged on the carrying surface 101 (the edge of the substrate deforms downward), and the edge of the substrate has a plurality of welding positions after the reflow soldering of the substrate and other elements. When the substrate is released to a free state, the internal stress of the welding positions of the edge of the substrate causes the edge of the substrate to deform upward, and the deformation caused by the internal stress is just complementary to the deformation of the substrate adapting to the carrying surface 101, so that the final deformation of the substrate is small, the warping phenomenon of the substrate after the reflow process is improved, and the risk of cracks or even failure of the substrate due to warping is reduced. The improvement of the warping phenomenon also benefits subsequent processes, for example, the vacuum adsorption performance in the subsequent process is improved, the glue overflow phenomenon is also improved, a larger process window is reserved for the subsequent work station, and the reliability of the power module composed of the substrate meets the requirements.

[0050] In addition, after the substrate is completed in the previous process, there is also a certain warping phenomenon that the middle part of the substrate is arched and the edge deforms downward. The deformation makes the shape of the substrate substantially adapt to the shape of the carrying surface 101, so that the carrying surface 101 arranged as an arched structure in the middle part is also beneficial to closely contact with the substrate, and the carrying surface 101 can accurately control the shape of the substrate in the reflow soldering process, so that the warping of the substrate after the reflow process is controllable.

[0051] As shown, Figure 4 the height of the boss 13 protruding from the first side surface 11 is in millimeters, that is, the height of the boss 13 is low. By arranging the boss 13 structure, the shape control of the carrying surface 101 and the machining of the arc-shaped carrying surface 101 are facilitated.

[0052] In other alternative embodiments, the boss can also not be provided. For example, the first side 11 of the bearing body 10 can be directly machined to form the arc surface structure of the middle part as the corresponding bearing surface. Figure 4

[0053] In the present embodiment, the bearing body 10 is provided in a plate structure, which on the one hand has a small volume, and is helpful to reduce the volume of the entire reflow clamp; on the other hand, it is conducive to reducing the material of the bearing body 10 and reducing the cost of materials. In other alternative embodiments, the bearing body 10 can be a block structure, a cylindrical structure or other shapes. The specific structure of the bearing body 10 can be adjusted based on the use requirements and the adaptability of the cooperation between the reflow clamp and other components.

[0054] In the present embodiment, the bearing surface 101 is a spherical surface. The spherical surface structure is conducive to optimizing the deformation of the bearing body 10 adhering to the bearing surface 101, and is conducive to improving the warping phenomenon after reflow.

[0055] In combination with FIG. 1, in the present embodiment, the middle part of the bearing surface 101 has the highest arch degree, the vertical distance from the highest part of the bearing surface 101 to the first side 11 is L1, and the vertical distance from the lowest part of the edge of the bearing surface 101 to the first side 11 is L2, the difference between L1 and L2 is not more than 3mm, and the height difference is preferably about 2mm. By controlling the reasonable curvature of the bearing surface 101 through the height difference, the deformation of the bearing body 10 adhering to the bearing surface 101 is ensured to be more appropriate, which is helpful to improve the warping phenomenon after reflow. In other alternative embodiments, the specific arch degree of the bearing surface 101 can be reasonably adjusted based on actual requirements. Figure 5 The outer contour of the bearing surface 101 is rectangular. The shape of the bearing surface 101 is adapted to the shape of the existing substrate, and the size of the bearing surface 101 is preferably adapted to the size of the substrate to be carried. In other alternative embodiments, the shape of the outer contour of the bearing surface 101 can be adjusted based on the actual shape of the substrate and the use requirements of the reflow clamp.

[0056] In combination with FIG. 1, in the present embodiment, the middle part of the bearing surface 101 has the highest arch degree, the vertical distance from the highest part of the bearing surface 101 to the first side 11 is L1, and the vertical distance from the lowest part of the edge of the bearing surface 101 to the first side 11 is L2, the difference between L1 and L2 is not more than 3mm, and the height difference is preferably about 2mm. By controlling the reasonable curvature of the bearing surface 101 through the height difference, the deformation of the bearing body 10 adhering to the bearing surface 101 is ensured to be more appropriate, which is helpful to improve the warping phenomenon after reflow. In other alternative embodiments, the specific arch degree of the bearing surface 101 can be reasonably adjusted based on actual requirements.

[0057] Figure 2 ​​As shown in the figure, the four edges of the bearing surface 101 are parallel to the four edges of the bearing body 10 respectively. The long edges of the bearing surface 101 are parallel to the long edges of the bearing body 10, and the short edges of the bearing surface 101 are parallel to the short edges of the bearing body 10, and the four edges of the bearing surface 101 are kept a certain distance from the four edges of the bearing body 10 respectively. In this way, the bearing surface 101 is adapted to the outer contour shape of the bearing body 10, the overall consistency of the entire bearing is better, and the surface of the bearing body 10 is maximized, which helps to reduce the volume of the reflow clamp bearing and reduce the material cost of the reflow clamp bearing.

[0058] Please refer to Figures 1 to 3 As shown in the figure, the reflow clamp bearing 100 further comprises a plurality of connecting parts 20, each of which is connected to the bearing body 10 and arranged around the bearing surface 101. The connecting part 20 is used to cooperate with other parts of the reflow clamp.

[0059] In this embodiment, the connecting part 20 comprises a square connecting table 21 and a transition piece 22 connected between the connecting table 21 and the bearing body 10. The transition piece 22 is integrally formed with the bearing body 10, and the thickness of the transition piece 22 is the same as that of the bearing body 10. The transition piece 22 forms a lateral protrusion in the direction parallel to the first side surface 11 and is connected with the connecting table 21. The thickness of the connecting table 21 is greater than that of the transition piece 22, and the bottom of the connecting table 21 is coplanar with the second side surface 12 (the lower surface of the bearing body 10), and the top of the connecting table 21 is higher than the first side surface 11 of the bearing body 10. A connecting hole is formed in the connecting table 21 for forming a connecting relationship with other parts of the reflow clamp.

[0060] In this embodiment, four connecting parts 20 are provided, which are arranged at the four corners of the bearing body 10. Then the entire bearing can stably form a cooperative connection relationship with other parts of the reflow clamp.

[0061] In other alternative embodiments, the connecting part 20 can also be provided in a cylindrical structure or other structures. The specific shape and arrangement position of the connecting part 20 can be adjusted based on the actual use requirements and the adaptability of the cooperation relationship with other parts of the reflow clamp.

[0062] The embodiment also provides a reflow clamp, which comprises the reflow clamp bearing 100 described above.

[0063] Combined with Figure 6 And Figure 7 As shown in the figure, the reflow clamp further comprises a pressing assembly 200 and a clamp seat 300; the reflow clamp bearing 100 is installed in the clamp seat 300.

[0064] The down-pressing assembly 200 is detachably arranged on the clamp seat 300. The down-pressing assembly 200 is used to apply force to the substrate supported on the supporting surface 101, so that the substrate is conformally fitted on the supporting surface 101.

[0065] The down-pressing assembly 200 comprises a first cover plate 210, a second cover plate 220 and a plurality of force applying members (not shown in the figure).

[0066] The clamp seat 300 is in a rectangular plate structure. The first cover plate 210 is in a rectangular structure similar in size to the clamp seat 300, and the first cover plate 210 is connected to the clamp seat 300 through four first connecting members 230 distributed in a quadrangle. The second cover plate 220 is in a rectangular plate structure similar in size to the clamp seat 300, and the second cover plate 220 is connected to the first cover plate 210 through four second connecting members 240 distributed in a quadrangle. The first cover plate 210 is located between the second cover plate 220 and the clamp seat 300.

[0067] The force applying members (not shown in the figure) are arranged on the first cover plate 210 and the second cover plate 220 to apply down-pressing force to the substrate and the elements for reflow soldering with the substrate.

[0068] In combination Figures 8 to 10 As shown in the figure, the clamp seat 300 is in a rectangular plate structure, and the middle part of the clamp seat 300 has a rectangular hollow area 310.

[0069] The overall shape of the hollow area 310 is adapted to the shape of the supporting body 10 of the reflow clamp supporting member 100, and the supporting body 10 is conformally mounted in the hollow area 310. As shown in the figure, Figure 10 The bottom of the clamp seat 300 is provided with a groove adapted to the shape of the four connecting parts 20, and the four connecting parts 20 of the reflow clamp supporting member 100 are conformally embedded in the groove and connected to the bottom of the clamp seat 300 through bolts. The supporting surface 101 of the reflow clamp supporting member 100 is just located in the hollow area 310, and the edge of the hollow area 310 can be used to position the substrate, so that the substrate is positioned relative to the supporting surface 101.

[0070] Please refer to Figure 8 and Figure 9As shown, the middle part of the clamp base 300 has a recessed area, the side wall of the recessed area forms two parallel ridges 320 extending along the length direction of the clamp base 300, the two ridges 320 are arranged along the width direction of the clamp base 300, and the hollow area 310 on the clamp base 300 is arranged in the recessed area between the two ridges 320. The surface in the recessed area between the two ridges 320 is further provided with two first positioning protrusions 330, the two first positioning protrusions 330 are arranged along the length direction of the clamp base 300 and are located on both sides of the hollow area 310.

[0071] The recessed area between the two ridges 320 is used to accommodate the components reflow soldered with the substrate 400, and the first positioning protrusions 330 are used to position the components. In combination with Figure 11 As shown, the substrate 400 is located in the hollow area 310 and placed on the bearing surface 101, the components reflow soldered with the substrate 400 are lead frames 500, the main body of the lead frame 500 is a plate type square box structure, the main body is placed in the recessed area between the two ridges 320, the main body of the lead frame 500 is attached to the surface of the recessed area, and the two long edges of the main body of the lead frame 500 are respectively attached to the two ridges 320, then the two ridges 320 are used to position the lead frame 500 along the width direction. The lead frame 500 is provided with a positioning hole, the first positioning protrusion 330 is located in the positioning hole, and the lead frame 500 is positioned along the length direction. The inner edge of the lead frame 500 has a connecting frame 510, which extends to the hollow area 310 and is used to be attached to the substrate 400 for welding connection.

[0072] In addition, the clamp base 300 is further provided with a plurality of process holes, which play the role of avoiding or reducing weight.

[0073] Please continue to refer to Figure 8 and Figure 9 As shown, the upper surface of the clamp base 300 is provided with two second positioning protrusions 340, and the second positioning protrusions 340 are located outside the recessed area of the clamp base 300. The two second positioning protrusions 340 are diagonally arranged on the clamp base 300. The second positioning protrusions 340 are used to cooperate with the first cover plate 210.

[0074] In combination with Figure 6 and Figure 7 As shown, the first cover plate 210 is provided with a positioning hole, the first cover plate 210 covers the clamp base 300, and the second positioning protrusion 340 is located in the positioning hole of the first cover plate 210 to position the first cover plate 210.

[0075] The first cover plate 210 is provided with a plurality of process holes, which play the role of connection, avoidance or weight reduction.

[0076] A plurality of force applying members (not shown in the figure) can be arranged on the first cover plate 210 and the second cover plate 220. For example, a part of the force applying members are arranged on the second cover plate 220, and the force applying members pass through the process holes on the first cover plate 210 to press on the connecting frame 510 of the lead frame 500, so that the connecting frame 510 is attached to the surface of the substrate 400. Another part of the force applying members are arranged on the first cover plate 210 and the second cover plate 220, and the force applying members press on the surface of the substrate 400, so that the substrate 400 is attached to the bearing surface 101.

[0077] The force applying members can be, for example, elastic force applying structures, which are used by a spring cooperating with a force applying column. The spring provides elastic force for the force applying column, so that the force applying column presses on the surface of the substrate 400 or the connecting frame 510. The force applying members can be consistent with the force applying structures on the existing reflow fixture. The force applying members are prior art, and will not be described here.

[0078] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0079] The above description is only a description of the preferred embodiments of the present application, and does not limit the scope of the present application in any way. Any modification or modification made by a person skilled in the art according to the above disclosure is within the protection scope of the claims.

Claims

1. A reflow clamp carrier, characterized by, The reflow clamp carrier comprises: a carrier body; a carrier surface on the carrier body for carrying a substrate, the carrier surface being in a convex arc surface structure; the carrier body has a first side surface, the first side surface has a boss thereon; vertically along the first side surface, an end surface of the boss away from the first side surface serves as the carrier surface.

2. The reflow clamp carrier of claim 1, wherein, The carrier surface is a spherical surface.

3. The reflow clamp carrier of claim 1, wherein, The height difference between the highest point and the lowest point of the carrier surface is not greater than 3mm.

4. The reflow clamp carrier of claim 1, wherein, The outer contour of the carrier surface is rectangular.

5. The reflow clamp carrier of claim 1, wherein, The reflow clamp carrier further comprises a plurality of connecting portions, each of the connecting portions is connected to the carrier body and is arranged around the carrier surface.

6. The reflow clamp carrier of any of claims 1-5, wherein, The carrier body is in a rectangular plate structure; when the outer contour of the carrier surface is rectangular, four edges of the carrier surface are parallel to four edges of the carrier body respectively; when the reflow clamp carrier comprises the connecting portions, the connecting portions are arranged at four corners of the carrier body.

7. A reflow clamp characterized by, The reflow clamp comprises the reflow clamp carrier as claimed in any one of claims 1 to 6.

8. The reflow clamp of claim 7, wherein, The reflow clamp further comprises a pressing assembly, the pressing assembly is used for applying a force to the substrate carried on the carrier surface, so that the substrate is conformally fitted to the carrier surface.

9. The reflow clamp of claim 8, wherein, The reflow clamp further comprises a clamp seat, the reflow clamp carrier is installed on the clamp seat, and the pressing assembly is detachably arranged on the clamp seat.

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