Storage jig for lead frame processing

Abstract

The invention belongs to the technical field of lead frame storage, and relates to a storage jig for lead frame processing. Comprising two side plates which are symmetrically distributed, a bottom plate and a top plate, the opposite sides of the two side plates are provided with bearing strips which are equal in number and distributed at equal intervals, the positions, close to the adjacent bearing strips, of the side plates are provided with side supporting pieces, and the side supporting pieces are provided with guide pieces. According to the invention, the lead frame is centrally guided by using the guide sheet, so that on the premise of not introducing additional equipment, on one hand, the probability that the lead frame enters the jig in a central state is improved, and on the other hand, the guide sheet can be prevented from hindering the movement of the lead frame under the condition that the lead frame deviates in the blanking process; therefore, the lead frame can still enter the jig on the premise that the lead frame does not deform, and the lead frame is guided by utilizing the trend that the side supporting pieces and the lead frame move downwards under the action of gravity, so that the lead frame can be kept in a centered static state in the jig.

Description

Technical Field

[0001] This invention relates to the field of leadframe storage technology, and more particularly to a storage fixture for leadframe fabrication. Background Technology

[0002] Leadframes are a critical carrier in the semiconductor device packaging process. During packaging, leadframes are typically temporarily stored in a dedicated storage fixture for transfer to the appropriate processing equipment. The storage fixture usually stores leadframes in a vertical array to facilitate push-type feeding. During feeding, a robotic arm pushes the leadframe from one end of the top layer of the storage fixture, moving it out from the other end, and continuously feeds the leadframes by coordinating with the fixture's lifting and lowering motion.

[0003] In the lead frame manufacturing process, strict requirements are typically placed on its positional accuracy to ensure product quality. However, in actual production, to facilitate the rapid and automatic loading and unloading of lead frames and to avoid frame deformation caused by fixture interference during loading and unloading, the width of the storage fixture for the lead frame is usually greater than the width of the lead frame itself. Although the lead frames are centered during unloading and storage, they can still easily slip and deviate from their central position when the operator moves the storage fixture to other equipment. Therefore, after loading the storage fixture onto the equipment, the lead frames within must be re-aligned, or a centering and positioning mechanism must be added to the equipment's conveying mechanism to readjust the frame position. This practice not only increases the length of the conveying mechanism at the front end of the equipment but also significantly increases the complexity and manufacturing cost of the equipment due to the introduction of additional positioning devices and sensor control systems. Summary of the Invention

[0004] This invention provides a storage fixture for lead frame processing, which overcomes the disadvantage of existing storage fixtures where the width of the internal storage space is greater than the width of the lead frame, causing the lead frame inside the storage fixture to easily shift position during movement.

[0005] Technical solution: A storage fixture for processing lead frame, comprising: two symmetrically distributed side plates, a bottom plate, and a top plate, wherein the bottom plate and the top plate are fixed between the two side plates; each of the two side plates has an equal number of equally spaced bearing strips on its facing sides; each bearing strip has a bearing surface for contacting the lead frame; each side plate has a side support near the adjacent bearing strip; each side support has a guide piece; the lower edges of the side support and the guide piece are in contact with the adjacent bearing surface; the horizontal distance between the facing sides of the two symmetrically distributed side supports on different side plates gradually increases from bottom to top; the side of the guide piece away from the adjacent side plate and the two edges of the adjacent side support that are close to the side away from the adjacent side plate are collinear; the guide piece is used to guide the movement of the lead frame.

[0006] Furthermore, there is an angle between the bearing surface and the horizontal plane, and the horizontal distance between two bearing surfaces that are symmetrically distributed on different side plates gradually increases from bottom to top, so that the lead frame is in line contact with the bearing surface, and the angle between the bearing surface and the horizontal plane is smaller than the angle between the side of the side support away from the adjacent side plate and the horizontal plane.

[0007] Furthermore, the bearing surface is coated with a chromium nitride coating to improve surface hardness and smoothness.

[0008] Furthermore, the angle between the bearing surface and the horizontal plane is between 10° and 15°.

[0009] Furthermore, each side plate is provided with a mounting groove near the adjacent support strip, and the support strip is snapped into the adjacent mounting groove.

[0010] Furthermore, the side support is fixedly connected to a limiting strip, which is used to limit the swing of the lead frame.

[0011] Furthermore, each side plate is provided with two sliding grooves near the adjacent side support member. The side support member slides within the adjacent sliding grooves. Two threaded rods are slidably and rotatably connected within the side plate. The side support member is threadedly connected to the adjacent threaded rod. The threaded rod is provided with a limiting groove. Each side plate is slidably connected with a limiting block near the adjacent threaded rod. The limiting block limits the adjacent threaded rod through the limiting groove.

[0012] Furthermore, the bearing strip is made of elastic material, the guide piece is fixed to the adjacent side support member by an elastic sheet, and the side of the elastic sheet away from the adjacent side plate is coplanar with the side of the side support member away from the adjacent side plate.

[0013] Furthermore, the two side plates are slidably connected to a sliding strip on the side closest to the adjacent guide plate. The sliding strip and the top plate are fixed together with two symmetrically distributed elastic strips. The bottom plate and the top plate are fixed together with two symmetrically distributed support strips on the side away from the sliding strips. The elastic strips and the support strips are used together to maintain the position of the lead frame.

[0014] Furthermore, the minimum horizontal spacing between the two elastic strips is less than the minimum horizontal spacing between the two side supports symmetrically distributed on different side plates.

[0015] Those skilled in the art will understand that the present invention has at least the following beneficial effects: 1. This invention utilizes guide plates to center the lead frame, thereby increasing the probability of the lead frame entering the fixture in a centered state without the need for additional equipment. Furthermore, in the event of deviation during the lead frame unloading process, the guide plates can prevent the lead frame from obstructing its movement, allowing it to enter the fixture without deformation. Additionally, the side supports and the downward tendency of the lead frame due to gravity guide the lead frame, ensuring it remains centered and stationary within the fixture.

[0016] 2. By using an inclined bearing surface to support the lead frame, the contact area between the lead frame and the bearing surface is reduced, which can reduce the area of ​​wear on the side of the lead frame during loading and unloading, thereby reducing the probability of metal debris generation.

[0017] 3. By rotating the threaded rod, the position of the side support is changed, causing relative sliding between the side support and the adjacent bearing surface. This changes the position of the lead frame in line contact with the bearing surface, thereby improving the utilization rate of the bearing surface, increasing the number of times the bearing surface is subjected to wear, and extending the service life of the bearing surface. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the side plate and top plate of the present invention; Figure 3 This is a three-dimensional structural diagram of the load-bearing strip and side support member of the present invention; Figure 4 This is a three-dimensional structural diagram of the side support and guide plate of the present invention; Figure 5 This is a three-dimensional structural diagram of the guide plate and limiting strip of the present invention; Figure 6 This is a three-dimensional structural diagram of the side support and threaded rod of the present invention; Figure 7 for Figure 6 Enlarged view of point A in the middle; Figure 8 This is a three-dimensional structural diagram of the base plate and sliding strip of the present invention; Figure 9 for Figure 8 Enlarged view of point B in the middle.

[0019] In the diagram: 1. Side plate, 2. Bottom plate, 3. Top plate, 4. Bearing strip, 401. Bearing surface, 402. Mounting groove, 5. Side support, 501. Sliding groove, 6. Guide plate, 7. Limiting strip, 8. Threaded rod, 801. Limiting groove, 9. Limiting block, 10. Sliding strip, 11. Elastic strip, 12. Support strip. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] Example 1

[0022] This embodiment provides a storage fixture for lead frame processing to solve the problem in the prior art where the lead frame inside the storage fixture is prone to positional displacement during movement because the width of the storage fixture is greater than the width of the lead frame.

[0023] See Figures 1 to 5 A storage fixture for processing lead frame includes: two symmetrically distributed side plates 1, a bottom plate 2, and a top plate 3. The bottom plate 2 and the top plate 3 are both fixed to the two side plates 1 by bolts. Each of the two side plates 1 has an equal number of equally spaced bearing strips 4 on its facing sides. The number of bearing strips 4 is determined by the vertical spacing between the bottom plate 2 and the top plate 3, and is not further limited here. The upper side of each bearing strip 4 has a bearing surface 401 for contacting the lead frame. The side plates 1 are positioned near adjacent bearing strips 4. There is a side support 5, and a guide plate 6 is provided on the front side of the side support 5. The lower edges of the side support 5 and the guide plate 6 are in contact with the adjacent bearing surface 401. The horizontal distance between the two side supports 5 facing each other on different side plates 1 gradually increases from bottom to top. That is, the facing sides of the two side supports 5 are inclined surfaces, and the angle between the inclined surfaces and the horizontal plane is 75°. The front side of the guide plate 6 is collinear with the two edges of the adjacent side of the side support 5. The guide plate 6 is used to guide the movement of the lead frame.

[0024] The above setup enables the guide plate 6 to center the lead frame, thereby increasing the probability of the lead frame entering the fixture in a centered state without the need for additional equipment. Furthermore, if the lead frame deviates during the unloading process, the guide plate 6 can prevent it from obstructing the movement of the lead frame, allowing it to enter the fixture without deformation. Additionally, the side support 5 and the downward tendency of the lead frame due to gravity guide the lead frame, ensuring it remains centered and stationary within the fixture.

[0025] It should be noted that in this embodiment, the relationship between the side support 5 and the adjacent guide piece 6 can be regarded as a fixed connection.

[0026] Lead frame cutting process: Adjust the height of the contact edge between the side support 5 and the bearing surface 401 to be equal to the height of the lower side edge of the lead frame when the lead frame is in the cutting position. The following description will take three cases as examples during the lead frame cutting process: centering, slight deviation due to non-centering, and large deviation due to non-centering.

[0027] If the lead frame is centered before entering the fixture, it can directly enter between the two side plates 1 during the material cutting process and be erected on the upper side of the two bearing surfaces 401, with the left and right sides of the lead frame contacting the two side supports 5 respectively. During the movement of the fixture, even if the lead frame is shaken, it can still return to the centered state under the guidance of the lateral tilting surfaces of the two side supports 5.

[0028] If the lead frame is slightly tilted before entering the fixture without being centered, as the lead frame moves into the fixture, one of its corners will first contact the guide plate 6 on one side. Under the guidance of the guide plate 6, the lead frame will gradually return to center and enter between the two side supports 5.

[0029] If the lead frame is significantly skewed before entering the fixture without being centered, as the lead frame moves into the fixture, its corners will contact the guide plate 6 and begin to slide along the side of the guide plate 6. Subsequently, the corners of the lead frame will contact the inclined surface of the side support 5 and continue to slide along the inclined surface of the side support 5 (the guide plate 6 will not completely obstruct the movement of the lead frame, so that the lead frame will not be deformed due to compression because one end cannot move). During the sliding process of the lead frame, the lead frame tends to straighten itself under the guidance of gravity, the side support 5 and the guide plate 6. Finally, the lead frame is erected on the upper side of the two bearing surfaces 401 in an inclined state. In this state, when transferring the fixture, slightly shaking the fixture will cause the lead frame to slide down along the side support 5 and eventually return to the centered state.

[0030] Example 2

[0031] Based on Example 1, this embodiment reduces the contact area between the lead frame and the bearing surface 401 to reduce the wear and tear on the lead frame during loading and unloading.

[0032] See Figures 3 to 5There is an angle between the bearing surface 401 and the horizontal plane, and the horizontal distance between two bearing surfaces 401 symmetrically distributed on different side plates 1 gradually increases from bottom to top, so that the lead frame is in line contact with the bearing surface 401, and the angle between the bearing surface 401 and the horizontal plane is smaller than the angle between the side of the side support 5 away from the adjacent side plate 1 and the horizontal plane; the bearing surface 401 is coated with a chromium nitride coating to improve surface hardness and smoothness, reduce the friction between the lead frame and the bearing surface 401, and thus reduce the wear rate of the bearing surface 401; the angle between the bearing surface 401 and the horizontal plane is between 10° and 15°, and while maintaining the line contact between the bearing surface 401 and the lead frame, the angle between the lead frame and the bearing surface 401 is always less than 45°, reducing the horizontal support force provided by the bearing surface 401 to the lead frame, and thus reducing the influence of the tilt angle of the bearing surface 401 on the adjustment of the lead frame by the side support 5.

[0033] The above configuration enables the lead frame to be supported by the inclined bearing surface 401, thereby reducing the contact area between the lead frame and the bearing surface 401. On the one hand, this reduces the area of ​​wear on the sides of the lead frame during loading and unloading, and on the other hand, it reduces the area that the edge of the lead frame needs to bear the supporting force. As a result, the lead frame can have a narrower edge during production, thereby improving the overall material utilization rate of the lead frame.

[0034] Example 3

[0035] Based on Example 2, this embodiment provides the function of a replaceable support bar 4 to extend the service life of the storage fixture and reduce production costs.

[0036] During the loading and unloading of the lead frame, the lead frame will slide relative to the storage fixture. As the number of sliding cycles increases, the contact area between the fixture and the lead frame will be worn, resulting in an increase in surface roughness at the contact area. In this case, both the lead frame and the fixture will be worn and generate metal shavings during the relative sliding process. Since the processing of the lead frame has high requirements for its surface cleanliness, the existing technology requires the fixture to be replaced in time after it is worn to a certain extent in order to control the generation of metal shavings, which undoubtedly increases the production cost.

[0037] See Figure 2 and Figure 3 Each side plate 1 is provided with a mounting groove 402 near the adjacent support bar 4. The support bar 4 is snapped into the adjacent mounting groove 402, so that the support bar 4 can be freely disassembled and replaced without replacing the entire storage fixture, thus reducing production costs.

[0038] Example 4

[0039] This embodiment is a further optimization based on embodiment 3.

[0040] See Figures 3 to 5 Side support 5 is fixedly connected to limit strip 7, which is used to limit the swing of the lead frame; bearing strip 4, adjacent side support 5, adjacent guide plate 6 and adjacent limit strip 7 together form a set of support units. Taking the two sets of support units on the lower side of the two side plates 1 as an example, the minimum distance between the limit strip 7 and the bearing strip 4 which is not in the same group is less than the minimum distance between the two side support 5. This limits the maximum tilt angle of the lead frame in the fixture, so that the lead frame cannot fall between the two bearing strips 4 within the tilt angle range.

[0041] The above setup enables the limiting strip 7 to guide and limit the lead frame entering the fixture. When the lead frame enters the fixture at an angle, the limiting strip 7 restricts the lead frame from excessively tilting and, in conjunction with the side support 5, guides the lead frame so that it tends to be centered between the two side support 5. During the transfer of the fixture, the limiting strip 7 limits the maximum offset angle of the lead frame to prevent the lead frame from falling between the two support strips 4.

[0042] Example 5

[0043] This embodiment is a further optimization based on embodiment 4, in order to extend the service life of a single load-bearing strip 4.

[0044] See Figure 2 , Figure 3 , Figure 6 and Figure 7 Each side plate 1 is provided with two symmetrically distributed sliding grooves 501 near the adjacent side support member 5. The side support member 5 slides vertically within the two adjacent sliding grooves 501. Two threaded rods 8 are slidably and rotatably connected within the side plate 1. The side support member 5 is threadedly connected to the adjacent threaded rod 8. A limit groove 801 is provided on the upper part of the threaded rod 8. A limit block 9 is slidably connected to each side plate 1 near the adjacent threaded rod 8. The projection of the limit block 9 on the horizontal plane is U-shaped. The limit block 9 limits the adjacent threaded rod 8 through the limit groove 801, so that the threaded rod 8 can only rotate and cannot slide vertically.

[0045] The above configuration enables the side support 5 to change its position by rotating the threaded rod 8, causing relative sliding between the side support 5 and the adjacent bearing surface 401, thereby changing the position of the lead frame in line contact with the bearing surface 401, thus improving the utilization rate of the bearing surface 401, increasing the number of times the bearing surface 401 is subjected to wear, and extending the service life of the bearing surface 401.

[0046] See Figure 4 and Figure 5The bearing strip 4 is made of elastic material, and the thickness of the bearing surface 401 on the bearing strip 4 is greater than the thickness of the bearing strip 4 at other positions, so that the bearing surface 401 remains flat when the bearing strip 4 is squeezed by the adjacent side support 5; the guide plate 6 is fixed to the adjacent side support 5 by an elastic sheet, and the side of the elastic sheet away from the adjacent side plate 1 is coplanar with the side of the side support 5 away from the adjacent side plate 1; after the bearing surface 401 is squeezed by the adjacent side support 5 and the angle changes, the angle of the lower edge of the guide plate 6 relative to the horizontal plane increases. At this time, the guide plate 6 can swing and change the position of contact with the bearing surface 401.

[0047] When the wear at the contact point between the bearing surface 401 and the adjacent side support 5 causes the bearing strip 4 to be unable to continue to be used normally (since the lead frame and the bearing surface 401 are in line contact, only the area corresponding to one line on the bearing surface 401 is worn at a time), the two threaded rods 8 on the side plate 1 are rotated. The threaded rods 8 drive the adjacent side support 5 to move downward through the threaded transmission. The side support 5 squeezes the adjacent bearing strip 4 and bends it. At the same time, the side support 5 slides downward along the adjacent bearing surface 401, changing the contact position between the bearing surface 401 and the adjacent side support 5. During the process of the side support 5 sliding downward along the adjacent bearing surface 401, the side support 5 drives the adjacent guide plate 6 to move downward. Under the action of the elastic plate and the side support 5, the guide plate 6 slides along the adjacent bearing surface 401 and causes the elastic plate of the guide plate 6 to bend and deform so as to always maintain contact with the adjacent bearing surface 401.

[0048] Example 6

[0049] This embodiment, based on embodiment 5, prevents the lead frame from slipping out of the fixture during the transfer process.

[0050] See Figure 1 , Figure 2 , Figure 8 and Figure 9The front of the lower side of the two side plates 1 are slidably connected to a sliding strip 10. The sliding strip 10 and the top plate 3 are fixed together with two symmetrically distributed elastic strips 11. Each elastic strip 11 has two grooves on its left and right sides. In the vertical direction, the four grooves on the facing side of the two elastic strips 11 are located between the four grooves on the opposite side of the two elastic strips 11. In the horizontal direction, the four grooves on the opposite side of the two elastic strips 11 are located between the four grooves on the facing side of the two elastic strips 11. This is used to control the bending position of the elastic strips 11. In the attached figure, the elastic strips 11 are in a bent and stored state. The rear side of the bottom plate 2 and the top plate 3 are fixed together with two symmetrically distributed support strips 12. The elastic strips 11 and the support strips 12 are used together to maintain the position of the lead frame. The minimum horizontal distance between the two elastic strips 11 and the two support strips 12 is less than the minimum horizontal distance between the two symmetrically distributed side supports 5 on different side plates 1. The maximum distance between the projections of the two elastic strips 11 on the horizontal plane is greater than the minimum horizontal distance between the two symmetrically distributed side supports 5 on different side plates 1.

[0051] The above setup enables the elastic strip 11 and the support strip 12 to restrict the lead frame in two directions respectively, preventing the lead frame from slipping out of the fixture during the transfer process.

[0052] It should be noted that the fixture in the attached drawings of this application is in a state of being situated on a plane, and the fixture as a whole is in a suspended state when the fixture is moved.

[0053] During the material cutting process, the width of the lead frame is equal to the minimum distance between the two side supports 5 in the left and right directions, and less than the minimum distance between the middle of the two elastic strips 11 in the left and right directions. In this state, the lead frame can smoothly enter between the two side plates 1, but when the lead frame moves backward to the state of contact with the support strip 12, it cannot continue to move backward. The support strip 12 is used to limit the extreme position of the lead frame to move backward.

[0054] During the transfer of the fixture, the fixture is suspended in the air. At this time, the sliding strip 10 moves downward relative to the side plate 1 under the action of gravity. At the same time, the two elastic strips 11 deform under the action of elasticity and tend to be straight. In this state, the maximum horizontal distance between the two elastic strips 11 in the left and right directions is less than the width of the lead frame. In this way, the two elastic strips 11 are used to restrict the forward movement of the lead frame and prevent the lead frame from slipping out of the fixture.

[0055] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A storage fixture for lead frame processing, characterized in that, include: Two symmetrically distributed side plates (1), a bottom plate (2), and a top plate (3) are provided. The bottom plate (2) and the top plate (3) are fixed between the two side plates (1). The two side plates (1) are provided with an equal number of equally spaced bearing strips (4) on their opposing sides. The bearing strips (4) are provided with bearing surfaces (401) for contacting the lead frame. The side plates (1) are provided with side supports (5) near the adjacent bearing strips (4). The side supports (5) are provided with guide pieces. (6) The lower edges of the side support (5) and the guide plate (6) are in contact with the adjacent bearing surface (401). The horizontal distance between the two side supports (5) symmetrically distributed on different side plates (1) gradually increases from bottom to top. The two edges of the guide plate (6) that are close to the side of the adjacent side plate (1) and the side of the adjacent side support (5) that are close to the side of the adjacent side plate (1) are collinear. The guide plate (6) is used to guide the movement of the lead frame.

2. A storage fixture for lead frame processing according to claim 1, characterized in that, There is an angle between the bearing surface (401) and the horizontal plane, and the horizontal distance between two bearing surfaces (401) that are symmetrically distributed on different side plates (1) gradually increases from bottom to top, so that the lead frame is in line contact with the bearing surface (401), and the angle between the bearing surface (401) and the horizontal plane is smaller than the angle between the side of the side support (5) away from the adjacent side plate (1) and the horizontal plane.

3. A storage fixture for lead frame processing according to claim 2, characterized in that, The bearing surface (401) is coated with a chromium nitride coating to improve surface hardness and smoothness.

4. A storage fixture for lead frame processing according to claim 2, characterized in that, The angle between the bearing surface (401) and the horizontal plane is between 10° and 15°.

5. A storage fixture for lead frame processing according to claim 1, characterized in that, Each side plate (1) is provided with a mounting groove (402) near the adjacent support strip (4), and the support strip (4) is snapped into the adjacent mounting groove (402).

6. A storage fixture for lead frame processing according to claim 1, characterized in that, The side support (5) is fixedly connected to a limiting strip (7), which is used to limit the swing of the lead frame.

7. A storage fixture for lead frame processing according to claim 6, characterized in that, The side plate (1) is provided with two sliding grooves (501) near the adjacent side support (5). The side support (5) slides within the adjacent sliding grooves (501). The side plate (1) is slidably and rotatably connected to two threaded rods (8). The side support (5) is threadedly connected to the adjacent threaded rod (8). The threaded rod (8) is provided with a limiting groove (801). The side plate (1) is slidably connected to a limiting block (9) near the adjacent threaded rod (8). The limiting block (9) limits the adjacent threaded rod (8) through the limiting groove (801).

8. A storage fixture for lead frame processing according to claim 7, characterized in that, The bearing strip (4) is made of elastic material. The guide piece (6) is fixed to the adjacent side support (5) by an elastic piece. The side of the elastic piece away from the adjacent side plate (1) is coplanar with the side of the side support (5) away from the adjacent side plate (1).

9. A storage fixture for lead frame processing according to claim 8, characterized in that, The two side plates (1) are slidably connected to a sliding strip (10) on the side close to the adjacent guide plate (6). The sliding strip (10) and the top plate (3) are fixed together with two symmetrically distributed elastic strips (11). The bottom plate (2) and the top plate (3) are fixed together with two symmetrically distributed support strips (12) on the side away from the sliding strip (10). The elastic strips (11) and the support strips (12) are used together to maintain the position of the lead frame.

10. A storage fixture for lead frame processing according to claim 9, characterized in that, The minimum horizontal spacing between the two elastic strips (11) is less than the minimum horizontal spacing between the two side supports (5) symmetrically distributed on different side plates (1).

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