Laser printing clamp for QFN sensor

Abstract

The utility model relates to a laser printing clamp for a QFN sensor, the laser printing clamp comprises a vacuum assembly and a clamping plate, the clamping plate is provided with at least two through grooves, the clamping plate is fixedly provided with a spacing plate and a clamping strip, the two adjacent through grooves are separated by the spacing plate, the spacing plate is provided with a first lower surface, and the clamping strip is provided with a second lower surface. The clamping plate is provided with a first lower surface, the clamping plate is provided with a second lower surface, the first lower surface is sunken in the second lower surface, a clamping groove is formed in the partition plate, a flexible sealing strip is installed in the clamping groove and protrudes out of the first lower surface, and the hardness of the sealing strip is smaller than the hardness of the clamping plate and the hardness of the base plate. The vacuum assembly can adsorb and fix a substrate, and the clamping strip and the sealing strip can press the substrate. According to the lettering clamp, the sealing strip is directly pressed on the substrate or a plastic package body which may deviate on the substrate, so that a stable clamping effect is achieved, damage to the plastic package body cannot be caused, and the fixing requirement of QFN sensor type substrates is met.

Description

Technical Field

[0001] This application relates to laser marking technology, and particularly to a laser marking fixture for QFN sensors. Background Art

[0002] Laser marking of integrated circuit QFN (Quad Flat No-leads Package) is a conventional process for integrated circuits. During the laser marking process of sensors, a fixing fixture is required to clamp the sensors. Currently, the substrate is usually clamped and fixed by the fixture in the spaces without plastic encapsulant at the front, rear, and middle in the conveying direction. In the traditional substrate, the spaces without plastic encapsulant at the front, rear, and middle are relatively large, basically more than 5 mm. However, for QFN sensor products, the spaces at the front and rear of the QFN substrate are very small, only 1 - 2 mm, and the non-encapsulated space in the middle is only 2 - 3 mm. Therefore, the current fixtures cannot meet the fixing requirements of QFN sensor substrates. Content of the Utility Model

[0003] In order to overcome the above defects, this application provides a laser marking fixture for QFN sensors. The marking fixture directly presses a sealing strip on the substrate or the plastic encapsulant that may shift on the substrate, which not only plays a role in stable clamping but also does not cause damage to the plastic encapsulant, meeting the fixing requirements of QFN sensor substrates.

[0004] The technical solution adopted by this application to solve its technical problems is as follows:

[0005] A laser marking fixture for QFN sensors includes a vacuum component and a clamping plate. At least two through slots are formed on the clamping plate. A spacer and a clamping strip are fixedly arranged on the clamping plate. Adjacent two through slots are separated by the spacer. The spacer has a first lower surface, and the clamping plate has a second lower surface. The first lower surface is recessed from the second lower surface. A clamping groove is formed on the spacer, and a flexible sealing strip is installed in the clamping groove. The sealing strip protrudes from the first lower surface. The hardness of the sealing strip is less than that of the clamping plate and the substrate. The vacuum component can adsorb and fix the substrate, and the clamping strip and the sealing strip can press on the substrate.

[0006] Optionally, the clamping plate is a clamping plate made of metal material, and the sealing strip is a sealing strip made of silicone material.

[0007] Optionally, the width H1 of the clamping groove is 0.5 ± 0.1 mm, the depth L1 of the clamping groove is 2.5 ± 0.2 mm, and the width H2 of the spacer is 1.0 ± 0.2 mm.

[0008] Optionally, the distance D between the first lower surface and the second lower surface is 0.8 ± 0.1 mm.

[0009] Optionally, an auxiliary groove is formed in the clamping plate, the width H3 of the auxiliary groove is 0.5 ± 0.1 mm, and the depth L2 of the auxiliary groove is 3.5 ± 0.2 mm.

[0010] Optionally, a device sensing window and a locking hole are provided on the clamping plate, the device sensing window communicates with at least one of the through grooves, and the clamping strip is arranged on the inner side wall of the through groove.

[0011] Optionally, the vacuum assembly includes a vacuum cover plate and a vacuum base. The vacuum cover plate is provided with a first groove and a suction hole. The vacuum base is provided with a vacuum chamber and a second groove. The vacuum cover plate is fixedly installed on the vacuum base, and the vacuum cover plate covers the vacuum chamber. The suction hole communicates with the vacuum chamber. The first groove and the second groove are spliced to form an avoidance groove. The vacuum assembly is connected to a vacuum pump, and the vacuum pump fixes the substrate on the vacuum cover plate through the vacuum chamber and the suction hole.

[0012] Optionally, the substrate is conveyed by a conveying unit. The conveying unit includes a frame and a conveyor belt. The substrate is placed on the conveyor belt. The vacuum assembly is installed on the frame below the conveyor belt, and the clamping plate is fixedly installed on the frame above the conveyor belt. The vacuum assembly is connected to a lifting unit, and the lifting unit can drive the substrate to move up and down so that the clamping plate clamps or loosens the substrate.

[0013] Optionally, the vacuum base includes a bottom plate and a side plate fixedly connected to the bottom plate. The bottom plate and the side plate enclose the vacuum chamber. A convex block extends towards the vacuum chamber on the bottom plate, and the vacuum cover plate is supported on the side plate and the convex block.

[0014] Optionally, the vacuum cover plate is fixedly installed on the vacuum base by locking screws, and the vacuum pump is connected to the vacuum chamber of the vacuum base through a vacuum tube.

[0015] The beneficial effects of the present application are as follows: In the present application, a vacuum component is used to suck the substrate, and the clamping strip and the sealing strip of the clamping plate are used to press the substrate tightly, thereby improving the fixing strength of the substrate, ensuring the printing quality of the substrate, and increasing the qualified rate of the substrate. In the present application, a clamping groove is opened on the clamping plate, and a sealing strip is installed in the clamping groove. The sealing strip is made of a flexible material and has a small width. By directly pressing the sealing strip on the substrate or the plastic package that may shift on the substrate, it not only plays a role in stable clamping but also does not cause damage to the plastic package, improving the qualified rate of the product, meeting the fixing requirements of QFN sensor substrates with a very small middle area, and can meet the requirement that the repeated measurement accuracy of printing is less than 50μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the vacuum component in the present application;

[0017] Figure 2 is one of the schematic structural diagrams of the vacuum cover plate in the present application;

[0018] Figure 3 is another schematic structural diagram of the vacuum cover plate in the present application;

[0019] Figure 4 is one of the schematic structural diagrams of the vacuum base in the present application;

[0020] Figure 5 is another schematic structural diagram of the vacuum base in the present application;

[0021] Figure 6 is one of the schematic structural diagrams of the clamping plate in the present application;

[0022] Figure 7 is another schematic structural diagram of the clamping plate in the present application;

[0023] Figure 8 is the third schematic structural diagram of the clamping plate in the present application;

[0024] Figure 9 is Figure 8 the enlarged view of A in

[0025] Figure 10 is the fourth schematic structural diagram of the clamping plate in the present application;

[0026] Figure 11 is Figure 10 the enlarged view of B in

[0027] Figure 12 is Figure 10 the enlarged view of C in

[0028] In the figure: 10 - vacuum cover plate, 11 - first groove, 12 - suction hole, 20 - vacuum base, 21 - bottom plate, 22 - side plate, 23 - bump, 24 - vacuum chamber, 25 - second groove, 30 - clamping plate, 31 - spacer plate, 32 - card slot, 33 - first lower surface, 34 - second lower surface, 35 - auxiliary groove, 36 - through groove, 37 - clamping strip, 38 - device sensing window, 39 - locking hole. Detailed implementation mode

[0029] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the following drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such objects can be interchanged under appropriate circumstances, so that the implementation modes of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] For the sake of description, spatial relative terms such as "above...", "above...", "on the upper surface of...", "above" etc. can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "above other devices or structures" will then be positioned as "below other devices or structures" or "beneath other devices or structures". Thus, the exemplary term "above..." can include both orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0032] Embodiment: As Figures 1-12As shown, a laser marking fixture for a QFN sensor includes a vacuum component and a clamping plate 30. At least two through slots 36 are formed in the clamping plate 30. A spacer plate 31 and a clamping strip 37 are fixedly arranged on the clamping plate 30. Adjacent two through slots 36 are separated by the spacer plate 31. The spacer plate 31 has a first lower surface 33, and the clamping plate 30 has a second lower surface 34. The first lower surface 33 is recessed from the second lower surface 34. A clamping groove 32 is formed in the spacer plate 31, and a flexible sealing strip is installed in the clamping groove 32. The sealing strip protrudes from the first lower surface 33. The hardness of the sealing strip is less than that of the clamping plate 30 and the substrate. The vacuum component can adsorb and fix the substrate, and the clamping strip 37 and the sealing strip can press tightly on the substrate.

[0033] In this application, the substrate is sucked by the vacuum component, and the clamping strip 37 and the sealing strip of the clamping plate 30 are used to press the substrate tightly, thereby improving the fixing strength of the substrate, ensuring the printing quality of the substrate, increasing the qualified rate of the substrate, and the hardness of the sealing strip is less than that of the clamping plate 30 and the substrate hardness to achieve soft clamping of the substrate and prevent damage to the surface of the substrate. In this application, a clamping groove 32 is formed in the clamping plate 30, and a sealing strip is installed in the clamping groove 32. The sealing strip is made of a flexible material and has a small width. The sealing strip is directly pressed on the substrate or the plastic package that may shift on the substrate, which not only plays a role in stable clamping but also does not cause damage to the plastic package, improving the qualified rate of the product, meeting the fixing requirements of QFN sensor substrates with a very small middle area, and can meet the requirement that the repeated measurement accuracy of printing is less than 50μm. In this application, taking the conveying direction as the reference, the front and rear positions of the clamping plate 30 do not contact the substrate or the package, that is, along the conveying direction, only the sealing body in the clamping plate 30 presses the middle position of the substrate, meeting the fixing requirements of the QFN substrate with a very small front and rear space, and avoiding the printing offset caused by the uneven printing of the whole plane of the substrate due to the influence of the plastic package and the clamping plate.

[0034] Optionally, the clamping plate 30 is a clamping plate made of a metal material, and the sealing strip is a sealing strip made of a silicone material. The sealing strip made of a silicone material is relatively soft and will not cause damage to the plastic package.

[0035] As Figure 11 shown, the width H1 of the clamping groove 32 is 0.5±0.1mm, the depth L1 of the clamping groove 32 is 2.5±0.2mm, and the width H2 of the spacer plate 31 is 1.0±0.2mm. The clamping groove 32 is used to clamp a sealing strip with a width of about 0.5mm. The sealing strip is directly pressed on the non-plastic package space in the middle part of the substrate, meeting the fixing requirements of the QFN sensor substrate with only a non-sealed space of 2-3mm in the middle part, or even if it presses on the plastic package that may shift on the substrate, it will not cause damage to the plastic package.

[0036] As Figure 9 shown, the distance D between the first lower surface 33 and the second lower surface 34 is 0.8 ± 0.1 mm. That is, the first lower surface 33 of the spacer 31 is located inside the second lower surface 34 of the clamping plate 30, so as to ensure that the rigid second lower surface 34 does not directly contact the substrate or the encapsulant, causing up and down deviation of the substrate plane, and leaving the gap required for the encapsulant to ensure that the offset of the encapsulant does not affect the printing plane.

[0037] As Figure 10 and Figure 12 shown, an auxiliary groove 35 is formed on the clamping plate 30. The width H3 of the auxiliary groove 35 is 0.5 ± 0.1 mm, and the depth L2 of the auxiliary groove 35 is 3.5 ± 0.2 mm. In order to ensure that the raised edge can be neatly left after the sealing strip is cut, that is, the sealing strip can protrude from the first lower surface 33, an auxiliary groove 35 for cutting the auxiliary sealing strip is formed in the large unused space area of the clamping plate 30. The width of the auxiliary groove 35 is the same as the width of the card slot 32, and the depth of the auxiliary groove 35 is about 1 mm larger than the depth of the card slot 32. In this way, it can be ensured that after the sealing strip is embedded in the card slot 32, it protrudes from the first lower surface 33 to form a raised edge of about 1 mm, which directly presses on the substrate or the possibly offset encapsulant, playing a role in stable clamping.

[0038] As Figure 6 shown, the clamping plate 30 is provided with an equipment sensing window 38 and a locking hole 39. The equipment sensing window 38 communicates with at least one of the through grooves 36, and the clamping strip 37 is arranged on the inner side wall of the through groove 36. The substrate is divided into two large left and right regions. The sealing strip on the spacer 31 is pressed against the middle region between the two large regions of the substrate. The through groove 36 is used to expose the encapsulant on the substrate for detection or printing. The locking hole 39 is used to fix the clamping plate 30 on the frame through a locking screw. The oval-shaped locking hole 39 can be used to finely adjust the fixing position of the clamping plate 30. The equipment sensing window 38 is convenient for detecting and positioning the substrate 40 by a laser device.

[0039] As Figure 10 shown, clamping strips 37 are arranged on the inner side walls of the through groove 36 in the up and down directions. The distance between the upper and lower clamping strips 37 is designed to be about 64.5 mm, so as to facilitate clamping the edge of the encapsulated substrate, cooperate with the vacuum cover plate 10 to fix the substrate, and prevent the substrate from shaking up and down. Optionally, the arrangement direction of the clamping strips 37 is perpendicular to the arrangement direction of the sealing strips.

[0040] As Figures 1-5As shown, the vacuum assembly includes a vacuum cover plate 10 and a vacuum base 20. The vacuum cover plate 10 is provided with a first groove 11 and a suction hole 12. The vacuum base 20 is provided with a vacuum chamber 24 and a second groove 25. The vacuum cover plate 10 is fixedly installed on the vacuum base 20, and the vacuum cover plate 10 covers the vacuum chamber 24. The suction hole 12 communicates with the vacuum chamber 24. The first groove 11 and the second groove 25 form an avoidance groove after being spliced. The vacuum assembly is connected to a vacuum pump. The vacuum pump fixes the substrate on the vacuum cover plate 10 through the vacuum chamber 24 and the suction hole 12. The substrate is clamped between the vacuum assembly and the clamping plate 30. There are several plastic packages on the substrate. The vacuum assembly is connected to the vacuum pump. The vacuum pump forms a negative pressure in the vacuum chamber 24 of the vacuum base 20 and adsorbs the substrate on the vacuum cover plate 10 through the suction hole 12. The upper part of the substrate is clamped by the clamping strip 37 and the sealing strip on the clamping plate 30, thereby improving the fixing strength of the substrate, ensuring the quality of the substrate printing, and improving the qualification rate of the substrate. Optionally, the width of the vacuum cover plate 10 is about 68 mm, so that the vacuum cover plate 10 can support the edge of the plastic package on the substrate.

[0041] Optionally, the substrate is conveyed by a conveying unit. The conveying unit includes a frame and a conveyor belt. The substrate is placed on the conveyor belt. The vacuum assembly is installed on the frame below the conveyor belt. The clamping plate 30 is fixedly installed on the frame above the conveyor belt. The vacuum assembly is connected to a lifting unit. The lifting unit can drive the substrate to move up and down, so that the clamping plate 30 clamps or releases the substrate. Optionally, the lifting unit is a lifting cylinder, and the clamping plate 30 is located above the vacuum assembly. When the conveyor belt conveys the substrate above the vacuum assembly, the vacuum pump is started to form a vacuum in the vacuum chamber 24 to adsorb the substrate on the vacuum cover plate 10 through the suction hole 12. Then the lifting cylinder pushes the substrate upward so that the clamping strip 37 on the clamping plate 30 clamps the upper surface of the substrate, thereby fixing the substrate for processes such as printing and detecting the substrate. In this application, the vacuum assembly adsorbs the lower surface of the substrate on the vacuum cover plate 10 by forming a vacuum, and further presses the substrate through the clamping strip and the sealing strip of the clamping plate 30, improving the fixing strength of the substrate, ensuring the quality of the substrate printing, and improving the qualification rate of the substrate; in this application, the first groove 11 and the second groove 25 are used to form an avoidance groove to facilitate avoiding the rollers on the conveying unit, thereby realizing the up and down movement of the vacuum assembly.

[0042] As Figure 4As shown, the vacuum base 20 includes a bottom plate 21 and side plates 22 fixedly connected to the bottom plate 21. The bottom plate 21 and the side plates 22 enclose the vacuum chamber 24. A bump 23 extends towards the inside of the vacuum chamber 24 on the bottom plate 21. The vacuum cover 10 is supported on the side plates 22 and the bump 23. The side plates 22 are arranged along the peripheral wall of the bottom plate 21. A plurality of bumps 23 are provided in the central area of the bottom plate 51. On the one hand, the bump 23 is used to support the vacuum cover 10 to prevent the vacuum cover 10 from sagging. On the other hand, the middle area of the vacuum cover 10 is locked to the vacuum base 20 by using locking screws, thereby improving the support strength and stability of the vacuum cover 10.

[0043] Optionally, the vacuum cover 10 is fixedly installed on the vacuum base 20 by locking screws. The vacuum pump is connected to the inside of the vacuum chamber 24 of the vacuum base 20 through a vacuum tube. As Figure 2 and Figure 4 shown, a plurality of screw holes are provided on the vacuum cover 10, and a plurality of screw holes are also provided on the side plates 22 of the vacuum base 20. Thus, the vacuum cover 10 is fixed to the vacuum base 20 by using locking screws to form a vacuum assembly. The vacuum cover 10, the bottom plate 21 and the side plates 22 enclose a closed vacuum chamber 24.

[0044] In this application, the solution of clamping the substrate before and after by the clamping plate 30 is directly removed, and a soft clamping in the middle, that is, a silicone sealing strip clamping design, is adopted. When the soft clamping design is used, an auxiliary groove for cutting the sealing strip is added, which improves the accuracy and efficiency of cutting the sealing strip. In addition, by using the stiffness of the substrate, the vacuum cover 10 is widened, and the width of the clamping strip 37 in the clamping plate 30 is enlarged, so that the clamping plate 30 and the vacuum cover 10 can clamp the substrate in the up and down direction by using the stiffness of the substrate, avoiding the position deviation caused by the movement and vibration in the middle stage of laser printing, and preventing the phenomenon of printing deviation from occurring.

[0045] It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several deformations and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application patent shall be subject to the appended claims.

Claims

1. A laser marking fixture for a QFN sensor, characterized in that: It includes a vacuum component and a clamping plate (30). At least two through slots (36) are formed in the clamping plate (30). A spacer plate (31) and a clamping strip (37) are fixedly arranged on the clamping plate (30). Adjacent two through slots (36) are separated by the spacer plate (31). The spacer plate (31) has a first lower surface (33), and the clamping plate (30) has a second lower surface (34). The first lower surface (33) is recessed from the second lower surface (34). A clamping slot (32) is formed in the spacer plate (31), and a flexible sealing strip is installed in the clamping slot (32). The sealing strip protrudes from the first lower surface (33). The hardness of the sealing strip is less than that of the clamping plate (30) and the substrate. The vacuum component can adsorb and fix the substrate, and the clamping strip (37) and the sealing strip can press against the substrate.

2. The laser marking fixture for QFN sensors according to claim 1, wherein: The clamping plate (30) is a clamping plate made of metal material, and the sealing strip is a sealing strip made of silicone material.

3. The laser marking fixture for QFN sensors according to claim 1, wherein: The width H1 of the clamping slot (32) is 0.5 ± 0.1 mm, the depth L1 of the clamping slot (32) is 2.5 ± 0.2 mm, and the width H2 of the spacer plate (31) is 1.0 ± 0.2 mm.

4. The laser marking fixture for QFN sensors according to claim 1, characterized in that: The distance D between the first lower surface (33) and the second lower surface (34) is 0.8 ± 0.1 mm.

5. The laser marking fixture for QFN sensors according to claim 1, characterized in that: An auxiliary slot (35) is formed in the clamping plate (30). The width H3 of the auxiliary slot (35) is 0.5 ± 0.1 mm, and the depth L2 of the auxiliary slot (35) is 3.5 ± 0.2 mm.

6. The laser marking fixture for QFN sensors according to claim 1, characterized in that: An equipment sensing window (38) and a locking hole (39) are arranged on the clamping plate (30). The equipment sensing window (38) communicates with at least one of the through slots (36), and the clamping strip (37) is arranged on the inner side wall of the through slot (36).

7. The laser marking fixture for QFN sensors according to any one of claims 1-6, characterized in that: The vacuum component includes a vacuum cover plate (10) and a vacuum base (20). A first groove (11) and a suction hole (12) are formed on the vacuum cover plate (10). A vacuum chamber (24) and a second groove (25) are formed in the vacuum base (20). The vacuum cover plate (10) is fixedly installed on the vacuum base (20), and the vacuum cover plate (10) covers the vacuum chamber (24). The suction hole (12) communicates with the vacuum chamber (24). The first groove (11) and the second groove (25) are spliced to form an avoidance groove. The vacuum component is connected to a vacuum pump, and the vacuum pump fixes the substrate on the vacuum cover plate (10) through the vacuum chamber (24) and the suction hole (12).

8. The laser marking fixture for QFN sensors according to claim 7, characterized in that: The substrate is conveyed by a conveying unit. The conveying unit includes a frame and a conveyor belt. The substrate is placed on the conveyor belt. The vacuum component is installed on the frame below the conveyor belt, and the clamping plate (30) is fixedly installed on the frame above the conveyor belt. The vacuum component is connected to a lifting unit, and the lifting unit can drive the substrate to move up and down so that the clamping plate (30) clamps or loosens the substrate.

9. The laser marking fixture for QFN sensors according to claim 7, characterized in that: The vacuum base (20) includes a bottom plate (21) and side plates (22) fixedly connected to the bottom plate (21). The bottom plate (21) and the side plates (22) enclose the vacuum chamber (24). A bump (23) extends towards the inside of the vacuum chamber (24) on the bottom plate (21). The vacuum cover plate (10) is supported on the side plates (22) and the bump (23).

10. The laser marking fixture for QFN sensors according to claim 7, characterized in that: The vacuum cover plate (10) is fixedly installed on the vacuum base (20) through locking screws. The vacuum pump is connected to the vacuum chamber (24) of the vacuum base (20) through a vacuum tube.

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