Lead bonding clamp for thermal printing head and application of lead bonding clamp

Abstract

The invention relates to the technical field of thermal printing head production and manufacturing, in particular to a lead bonding clamp for a thermal printing head and application of the lead bonding clamp for the thermal printing head, and the lead bonding clamp is beneficial to improving lead bonding efficiency and is characterized in that a positioning boss used for making contact with a to-be-machined product is arranged on the outer side, corresponding to a machining window, of the lower surface of a pressing plate; the two sides of the pressing plate are connected with the left side supporting arm and the right side supporting arm through pressing and leveling mechanisms respectively, each pressing and leveling mechanism comprises step-shaped pressing plate edges arranged on the two sides of the pressing plate, the height of the pressing plate edges is larger than that of a pressing plate body, and the upper surfaces and the lower surfaces of the pressing plate edges are provided with corresponding inwards-concave parts respectively; a U-shaped groove is formed in the end of the left supporting arm / the right supporting arm, the edge of the pressing plate is arranged in the U-shaped groove, an inner groove used for containing the balls is formed in the position, corresponding to the inner concave portion of the pressing plate, of the inner side of the U-shaped groove, and the upper side and the lower side of the edge of the pressing plate are limited in the U-shaped groove through the balls.

Description

Technical field:

[0001] The present invention relates to the technical field of thermal print head production and manufacturing, and more specifically to a wire bonding fixture for thermal print heads having a reasonable structure and stable clamping, which can improve the flatness of the product clamping surface, thereby overcoming the problem of porcelain nozzle collision caused by component warping, and is beneficial to improving the wire bonding efficiency and its application. Background technology:

[0002] The key component of the thermal print head is the heating substrate, on which strip-shaped heating resistors and related circuits are arranged, and wire bonding is required during the processing. In addition, different types of thermal print head products have different device heights, base glaze layer thicknesses, and device layout areas on the heating substrate. During the wire bonding process, a pressure plate and a supporting fixture are required to clamp the device to be processed. After clamping, the top of the processing area should be kept flat, and the bonding area should be exposed from the bonding window on the pressure plate. However, at this stage, since the surface of the thermal print head heating substrate product is provided with several protrusions (especially the heating resistor significantly protrudes from the substrate surface), after the pressure plate is pressed, the flatness above the operating plane is poor, and the surface of the pressure plate is prone to warping. The maximum height of the ignition rod from the upper surface of the operating plane in the wire bonding equipment is only 1.5mm, resulting in component contact damage.

[0003] In addition, for the bonding operation of the thermal print head heating substrate, it is necessary to first place the product to be processed on the supporting fixture, and use the clamp to send the supporting fixture after the product is placed to the operating platform. There is a preheating area on the operating platform. The supporting fixture is placed in the preheating area for preheating, and then the supporting fixture and the product to be processed are pushed to the processing area, and the pressure plate is pressed down to complete the wire bonding. After the processed parts are pushed out of the processing area, they are pushed to the cooling area for subsequent processing. At this time, the processing area is empty, and the next preheated part to be processed is pushed in to prepare for the wire bonding operation. The existing processing efficiency is low. This is because only one part to be processed can be preheated and wire bonded at a time. The wire bonding operation of two adjacent parts to be processed requires the preheating time of each processed part to be reserved, resulting in the inability to continuously process. In view of the above problems, there is an urgent need for a device that can significantly improve the flatness of the component clamping and improve the efficiency of the wire bonding process. Summary of the invention:

[0004] In view of the shortcomings and deficiencies in the prior art, the present invention proposes a wire bonding fixture for a thermal print head and its application which has a reasonable structure and stable clamping, can improve the flatness of the product clamping surface, thereby overcoming the problem of porcelain nozzle collision caused by warping of components, and is beneficial to improving the wire bonding efficiency.

[0005] The present invention is achieved by the following measures:

[0006] The support frame is provided with a plurality of holes for receiving the processing product, and the plurality of holes are provided with a plurality of holes for receiving the processing product.

[0007] The ball described in the present invention is installed in the inner groove of the U-shaped groove via a spring or a spring sheet. When the pressure plate is pressed down to the surface of the product to be processed, the pressing and leveling mechanism on both sides of the pressure plate uses the spring or spring sheet to complete the leveling of the upper surface of the processing area. During this process, the positioning boss on the lower surface of the pressure plate contacts the surface of the product to be processed, but avoids interference from devices on the surface of the product to be processed. Such devices include control ICs, raised strip resistors, etc.

[0008] The engaging boss on the lower surface of the pressing plate described in the present invention is arranged along the length direction of the processing window, and is used to contact the surface of the heating substrate for the thermal print head to be processed when the pressing plate is pressed down to the surface of the product to be processed, so as to ensure that the pressing plate is successfully pressed on the surface of the product to be processed. Since the positioning boss is parallel to the length direction of the processing window, that is, perpendicular to the line connecting the left / right support arms, the surface of the pressing plate will not be warped due to pressure deviation during the pressing process supported by the left / right support arms; further, more than two processing windows on the pressing plate are arranged along the vertical direction, that is, the corresponding products to be clamped are clamped side by side in the vertical direction. At this time, the left support arm and the right support arm are respectively provided on both sides of the pressing plate. During the pressing process, the positioning bosses corresponding to the more than two processing windows respectively press more than two products to be processed, which further increases the number of support points below the pressing plate and the product, and overcomes the problem of warping of the pressing plate surface; preferably, three processing windows side by side are arranged to achieve one-time clamping of three products to be processed.

[0009] The present invention also proposes a method for realizing continuous wire bonding of products by using the wire bonding fixture for a thermal print head as described above, which is realized on a wire bonding operation work platform, wherein the wire bonding operation work platform is provided with a preheating zone, a processing zone, and a cooling zone arranged in sequence along a straight line, and is characterized in that the method comprises the following steps:

[0010] Step 1: Place two or more products to be processed on the supporting base plate, and use a pressing plate to press the surface of the products to be processed, so that the engaging boss on the lower surface of the pressing plate engages with the engaging groove on the supporting base plate to complete the clamping of the products to be processed;

[0011] Step 2: Grasp the fixture that clamps the product to be processed by the clamping claw, and place the fixture that clamps the product to be processed in the product preheating area for preheating;

[0012] Step 3: The preheated products to be processed and the fixtures are pushed to the processing area, and the wire bonding equipment completes the wire bonding corresponding to each processing window one by one;

[0013] Step 4: The wire-bonded products and fixtures are pushed to the cooling area and unloaded after cooling.

[0014] Compared with the prior art, the present invention increases the number of processing windows in the wire bonding fixture, so that the wire bonding operation can carry more than two products to be processed at a time, and the effective working range of the welding processing area is more than doubled compared with the prior art, thereby realizing the continuous processing of more than two products to be processed. In addition, by clamping and fixing more than two products to be processed at the same time, the lower surface of the pressure plate in the fixture contacts multiple products to be processed at multiple points, which is beneficial to improving the surface flatness of the pressure plate, avoiding warping of the pressure plate, and reducing the risk of component damage.

[0015] Compared with the prior art, the present invention has the advantages of reasonable structure, stable clamping, and the ability to significantly improve product wire bonding processing efficiency. Description of the drawings:

[0016] Attached Figure 1 Schematic diagram of the structure of the wire bonding fixture for the thermal print head in the present invention. Figure 2 Schematic diagram of a structure of a pressure plate in a wire bonding fixture for a thermal print head of the present invention, wherein Figure 2 (a) is the top view of the pressure plate. Figure 2 (b) is the front view of the pressure plate.

[0017] Attached Figure 3 It is a work flow chart of an embodiment of the present invention.

[0018] Attached Figure 4 It is a structural schematic diagram of the pressing and leveling mechanism on both sides of the pressure plate in the present invention.

[0019] Attached Figure 5 It is a schematic diagram of the structure of the left supporting arm / right supporting arm end portions corresponding to the pressing and leveling mechanism in the present invention.

[0020] Attached Figure 6 It is a schematic diagram of the structure of a comparative implementation method in an embodiment of the present invention.

[0021] Attached Figure 7 It is a schematic diagram of the tilting of the pressure plate in the comparative implementation mode in the embodiment of the present invention.

[0022] Attached Figure 8 It is a schematic diagram of equipment damage caused by the tilting of the pressure plate in an embodiment of the present invention.

[0023] Figure numerals: supporting base plate 1, pressure plate 2, processing window 3, positioning boss 4, bonding device 5, left support arm 6, right support arm 7, U-shaped groove 8, ball 9, product to be processed 10. Specific implementation method:

[0024] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0025] Example:

[0026] As attached Figure 1 , 2 As shown, this example provides a wire bonding fixture for a thermal print head with three processing windows, which is provided with a supporting base plate 1 for supporting a part to be processed, a pressing plate 2 is provided above the supporting base plate 1, and a hollow processing window 3 is provided on the pressing plate 2 corresponding to the processing area of ​​the part to be processed, a groove for accommodating the product to be processed is provided on the supporting base plate 1, and a positioning boss 4 is provided on the lower surface of the pressing plate 2 corresponding to the outer side of the processing window 3, and the positioning boss 4 on the lower surface of the pressing plate 2 contacts the surface of the product to be processed 10 placed on the supporting base plate 1 to complete the pressing and positioning, and the pressing plate 2 and the supporting base plate 1 complete the clamping of the product to be processed 10;

[0027] In this example, a pressing and leveling mechanism is also provided on both sides of the pressing plate 2, and the two sides of the pressing plate are respectively connected to the left support arm 6 and the right support arm 7 through the pressing and leveling mechanism. The pressing and leveling mechanism includes a stepped pressing plate edge arranged on both sides of the pressing plate 2, and the height of the pressing plate edge is greater than the height of the pressing plate body. The upper surface and the lower surface of the pressing plate edge are respectively provided with corresponding inner recesses. A U-shaped groove 8 is provided at the end of the left support arm / the right support arm, and the pressing plate edge is placed in the U-shaped groove 8. An inner groove for accommodating a ball is also provided at the inner side of the U-shaped groove 8 corresponding to the inner recess of the pressing plate. The upper and lower sides of the pressing plate edge are respectively limited between the U-shaped groove 8 by the ball 9, and the pressing and leveling mechanism can It can meet the needs of pressing and leveling of products with different thicknesses: that is, when the thicker product is clamped between the supporting base plate and the pressing plate, the positioning boss on the lower surface of the pressing plate contacts the surface of the substrate of the product, and the pressing plate is automatically leveled by the pressing and leveling mechanisms on both sides, so that the surface of the bonding operation area above the pressing plate remains flat; however, since the surface of the thermal print head heating substrate product is provided with devices of different thicknesses, such as the bottom glaze layer protruding from the surface of the substrate, the heating resistor, etc., when the pressing plate leveling mechanism is set at both ends of the length direction of the product, when the pressing plate cannot be pressed down along the center line of the product, it will cause the pressing plate to deviate to the side, and the pressing plate will damage the bonding equipment after it is warped;

[0028] In order to solve the above problems, the present example defines that the pressing plate leveling mechanism is arranged on both sides of the length direction of the processing window, that is, the connecting line of the two pressing plate leveling mechanisms is perpendicular to the length direction of the processing window, and further arranges more than two processing windows on the pressing plate, providing multiple contact support points (positioning bosses) between the pressing plate and the product to be processed, so as to improve the reliability of the pressing plate leveling;

[0029] In this example, three processing windows 3 are arranged side by side in the vertical direction on the upper side of the pressing plate 2, and an engaging boss 4 is arranged corresponding to the outer edge of the processing window on the lower surface of the pressing plate 2, and an engaging groove 5 matching the engaging boss 4 is arranged on the supporting bottom plate 1, so as to clamp three products to be processed at one time;

[0030] When in use, fix the pressing plate with the left and right support arms, and then fix the product through the raised part on the back of the pressing plate by moving the support arms up and down. If the pressing plate only clamps one product along the length direction of the product to be processed, such as the attached Figure 6 As shown, there are the following problems: when the pressure plate presses the product, the uniformity of the vertical force is controlled by the spherical mechanism that fixes the pressure plate on the support arm. This mechanism is a pressing and leveling mechanism that is used to meet the fixing requirements of products of different thicknesses and automatically balances according to the force conditions of the pressure plate. Since the area where the components are arranged on the heating substrate for the thermal print head is limited by the product size and model, it cannot be guaranteed that the force points of the product and the pressure plate are always at the center line position of the pressure plate. This will cause the pressure plate to tilt at a certain angle in the vertical direction, as shown in the attached figure. Figure 7 As shown in the figure, the surface of the pressure plate is lifted, which causes the following effects: (1) The product is not fixed stably, because wire bonding uses a thermal ultrasonic welding method. During the ultrasonic output of the welding operation, the product must be fixed firmly and stably, which will affect the welding quality; (2) It is easy to cause damage to the relevant parts of the equipment, and there are certain safety hazards such as Figure 8 As shown;

[0031] In this example, the continuous wire bonding of the product is achieved by using the wire bonding fixture for the thermal print head as described above, which is specifically achieved on a wire bonding operation work platform, wherein the wire bonding operation work platform is provided with a preheating area, a processing area, and a cooling area arranged in sequence along a straight line, as shown in the attached Figure 3 As shown, the following steps are included:

[0032] Step 1: Place two or more products to be processed on the supporting base plate, and use a pressing plate to press the surface of the products to be processed, so that the engaging boss on the lower surface of the pressing plate engages with the engaging groove on the supporting base plate to complete the clamping of the products to be processed;

[0033] Step 2: Grasp the fixture that clamps the product to be processed by the clamping claw, and place the fixture that clamps the product to be processed in the product preheating area for preheating;

[0034] Step 3: The preheated products to be processed and the fixtures are pushed to the processing area, and the wire bonding equipment completes the wire bonding corresponding to each processing window one by one;

[0035] Step 4: The wire-bonded products and fixtures are pushed to the cooling area and unloaded after cooling.

[0036] Compared with the comparative implementation method of welding one product at a time, this example can significantly improve the processing efficiency, as shown in Table 1:

[0037] Table 1 Performance comparison between this example and single welding implementation method

[0038]

[0039] Compared with the prior art, the present invention increases the number of processing windows in the wire bonding fixture, so that the wire bonding operation can carry more than two products to be processed at a time, and the effective working range of the welding processing area is more than doubled compared with the prior art, thereby realizing the continuous processing of more than two products to be processed. In addition, by clamping and fixing more than two products to be processed at the same time, the lower surface of the pressure plate in the fixture contacts multiple products to be processed at multiple points, which is beneficial to improving the surface flatness of the pressure plate, avoiding warping of the pressure plate, and reducing the risk of component damage.

Claims

1. A wire bonding fixture for a thermal print head, provided with a supporting base plate for supporting a part to be processed, a pressing plate provided above the supporting base plate, a hollow processing window provided on the pressing plate corresponding to a processing area of ​​the part to be processed, and a groove provided on the supporting base plate for accommodating the product to be processed, characterized in that: The lower surface of the pressing plate corresponds to the outer side of the processing window and is provided with a positioning boss for contacting the product to be processed. The two sides of the pressing plate are respectively connected to the left support arm and the right support arm through a pressing and leveling mechanism. The pressing and leveling mechanism includes a stepped pressing plate edge arranged on both sides of the pressing plate. The height of the pressing plate edge is greater than the height of the pressing plate body. The upper and lower surfaces of the pressing plate edge are respectively provided with corresponding inner recesses. A U-shaped groove is provided at the end of the left support arm / right support arm, and the edge of the pressing plate is placed in the U-shaped groove. An inner groove for accommodating a ball is also provided on the inner side of the U-shaped groove corresponding to the inner recess of the pressing plate. The upper and lower sides of the pressing plate edge are respectively limited between the U-shaped grooves by balls. The connecting line between the left support arm and the right support arm is perpendicular to the length direction of the processing window on the pressing plate, and more than two processing windows are arranged side by side on the pressing plate.

2. The wire bonding jig for a thermal print head according to claim 1, characterized in that: The engaging boss on the lower surface of the pressure plate is arranged along the length direction of the processing window, and is used to contact the surface of the heating substrate for the thermal print head to be processed when the pressure plate is pressed down to the surface of the product to be processed, so as to ensure that the pressure plate is successfully pressed on the surface of the product to be processed. Since the positioning boss is parallel to the length direction of the processing window, that is, perpendicular to the line connecting the left / right support arms, the pressure plate surface will not be warped due to pressure deviation during the process of the pressure plate being pressed down with the support of the left / right support arms.

3. The wire bonding jig for a thermal print head according to claim 2, characterized in that: More than two processing windows on the pressure plate are arranged in the vertical direction, that is, the corresponding products to be clamped are clamped side by side in the vertical direction. At this time, a left support arm and a right support arm are respectively provided on both sides of the pressure plate. During the pressing process, the positioning bosses corresponding to the more than two processing windows respectively press the more than two products to be processed, thereby increasing the number of support points under the pressure plate and the product, and overcoming the problem of warping on the surface of the pressure plate.

4. The wire bonding jig for a thermal print head according to claim 3, characterized in that: Three processing windows are arranged side by side, so that three products to be processed can be clamped at one time.

5. A method for realizing continuous wire bonding of products using the wire bonding fixture for a thermal print head as claimed in any one of claims 1 to 4, which is realized on a wire bonding operation work platform, wherein the wire bonding operation work platform is provided with a preheating zone, a processing zone, and a cooling zone arranged in sequence along a straight line, characterized in that: The following steps are involved: Step 1: Place two or more products to be processed on the supporting base plate, and use a pressing plate to press the surface of the products to be processed, so that the engaging boss on the lower surface of the pressing plate engages with the engaging groove on the supporting base plate to complete the clamping of the products to be processed; Step 2: Grasp the fixture that clamps the product to be processed by the clamping claw, and place the fixture that clamps the product to be processed in the product preheating area for preheating; Step 3: The preheated products to be processed and the fixtures are pushed to the processing area, and the wire bonding equipment completes the wire bonding corresponding to each processing window one by one; Step 4: The wire-bonded products and fixtures are pushed to the cooling area and unloaded after cooling.

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