A pressure output control device and control method for a chip mounter

Abstract

This invention discloses a pressure output control device and method for a pick-and-place machine, relating to the field of SMT (Surface Mount Technology) technology. In this invention: two guide tubes located around a vacuum suction tube are connected to the bottom side of the nozzle mechanism, with lightweight push pins movably positioned at the guide tube positions. Two micro-drive cavities symmetrical about the vacuum suction tube are formed inside the nozzle mechanism. The upper ends of the lightweight push pins extend into the micro-drive cavities, and micro-adjustment blocks fixedly connected to the upper ends of the lightweight push pins are disposed within the micro-drive cavities. A magnetic plate is disposed on the upper part of the micro-adjustment block, and an electromagnetic module directly opposite the magnetic plate is embedded on the top side of the micro-drive cavity. A limiting protrusion directly opposite the micro-adjustment block is disposed on the bottom side of the micro-drive cavity. The micro-adjustment block includes a pressing contact plate, and an elastic bead is disposed between the bottom side of the micro-drive cavity and the pressing contact plate. This invention reduces the processing time required for placing surface mount components while ensuring appropriate pressing contact between the soldering part of the surface mount component and the solder paste area on the PCB board.

Description

Technical Field

[0001] This invention relates to the field of SMT placement technology, and in particular to a pressure output control device and control method for a placement machine. Background Technology

[0002] The nozzle of a pick-and-place machine is a key component for picking up and placing surface mount components (SMT) devices. Many existing SMT nozzles use vacuum suction to pick up SMT devices. After reaching the placement position, in order to ensure that the solder paste of the SMT device is properly pressed into the corresponding position on the PCB, high-pressure air is blown from the nozzle onto the circuit board through the vacuum suction tube when placing the SMT device. However, high-pressure air blowing via vacuum suction tubes requires releasing the negative pressure within the tube before high-pressure gas is expelled. This necessitates switching and controlling the gas output state, undoubtedly increasing the nozzle's operating time. Furthermore, the high-pressure air blowing method of the vacuum suction tube to press down on the surface mount components makes precise control over the pressing depth difficult. Insufficient air pressure may result in insufficient contact between the surface mount component's solder joint and the solder paste on the PCB. If the PCB moves or is affected by air blowing from other surface mount components, the surface mount component may shift. Excessive air pressure may cause the surface mount component's solder joint to over-compress the solder paste on the PCB, causing it to overflow from the original soldering area. This could potentially contaminate other areas of the PCB and negatively impact subsequent reflow soldering. Therefore, reducing the processing time required for surface mount component placement while ensuring adequate compression contact between the surface mount component's solder joint and the solder paste on the PCB becomes a crucial issue to address in the efficient and high-quality placement of surface mount components. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a pressure output control device and control method for a chip mounter, thereby reducing the process time required for chip mounter components during placement, while ensuring appropriate compression contact between the soldering part of the chip mounter component and the solder paste part of the PCB board.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] This invention provides a pressure output control device for a pick-and-place machine. The control device includes a nozzle mechanism with a vacuum suction tube. The pick-and-place element is adsorbed at the lower opening of the vacuum suction tube. Two guide tubes located around the vacuum suction tube are connected to the bottom side of the nozzle mechanism. Lightweight push pins are movably positioned at the guide tube positions. The nozzle mechanism has two micro-drive cavities symmetrical about the vacuum suction tube. The upper end of the lightweight push pin extends into the micro-drive cavity. A micro-adjustment block is fixedly connected to the upper end of the lightweight push pin within the micro-drive cavity. A magnetic plate is mounted on the upper part of the micro-adjustment block. An electromagnetic module is embedded on the top side of the micro-drive cavity, directly opposite the magnetic plate. A limiting protrusion is mounted on the bottom side of the micro-drive cavity, directly opposite the micro-adjustment block. The micro-adjustment block includes a pressing contact plate. An elastic bead is positioned between the bottom side of the micro-drive cavity and the pressing contact plate.

[0006] In the pressure output control device of the pick-and-place machine of the present invention: let Fa be the elastic force generated by the minimum deformation of the elastic bead located between the bottom side of the micro drive cavity and the extrusion contact plate, and let Fg be the total weight of the lightweight push pin and the fine adjustment block, then Fa>Fg.

[0007] In the pick-and-place machine pressure output control device of the present invention: a through hole structure is opened at the bottom of the nozzle mechanism to connect the micro drive cavity and the inner cavity of the guide tube, and a lightweight pusher moves through the through hole structure and the inner cavity of the guide tube.

[0008] In the pressure output control device of the pick-and-place machine of the present invention: when the electromagnetic module is not powered on, the horizontal position of the bottom of the lightweight push pin is higher than the horizontal position of the bottom of the vacuum adsorption tube. Let the height difference between the bottom of the lightweight push pin and the bottom of the vacuum adsorption tube be H, and let the distance between the bottom side of the fine adjustment block and the vertex of the limiting protrusion be D, then D>H.

[0009] In the pick-and-place machine pressure output control device of the present invention: let the lateral span dimension of the two lightweight push pins be La, and let the width dimension of the placement element be Lb, then La <Lb。

[0010] This invention provides a method for controlling the pressure output of a pick-and-place machine, comprising the following steps:

[0011] S1. The suction nozzle mechanism moves to the material picking area and picks up the chip components through the vacuum suction tube.

[0012] S2. Based on the weight of the surface mount component, after the vacuum suction tube of the nozzle mechanism picks up the component, the electromagnetic module immediately conducts a current matching the weight of the component, causing the electromagnetic module to generate the same magnetism as the magnetic plate. This drives the lightweight push pin to move downwards, and the bottom end of the lightweight push pin makes contact with the upper side of the surface mount component. Let F be the negative pressure suction force exerted by the vacuum suction tube of the nozzle mechanism on the surface mount component. a Let F be the gravitational force acting on the surface mount component itself. G Assume that the pressure exerted by the bottom of the lightweight push pin on the surface mount element after the electromagnetic module is energized is F. b Then Fa >F G +F b .

[0013] S3. The vacuum suction tube of the suction nozzle mechanism picks up the patch element and reaches the position where the patch element is placed.

[0014] S4. The vacuum suction tube of the suction nozzle mechanism releases negative pressure. Under the repulsive action between the electromagnetic module and the magnetic plate, the lightweight pusher applies pressure to the surface mount component, pressing the solder joint onto the solder paste position.

[0015] S5. After the nozzle mechanism completes the placement operation of the current component, it returns to the placement area and repeats steps S1 to S4. During the return stroke, the electromagnetic module is de-energized, and the elastic bead moves upward, causing the fine-tuning block and lightweight push pin to move upward.

[0016] Furthermore, in the pick-and-place machine pressure output control method of this invention: when the electromagnetic module is energized to drive the lightweight push pin to move downward, let the magnitude of the electromagnetic module's energizing current be Ix, then there exists a database set value mapping relationship A(I X )∝A -1 (F G ), where the G patch element itself is subjected to gravity.

[0017] Compared with existing technologies, the beneficial effects of this invention are:

[0018] This invention configures a fine-tuning block, a lightweight push pin, a magnetic plate, and an electromagnetic module at the micro-drive cavity position of the suction nozzle mechanism. When the suction nozzle mechanism picks up the surface mount component under negative pressure, the electromagnetic module is pre-energized to pre-form the downward pressure of the lightweight push pin on the surface mount component. When the suction nozzle mechanism releases the negative pressure suction force on the surface mount component, the appropriate downward pressure on the surface mount component is completed simultaneously, quickly completing the appropriate bonding between the surface mount component soldering part and the PCB board solder paste. This reduces the process time required for surface mount component placement and ensures appropriate compression contact between the surface mount component soldering part and the PCB board solder paste part. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the patch pressure output control device (in negative pressure suction state) in this invention.

[0020] Figure 2 for Figure 1 A magnified schematic diagram of a portion of point A in the middle.

[0021] Figure 3 This is a schematic diagram of the structure of the patch pressure output control device (negative pressure release, vacuum adsorption tube discharge) in this invention.

[0022] Figure 4 for Figure 3Schematic diagram of partial enlargement at position B in the [object].

[0023] Figure 5 Schematic diagram when the electromagnetic module in the present invention is not powered on.

[0024] Where: 1 - PCB board, 101 - solder paste; 2 - nozzle mechanism, 201 - vacuum adsorption tube, 202 - micro - drive cavity, 203 - conduit, 204 - lightweight push pin, 205 - fine - tuning block, 206 - extrusion contact plate, 207 - magnetic plate, 208 - limit bump, 209 - elastic bead, 210 - electromagnetic module; 3 - patch component, 301 - welding part. Specific implementation mode

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Embodiment 1

[0027] Please refer to<​​​​​​​​​The limiting protrusion 208 can limit the downward movement of the fine adjustment block 205 to prevent the welding part 301 and the solder paste 101 from being "excessively squeezed" due to the "excessive" downward movement of the fine adjustment block 205 and the lightweight push pin 204. The fine adjustment block 205 includes a pressing contact plate 206 and an elastic bead 209 disposed between the bottom side of the micro-drive cavity 202 and the pressing contact plate 206.

[0029] Please see Figure 3 The surface mount component 3 includes a soldering part 301, which is bonded to the solder paste 101 at the corresponding position on the PCB board 1 and then re-soldered by reflow soldering.

[0030] Please see Figure 2 , Figure 4 Let Fa be the elastic force generated by the minimum deformation of the elastic bead 209 located between the bottom side of the micro-drive cavity 202 and the extrusion contact plate 206 (the minimum deformation of the elastic bead 209, which is actually the deformation of the elastic bead 209 when it pushes the magnetic plate 207 into complete contact with the top side of the micro-drive cavity 202). Let Fg be the total weight of the lightweight pusher 204 and the fine-tuning block 205 (including the magnetic plate 207 and the extrusion contact plate 206). Then Fa > Fg.

[0031] Please see Figure 5 When the electromagnetic module 210 is not powered on, the lightweight push pin 204 is in a "high position" due to the elastic force of the elastic bead 209, and the horizontal position of the bottom of the lightweight push pin 204 is higher than the horizontal position of the bottom of the vacuum adsorption tube 201. Let the height difference between the bottom of the lightweight push pin 204 and the bottom of the vacuum adsorption tube 201 be H, combined with... Figure 2 Let D be the distance between the bottom side of the fine adjustment block 205 and the vertex of the limiting protrusion 208. Then D>H (so that under the limiting condition of the limiting protrusion 208, the lightweight push pin 204 presses down on the surface mount component 3 to a certain extent, ensuring that the soldering part 301 is pressed into the solder paste 101).

[0032] Example 2

[0033] This invention relates to a method for controlling the pressure output of a pick-and-place machine, the details of which are as follows:

[0034] In the first step, the suction nozzle mechanism 2 moves to the material picking area and picks up the chip components through the vacuum suction tube 201.

[0035] The second step involves the electromagnetic module immediately conducting a current matching the weight of the patch element 3 after the vacuum suction tube of the nozzle mechanism 2 picks up the patch element 3, based on the weight of the patch element 3 itself. This causes the electromagnetic module 210 to generate the same magnetism as the magnetic plate 207, driving the lightweight push pin 204 to move downwards. The bottom end of the lightweight push pin 204 then makes contact with the upper side of the patch element 3.

[0036] Let F be the negative pressure adsorption force of the vacuum adsorption tube 201 of the suction nozzle mechanism 2 on the patch element 3. a Let the gravitational force acting on the surface mount element 3 be F. G Assume that the pressure exerted by the bottom end of the lightweight push pin 204 on the surface mount element 3 after the electromagnetic module 210 is energized is F. b Then F a >F G +F b .

[0037] When the electromagnetic module 210 is energized and applies a downward force to the lightweight push pin 204, assuming the magnitude of the energized current of the electromagnetic module 210 is Ix, then there exists a database set value mapping relationship A(Ix). X )∝A -1 (F G ), where G is the gravity acting on the surface mount element 3 itself. The mapping relationship of this database set values ​​can be obtained through mechanical analysis and actual experimental testing based on the extrusion requirement between the solder joint 301 and the solder paste 101. Generally, the current supplied to the electromagnetic module 210 is inversely proportional to the weight of the surface mount element 3 itself. Because the degree of extrusion between the solder joint 301 and the solder paste 101 is generally at a suitable level, it can be assumed that the amount of solder paste 101 pressed into the solder joint 301 is a fixed value. The greater the weight of the surface mount element 3 itself, the smaller the current required to power the electromagnetic module 210.

[0038] The third step is that the vacuum suction tube 201 of the suction nozzle mechanism 2 picks up the patch element 3 and reaches the position where the patch element 3 is placed.

[0039] In the fourth step, the vacuum suction tube 201 of the suction mechanism 2 releases negative pressure. At this time, the surface mount component 3 is no longer attracted by the negative pressure of the vacuum suction tube 201. Under the repulsive action of the electromagnetic module 210 and the magnetic plate 207, the lightweight push pin 204 applies pressure to the surface mount component 3, pressing the solder part 301 onto the solder paste 101. The pressure of the lightweight push pin 204 on the surface mount component 3 is constant. The moment the vacuum suction tube 201 releases negative pressure, the downward pressure of the lightweight push pin 204 on the surface mount component 3 is also completed instantly, completing the bonding between the solder part 301 and the solder paste 101. After the vacuum suction tube 201 releases negative pressure, the suction mechanism 2 can continue to perform the "return" action, returning to the material picking area to pick up materials, reducing the switching and control time of the high-pressure blowing action on the surface mount component 3.

[0040] In the fifth step, after the nozzle mechanism 2 completes the placement operation of the current component 3, it returns to the placement area and repeats the steps from the first to the fourth step. During the return stroke of the nozzle mechanism 2 in the fifth step, the electromagnetic module 210 is de-energized, and the elastic bead 209 moves the fine-tuning block 205 and the lightweight push pin 204 upwards. Under the elastic force of the elastic bead 209, the magnetic plate 207 on the upper side of the fine-tuning block 205 contacts the top side of the micro-drive cavity 202, and the fine-tuning block 205 reaches its "highest position" within the micro-drive cavity 202.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressure output control device for a chip mounter, the control device comprising a nozzle mechanism (2), the nozzle mechanism (2) being equipped with a vacuum adsorption tube (201), wherein the chip mount element (3) is adsorbed at the lower opening of the vacuum adsorption tube (201), characterized in that: The suction nozzle mechanism (2) has two conduits (203) connected to the bottom side of the vacuum suction tube (201), and a lightweight pusher (204) is movably arranged at the position of the conduit (203). The suction nozzle mechanism (2) has two micro-drive cavities (202) symmetrical about the vacuum adsorption tube (201) inside. The upper end of the lightweight pusher (204) extends into the micro-drive cavity (202). A fine-tuning block (205) fixedly connected to the upper end of the lightweight pusher (204) is arranged in the micro-drive cavity (202). A magnetic plate (207) is arranged on the upper part of the fine-tuning block (205). An electromagnetic module (210) is embedded on the top side of the micro-drive cavity (202) facing the magnetic plate (207). A limiting protrusion (208) is arranged on the bottom side of the micro-drive cavity (202) facing the fine-tuning block (205). The fine-tuning block (205) includes a pressing contact plate (206). An elastic bead (209) is arranged between the bottom side of the micro-drive cavity (202) and the pressing contact plate (206).

2. The pressure output control device for a pick-and-place machine according to claim 1, characterized in that: Let Fa be the elastic force generated by the minimum deformation of the elastic bead (209) located between the bottom side of the micro-drive cavity (202) and the extrusion contact plate (206), and let Fg be the total weight of the lightweight push pin (204) and the fine-tuning block (205). Then Fa>Fg.

3. The pressure output control device for a pick-and-place machine according to claim 1, characterized in that: The nozzle mechanism (2) has a through hole structure at the bottom that connects the micro-drive cavity (202) and the inner cavity of the conduit (203). The lightweight pusher (204) moves through the through hole structure and the inner cavity of the conduit (203).

4. The pressure output control device for a pick-and-place machine according to claim 1, characterized in that: When the electromagnetic module (210) is not powered on, the horizontal position of the bottommost end of the lightweight pusher (204) is higher than the horizontal position of the bottommost end of the vacuum adsorption tube (201). Let H be the height difference between the bottom of the lightweight pusher (204) and the bottom of the vacuum adsorption tube (201), and let D be the distance between the bottom side of the fine adjustment block (205) and the top of the limiting protrusion (208). Then D>H.

5. The pressure output control device for a pick-and-place machine according to claim 1, characterized in that: Let the lateral span of the two lightweight push pins (204) be La, and the width of the surface mount element (3) be Lb, then La <Lb。 6. A method for controlling the pressure output of a pick-and-place machine, characterized in that, The pressure output control device for a pick-and-place machine according to any one of claims 1 to 5 includes the following steps: S1. The suction nozzle mechanism (2) moves to the material picking area and picks up the patch element through the vacuum suction tube (201); S2. Based on the weight of the patch element (3) itself, after the vacuum suction tube of the suction nozzle mechanism (2) picks up the patch element (3), the electromagnetic module immediately conducts a current that matches the weight of the patch element (3) itself, so that the electromagnetic module (210) generates the same magnetism as the magnetic plate (207), driving the lightweight push pin (204) to move down, and the bottom end of the lightweight push pin (204) presses against the upper side of the patch element (3); Wherein, the negative pressure adsorption force of the vacuum adsorption tube (201) of the suction nozzle mechanism (2) on the patch element (3) is: Let the gravitational force acting on the surface mount element (3) itself be... Let the pressure exerted by the bottom end of the lightweight push pin (204) on the surface mount element (3) after the electromagnetic module (210) is energized be... ,but ; S3, the vacuum suction tube (201) of the suction nozzle mechanism (2) picks up the patch element (3) and reaches the position where the patch element (3) is placed; S4. The vacuum suction tube (201) of the suction nozzle mechanism (2) releases negative pressure. Under the repulsive action between the electromagnetic module (210) and the magnetic plate (207), the lightweight push pin (204) applies pressure to the surface mount component (3) and presses the solder part (301) onto the solder paste (101). S5. After the nozzle mechanism (2) completes the placement operation of the current component (3), the nozzle mechanism (2) returns to the placement and picking area and repeats the steps of S1 to S4. When the suction nozzle mechanism (2) returns to its starting position, the electromagnetic module (210) is de-energized, and the elastic bead (209) moves upward, causing the fine-tuning block (205) and the lightweight pusher (204) to move upward.

7. The method for controlling the pressure output of a pick-and-place machine according to claim 6, characterized in that: When the electromagnetic module (210) is energized and drives the lightweight push pin (204) to move downward, let the magnitude of the energized current of the electromagnetic module (210) be Ix, then there exists a database set value mapping relationship. ,in, The gravity acting on the surface mount element (3) itself.

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