Method for controlling mounting head

Abstract

According to an embodiment of the present invention, a method for controlling a mounting head comprises the steps in which: a first motor is driven and a head unit descends to a substrate in a state where a collet picks up a component; an encoder recognizes that a solder part comes in contact with the substrate; and a control unit coverts position control of the component into force control on the basis of a contact recognition signal of the encoder and controls driving of a second motor on the basis of information on a force applied to a load cell so as to precisely adjust a bonding position of the component.

Description

Control method of the mounting head

[0001] Embodiments of the present invention relate to a method for controlling a mounting head of a mounting device that mounts semiconductor dies or chips on a substrate.

[0002] Semiconductor dies or chips are formed together on a single wafer. The wafer undergoes a cutting process to separate the individual dies, and each die must be individually mounted through a die bonding process.

[0003] An electrical connection is created between the mounted dies and external devices, and the surfaces are then sealed to protect the dies from damage.

[0004] In general, in the method of bonding a die to a substrate, the die is picked up and the temperature is raised to melt the solder, the die is bonded to the substrate, and then the temperature is cooled to solidify.

[0005] At this time, the collet and head spindle expand thermally due to the increase in temperature during the process of melting and solidifying the solder, which becomes a variable in precisely bonding the die.

[0006] In addition, after contact between the solder and the joint surface for bonding is detected, when the solder melts and descends, the position where the solder descends is compensated by moving the Z-axis of the head upward to a preset height.

[0007] However, the system that compensates for the solder joint position by raising the Z-axis position of the head by a preset position has difficulty precisely compensating for the minute downward position change depending on the amount of solder melting.

[0008] According to one aspect of the present invention, the main object is to provide a method for controlling a mounting head capable of compensating for a change in collet position due to thermal expansion occurring in the collet and spindle while increasing the temperature to melt solder using a second motor and a change in collet position due to downward movement as solder melts.

[0009] However, these tasks are exemplary, and the tasks to be solved by the present invention are not limited thereto.

[0010] A control method of a mounting head according to one embodiment of the present invention comprises the steps of: a first motor being driven, a head portion being lowered to a substrate while a collet picks up a component; an encoder recognizing that solder is in contact with the substrate; and a control portion converting position control of the component into force control based on a contact recognition signal of the encoder, and controlling the operation of a second motor based on force information applied to a load cell to precisely adjust a bonding position of the component.

[0011] The step of converting the position control of the component into force control based on the contact recognition signal of the encoder and precisely adjusting the bonding position of the component may further include the step of moving the component upward by the second motor when the solder is melted and lowered.

[0012] The method may further include a step of driving the first motor and lowering the head portion to the substrate while the collet picks up the component, and raising the temperature of the heater to a temperature higher than the melting point of the solder formed on the component, before the step of driving the first motor and lowering the head portion to the substrate while the collet picks up the component.

[0013] The step of moving the substrate to the bonding stage and then preheating it may be further included before the step of the head lowering to the substrate while the first motor is driven and the collet picks up the part.

[0014] The control unit may further include a step of converting the position control of the component into force control based on the contact recognition signal of the encoder, driving the second motor to precisely adjust the bonding position of the component, and then performing a bonding process of the component to the substrate.

[0015] After the step of performing the bonding process of the above-mentioned component to the above-mentioned substrate, when the bonding of the above-mentioned component to the above-mentioned substrate is completed, the step of re-driving the above-mentioned first motor, separating the above-mentioned component from the above-mentioned substrate, and moving upward again may be further included.

[0016] Other aspects, features and advantages other than those described above will become apparent from the following detailed description, claims and drawings for carrying out the invention.

[0017] According to one embodiment of the present invention, the mounting head has a rotation motor and first and second motors driven separately so that the bonding position of a component absorbed into a collet can be controlled more precisely.

[0018] In addition, the mounting head according to one embodiment of the present invention can enable more precise rotational position control for the bonding position by eliminating the general bearing structure and directly connecting the rotation motor and the spindle.

[0019] In addition, the mounting head according to one embodiment of the present invention employs a second motor that is positioned above the spindle and more precisely controls the up-and-down movement of the spindle based on the primary position set by the first motor, in addition to the first motor that moves the entire head up and down, thereby enabling doubly precise control of the force required for bonding a component absorbed in a collet.

[0020] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0021] FIG. 1 is a front view of a mounting head according to one embodiment of the present invention.

[0022] Figure 2 is a plan view of a mounting head according to one embodiment of the present invention.

[0023] FIG. 3 is a partial cross-sectional view of the main body of the mounting head according to one embodiment of the present invention, taken along the line AA' of FIG. 2.

[0024] FIG. 4 is a partial cross-sectional view of the head portion of the mounting head according to one embodiment of the present invention, taken along the line BB' of FIG. 2.

[0025] FIG. 5 is a block diagram showing a configuration linked to a control unit of a mounting head according to one embodiment of the present invention.

[0026] FIG. 6 is a cross-sectional view taken along line CC' of FIG. 2, showing the basic state of a mounting head according to one embodiment of the present invention.

[0027] Figure 7 is a drawing showing the collet moving downward by the driving of the first motor in Figure 6.

[0028] Figure 8 is a drawing showing the collet moved upward again by the driving of the second motor in Figure 7.

[0029] Figure 9 is a flowchart of a control method of a mounting head according to one embodiment of the present invention.

[0030] FIG. 10 is a conceptual diagram illustrating a head lowering to a substrate while the first motor is driven and the collet picks up a part, according to one embodiment of the present invention.

[0031] FIG. 11 is a conceptual diagram illustrating, according to one embodiment of the present invention, the operation of the first motor is stopped and the collet is lowered by the second motor until the solder of the component touches the substrate.

[0032] FIG. 12 is a conceptual diagram illustrating an encoder recognizing that solder has touched a substrate and that the solder has melted and flowed downward, according to one embodiment of the present invention.

[0033] FIG. 13 is a conceptual diagram showing, according to one embodiment of the present invention, a control unit converts position control of a component into force control based on a contact recognition signal of an encoder, drives a second motor to precisely adjust the bonding position of the component, and drives the second motor to move the collet upward again to compensate for the position of solder that has flowed down.

[0034] FIG. 14 is a conceptual diagram illustrating, according to one embodiment of the present invention, when bonding of a component to a substrate is completed, the first motor is restarted, the head is separated from the component bonded to the substrate, and moves upward again.

[0035] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. In describing the present invention, identical components are identified by the same reference numerals even when illustrated in different embodiments.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals and redundant descriptions thereof will be omitted.

[0037] In the examples below, the terms first, second, etc. are not used in a limiting sense, but are used for the purpose of distinguishing one component from another.

[0038] In the examples below, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0039] In the examples below, terms such as “include” or “have” mean that a feature or component described in the specification is present, and do not preclude the possibility that one or more other features or components may be added.

[0040] For convenience of explanation, the sizes of components in the drawings may be exaggerated or reduced. For example, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to what is shown.

[0041] In some embodiments, where implementations are otherwise feasible, specific process sequences may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0042] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. In this application, terms such as "comprise" or "have" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0043] Fig. 1 is a front view of a mounting head according to an embodiment of the present invention. Fig. 2 is a plan view of a mounting head according to an embodiment of the present invention. Fig. 3 is a partial cross-sectional view of a main body of a mounting head according to an embodiment of the present invention, taken along line AA' of Fig. 2. Fig. 4 is a partial cross-sectional view of a head of a mounting head according to an embodiment of the present invention, taken along line BB' of Fig. 2. Fig. 5 is a block diagram showing a configuration linked to a control unit of a mounting head according to an embodiment of the present invention.

[0044] Hereinafter, referring to FIGS. 1 to 5, a mounting head according to one embodiment of the present invention includes a base (101), a first motor (100) mounted on the base (101), a spindle guide (30) connected to the first motor (100), a spindle (500) disposed inside the spindle guide (30) and capable of rotating and / or moving separately from the spindle guide (30), and a motor receiving portion (20) mounted on the upper side of the spindle guide (30).

[0045] At this time, the spindle guide (30) and spindle (500) are moved in the Z-axis direction by the first motor (100), and the spindle (500) is moved in the Z-axis direction separately from the spindle guide (30) by the second motor (200).

[0046] The mounting head according to the present embodiment may include a main body (1) and a head part (2). The main body (1) forms the main body of the mounting head, and serves as a position reference point of the mounting head, while simultaneously allowing the head part (2) to be moved to determine the position of the head part (2). The head part (2) moves around the main body (1) and can bond a semiconductor die or chip to a substrate.

[0047] The main body (1) may include a base (101). A first motor (100) may be mounted on the base (101). The first motor (100) is connected to a first rotational axis (110), and when the first motor (100) is driven, the first rotational axis (110) may rotate around an axis parallel to the Z1 axis of FIG. 4.

[0048] The first rotation shaft (110) can be connected to the second rotation shaft (120) on the lower side through a coupling (130). A ball screw part (121) is formed on the inner side of the second rotation shaft (120), and the ball screw part (121) can be coupled to the coupling (130). When the first motor (100) is driven, the rotational motion of the first rotation shaft (110) is transmitted to the rotational motion of the second rotation shaft (120), and at this time, the rotational motion of the first rotation shaft (110) can be converted into the linear motion of the second rotation shaft in the Z-axis direction by the ball screw part (121) of the second rotation shaft (120). The first rotation shaft (110) and the second rotation shaft (120) can be formed in a long cylindrical rod shape. The outer circumference of the ball screw portion (121) may be formed in a spiral screw shape, and the inner hollow portion of the second rotational shaft (120) may be formed in a spiral recessed shape corresponding to the shape of the outer circumference of the ball screw portion (121). When the ball screw portion (121) rotates, the second rotational shaft (120) may move up and down in the Z-axis direction along the spiral screw shape of the ball screw portion (121).

[0049] The first rotation axis (110) and the second rotation axis (120) can be formed with the Z-axis direction as the longitudinal direction. A rotation axis coupling portion (140) connected to the second rotation axis can be formed at the lower portion of the second rotation axis (120). A connection portion (150) can be formed between the rotation axis coupling portion (140) and the first base (160). The rotation axis coupling portion (140) is coupled to the second rotation axis (120) and can move up and down in the Z-axis direction together with the second rotation axis (120). The connection portion (150) can mutually couple the rotation axis coupling portion (140), the second rotation axis (120), and the first base (160).

[0050] The rotational axis coupling portion (140) may be formed to surround the second rotational axis (120). The first base (160) may be formed in a plate shape with a thickness and a direction perpendicular to the Z-axis direction as the plane direction. The connecting portion (150) may be coupled to the plane direction of the first base (160).

[0051] The first base (160) can be combined with the second base (170). The second base (170) is arranged parallel to the first base (160), and, like the first base (160), has a surface direction perpendicular to the Z-axis direction, and can be formed in a plate shape with a thickness.

[0052] The second base (170) may include a spindle upper connection portion (171) and a spindle lower connection portion (172). The spindle upper connection portion (171) and the spindle lower connection portion (172) may be respectively coupled to the spindle guide upper portion (31) and the spindle guide lower portion (32) of the spindle guide (30). The spindle upper connection portion (171) and the spindle lower connection portion (172) are formed to protrude in the direction in which the spindle guide (30) is located, and the spindle upper connection portion (171) and the spindle lower connection portion (172) may be respectively fitted into the recessed portions of the spindle guide upper portion (31) and the spindle guide lower portion (32).

[0053] The upper part of the spindle guide (31) may be formed to protrude outwardly from the spindle guide from the upper periphery of the spindle guide (30). The lower part of the spindle guide (32) may be formed to protrude outwardly from the spindle guide from the lower periphery of the spindle guide (30).

[0054] The head portion (2) may include a spindle guide (30) in which a spindle (500) is accommodated, and a motor receiving portion (20) arranged on the upper side of the spindle guide. Inside the motor receiving portion (20), a second motor (200), a rotational motor (400) connected to the second motor (200), and a load cell (300) arranged between the second motor (200) and the rotational motor (400) may be arranged. The second motor (200), the rotational motor (400), and the load cell (300) may move up and down in the Z-axis direction together with the motor receiving portion (20).

[0055] The spindle guide (30) can accommodate a spindle (500). The spindle (500) is connected to a rotation motor (400) and can move up and down in the Z-axis direction together with the rotation motor (400). The spindle guide (30) can move up and down in the Z-axis direction together with a motor receiving portion (20) coupled to the spindle guide from the upper side.

[0056] A spindle connection part (40) coupled with the spindle (500) may be arranged on the lower side of the spindle connection part (40). An air gyro (50) coupled with the spindle connection part (40) is coupled on the lower side of the spindle connection part (40). The air gyro (50) may balance the head part (2) so that the head part (2) can maintain balance in the horizontal direction as a whole. A heater (700) may be arranged on the lower side of the air gyro (50). A collet (800) coupled with the heater (700) may be placed on the lower side of the heater (700). According to the present embodiment, the first motor (100) moves the entire head portion (2) connected to the spindle guide (30) in the Z-axis direction, and the second motor (200) moves the spindle (500) and the spindle connection portion (40) connected to the lower end of the spindle (500), the heater (700), and the collet (800) in the Z-axis direction.

[0057] That is, the first motor (100) moves all components of the head portion (2) to bring the component (C) adsorbed on the collet (800) closer to the surface of the substrate, thereby primarily determining the bonding position of the component. Thereafter, the height position difference that occurs as the solder for bonding the component melts can be precisely compensated for through the second motor (200).

[0058] For example, when melting and then solidifying the solder in a collet to bond a component to a substrate, the collet and spindle may thermally expand due to the temperature rise in the collet. This can lead to errors in the mounting position when precisely mounting the component to the desired location on the substrate. Furthermore, as the solder melts, it moves downward, requiring the collet to be slightly raised to compensate for the downward movement of the solder as it melts.

[0059] In this way, in addition to the rotation motor (400) for compensating for the misalignment of the Theta (θ) axis and the first motor (100) for controlling the bonding position in the Z-axis direction, compensation for a minute position error that may occur during bonding work at the position of the collet (800) primarily controlled by the first motor (100) as in this embodiment can be secondarily resolved through the operation of the second motor (200), so that the bonding position of the component (C) can be controlled more precisely.

[0060] In addition, according to this embodiment, a general bearing structure is deleted, and instead, a structure is adopted in which a rotation motor (400) and a spindle (500) for Theta axis compensation are directly coupled and rotate together, so that Theta value compensation through rotational position control can be performed more precisely.

[0061] According to the present embodiment, a control unit (con) may be further included. The control unit (con) may control the operation of the first motor (100), the second motor (200), and the rotary motor (400). At this time, the control unit (con) may separately control the first motor (100), the second motor (200), and the rotary motor (400).

[0062] For example, when mounting a component on a substrate, the control unit (con) transmits a control signal to the first motor (100), and according to the control signal, the first motor (100) can be driven so that the collet of the head unit (2) approaches downward (+Z direction) close to the substrate while holding the component, or so that it touches the substrate. In addition, when the solder moves downward during the soldering process for bonding the component to the substrate, the control unit (con) transmits a control signal to the second motor (200), and according to the control signal, the second motor (200) can minutely move the position of the collet (800) connected to the second motor (200) so that the collet (800) of the head unit (2) moves upward (-Z direction) by the amount that it is lowered by the solder. In addition, when the Theta angle error of a component bonded to a substrate needs to be corrected, the control unit (con) transmits a control signal to the rotation motor (400), and the rotation motor (400) can adjust the rotation angle of the component bonded to the substrate according to the control signal. The rotation motor (400) is connected to the second motor (200), and when the second motor (200) is driven and the coil unit (220) is lowered downward, it is lowered downward together with the coil unit (220) to adjust the rotation angle of the component.

[0063] The control unit (con) can lower the collet (800) to the contact surface of the substrate or component (C) and the substrate (S) of the first motor (100). At this time, if the component (C) of the collet (800) and the solder formed on the component (C) touch the substrate or the contact surface of the substrate, the control unit (con) can stop the operation of the first motor (100).

[0064] Afterwards, if it is necessary to finely adjust the position of the collet (800) due to the descent of the solder, etc., the control unit (con) can adjust the position of the collet (800) using the second motor (200) while the operation of the first motor (100) is stopped. At this time, the control unit (con) is arranged to be in contact with the second motor (200), and receives force information applied to the load cell (300) through the load cell (300) arranged between the collet (800) and the second motor (200), and can control the operation of the second motor (200) based on the force information applied to the load cell (300). The load cell (300) may be arranged between the rotary motor (400) and the second motor (200).

[0065] At this time, the load cell (300) can measure the force pressing the load cell (300), the reaction force generated when the collet (800) contacts the substrate with solder, the magnitude of the force generated by the solder melting and deformation, etc. The value measured through the load cell (300) is transmitted to the control unit (con), and the control unit (con) can control the operation of the second motor (200) based on the magnitude of the force transmitted from the load cell (300). For example, when the magnitude of the force transmitted from the load cell (300), i.e., the reaction force, is relatively large, the position of the collet (800) can be raised relatively more. Conversely, when the magnitude of the force transmitted from the load cell (300), i.e., the reaction force, is relatively small, the position of the collet (800) can be raised relatively less.

[0066] According to the present embodiment, a first rotation shaft (110) and a second rotation shaft (120) connected to a first motor and a coupling (130) connecting the first rotation shaft (110) and the second rotation shaft (120) may be further included. At this time, a ball screw part (121) is formed on the second rotation shaft (120), and the ball screw part (121) may be coupled with the coupling (130) together with the first rotation shaft (110). Here, the coupling (130) may convert the rotational motion of the first rotation shaft (110) into the rotational motion of the ball screw part (121). The rotational motion of the ball screw part (121) may be converted into the linear motion of the second rotation shaft (120) by the screw structure. Through this, as the second rotation shaft (120) moves in the Z-axis direction, the entire head part (2) may move up and down in the Z-axis direction together with the second rotation shaft (120).

[0067] According to the present embodiment, it further includes a connecting portion (150) connected to a second rotation shaft (120), a first base (160) connected to the connecting portion (150), and a second base (170) connected to the first base (160), and a spindle upper connecting portion (171) and a spindle lower connecting portion (172) are formed on the second base (170), and the spindle upper connecting portion (171) and the spindle lower connecting portion (172) can be connected to the upper portion (31) and the lower portion (32) of the spindle guide (30).

[0068] According to the present embodiment, the second motor (200) of the head unit (2) may be formed as a VCM (Voice Coil Motor) motor. Accordingly, the second motor (200) may include a permanent magnet unit (210) and a coil unit (220). When the second motor (200) is driven in response to the generation of a driving signal, the permanent magnet unit (210) maintains a state of being coupled to the inner upper portion of the motor receiving unit (20), and the coil unit (220) moves downward with respect to the permanent magnet unit (210), and the Z-axis direction width of the second motor (200) may increase. As the Z-axis width of the second motor (200) increases, the rotation motor (400), spindle (500), spindle connection (40), heater (700), and collet (800) connected to the lower end of the second motor (200) move by the increased width of the second motor (200), so that the bonding position of the component (C) adsorbed on the lower end of the collet (800) can be finely adjusted.

[0069] The rotary motor (400) can rotate the spindle (500) around the theta axis. The rotary motor (400) is placed inside the motor receiving portion (20), and can be placed between the second motor (200) and the spindle (500) inside the motor receiving portion (20).

[0070] A spindle (500) may be placed below the rotary motor (400). The spindle (500) is coupled to the rotary motor (400) and can rotate integrally when the rotary motor (400) rotates. In addition, the spindle (500) can be moved up and down in the Z-axis direction to correspond to the degree of width change of the second motor as the Z-axis width of the second motor changes when the second motor (200) is driven. The spindle (500) is placed on the inner hollow portion of the spindle guide (30) and can move and rotate independently from the spindle guide (30). The inner hollow portion of the spindle guide (30) is formed as a cylindrical space and is designed so that friction does not occur with the spindle guide when the spindle (500) rotates and moves up and down. The spindle (500) can be rotated around the Z1 axis.

[0071] A spindle connection part (40) may be arranged at the lower end of the spindle (500). At this time, the spindle connection part (40) may move in the Z-axis direction and the rotational direction together with the spindle (500). Here, an encoder (600) may be arranged in the lateral circumferential direction of the spindle connection part (40). The encoder (600) is arranged at a position adjacent to a heater (700) that increases the temperature of the collet (800), so as to measure thermal expansion displacement values ​​for peripheral components such as the spindle (500), the spindle connection part (40), and the collet (800). According to the present embodiment, the encoder (600) may include a Theta-axis displacement measuring part and a Z-axis displacement measuring part. Accordingly, the encoder (600) can measure both the Theta-axis displacement and the Z-axis displacement according to thermal expansion.

[0072] The displacement measured through the encoder (600) can be transmitted to the control unit (con). The control unit (con) can further reflect the displacement value measured through the encoder (600) when driving the second motor, thereby controlling the Z-axis and Theta-axis positions of the collet (800) more precisely.

[0073] A heater (700) may be placed at the lower end of the spindle connection portion (40). The heater (700) may be moved in the Z-axis direction and the rotational direction together with the spindle (500). The heater (700) may be heated to a temperature higher than the melting temperature of the solder formed on the component (C) to melt the solder. In addition, when the solder is to be solidified again for bonding, the control portion (con) turns off the heater (700) so that the solder can solidify through external air.

[0074] A collet (800) can be placed at the lower end of the heater (700). The collet (800) can also be moved in the Z-axis direction and rotational direction together with the spindle (500).

[0075] The collet (800) can vacuum-absorb a component (C), for example, a die or a chip. The control unit (con) transmits an absorption signal to the collet (800), and the collet (800) can absorb and transport the component (C) according to the absorption signal. At this time, solder can be formed at the part where the component (C) meets the substrate (S) and the adhesive surface of the substrate. When the molten solder meets the substrate or the adhesive surface of the substrate, and the solder solidifies in the contact state, the component (C) can be mounted on the substrate (S).

[0076] Fig. 6 is a cross-sectional view taken along line CC' of Fig. 2, showing the basic state of the mounting head according to one embodiment of the present invention. Fig. 7 is a drawing showing the collet moved downward by the driving of the first motor in Fig. 6. Fig. 8 is a drawing showing the collet moved upward again by the driving of the second motor in Fig. 7.

[0077] Fig. 6 is a drawing showing the basic state of the mounting head. At this time, as shown in Fig. 7, when the first motor is driven through the control unit (con), the first motor (100) can move the entire head unit (2) to the lower side where the substrate (S) is located. At this time, the solder (sol) formed on the lower side of the component (C) can come into contact with the substrate (S) or the adhesive surface of the substrate.

[0078] Referring to Fig. 8, it can be confirmed that as the solder (sol) is melted by the heating of the heater (700) and the melted solder (sol) moves downward, the collet (800) moves relatively upward. It can be confirmed that the collet (800) moves upward by the amount of width reduced as the permanent magnet portion (210) and coil portion (220) of the second motor (200) move.

[0079] FIG. 9 is a flowchart illustrating a method for controlling a mounting head according to an embodiment of the present invention. FIG. 10 is a conceptual diagram illustrating a head portion descending to a substrate while a first motor is driven and a collet picks up a component according to an embodiment of the present invention. FIG. 11 is a conceptual diagram illustrating a collet portion descending until the solder of the component touches the substrate after the first motor is stopped, according to an embodiment of the present invention. FIG. 12 is a conceptual diagram illustrating a solder melting and flowing downwards when an encoder recognizes that solder has touched the substrate according to an embodiment of the present invention. FIG. 13 is a conceptual diagram illustrating a control unit converting a position control of a component into force control based on a contact recognition signal of an encoder, driving a second motor to precisely adjust a bonding position of a component, and driving a second motor to move the collet upwards again to compensate for the position of the solder that has flowed downwards according to an embodiment of the present invention. FIG. 14 is a conceptual diagram illustrating, according to one embodiment of the present invention, when bonding of a component to a substrate is completed, the first motor is restarted, the head is separated from the component bonded to the substrate, and moves upward again.

[0080] Referring to FIGS. 9 to 14, a control method of a mounting head according to an embodiment of the present invention includes a step (S100) in which a first motor (100) is driven, a collet (800) picks up a component (C) and the head (2) is lowered to a substrate (S), a step (S200) in which an encoder (600) recognizes that solder (Sol) is in contact with the substrate (S), and a step (S300) in which a control unit (con) converts position control of the component (C) into force control based on a contact recognition signal of the encoder (600), and controls the operation of the second motor (200) based on force information acting on a load cell (300) to precisely adjust the bonding position of the component (C).

[0081] When the head unit (2) picks up the dyna chip and raises the solder (Sol) above the melting temperature through the heater (700), thermal expansion may occur in the heater (700) connected to the lower part of the spindle (500) and structures connected to the heater (700). In this case, by compensating for the thermal expansion displacement value through the Theta-axis encoder and the Z-axis encoder connected to the heater (700-) at the closest position to the heater (700) that raises the temperature, the bonding position precision can be improved during bonding of the dyna chip.

[0082] At this time, the encoder (600) simultaneously measures the Theta axis and the Z axis to compensate for the displacement value for minute thermal expansion and enable precise position control for the bonding position.

[0083] Referring to FIGS. 10 to 14, a component (C) may be positioned in a picked-up state at the lower end of the collet (800). At this time, a filler (P) may be formed at the lower end of the component (C), and solder (Sol) may be formed under the filler (P). The solder (Sol) may be in contact with the substrate (S) or the bonding surface of the substrate (S), i.e., the bond pad (BP). The substrate (S) may be moved and installed on the bonding stage (BS).

[0084] According to the present embodiment, the step (S300) in which the control unit (con) converts the position control of the component (C) into force control based on the contact recognition signal of the encoder (600) and precisely adjusts the bonding position of the component (C) may further include a step in which, when the solder (Sol) melts and descends, the second motor (200) moves the component (C) upward.

[0085] As the temperature of the heater (700) rises and the solder (Sol) reaches its melting point and melts, the collet (800) can move slightly downward due to the vertical force of the spindle (500). That is, when the head part (2) is first lowered to the substrate (S) or bond pad (BP) using the first motor (100), and the solder (Sol) of the component (C) located at the lowest end of the head part (2) comes into contact with the substrate (S) or bond pad (BP), the first motor (100) stops, and the position of the component (C) is controlled using the second motor (200). At this time, the second motor (200) controls the bonding position of the component (C) according to the amount of force applied to the head part (2).

[0086] Here, when the solder (Sol) of the component (C) is pressing the substrate (S) or bonding pad (BP) with a slight force, and the solder reaches its melting point due to the temperature increase of the heater (700), the solder (Sol) may move downward in the direction in which the solder (Sol) presses the substrate (S) as it melts (see FIG. 12). At this time, the control unit (con) measures the reaction force applied to the head unit (2) as the solder (Sol) moves downward using the load cell (300), and since the reaction force also increases as the solder (Sol) moves downward more, the second motor (200) may slightly move the bonding position of the collet (800) and the component (C) upward as the reaction force increases (see FIG. 13).

[0087] However, the second motor (200) can measure in real time through the load cell (300) not only the force that presses the second motor (200) from the top of the head (2) when the solder (Sol) moves downward, but also the force generated when the solder (Sol) touches the substrate (S) or the contact surface of the substrate (S), and the amount of force that changes as the solder (Sol) melts, so that the up-and-down movement position of the collet (800) can be variably adjusted according to the real-time situation.

[0088] According to the present embodiment, before the step of lowering the head part (2) to the substrate (S) while the first motor (100) is driven and the collet (800) picks up the part (C), the step of raising the temperature of the heater (700) to a temperature higher than the melting point of the solder (Sol) formed on the part (C) may further be included.

[0089] The collet (800) can pick up the component (C) by suction. The heater (700) is heated above the melting point of the solder (Sol), and is ready to melt the solder (Sol) formed on the lower side of the component (C).

[0090] According to the present embodiment, before the step of lowering the head portion (2) to the substrate (S) while the first motor (100) is driven and the collet (800) picks up the component (C), a step of preheating the substrate (S) after moving it to the bonding stage (BS) may be further included. By preheating the substrate (S), when the molten solder (Sol) comes into contact with the substrate (S), the contact area of ​​the substrate (S) is not solidified first, but the solder (Sol) is solidified evenly throughout the entire substrate.

[0091] According to the present embodiment, the control unit (con) converts the position control of the component (C) into force control based on the contact recognition signal of the encoder (600), stops the operation of the first motor (100) while driving the second motor (200) to precisely adjust the bonding position of the component (C), and may further include a step of performing a bonding process for the substrate of the component (C). At this time, the preheating of the substrate (S) is stopped, the heater (700) is turned off, and the solder (Sol) goes through a process of cooling down and solidifying again.

[0092] After the bonding process of the component (C) to the substrate is performed, when the bonding of the component (C) to the substrate (S) is completed, the first motor (100) is restarted, and the head unit (2) is separated from the component (C) bonded to the substrate (S) and moved upward again, which may further include a step (see Fig. 14). Accordingly, when the bonding work of one component (C) is completed, the head unit (2) can be separated from the bonded component and moved upward again in order to pick up another component.

[0093] While the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely examples. Those skilled in the art will readily appreciate that various modifications and equivalent alternative embodiments are possible based on the embodiments described herein. Therefore, the true scope of technical protection of the present invention should be determined based on the appended claims.

[0094] Specific technical details described in the embodiments are merely examples and do not limit the technical scope of the embodiments. In order to describe the invention concisely and clearly, descriptions of conventional general techniques and configurations may be omitted. In addition, the connection or absence of connection between the lines of components illustrated in the drawings are merely examples of functional connections and / or physical or circuit connections, and in an actual device, they may be expressed as various functional connections, physical connections, or circuit connections that are replaceable or additional. In addition, if there is no specific mention such as "essential" or "important," it may not be a component absolutely necessary for the application of the present invention.

[0095] The terms "above" and "above" or similar designators used in the description and claims of the invention can refer to both singular and plural numbers, unless specifically limited. In addition, when a range is described in an embodiment, it is intended that the invention includes the application of individual values ​​falling within the range (unless otherwise stated), and it is equivalent to describing each individual value constituting the range in the description of the invention. In addition, unless the order of steps constituting a method according to an embodiment is explicitly stated or stated to the contrary, the steps can be performed in any appropriate order. The embodiments are not necessarily limited by the order in which the steps are described. The use of all examples or exemplary terms (e.g., "for example," etc.) in the embodiments is merely for the purpose of describing the embodiments in more detail, and the scope of the embodiments is not limited by the examples or exemplary terms, unless otherwise limited by the claims. In addition, those skilled in the art will recognize that various modifications, combinations, and variations can be configured according to design conditions and factors within the scope of the appended claims or their equivalents.

Claims

1. The first motor is driven, and the head is lowered to the substrate while the collet picks up the part; a step of the encoder recognizing that the solder is in contact with the substrate; and A control method for a mounting head, comprising a step of converting position control of the component into force control based on a contact recognition signal of the encoder, and controlling the operation of a second motor based on force information applied to a load cell to precisely adjust the bonding position of the component.

2. In paragraph 1, The step of the control unit converting the position control of the component into force control based on the contact recognition signal of the encoder and precisely adjusting the bonding position of the component is as follows: A method for controlling a mounting head, further comprising the step of: when the solder is melted and descends, the second motor moves the component upward.

3. In paragraph 1, Before the first motor is driven and the head is lowered to the substrate with the collet picking up the part, A control method for a mounting head, further comprising a step of allowing a collet of the head portion to pick up the component, and increasing the temperature of the heater above the melting point of the solder formed on the component.

4. In paragraph 1, Before the first motor is driven and the head is lowered to the substrate with the collet picking up the part, A method for controlling a mounting head, further comprising a step of preheating the substrate after moving it to a bonding stage.

5. In paragraph 1, After the control unit converts the position control of the component into force control based on the contact recognition signal of the encoder and drives the second motor to precisely adjust the bonding position of the component, A control method for a mounting head, further comprising a step of performing a bonding process of the above-mentioned component to the above-mentioned substrate.

6. In paragraph 5, After the bonding process of the above components to the above substrate is performed, A control method of a mounting head, further comprising the step of: when the bonding of the component to the substrate is completed, the first motor is restarted, the head portion is separated from the component bonded to the substrate, and moves upward again.

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