Elastic pressure applying unit and die bonding swing arm

Abstract

The utility model relates to the technical field of fixed crystal, specifically disclose a kind of elastic pressure unit and fixed crystal swing arm, comprising: base assembly;Suction nozzle mounting arm, with base assembly upper and lower sliding connection;Elastic member, for drive the suction nozzle mounting arm relative to the downward motion of base assembly;Force control unit, installed on the base assembly and drive end is connected in the suction nozzle mounting arm, for the suction nozzle mounting arm upward pressure.This elastic pressure unit and fixed crystal swing arm provided by the utility model can solve the problem that the minimum fixed crystal pressure of existing fixed crystal swing arm is limited by the weight of suction nozzle mounting arm and pick-up crystal suction nozzle, and the suction nozzle mounting arm and pick-up crystal suction nozzle are easy to shake when the fixed crystal pressure is small.

Description

Technical Field

[0001] This utility model relates to the field of die bonding technology, and in particular to an elastic pressure unit and a die bonding swing arm. Background Technology

[0002] In semiconductor chip packaging and die bonding processes, the die bonding arm is the core mechanism for achieving chip pickup, transfer, and precise bonding. It typically includes a base assembly, a nozzle mounting arm slidably connected to the base assembly, a die-picking nozzle mounted at the end of the nozzle mounting arm, and a force control unit (usually a voice coil motor) connected to the nozzle mounting arm. The existing force control principle is that the final die bonding pressure FG is the sum of the weight G of the lifting assembly consisting of the nozzle mounting arm and the die-picking nozzle, and the active downward pressure FL applied by the force control unit, i.e., FG = G + FL.

[0003] However, it is precisely this inherent force-controlled superposition model that leads to two interconnected and fundamental technical bottlenecks:

[0004] (1) There is an insurmountable theoretical limit to the lower limit of die bonding pressure: In this model, when the process requires the application of extremely small die bonding pressure, the output FL of the force control unit can approach zero, but the die bonding pressure FG can never be lower than the weight G of the lifting component (i.e., the minimum die bonding pressure Fmin = G). This strictly limits the application of this technology in precision die bonding scenarios that require small pressure (FG < G), such as ultra-thin chips, flexible substrates or fragile materials.

[0005] (2) Inherent instability of motion stability under micro-pressure conditions: In order to obtain a small die-bonding pressure, the force control unit must be in a state of extremely small driving force output. This weak downward pressure FL is difficult to form an effective and stable drive and damping for the lifting component, which directly leads to low-frequency jitter or crawling phenomena during the movement, seriously damaging the dynamic stability of the die-bonding process, causing die-bonding position deviation and product yield reduction.

[0006] Therefore, the existing die-bonding arm needs to be improved to solve the problems that its minimum die-bonding pressure is limited by the weight of the nozzle mounting arm and the die-pickup nozzle, and that the nozzle mounting arm and the die-pickup nozzle are prone to shaking when the die-bonding pressure is low.

[0007] The information disclosed in this background section is included only to enhance the understanding of the context of this disclosure, and therefore may contain information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0008] One objective of this invention is to provide an elastic pressure unit and a die-bonding swing arm that can solve the problems of the minimum die-bonding pressure of existing die-bonding swing arms being limited by the weight of the nozzle mounting arm and the die-picking nozzle, and the nozzle mounting arm and the die-picking nozzle being prone to vibration when the die-bonding pressure is low.

[0009] To achieve the above objectives, on the one hand, this utility model provides an elastic pressure application unit, comprising:

[0010] Base assembly;

[0011] The nozzle mounting arm slides vertically and vertically connected to the base assembly;

[0012] An elastic element is used to drive the nozzle mounting arm to move downward relative to the base assembly;

[0013] A force control unit, mounted on the base assembly and with its drive end connected to the nozzle mounting arm, is used to apply upward pressure to the nozzle mounting arm.

[0014] Optionally, the suction nozzle mounting arm is provided with a protruding portion;

[0015] The base assembly includes:

[0016] The base body is slidably connected to the nozzle mounting arm.

[0017] A lifting plate, wherein the lifting plate is disposed opposite to the protruding portion;

[0018] An adjusting screw is located on the side of the lifting plate away from the protrusion, with one end of the adjusting screw rotatably connected to the lifting plate and the other end threaded through the base assembly;

[0019] One end of the elastic element is connected to the protruding part, and the other end is connected to the lifting plate.

[0020] Optionally, the elastic element is a compression spring.

[0021] The lifting plate is located above the protruding part, and the top of the compression spring abuts against the bottom surface of the lifting plate and the bottom of the compression spring abuts against the top surface of the protruding part.

[0022] Optionally, the elastic element is a tension spring.

[0023] The lifting plate is located below the protrusion, the top of the tension spring is connected to the bottom surface of the protrusion, and the bottom of the tension spring is connected to the top surface of the lifting plate.

[0024] Optionally, the force control unit is a voice coil motor or a piezoelectric ceramic motor.

[0025] Optionally, a detection mechanism may also be included for obtaining the displacement travel of the nozzle mounting arm relative to the base assembly.

[0026] Optionally, the detection mechanism is a capacitive grating sensor or a grating ruler.

[0027] On the other hand, a die-bonding swing arm is provided, including the aforementioned elastic pressure unit and a die-picking nozzle mounted on the nozzle mounting arm of the elastic pressure unit.

[0028] The beneficial effect of this utility model is that it provides an elastic pressure application unit and a die-bonding swing arm:

[0029] (1) Breaking the theoretical limit of the lower limit of die bonding pressure: By applying pressure upward through the force control unit, the weight of the nozzle mounting arm and the die pick-up nozzle can be completely or partially offset, so that the minimum die bonding pressure is no longer limited by the weight G, and can achieve a small pressure of FG < G or even FG = 0, which meets the needs of precision die bonding scenarios such as ultra-thin chips and flexible substrates.

[0030] (2) Improve motion stability under micro-pressure conditions: Under most operating conditions (especially when micro-pressure is required), the force control unit can operate in a large, stable, and linear output range (FL is slightly smaller than G + FT), rather than a near-zero, unstable "zero-drift" range. The final micro-pressure (FG) is achieved by subtracting a large, stable upward force (FL) from a large, stable downward force (G + FT). This "large force difference" control method is much more stable and precise than "directly generating a micro-force", thus effectively suppressing low-frequency vibration or creeping of the nozzle mounting arm and improving dynamic stability and die bonding accuracy.

[0031] Therefore, the elastic pressure unit and die-bonding swing arm provided by this utility model can solve the problems that the minimum die-bonding pressure of the existing die-bonding swing arm is limited by the weight of the nozzle mounting arm and the die-picking nozzle, and that the nozzle mounting arm and the die-picking nozzle are prone to shaking when the die-bonding pressure is low. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the die-bonding swing arm provided in the embodiment.

[0034] In the picture:

[0035] 1. Elastic pressure application unit;

[0036] 101. Base assembly; 1011. Base body; 1012. Lifting plate; 1013. Adjusting screw;

[0037] 102. Suction nozzle mounting arm; 1021. Protrusion;

[0038] 103. Elastic components;

[0039] 104. Force control unit;

[0040] 105. Testing institutions;

[0041] 2. Crystal pickup nozzle. Detailed Implementation

[0042] In this utility model, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this utility model. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this utility model, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0043] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit the invention.

[0044] In the description of this utility model, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " generally indicates that the preceding and following objects have an "or" logical relationship.

[0045] In this invention, terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy, or order between these entities or operations.

[0046] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this invention is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a series of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0047] Similar to the understanding in the Examination Guidelines, in this utility model, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments of this utility model, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0048] In the description of the embodiments of this utility model, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the convenience of describing the specific embodiments of this utility model or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0049] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this utility model, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this utility model pertains, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.

[0050] The direct drive mechanism in this invention can be a linear motor, a cylinder, a hydraulic cylinder, or a motor lead screw and slider assembly, etc.; the rotary drive mechanism can be a servo motor, a stepper motor, or a rotary cylinder, etc.

[0051] This invention provides an elastic pressure application unit and a die-bonding swing arm, which can solve the problems of existing die-bonding swing arms having minimum die-bonding pressure limited by the weight of the nozzle mounting arm and the die-pickup nozzle, and the nozzle mounting arm and the die-pickup nozzle being prone to vibration when the die-bonding pressure is low.

[0052] See Figure 1 The die-bonding swing arm provided in this embodiment includes an elastic pressure unit 1 and a die-picking nozzle 2 mounted on the elastic pressure unit 1.

[0053] Specifically, the elastic pressure application unit 1 includes:

[0054] Base assembly 101;

[0055] The nozzle mounting arm 102 is slidably connected to the base assembly 101 in a vertical manner.

[0056] The elastic element 103 is used to drive the nozzle mounting arm 102 to move downward relative to the base assembly 101;

[0057] Force control unit 104 is mounted on the base assembly 101 and its drive end is connected to the nozzle mounting arm 102, and is used to apply upward pressure to the nozzle mounting arm 102.

[0058] In the die bonding process, the die bonding arm is moved as a whole by a drive mechanism (such as a die bonding robot) until the pick-up nozzle 2 is directly above the chip and picks up the chip lifted by the ejector pin mechanism. Then, the die bonding arm is moved as a whole to the die bonding position by the drive mechanism (such as a die bonding robot) and places the chip downward into the substrate. At this time, the force control unit 104 applies upward pressure according to the process requirements, thereby adjusting the net downward pressure (i.e., the die bonding pressure FG applied downward by the pick-up nozzle 2 to the chip) to achieve precise die bonding of the chip.

[0059] The core of the elastic pressure application unit 1 lies in achieving precise pressure application to the nozzle mounting arm 102 through the coordinated action of the elastic element 103 and the force control unit 104. Specifically:

[0060] In the initial state, the elastic element 103 continuously drives the nozzle mounting arm 102 to move downward relative to the base assembly 101, so that the crystal picking nozzle 2 mounted on the nozzle mounting arm 102 has a downward tendency.

[0061] When the die bonding process starts, the force control unit 104 is activated, and its driving end applies an upward force (i.e., exerts upward pressure) to the nozzle mounting arm 102. By controlling the magnitude of the output force of the force control unit 104, part or all of the self-weight of the nozzle mounting arm 102 and the pick-up nozzle 2 (i.e., the gravity G of the lifting assembly) can be counteracted. The net downward die bonding pressure (FG) is jointly determined by the downward force (FT) of the elastic member 103, the upward force (FL) of the force control unit 104, and the gravity G of the lifting assembly, and the relational expression is: FG = G + FT - FL. By adjusting FL, FG can be continuously adjusted between zero and the maximum value Fmax (Fmax=G + FT, FL=0), and even negative pressure (upward force) can be achieved. However, in the normal die bonding process, FL ≤ G + FT is controlled to ensure that downward pressure is applied to the chip to realize die bonding. Under the micro-pressure working condition, the force control unit 104 can operate in a large output range (rather than a very small output) to avoid an unstable state.

[0062] Through the above modifications, the following technical effects are achieved:

[0063] (1) Breaking the theoretical limit of the lower limit of die bonding pressure: By applying upward pressure through the force control unit 104, the self-weight of the nozzle mounting arm 102 and the pick-up nozzle 2 can be completely or partially counteracted, so that the minimum die bonding pressure is no longer limited by the self-weight G, and a tiny pressure of FG < G or even FG = 0 can be realized, which meets the requirements of precision die bonding scenarios such as ultra-thin chips and flexible substrates.

[0064] (2) Improving the motion stability under micro-pressure working conditions:

[0065] The force control unit 104 can operate in a large, stable, and good-linearity output interval (FL is slightly less than G + FT) under most working conditions (especially when a tiny pressure is required), rather than an unstable "zero drift" interval close to zero. The final tiny pressure (FG) is realized by subtracting a large and stable upward force (FL) from a large and stable downward force (G + FT). This control method of "large force difference" is far more stable and accurate than "directly generating a tiny force", so it can effectively suppress low-frequency jitter or crawling of the nozzle mounting arm 102, and improve dynamic stability and die bonding accuracy.

[0066] Therefore, the elastic pressing unit 1 and the die bonding swing arm provided by the utility model can solve the problems that the minimum die bonding pressure of the existing die bonding swing arm is limited by the self-weight of the nozzle mounting arm 102 and the pick-up nozzle 2, and the nozzle mounting arm 102 and the pick-up nozzle 2 are prone to jitter when the die bonding pressure is small.

[0067] In this embodiment, the nozzle mounting arm 102 is provided with a protruding portion 1021;

[0068] The base assembly 101 includes:

[0069] The base body 1011 is slidably connected to the nozzle mounting arm 102 in a vertical manner.

[0070] A lifting plate 1012 is disposed opposite to the protrusion 1021;

[0071] An adjusting screw 1013 is located on the side of the lifting plate 1012 away from the protrusion 1021, and one end of the adjusting screw 1013 is rotatably connected to the lifting plate 1012, while the other end is threaded through the base assembly 101.

[0072] One end of the elastic member 103 is connected to the protrusion 1021, and the other end is connected to the lifting plate 1012.

[0073] When the adjusting screw 1013 is turned, its rotation pushes or pulls the lifting plate 1012 along the thread direction, thereby changing the distance between the lifting plate 1012 and the protrusion 1021. This change in distance directly alters the compression or tension of the elastic element 103, thus adjusting the initial elastic force (i.e., preload) of the elastic element 103. For example, tightening the adjusting screw 1013 brings the lifting plate 1012 closer to the protrusion 1021, increasing the compression of the elastic element 103 and increasing the initial elastic force; loosening it has the opposite effect. This adjustment allows for the adjustment of the downward driving force of the elastic element 103 on the nozzle mounting arm 102 without changing the output of the force control unit 104.

[0074] In this embodiment, the elastic element 103 is a compression spring, the lifting plate 1012 is located above the protrusion 1021, the top of the compression spring abuts against the bottom surface of the lifting plate 1012, and the bottom of the compression spring abuts against the top surface of the protrusion 1021.

[0075] When the adjusting screw 1013 is turned, the lifting plate 1012 moves up and down, changing the compression of the spring: when the lifting plate 1012 moves down, the compression increases and the elastic force increases; when the lifting plate 1012 moves up, the compression decreases and the elastic force decreases. This elastic force works in conjunction with the upward force of the force control unit 104 to control the net downward pressure.

[0076] In some other embodiments, the elastic element 103 is a tension spring, the lifting plate 1012 is located below the protrusion 1021, the top of the tension spring is connected to the bottom surface of the protrusion 1021, and the bottom of the tension spring is connected to the top surface of the lifting plate 1012.

[0077] In its natural state, the tension spring is pre-stretched, creating a tendency to contract and thus applying a downward pulling force to the nozzle mounting arm 102. Turning the adjusting screw 1013 drives the lifting plate 1012 to move, changing the tension of the spring: a downward movement of the lifting plate 1012 increases the tension and elastic force; an upward movement of the lifting plate 1012 decreases the tension and elastic force. This pulling force balances with the upward force of the force control unit 104, achieving pressure regulation.

[0078] In this embodiment, the force control unit 104 is a voice coil motor or a piezoelectric ceramic motor. A voice coil motor, based on electromagnetic principles, outputs a continuous upward force through current control; a piezoelectric ceramic motor utilizes the piezoelectric effect to generate precise micro-displacement and force through voltage control. During operation, the force control unit 104 receives signals from the control system and adjusts the output force at the drive end in real time to precisely counteract its own weight or provide the required upward pressure. For example, during die bonding, the voice coil motor can quickly respond to pressure changes, achieving dynamic force control.

[0079] In this embodiment, the elastic pressure unit 1 further includes a detection mechanism 105 for obtaining the displacement stroke of the nozzle mounting arm 102 relative to the base assembly 101.

[0080] Optionally, the detection mechanism 105 can be a capacitive sensor or a linear encoder:

[0081] Capacitive grating sensor: Its fixed scale is fixed to the base assembly 101, and the movable scale moves with the nozzle mounting arm 102, detecting displacement through capacitance changes;

[0082] Grating ruler: includes a grating ruler body (reading head) fixed to the base assembly 101 and a scale that moves with the nozzle mounting arm 102, and measures displacement through the principle of grating interference.

[0083] In some other embodiments, a camera that captures images of the nozzle mounting arm 102 and the base assembly 101 can be used as a detection mechanism 105 to detect the displacement of the nozzle mounting arm 102 relative to the base assembly 101 through visual recognition.

[0084] The detection mechanism 105 acquires the displacement stroke ΔX of the nozzle mounting arm 102 relative to the base assembly 101 in real time. This displacement is the deformation of the elastic element 103. The control system calculates the elastic force FT in real time using the formula FT = k×ΔX based on the known elastic coefficient k of the elastic element 103. Thus, the system can accurately know all the components of the solidification pressure: the self-weight G (downward), the elastic force FT (downward), and the FL (upward) provided by the force control unit 104, and can therefore successfully calculate FG = G + FT - FL.

[0085] The control system continuously calculates FT through displacement feedback and dynamically adjusts the output FL of the force control unit 104 accordingly, forming a high-precision closed-loop control that enables FG to accurately track the set value.

[0086] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. An elastic pressure application unit (1), characterized in that, include: Base assembly (101); The nozzle mounting arm (102) is slidably connected to the base assembly (101) in the upper and lower parts; An elastic element (103) is used to drive the nozzle mounting arm (102) to move downward relative to the base assembly (101); A force control unit (104) is mounted on the base assembly (101) and its drive end is connected to the nozzle mounting arm (102) for applying upward pressure to the nozzle mounting arm (102).

2. The elastic pressure unit (1) according to claim 1, characterized in that, The nozzle mounting arm (102) is provided with a protrusion (1021). The base assembly (101) includes: The base body (1011) is slidably connected to the nozzle mounting arm (102) in a vertical manner; A lifting plate (1012) is disposed opposite to the protruding part (1021); An adjusting screw (1013) is located on the side of the lifting plate (1012) away from the protrusion (1021), and one end of the adjusting screw (1013) is rotatably connected to the lifting plate (1012), and the other end is threaded through the base assembly (101). One end of the elastic element (103) is connected to the protrusion (1021), and the other end is connected to the lifting plate (1012).

3. The elastic pressure unit (1) according to claim 2, characterized in that, The elastic element (103) is a compression spring. The lifting plate (1012) is located above the protrusion (1021), the top of the compression spring abuts against the bottom surface of the lifting plate (1012), and the bottom of the compression spring abuts against the top surface of the protrusion (1021).

4. The elastic pressure unit (1) according to claim 2, characterized in that, The elastic element (103) is a tension spring. The lifting plate (1012) is located below the protrusion (1021), the top of the tension spring is connected to the bottom surface of the protrusion (1021), and the bottom of the tension spring is connected to the top surface of the lifting plate (1012).

5. The elastic pressure unit (1) according to claim 1, characterized in that, The force control unit (104) is a voice coil motor or a piezoelectric ceramic motor.

6. The elastic pressure unit (1) according to claim 1, characterized in that, It also includes a detection mechanism (105) for obtaining the displacement stroke of the nozzle mounting arm (102) relative to the base assembly (101).

7. The elastic pressure unit (1) according to claim 6, characterized in that, The detection mechanism (105) is a capacitive grating sensor or a grating ruler.

8. A die-bonding swing arm, characterized in that, Includes the elastic pressure unit (1) as described in any one of claims 1-7, and the crystal-collecting nozzle (2) mounted on the nozzle mounting arm (102) of the elastic pressure unit (1).

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