Inclination adjusting mechanism for chip thermocompression bonding and adjusting method thereof

Abstract

The invention discloses an inclination adjusting mechanism for chip thermocompression bonding, which comprises a base, a pressing table, a rotating table and an inclined table, a heating device is arranged on the pressing table, the base is pivoted with the rotating table through a first bearing, and the pressing table is pivoted with the inclined table through a second bearing; the pressing table is in linkage with the base through a coupler, and a first driving mechanism drives the base and the pressing table to rotate in the Y direction of a longitudinal axis. The inclined table is linked with the rotating table, and a second driving mechanism drives the inclined table and the pressing table to rotate in the X direction of the transverse shaft; through rotation of the pressing table in the longitudinal axis Y direction and the transverse axis X direction, inclination adjustment acting on the bonding surface of the chip on the pressing table is achieved. According to the invention, the inclination adjustment of the bonding surface is realized through the inclination adjustment mechanism, and the final bonding quality of the chip is ensured. The inclination adjusting mechanism can ensure the uniform stress of the bonding surface through real-time dynamic leveling, reduces the defects of pseudo soldering, bubbles and the like, and improves the bonding strength and reliability.

Description

Technical Field

[0001] This invention relates to the field of chip bonding apparatus technology, and specifically to an adjustment method for a tilt adjustment mechanism used in chip thermoforming. Background Technology

[0002] A chip bonding machine is a device that picks up semiconductor chips from a semiconductor chip supply source (such as a wafer tray) and places them onto a semiconductor chip carrier (such as a lead frame). This process is called chip bonding. See [link to documentation]. Figure 1 As shown, the chip bonding machine contains two important modules: 1. Bonding head 01, used to transfer and bond semiconductor chip 03 to another semiconductor chip or carrier 04; 2. Bonding stage 02, used to place another semiconductor chip or carrier 04 during the chip bonding process.

[0003] To ensure the quality and reliability of the chip bonding process, the bonding head and bonding stage must be precisely aligned. Therefore, before placing another semiconductor chip carrier on the bonding stage for chip bonding, the surfaces of the bonding head and bonding stage facing each other should be parallel.

[0004] See Chinese utility model patent CN222674877U, which discloses a chip manufacturing equipment. The hot-press die bonding mechanism includes a hot-press plate and a bonding stage mounted on a frame. The bonding stage receives chips transferred by the mass transfer mechanism. The hot-press plate presses all the chip dies onto the substrate and conducts heat to the chips, making the anisotropic conductive adhesive conductive in the thickness direction of the substrate, thereby achieving electrical connection between the substrate and multiple chip dies. This significantly reduces problems such as poor solder joints or solder drift during die bonding.

[0005] In current thermoforming chip bonding processes, the bonding head presses the bonding surface of the semiconductor chip against the semiconductor chip carrier with a specified force and a specific temperature profile. Since the bonding surface of the semiconductor chip contains many solder or gold bumps no larger than a few hundred micrometers, alignment deviations of the bonding head relative to the bonding stage (e.g., 10 micrometers) can lead to lateral forces and mounting errors, thus affecting the quality and reliability of the chip bonding process. Therefore, maintaining precise alignment of the bonding head relative to the bonding stage is crucial for ensuring the quality and reliability of the chip bonding process.

[0006] The current chip thermal bonding process has the following problems: 1. Bonding surface tilt is difficult to control precisely: Traditional methods for leveling the bonding surface rely on manual or static adjustment, that is, adjusting the parallelism between the bonding head and the bonding stage before chip bonding. During the bonding process, it is difficult to compensate for assembly errors or thermal deformation in real time as the bonding head moves the chip towards the bonding stage, resulting in uneven bonding pressure distribution.

[0007] 2. Defects caused by differences in thermal expansion: At high temperatures, the thermal expansion coefficients of the chip and the substrate do not match, which can easily cause warping or localized poor soldering, affecting the bonding strength.

[0008] 3. Insufficient process stability: Large-size chips or flexible substrates are prone to defects such as bubbles and cracks due to poor deformation adaptability, which reduces yield.

[0009] Based on the above, the inventors propose the following technical solutions.

[0010] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and to propose a tilt adjustment mechanism and adjustment method for chip thermo-bonding.

[0011] To solve the above-mentioned technical problems, the tilt adjustment mechanism for chip thermoforming bonding described in this invention adopts the following technical solution: A tilt adjustment mechanism for chip thermoforming bonding includes: a base, a pressing table, a rotating table, and a tilting table. A heating device is provided on the pressing table. The base is pivotally connected to the rotating table via a first bearing, and the pressing table is pivotally connected to the tilting table via a second bearing. The pressing table is connected to the base via a coupling, and a first driving mechanism drives the base and the pressing table to rotate along the longitudinal axis Y. The tilting table is connected to the rotating table, and a second driving mechanism drives the tilting table and the pressing table to rotate along the transverse axis X. The tilt adjustment of the bonding surface acting on the chip on the pressing table is achieved by rotating the pressing table in the longitudinal axis Y and transverse axis X.

[0012] Furthermore, in the above technical solution, both the first bearing and the second bearing are cross roller bearings.

[0013] Furthermore, in the above technical solution, the first drive mechanism and the second drive mechanism adopt frameless torque motors.

[0014] Furthermore, in the above technical solution, the coupling is a bellows coupling.

[0015] Furthermore, in the above technical solution, the heating device is located below or inside the pressing table.

[0016] Based on the above-mentioned tilt adjustment mechanism for chip thermal bonding, the adjustment method includes the following steps: First, initial positioning: determine the tilt angle θ of the bonding surface of the pressing stage relative to the reference surface, and then the first drive mechanism starts to rotate, driving the pressing stage to rotate along the longitudinal axis Y direction until the bonding surface of the pressing stage rotates to the position corresponding to the tilt angle θ; Second, tilt angle adjustment: the first drive mechanism stops rotating, and the second drive mechanism starts to rotate, driving the pressing stage to rotate along the transverse axis X direction until the bonding surface of the pressing stage rotates to be parallel to the reference surface; Third, rotation locking: after tilting is completed, the rotating stage fixes the pressing stage through the locking mechanism, and the bonding surface of the pressing stage is locked relative to the reference surface.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. During the chip bonding process, this invention uses a tilt adjustment mechanism to adjust the tilt of the bonding surface, ensuring the final bonding quality of the chip. This tilt adjustment mechanism can dynamically level in real time to ensure uniform force on the bonding surface, reduce defects such as cold solder joints and bubbles, and improve bonding strength and reliability.

[0018] 2. In this invention, the pressing stage and the base are connected by a bellows coupling. During the relative tilting adjustment of the pressing stage, the bellows coupling can adaptively compensate for displacement and improve the support provided by the pressing stage in the longitudinal Y direction, ensuring stable chip bonding.

[0019] 3. This invention features automatic compensation for thermal deformation and assembly errors, making it applicable to bonding chips and substrates of different sizes and materials, effectively reducing the risk of warpage and crack formation. Simultaneously, this invention optimizes production efficiency, reduces manual leveling steps, shortens process debugging time, and improves production stability and yield. This device effectively solves the tilt control problem in traditional thermoforming bonding, making it particularly suitable for high-precision packaging requirements. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of existing chip bonding equipment; Figure 2 This is a schematic diagram of the tilt adjustment mechanism in this invention; Figure 3 This is a schematic diagram of the adjustment method in this invention. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0022] See Figure 2 As shown, this is the tilt adjustment mechanism used in this invention, which includes: a base 1, a pressing table 2, a rotating table 4, and a tilting table 5. A heating device 3 is provided on the pressing table 2.

[0023] The base 1 and the pressing table 2 are arranged along the Y-axis, and are connected by a coupling 6. In this embodiment, the coupling 6 is a bellows coupling, which can not only adaptively compensate for displacement, but also improve the support provided by the pressing table in the longitudinal Y-axis direction.

[0024] The base 1 is linked to the first drive mechanism 11, which drives the base 1 to rotate. Simultaneously, the base 1 rotates, and the coupling 6 drives the pressing table 2 to rotate as well. That is, the first drive mechanism 11 can drive the base 1 and the pressing table 2 to rotate about the longitudinal axis Y.

[0025] The rotary table 4 is located around the base 1 and the pressing table 2. The base 1 and the pressing table 2 rotate relative to the rotary table 4 under the drive of the first drive mechanism 11. During assembly, the rotary table 4 serves as a receiving part connected to the chip bonding equipment. A tilting platform 5 is provided between the rotary table 4 and the pressing table 2.

[0026] The base 1 is pivotally connected to the rotary table 4 via a first bearing 7, and the pressing table 2 is pivotally connected to the tilting table 5 via a second bearing 8. Using the first bearing 7 and the second bearing 8, the base 1 and the pressing table 2 rotate relative to the rotary table 4 and the tilting table 5 under the drive of the first drive mechanism 11. In this embodiment, the first bearing 7 and the second bearing 8 are crossed roller bearings, which can simultaneously withstand loads in all directions, including radial, axial, and torque, and can effectively suppress deformation and displacement under load, maintaining extremely high motion accuracy and positioning precision.

[0027] The tilting platform 5 is linked to the rotating platform 4, and the second driving mechanism 41 drives the tilting platform 5 and the pressing platform 2 to rotate along the horizontal axis X.

[0028] In this embodiment, the first drive mechanism 11 and the second drive mechanism 41 adopt frameless torque motors to provide higher positioning accuracy and rigidity.

[0029] like Figure 2 As shown, when the present invention is in operation, the first driving mechanism 11 drives the base 1 and the pressing table 2 to rotate along the longitudinal axis Y, while the rotary table 4 and the tilting table 5 remain relatively stationary. When the second driving mechanism 41 is in operation, it drives the tilting table 5 and the pressing table 2 to rotate along the transverse axis X, while the rotary table 4 and the base 1 remain relatively stationary. By rotating the pressing table 2 in the longitudinal axis Y and transverse axis X, the tilt adjustment of the bonding surface of the chip acting on the pressing table 2 is achieved.

[0030] In this invention, the bonding surface refers to the surface used for bonding the chip. Since this invention uses thermo-press bonding, a heating device 3 is provided. Figure 2As shown, the heating device 3 can be directly installed below the pressing table 2, or it can be directly integrated inside the pressing table 2.

[0031] The following is combined with Figure 3 The adjustment method of the tilt adjustment mechanism of the present invention is described.

[0032] The first step is initial positioning: determining the tilt angle θ between the bonding surface A of the pressing table 2 and the reference surface B. The bonding surface A is the bottom surface of the pressing table 2 (or the bottom surface of the heating device 3). The reference surface B is set as a horizontal plane. The relative tilt angle θ between the bonding surface A and the reference surface B can be measured by a detection mechanism (using a multi-point laser rangefinder).

[0033] During adjustment, to simplify the algorithm, the bonding surface A needs to be rotated to the position corresponding to the tilt angle θ. At this time, the first drive mechanism 11 is activated, while the second drive mechanism 41 remains stationary. When the first drive mechanism 11 starts to rotate, it drives the pressing table 2 to rotate a certain angle along the longitudinal axis Y until the bonding surface of the pressing table 2 rotates to the position corresponding to the tilt angle θ. That is, at this time, the intersection line of the bonding surface A and the reference surface B is exactly parallel to the transverse axis X, which facilitates subsequent tilt adjustment.

[0034] The second step is to adjust the tilt angle: When the bonding surface of the pressing table 2 rotates to the position corresponding to the tilt angle θ, the first drive mechanism 11 stops rotating and the second drive mechanism 41 starts rotating. It drives the tilt table 5 to rotate along the horizontal axis X. While the tilt table 5 rotates along the horizontal axis X, it drives the pressing table 2 to rotate synchronously along the horizontal axis X until the bonding surface A of the pressing table 2 rotates to be parallel to the reference surface B.

[0035] During the tilt angle adjustment process, the flexible connection of the bellows coupling is utilized, and the tilting table 5 tilts smoothly without being limited by the bending stroke, providing stable adjustment over a large tilt angle range.

[0036] The third step is rotation locking. After tilting, the rotary table 4 fixes the pressing table 2 through the locking mechanism, and the bonding surface A of the pressing table 2 is locked relative to the reference surface B.

[0037] The locking mechanism can be a clamping device or a locking device, for example, a locking mechanism 42 can be set between the rotary table 4 and the tilting table 5. After tilting is completed, the locking mechanism 42 fixes the rotary table 4 and the tilting table 5, so that even if the second drive mechanism 41 is activated, the tilting table 5 cannot be rotated.

[0038] Furthermore, during the chip bonding process, if it is necessary to readjust the tilt angle of bonding surface A relative to reference surface B, this can be done at any time. Simply activate the locking mechanism and repeat the adjustment process. Alternatively, if only the orientation of bonding surface A needs adjustment and the second tilt angle adjustment is not required, the first drive mechanism 11 can be activated to rotate the bonding stage 2 along the longitudinal axis Y by the desired angle, thus adjusting the orientation of bonding surface A. In this case, the tilt angle between bonding surface A and reference surface B will not be disturbed and requires no adjustment.

[0039] Of course, the above description is only a specific embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A tilt adjustment mechanism for chip thermal bonding, comprising: The base (1), pressing table (2), rotating table (4), and tilting table (5), wherein a heating device (3) is provided on the pressing table (2), characterized in that: The base (1) is pivotally connected to the rotary table (4) via the first bearing (7), and the pressing table (2) is pivotally connected to the tilting table (5) via the second bearing (8); The pressing table (2) is connected to the base (1) via a coupling (6), and the first driving mechanism (11) drives the base (1) and the pressing table (2) to rotate along the longitudinal axis Y. The tilting platform (5) is linked to the rotating platform (4), and the second driving mechanism (41) drives the tilting platform (5) and the pressing platform (2) to rotate along the horizontal axis X. By rotating the pressing stage (2) in the longitudinal Y direction and the transverse X direction, the tilt adjustment of the bonding surface of the chip on the pressing stage (2) can be achieved.

2. The tilt adjustment mechanism for chip thermo-bonding according to claim 1, characterized in that: Both the first bearing (7) and the second bearing (8) are cross roller bearings.

3. The tilt adjustment mechanism for chip thermo-bonding according to claim 1, characterized in that: The first drive mechanism (11) and the second drive mechanism (41) are frameless torque motors.

4. The tilt adjustment mechanism for chip thermo-bonding according to claim 1, characterized in that: The coupling (6) mentioned above is a bellows coupling.

5. The tilt adjustment mechanism for chip thermo-bonding according to claim 1, characterized in that: The heating device is located below or inside the pressing table (2).

6. A method for adjusting a tilt adjustment mechanism for chip thermosetting bonding, characterized in that: It employs a tilt adjustment mechanism for chip thermoforming as described in claims 1-5, the adjustment method of which includes the following steps: Step 1, initial positioning: determine the tilt angle θ of the bonding surface of the pressing table (2) relative to the reference surface, and then the first drive mechanism (11) starts to rotate, driving the pressing table (2) to rotate along the longitudinal axis Y direction until the bonding surface of the pressing table (2) rotates to the position corresponding to the tilt angle θ. The second step is to adjust the tilt angle: the first drive mechanism (11) stops rotating and the second drive mechanism (41) starts rotating, driving the pressing table (2) to rotate along the horizontal axis X direction until the bonding surface of the pressing table (2) rotates to be parallel to the reference surface. The third step is rotation locking. After tilting, the rotary table (4) fixes the pressing table (2) through the locking mechanism, and the bonding surface of the pressing table (2) is locked relative to the reference surface.

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