Board level planarization device and method

Abstract

The invention is suitable for the technical field of board-level polishing, and provides a board-level planarization device and method. The device comprises a polishing disc, a polishing pad, a polishing head and a polishing solution inlet, the polishing pad is placed on the upper surface of the polishing disc; the polishing head is arranged above the polishing pad and is used for adsorbing the board-level substrate on the polishing pad; the polishing liquid inlet is formed in the center of the polishing disc and the polishing pad, vertically penetrates through the interiors of the polishing pad and the polishing disc and is connected with a liquid inlet control part; the control component is used for controlling the polishing liquid to pass through the interior of the polishing disc from bottom to top to be output from the center of the polishing pad through pressure to form an under-disc liquid inlet mode. The polishing effect of the board-level substrate can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of plate-level polishing, and in particular, relates to a plate-level planarization device and method. Background Art

[0002] As electronic devices become thinner and lighter, and more powerful, the requirements for chip integration and performance continue to increase. Panel-level packaging can provide higher integration and better performance. Panel-level packaging can improve production efficiency and reduce the packaging cost per chip by processing multiple chips simultaneously on a large-size panel.

[0003] In order to achieve high-precision processing of these board-level materials, chemical mechanical polishing (CMP) technology is widely used. As a typical board-level global polishing method, traditional chemical mechanical polishing usually adsorbs the board level on the lower part of the carrier head so that it directly contacts the rotating polishing pad. The polishing liquid spray head is located above the polishing pad and continuously sprays the polishing liquid onto the polishing pad. During the process, the pressure, rotation speed, polishing time and other parameters are adjusted to achieve the flatness of the board-level surface.

[0004] Because the plate-level wafer is larger in size and square in shape than ordinary wafers, this method of polishing liquid feeding results in insufficient supply and renewal of the grinding liquid, uneven flow rate and flow field distribution, which will produce uneven polishing effects on the material surface, increase surface roughness, and affect material properties. Summary of the invention

[0005] In order to overcome the problems existing in the related art, the embodiments of the present application provide a board-level planarization device and method, which can improve the polishing effect of the board-level substrate.

[0006] This application is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a board-level planarization device, including a polishing plate, a polishing pad, a polishing head, and a polishing liquid inlet;

[0008] The polishing pad is placed on the upper surface of the polishing plate;

[0009] The polishing head is arranged above the polishing pad and is used for adsorbing the board-level substrate on the polishing pad;

[0010] The polishing liquid inlet is located at the center of the polishing plate and the polishing pad, vertically passes through the interior of the polishing plate and the polishing plate and is connected to the liquid inlet control component; the control component is used to control the polishing liquid from bottom to top through the interior of the polishing plate and output from the center of the polishing pad through pressure, forming a liquid inlet method under the plate.

[0011] In one embodiment, the polishing liquid inlet is circular in shape; the polishing liquid inlet includes a plurality of evenly distributed small holes; and the polishing liquid is output through the plurality of small holes.

[0012] In one embodiment, the plurality of small holes are distributed around a circle at a first preset distance from the center of the polishing liquid inlet.

[0013] One embodiment further includes an endpoint detection window;

[0014] The endpoint detection window is arranged in the polishing pad, and the endpoint detection window is used to monitor the thickness of the metal film of the board-level substrate.

[0015] In one embodiment, a plurality of independent airbag structures are disposed at the bottom of the polishing head; the pressure in the area where each airbag structure is located is different.

[0016] One embodiment further includes a polishing pad conditioner;

[0017] The polishing pad dresser is arranged above the polishing pad and is used for cleaning the polishing pad following the trajectory of the polishing head.

[0018] In one embodiment, the first preset distance is 110 mm to 130 mm; the diameter of the small holes is in the range of 5 mm to 7 mm; and the number of the small holes is in the range of 10 to 14.

[0019] In one embodiment, the diameter of the polishing head is 700mm~1200mm; the diameter of the polishing pad is 1.3m~1.5m; the rotation speed of the polishing disc is 30rpm~120rpm, the rotation speed of the polishing head is 40rpm~110rpm, the main polishing pressure of the polishing disc is 0.5psi~6psi, and the flow rate of the polishing liquid is 200mL / min~1000mL / min.

[0020] In a second aspect, an embodiment of the present application provides a board-level planarization method, which is implemented using the board-level planarization device in the first aspect. The board-level planarization method includes:

[0021] Controlling the polishing head to adsorb the board-level substrate onto the polishing pad for polishing;

[0022] At the same time, the polishing liquid is controlled to pass through the inside of the polishing disk from the center of the polishing pad to the surface of the polishing pad from bottom to top; the position of the polishing liquid inlet is set in the center of the polishing disk and the polishing pad, vertically passes through the polishing pad and the inside of the polishing disk and is connected to the liquid inlet control component; the control component is used to control the polishing liquid from bottom to top through the inside of the polishing disk and be output from the center of the polishing pad through pressure, forming a liquid inlet method under the disk.

[0023] In one embodiment, the board-level planarization method further includes:

[0024] During the polishing process, the thickness of the metal film of the board-level substrate is monitored in real time using an endpoint detection window, and the polishing operation is controlled based on the thickness of the metal film.

[0025] Compared with the related art, the embodiments of the present application have the following beneficial effects:

[0026] In the embodiment of the present application, the polishing liquid inlet is vertically arranged at the center of the polishing disk and the polishing pad, and the polishing liquid is output from bottom to top, so that the polishing liquid can be evenly distributed on the polishing pad. This under-disk liquid inlet method avoids the problem of uneven distribution of the polishing liquid on the surface of the polishing pad due to the influence of gravity, thereby improving the flattening uniformity of the board-level substrate during the polishing process, realizing the effective supply of polishing liquid, and can improve the service life of the polishing pad and the overall efficiency of the polishing process.

[0027] The beneficial effects of the second aspect mentioned above refer to the beneficial effects of the board-level planarization device of the first aspect, which will not be repeated here.

[0028] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 is a schematic structural diagram of a board-level planarization device provided in one embodiment of the present application;

[0031] Figure 2 is a top view of a board-level planarization device provided by an embodiment of the present application;

[0032] Figure 3 is a cross-sectional view of a panel-level planarization device provided by an embodiment of the present application;

[0033] Figure 4 It is a flow field distribution diagram of the polishing liquid at different times during the simulation process provided by an embodiment of the present application; Figure 4 (a) is the flow field distribution diagram of the first spraying of the polishing liquid; Figure 4 (b) is the flow field distribution diagram of the polishing liquid entering the slip domain; Figure 4 (c) is the flow field distribution diagram before the board-level substrate enters the liquid film of the polishing liquid for the first time;

[0034] Figure 4 (d) is the flow field distribution diagram after the board-level substrate enters the liquid film of the polishing liquid for the first time; Figure 4 (e) is the flow field distribution diagram before the second board-level substrate enters the liquid film of the polishing liquid; Figure 4(f) is the flow field distribution diagram after the board-level substrate enters the liquid film of the polishing liquid for the second time;

[0035] Figure 5 is a flow field distribution diagram of different opening positions and numbers provided in one embodiment of the present application; Figure 5 (a) is a schematic diagram of 12 vertical holes; Figure 5 (b) is a schematic diagram of a vertical single hole; Figure 5 (c) is a schematic diagram of 6 vertical multiple holes; Figure 5 (d) is the flow field distribution diagram of 12 vertical holes; Figure 5 (e) is the flow field distribution diagram of a vertical single hole; Figure 5 (f) is the flow field distribution diagram of 6 vertical multiple holes;

[0036] Figure 6 The flow field distribution of the central vertical single hole and the non-central vertical single hole provided in one embodiment of the present application; Figure 6 (a) is a schematic diagram of a central vertical single hole; Figure 6 (b) is a schematic diagram of a non-central vertical single hole; Figure 6 (c) is the flow field distribution diagram of the central vertical single hole; Figure 6 (d) is the flow field distribution diagram of the non-central vertical single hole;

[0037] Figure 7 is a side view of a polishing head provided in one embodiment of the present application;

[0038] Figure 8 is an endpoint detection window detection flow chart provided in an embodiment of the present application;

[0039] Fig. 9 It is a schematic diagram of the structure of a controller provided in one embodiment of the present application. DETAILED DESCRIPTION

[0040] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, methods, and controllers are omitted to prevent unnecessary details from obstructing the description of the present application.

[0041] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0042] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0044] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] As described in the above background technology, as the requirements of electronic products for chip performance, integration and cost continue to increase, traditional packaging technology has gradually become difficult to meet the requirements in some aspects. In the field of chip manufacturing, the pursuit of higher production efficiency and lower costs has always been an important goal. The traditional single chip packaging method is relatively inefficient, while panel-level packaging can process multiple chips simultaneously on a large-size panel, thereby significantly improving production efficiency and reducing unit costs. In addition, the functions of electronic products are becoming increasingly complex, and the requirements for chip integration are getting higher and higher. Panel-level packaging can better achieve high-density integration of chips and meet the development trend of miniaturization and thinness of electronic products. At the same time, the consumer electronics market is highly competitive, and it is crucial to quickly launch new products and meet changes in market demand. The flexibility and scalability of panel-level packaging enable it to adapt to changes in market demand more quickly and accelerate the time to market for products.

[0047] From the perspective of the carrier materials of panel-level packaging, they can be mainly divided into three categories: organic substrates, silicon substrates and glass substrates. Among them, glass substrates, as an inorganic non-metallic material, have many advantages, such as high light transmittance, high thermal stability, high chemical stability and excellent electrical insulation performance. These characteristics make glass substrates occupy an important position in the field of semiconductor packaging. The high light transmittance of glass substrates makes them very suitable as optical windows for encapsulating optical sensors. Its high thermal stability and chemical stability ensure performance stability under extreme temperature and humidity conditions, thereby ensuring the reliability of semiconductor devices. In addition, the electrical insulation performance of glass substrates is also excellent, which can effectively prevent electrical failures and enhance the safety of semiconductor devices. Glass substrates are also easy to process and can perform precise cutting, drilling and grinding operations to meet diverse packaging needs.

[0048] In panel-level packaging, chemical mechanical polishing (CMP) can ensure that the surface flatness meets extremely high precision requirements. This is crucial for the stacking of multi-layer structures and subsequent wiring. If the surface is uneven, it will affect the stability and reliability of electrical signal transmission, thereby reducing the performance of the chip. Secondly, good chemical mechanical polishing (CMP) can reduce the generation of defects and flaws, and improve the yield and quality of the chip. Furthermore, it helps to achieve finer line patterns and increase wiring density, thereby improving the integration of the chip. In addition, precise polishing can reduce parasitic capacitance and resistance between layers, improve the electrical performance of the chip, reduce power consumption, and increase the operating frequency. Finally, for large-scale panel-level production, consistent and high-quality chemical mechanical polishing processes help ensure product consistency and stability, reduce production costs, and improve production efficiency.

[0049] Traditional chemical mechanical polishing is a typical board-level global polishing method. The board-level substrate is usually adsorbed on the lower part of the carrier head so that it is directly in contact with the rotating polishing pad. The polishing liquid spray head is usually located above the polishing pad. During the polishing process, the polishing liquid is sprayed onto the polishing pad through the polishing liquid spray head, so that it flows to the processed area under the action of centrifugal force, and contacts with the rotating polishing pad and the board to be polished. Polishing begins under the downward pressure and rotation of the polishing head. During the process, parameters such as pressure, rotation speed, and polishing time are adjusted. After completion, subsequent processes such as cleaning and testing are carried out to ensure that the panel quality meets the requirements.

[0050] However, the traditional plate-level chemical mechanical polishing method has some disadvantages. First, using the traditional plate-level chemical mechanical polishing equipment, the polishing liquid is sprayed from the top of the polishing pad. For large-sized and square plates, it is easy to cause the local polishing liquid flow rate to decrease and the flow field distribution to be uneven. The uneven distribution of the grinding liquid may cause uneven wear on the polishing surface, resulting in surface defects such as scratches, unevenness or local over-polishing, and poor processing effect. In addition, some areas may not get enough lubrication and cooling, resulting in increased surface roughness in these areas. Second, the liquid supply in the disk has great advantages for plate-level polishing, but the position and number of different liquid inlet points greatly affect the distribution of the flow field. For example, the flow field of a single liquid inlet hole is slowly dispersed and cannot quickly cover the entire polishing disk, resulting in the plate level not being able to react with the polishing liquid in time, increasing the polishing time, and the uneven multiple dispersed liquid inlet holes cannot cover the entire polishing pad due to the centrifugal force, affecting the polishing efficiency. Low polishing efficiency will increase the use of consumables, and it may be necessary to replace the polishing pad more frequently and perform equipment maintenance, increasing costs. In addition, the instability of the polishing process may lead to production interruptions, requiring additional time to adjust and optimize polishing parameters, thereby reducing overall production efficiency. Due to the unstable polishing quality, the performance of the material may be affected and the product defect rate will increase. Third, during the grinding process, pressure directly affects the material removal rate. Higher pressure usually increases the contact force between the polishing pad and the polished surface, thereby accelerating the material removal rate. However, excessive pressure may lead to over-polishing, affecting the surface flatness and precision, and even causing surface damage. Therefore, reasonable regulation of pressure helps to ensure the uniformity of polishing. If the pressure distribution is uneven, the polishing degree of different areas of the panel will be inconsistent, resulting in local over-polishing or under-polishing, affecting the quality and performance of the entire panel. By accurately adjusting the pressure, a smooth transition from rough polishing to fine polishing can be achieved to obtain an ideal surface roughness. Therefore, it is necessary to reasonably control the pressure during the polishing process, which helps to extend the service life of the polishing pad and other consumables and reduce production costs.

[0051] Based on the above problems, the present invention proposes a board-level flattening device that introduces liquid from bottom to top according to the shape, size and polishing process requirements of the board level, and uses an endpoint detection closed-loop control function to monitor key parameters in the polishing process in real time, and automatically adjust the polishing pressure according to the deviation, so as to achieve uniform distribution of the polishing liquid during the polishing process, and accurately control the polishing process, thereby improving the accuracy and consistency of polishing, improving the polishing effect of the board-level substrate, and reducing product differences.

[0052] Next, a board-level planarization device and method provided by the present invention are described in detail.

[0053] Figure 1 is a schematic structural diagram of a board-level planarization device provided in one embodiment of the present application; Figure 2 is a top view of a board-level planarization device provided by an embodiment of the present application; Figure 3 is a cross-sectional view of a panel-level planarization device provided by an embodiment of the present application. Figures 1 to 3 , the board-level planarization device is described in detail as follows:

[0054] A plate-level planarization device includes a polishing disc 101, a polishing pad 102, a polishing head 103 and a polishing liquid inlet 104.

[0055] The polishing pad 102 is placed on the upper surface of the polishing plate 101 .

[0056] The polishing head 103 is disposed above the polishing pad 102 and is used for adsorbing the board-level substrate 105 on the polishing pad 102 .

[0057] The polishing liquid inlet 104 is positioned at the center of the polishing disc 101 and the polishing pad 102, vertically passes through the interior of the polishing disc 102 and the polishing disc 101 and is connected to a liquid inlet control component; the control component is used to control the polishing liquid through pressure from bottom to top through the interior of the polishing disc 101 and output from the center of the polishing pad 102, forming a liquid inlet method under the disc.

[0058] Exemplarily, the liquid inlet control component can be in the form of a polishing liquid inlet pipe connected to a rotary joint, such as Figure 1 As shown, or other feasible liquid inlet forms. Figures 1 to 3 In the figure, the specific method of liquid entry under the plate can be seen. Through the connection of the rotary joint under the plate, the polishing liquid flows from the polishing liquid inlet pipe through the center of the polishing plate 101 and the polishing pad 102. The polishing liquid is sprayed on the polishing pad 102 through the pressure and flow control of the rotary joint, and is evenly distributed on the polishing pad 102 faster.

[0059] Considering that the object of polishing is a panel-level substrate 105, mainly a glass substrate 105, compared with an ordinary 12-inch wafer, the area of ​​the glass substrate 105 is very large, with a length and width of approximately 510mm×515mm, so the diameter of the adapted polishing pad 102 is approximately 1.3m~2m. Due to the larger size of the glass substrate 105 and the polishing pad 102, if the previous polishing liquid inlet position is used, the amount of polishing liquid will become less and less as it goes outward, and the outermost circle of the glass substrate 105 cannot enter the polishing liquid, affecting the polishing effect.

[0060] If a top-down liquid spraying method is adopted, in the initial stage, the polishing liquid falls from the guide arm to the center of the disk, and then diffuses to the surroundings under the combined action of gravity and the centrifugal force generated by the rotation of the polishing pad 102. However, a higher concentration will appear below the liquid supply point, and it will take a certain amount of time to achieve better uniformity.

[0061] Based on the above actual conditions, the present solution adopts a bottom-up liquid spraying method. The polishing liquid penetrates evenly from the bottom and can more directly reach various parts of the contact interface between the board-level substrate 105 and the polishing pad 102, avoiding the situation where the concentration below the liquid supply point is high due to gravity. It is relatively easier to achieve uniform distribution of the polishing liquid in the entire polishing area, especially for large-area wafers, such as board-level substrates, this uniformity advantage is more obvious.

[0062] Figure 4 To simulate the flow field distribution of the polishing liquid at different times during the process, the polishing pad 102 uses a Circle groove. When the polishing liquid is first sprayed onto the polishing pad 102, the distribution of the polishing liquid is circular, such as Figure 4 As shown in (a). As the polishing disc 101 rotates, due to the centrifugal force, the polishing liquid on the polishing pad 102 begins to diffuse outward, and the Circle groove helps to evenly distribute the abrasive and chemical active agent to the entire polishing area, and the diffusion pattern remains roughly circular. When the board-level substrate 105 rotates on the polishing head 103 and passes through the polishing liquid to form a liquid film, part of the polishing liquid will be carried away along the rotation direction of the board-level substrate 105. This carried-away polishing liquid helps to form a uniform polishing liquid film on the surface of the board-level substrate 105, and also affects the distribution of the polishing liquid on the polishing pad 102. Although the rotation of the board level will carry away part of the polishing liquid, the overall distribution of the polishing liquid on the polishing pad 102 is still close to a circle, as shown in FIG. Figure 4 (b) to Figure 4 (f) This indicates that the design of the polishing liquid inlet 104 can effectively maintain the uniform distribution of the polishing liquid and maintain the consistency of the polishing effect even in the dynamic polishing process.

[0063] In this embodiment, the polishing liquid inlet 104 is vertically arranged at the center of the polishing disk 101 and the polishing pad 102, and the polishing liquid is output from bottom to top, which can ensure that the polishing liquid is evenly distributed on the polishing pad 102. This under-disk liquid inlet method avoids the problem of uneven distribution of the polishing liquid on the surface of the polishing pad 102 due to the influence of gravity, thereby improving the flattening uniformity of the board-level substrate 105 during the polishing process, realizing the effective supply of polishing liquid, and can improve the service life of the polishing pad 102 and the overall efficiency of the polishing process.

[0064] In one embodiment, the polishing liquid inlet 104 is circular in shape; the polishing liquid inlet 104 includes a plurality of evenly distributed small holes; and the polishing liquid is output through the plurality of small holes.

[0065] For example, the plurality of small holes are distributed around a first preset distance from the center of the polishing liquid inlet 104. The first preset distance can be set to 110 mm to 130 mm; the diameter of the small holes ranges from 5 mm to 7 mm; and the number of the small holes ranges from 10 to 14.

[0066] The diameter of the polishing head 103 is 700mm~1200mm; the diameter of the polishing pad 102 is 1.3m~1.5m; the rotation speed of the polishing disc 101 is 30rpm~120rpm, the rotation speed of the polishing head 103 is 40rpm~110rpm, the main polishing pressure of the polishing disc 101 is 0.5psi~6psi, and the flow rate of the polishing liquid is 200mL / min~1000mL / min. The above process parameters can all be defined in the process menu.

[0067] Exemplarily, the polishing head 103 is circular with a diameter of 930 mm, the polishing pad 102 has a diameter of 1300 mm, and can accommodate boards with a size of 515 mm×510 mm to 657 mm×657 mm.

[0068] It should be noted that the polishing head 103 can be square or circular, and its size can be appropriately enlarged, mainly in that it can be larger than the board-level substrate 105 .

[0069] In order to verify the distribution of the polishing liquid during CMP operation, the central axis of the board-level substrate 105 is used as the reference axis 1, and the substrate 105 rotates around the center of the circle. The central axis of the polishing disc 101 is used as the reference axis 2, and the polishing disc 101 rotates around the center of the circle to form flow field distributions with different opening positions and numbers, such as Figure 5 As shown. Three examples are given: the polishing liquid inlet 104 is vertically multi-hole, the number of holes is 12, and the hole diameter is 6mm, as shown in FIG. Figure 5 (a) As shown; the polishing liquid inlet 104 is a vertical single hole (1), the hole diameter is 6.36mm, as Figure 5 (b) As shown; the polishing liquid inlet 104 is vertically porous, the number of holes is 6, and the hole diameter is 6mm, as shown Figure 5 (c) The pressure setting conditions and rotation speeds of the three cases are the same as the actual situation. The flow field distribution of the polishing liquid during the working process is analyzed, as shown in Figure 5 (d) Flow field distribution of polishing liquid with 12 holes. Figure 5 (e) Flow field distribution of polishing liquid with one hole and Figure 5 (f) As shown in the flow field distribution of the polishing liquid with 6 holes, through simulation analysis of these three cases, the flow field distribution when the number of holes at the polishing liquid inlet 104 is 12 is more uniform than that in the other two cases. This stable and uniform flow field ensures the uniform distribution of the abrasive on the plate-level plane, thereby achieving a high-precision flattening effect.

[0070] Under the same working conditions, the grooves of the polishing pad 102 are simulated, and simulations are performed in two cases: a vertical opening in the center of the polishing pad 102 and a vertical opening at a non-central location of the polishing pad 102, and the distribution of the polishing liquid is analyzed. Figure 6 It can be seen that in the case of a central vertical opening, the polishing liquid gradually flows from the center of the polishing pad 102 to the edge of the polishing pad 102, and as time goes by, it will be more evenly spread over the entire polishing pad 102. Figure 6 (a) and Figure 6 As shown in (c), the non-central opening cannot distribute the polishing liquid in the central area of ​​the board-level substrate 105, such as Figure 6 (b) and Figure 6 (d) as shown.

[0071] When the polishing liquid flows out of the hole, it will be affected by centrifugal force as the polishing disc 101 rotates. The centrifugal force formula is F = mwr. 2 (Where F is the centrifugal force, m is the mass of the object, w is the angular velocity, and r is the radius of rotation). When the polishing liquid droplet gushes out from the center of the central vertical single hole, r is approximately 0, so the centrifugal force it is subjected to at this time approaches 0. As the polishing disc 101 rotates, the centrifugal force it is subjected to gradually increases. If there is enough time, the polishing liquid can evenly cover the entire polishing disc 101. However, the polishing liquid flowing out from the non-central vertical single hole, that is, the polishing liquid remaining from the edge hole, has a relatively large r value at the beginning, and is subjected to a large centrifugal force. As the polishing disc 101 rotates, it will flow in the form of a stream following the rotation trend of the polishing disc 101, and it is difficult to distribute to the center, and the dispersion is uneven, and it cannot cover the entire polishing disc 101.

[0072] Through a series of experiments such as comparing the central vertical multiple holes (12) and the non-central vertical multiple holes (12), and using the above simulated flow field distribution, it is possible to select the optimal opening position as the central vertical multiple holes (12), and the polishing liquid will be better discharged from the center area of ​​the polishing pad 102.

[0073] For an embodiment, see Figure 1 and Figure 2 The board-level planarization device further includes an endpoint detection window 106 .

[0074] The endpoint detection window 106 is disposed in the polishing pad 102 , and the endpoint detection window 106 is used to monitor the thickness of the metal film on the board-level substrate 105 .

[0075] Exemplarily, a sensor is arranged under the endpoint detection window 106. Different sensors can monitor different signal values, such as eddy current, white light, laser, etc. Taking the eddy current signal sensor as an example, during the polishing process, the system can obtain the signal value of the metal detection part caused by the eddy current effect, and can accurately and precisely obtain the thickness of the metal film in real time. The obtained thickness of the metal film is further used for closed-loop control, thereby significantly improving the flattening uniformity and accuracy of the board level.

[0076] Exemplarily, the bottom of the polishing head 103 is provided with a plurality of independent airbag structures, such as Figure 7 The side view of the polishing head 103 is shown, wherein the pressure in the area where each airbag structure is located is different.

[0077] The pressure of the polishing head 103 is divided into 4 zones and above. For example, the 4 zones include Z1 zone, Z2 zone, Z3 zone and Z4 zone. By applying different pressures in different zones, more precise polishing control can be performed on specific parts of the substrate surface to meet the polishing requirements of different areas. According to the material properties or initial states of different areas of the panel, the pressure partition is adjusted to optimize the polishing rate and surface quality.

[0078] The polishing head 103 may be, but is not limited to, circular, and the Z1 region, the Z2 region, the Z3 region, and the Z4 region are respectively arranged in a circular shape along the center of the polishing head 103 .

[0079] The CMP polishing head 103 uses an airbag structure to achieve pressure zoning. There are multiple independent airbag areas at the bottom of the polishing head 103, and these airbags can be controlled by an independent gas circuit system. Each airbag is called a zone. By filling different zones with gases of different pressures, the contact pressure between the corresponding area of ​​the polishing head 103 and the surface of the board-level substrate 105 can be changed. Before CMP, the surface of the board-level substrate 105 is not completely flat. In the process of multi-layer chip manufacturing, due to the deposition and patterning of different layers, there may be local protrusions or depressions on the surface of the board-level substrate 105. When the polishing head 103 encounters a protruding area, if the pressure of the entire polishing head 103 is uniform, it may cause the protruding area to be over-polished or the concave area to be under-polished. Through pressure zoning, when encountering a protruding area, the pressure of the area can be appropriately reduced, and the pressure can be increased in the concave area, so that the entire board-level substrate 105 surface can be polished more evenly and the polishing flatness can be improved. By performing pressure zoning on the polishing head 103, the material removal amount of different areas on the surface of the board-level substrate 105 can be accurately controlled.

[0080] In one embodiment, the panel-level planarization apparatus further includes a polishing pad conditioner 107 .

[0081] The polishing pad dresser 107 is disposed above the polishing pad 102 and is used to clean the polishing pad 102 by following the trajectory of the polishing head 103 .

[0082] The polishing pad dresser 107 is mainly composed of a dressing head and a connecting arm. The material of the dressing head should have a certain hardness to effectively remove dirt and residues on the surface of the polishing pad 102, but not too hard to avoid damaging the polishing pad 102. The connecting arm is responsible for connecting the dressing head with the relevant power device and control system to ensure that the dresser 107 can accurately follow the trajectory of the polishing head 103.

[0083] The cleanliness of the polishing pad 102 has a crucial impact on the quality of the entire polishing process. If there are too many impurities on the surface of the polishing pad 102, it will not only affect the efficiency of polishing, but also may cause scratches or other defects on the surface of the polished workpiece. The existence of the polishing pad dresser 107 effectively solves this problem. It ensures that the polishing pad 102 is always in good working condition by timely cleaning the polishing pad 102, thereby improving the stability and reliability of the entire polishing process.

[0084] The embodiments of the present application propose a vertically porous liquid inlet position in the center of the polishing disk. The polishing liquid inlet is vertically arranged in the center of the polishing disk and the polishing pad, and the polishing liquid is output from bottom to top. This ensures that the polishing liquid is evenly distributed on the polishing pad. This under-disk liquid inlet method avoids the problem of uneven distribution of the polishing liquid on the surface of the polishing pad due to the influence of gravity, thereby improving the flattening uniformity of the board-level substrate during the polishing process, realizing the effective supply of polishing liquid, and can improve the service life of the polishing pad and the overall efficiency of the polishing process.

[0085] Among them, the preferred position is 10 to 14 small holes in the center of the disk, the diameter of the small holes is 5mm to 7mm, and the distance between the center of the hole and the center of the polishing disk is 110mm to 130mm. Under the same working conditions, the polishing liquid entering at this position can be more quickly spread throughout the entire board-level substrate and polishing head. By setting an end point detection window on the polishing pad and installing a sensor under the corresponding window, it can receive signals such as eddy current, white light, and laser, thereby realizing real-time monitoring of key parameters of the polishing process, judging whether the board-level processing has reached the end point, and through the closed-loop control function, the system can compare the real-time monitored data with the preset thickness value, and automatically adjust the polishing pressure according to the deviation to ensure the quality of polishing.

[0086] The sizes of the components used in the board-level flattening device are pointed out specifically. The polishing head is round with a diameter of 700mm to 1200mm. The pressure zone of the polishing head is 4 zones and above. The diameter of the polishing pad is 1.3m to 1.5m, which is suitable for larger and irregularly shaped board-level substrates.

[0087] The mechanical parameter settings of the board-level flattening device in this application are as follows: the polishing disc rotation speed is 30rpm~120rpm, the polishing head rotation speed is 40rpm~110rpm, the directions of the polishing disc and the polishing head are both counterclockwise rotation, the main polishing pressure of the polishing disc is 0.5psi~6psi, and the polishing liquid flow rate is 200mL / min~1000mL / min.

[0088] The present application embodiment provides a board-level planarization method, which is implemented by using the board-level planarization device in the above embodiment. The board-level planarization method includes:

[0089] The polishing head 103 is controlled to adsorb the plate-level substrate 105 on the polishing pad 102 for polishing.

[0090] At the same time, the polishing liquid is controlled to pass through the inside of the polishing disk 101 from the center of the polishing pad 102 to the surface of the polishing pad 102 from the bottom to the top; the polishing liquid inlet 104 is arranged at the center of the polishing disk 101 and the polishing pad 102, vertically passes through the inside of the polishing pad 102 and the polishing disk 101 and is connected to the liquid inlet control component; the control component is used to control the polishing liquid from the bottom to the top through the inside of the polishing disk 101 and the center of the polishing pad 102 to form an under-disk liquid inlet method.

[0091] Exemplarily, the board-level planarization method further includes:

[0092] During the polishing process, the thickness of the metal film of the board-level substrate 105 is monitored in real time using the endpoint detection window 106 , and the polishing operation is controlled based on the thickness of the metal film.

[0093] During the polishing process, the polishing liquid enters from the polishing liquid inlet 104 (polishing liquid inlet pipe), and is evenly sprayed onto the surface of the polishing pad 102 through pressure and the rotation of the polishing disc 101, providing the necessary chemically active components and abrasive particles for polishing. By setting different pressure values ​​for different zones of the polishing head 103, the board-level substrate 105 is fixed so that the board-level substrate 105 is in close contact with the polishing pad 102. The polishing head 103 drives the board-level substrate 105 to rotate or reciprocate to ensure that the entire surface of the board-level substrate 105 can be polished. At the same time, the rotation of the polishing disc 101 drives the polishing pad 102 to rotate, and generates relative motion with the board-level substrate 105 to promote the polishing process. The polishing rate and polishing effect can be controlled by adjusting parameters such as the rotation speed, pressure and flow rate of the polishing head 103 and the polishing disc 101. The polishing pad 102 will gradually wear out during use, and the polishing pad dresser 107 follows the trajectory of the polishing head 103 to clean the polishing pad 102. During the polishing process, if Figure 8As shown in the flowchart, taking the eddy current endpoint detection method as an example, the sensor under the endpoint detection window 106 will monitor the real-time thickness and flatness of the metal layer on the board surface in real time. The controller receives the data from the sensor and compares and analyzes it with the preset thickness. According to the deviation between the real-time thickness of the metal film and the preset thickness, the process parameters that need to be adjusted are calculated, and the pressure value of the polishing head is adjusted in real time. Once the preset polishing endpoint is reached, the polishing process stops and the board-level substrate is transferred to the cleaning process.

[0094] The beneficial effects of the panel-level planarization method according to the embodiment of the present application refer to the beneficial effects of the panel-level planarization device described above.

[0095] It should be understood that the execution order of the above processes should be determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. In order to reduce the complexity of the patent description, the present invention provides a detection method involved in a compound plate-level planarization device, and the sensor types used and the calculation process are all included in the protection scope of this patent.

[0096] It should be noted that the information interaction, execution process and other contents between the above-mentioned devices are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0097] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0098] See also Fig. 9 , one embodiment provides a controller, which is used to execute the board-level planarization method in the above embodiment.

[0099] The present application also provides a controller, see Fig. 9The controller 200 may include: at least one processor 210 and a memory 220, wherein the memory 220 stores a computer program that can be run on at least one processor 210, and when the processor 210 executes the computer program, the steps in any of the above method embodiments are implemented.

[0100] Exemplarily, the computer program may be divided into one or more modules / units, one or more modules / units are stored in the memory 220, and executed by the processor 210 to complete the present application. One or more modules / units may be a series of computer program segments capable of completing specific functions, and the program segments are used to describe the execution process of the computer program in the controller 200.

[0101] Those skilled in the art will understand that Fig. 9 These are merely examples of controllers and do not constitute a limitation of the controller, which may include more or fewer components than those shown in the figure, or a combination of certain components, or different components, such as input and output devices, network access devices, buses, etc.

[0102] The processor 210 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0103] The memory 220 may be an internal storage unit of the controller or an external storage device of the controller, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. The memory 220 is used to store computer programs and other programs and data required by the controller. The memory 220 may also be used to temporarily store data that has been output or is to be output.

[0104] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0105] The board-level planarization method provided in the embodiment of the present application can be applied to controllers such as computers, tablet computers, laptop computers, netbooks, personal digital assistants (PDAs), etc. The embodiment of the present application does not impose any restrictions on the specific type of controller.

[0106] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0107] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A board-level planarization device, characterized in that: It includes a polishing disc, a polishing pad, a polishing head and a polishing liquid inlet; The polishing pad is placed on the upper surface of the polishing plate; The polishing head is arranged above the polishing pad and is used for adsorbing the board-level substrate on the polishing pad; The polishing liquid inlet is located at the center of the polishing plate and the polishing pad, vertically passes through the polishing pad and the interior of the polishing plate and is connected to a liquid inlet control component; the control component is used to control the polishing liquid through pressure from bottom to top through the interior of the polishing plate and output from the center of the polishing pad, forming a liquid inlet method under the plate.

2. The board-level planarization device according to claim 1, characterized in that: The polishing liquid inlet is circular in shape; the polishing liquid inlet comprises a plurality of evenly distributed small holes; the polishing liquid is output through the plurality of small holes.

3. The board-level planarization device according to claim 2, characterized in that: The plurality of small holes are distributed around a circle with a first preset distance from the center of the polishing liquid inlet.

4. The board-level planarization device according to claim 1, characterized in that: Also includes an endpoint detection window; The endpoint detection window is arranged in the polishing pad, and the endpoint detection window is used to monitor the thickness of the metal film of the board-level substrate.

5. The board-level planarization device according to claim 1, characterized in that: A plurality of independent airbag structures are arranged at the bottom of the polishing head; and the pressures in the areas where the airbag structures are located are different.

6. The board-level planarization device according to claim 1, characterized in that: Also included is a polishing pad conditioner; The polishing pad dresser is arranged above the polishing pad and is used for cleaning the polishing pad following the trajectory of the polishing head.

7. The board-level planarization device according to claim 3, characterized in that: The first preset distance is 110 mm to 130 mm; the diameter of the small holes is in the range of 5 mm to 7 mm; and the number of the small holes is in the range of 10 to 14.

8. The panel-level planarization device according to any one of claims 1 to 7, characterized in that: The diameter of the polishing head is 700mm~1200mm; the diameter of the polishing pad is 1.3m~1.5m; the rotation speed of the polishing disc is 30rpm~120rpm, the rotation speed of the polishing head is 40rpm~110rpm, the main polishing pressure of the polishing disc is 0.5psi~6psi, and the flow rate of the polishing liquid is 200mL / min~1000mL / min.

9. A board-level planarization method, characterized in that: The board-level planarization method is implemented by using the board-level planarization device according to any one of claims 1 to 8, wherein the board-level planarization method comprises: Controlling the polishing head to adsorb the plate-level substrate onto the polishing pad for polishing; At the same time, the polishing liquid is controlled to pass through the inside of the polishing disk from bottom to top and be output from the center of the polishing pad to the surface of the polishing pad; the position of the polishing liquid inlet is set at the center of the polishing disk and the polishing pad, vertically passes through the polishing pad and the inside of the polishing disk and is connected to the liquid inlet control component; the control component is used to control the polishing liquid from bottom to top through the inside of the polishing disk and be output from the center of the polishing pad through pressure, forming a liquid inlet method under the disk.

10. The board-level planarization method according to claim 9, characterized in that: Also includes: During the polishing process, the thickness of the metal film of the board-level substrate is monitored in real time using an endpoint detection window, and the polishing operation is controlled based on the thickness of the metal film.

Images