A method, apparatus and device for thinning a semiconductor package

Abstract

The application relates to the technical field of semiconductor processing, in particular to a thinning method, device and equipment for a semiconductor package, wherein the method comprises the following steps: after the semiconductor package is placed on a chuck of a thinning equipment, a coarse grinding shaft is controlled to perform coarse grinding thinning on the semiconductor package on the chuck according to preset first grinding parameters, so that the thickness of the plastic package is thinned to a first target thickness; a first fine grinding shaft is controlled to perform first-stage fine grinding thinning on the semiconductor package thinned by the coarse grinding according to preset second grinding parameters, so that the thickness of the chip is thinned to a second target thickness; and a second fine grinding shaft is controlled to perform second-stage fine grinding thinning on the semiconductor package thinned by the first-stage fine grinding according to preset third grinding parameters, so that the thinning processing of the semiconductor package is completed, and the accurate thinning processing of the single and separated semiconductor package after cutting and splitting is realized.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing technology, and in particular to a method, apparatus and equipment for thinning a semiconductor package. Background Technology

[0002] Existing processing methods for thinning semiconductor devices can only perform overall thinning of uncut semiconductor wafers, and do not specifically target the thinning of individual discrete semiconductor packages formed after cutting and splitting.

[0003] Therefore, a method for thinning discrete semiconductor packages is urgently needed. Summary of the Invention

[0004] This application provides a method, apparatus, and equipment for thinning semiconductor packages, which can achieve precise thinning of individual discrete semiconductor packages after cutting and splitting.

[0005] In a first aspect, a method for thinning a semiconductor package is provided, applied to a thinning device. The semiconductor package is a package formed by processing a semiconductor package workpiece using a cutting device. The semiconductor package includes a PCB board, a chip fixed on the PCB board, and a molding compound disposed on the upper surface and outer side of the chip to encapsulate the chip on the PCB board. The method includes: After the semiconductor package is placed on the suction cup of the thinning device, the coarse grinding shaft on the thinning device is controlled to perform coarse grinding and thinning on the semiconductor package located on the suction cup according to the preset first grinding parameters, so that the thickness of the plastic package is reduced to the first target thickness. According to the preset second grinding parameters, the first fine grinding shaft on the thinning device is controlled to perform first-stage fine grinding on the semiconductor package that has been coarsely ground and thinned on the suction cup, so that the thickness of the chip is reduced to the second target thickness. According to the preset third grinding parameters, the second fine grinding shaft on the thinning equipment is controlled to perform a second fine grinding on the semiconductor package that has been thinned by the first-stage fine grinding on the suction cup, so that the thickness of the chip is reduced to the third target thickness, thereby completing the thinning process of the semiconductor package.

[0006] Optionally, the first grinding parameters include: a first spindle speed of 1700 rpm to 2700 rpm, a first longitudinal feed speed of 0.3 µm / s to 1.8 µm / s, and a first chuck axial speed of 70 rpm to 110 rpm; The second grinding parameters include: the second spindle speed is 1700rpm~2700rpm, the second longitudinal feed speed is 0.2µm / s~1.2µm / s, and the second chuck axial speed is 70rpm~110rpm; The third grinding parameters include: the third spindle speed is 1700rpm~2700rpm, the third longitudinal feed speed is 0.05µm / s~1.0µm / s, and the third chuck axial speed is 70rpm~110rpm.

[0007] Optionally, the thinning device has multiple suction cups, which are distributed on a working plate. Each suction cup can rotate axially on the working plate. Each suction cup has multiple adsorption grooves, which are evenly distributed in a ring around the axis of the suction cup. The angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is within a preset range. The adsorption grooves are used to adsorb and fix the semiconductor package onto the suction cup. Accordingly, before the semiconductor package is placed onto the suction cup of the thinning device, the device further includes: A three-dimensional simulation model corresponding to the thinning equipment is constructed. The three-dimensional simulation model includes a first sub-model corresponding to the suction cup, a second sub-model corresponding to the coarse grinding shaft, a third sub-model corresponding to the first fine grinding shaft, a fourth sub-model corresponding to the second fine grinding shaft, and a fifth sub-model corresponding to the semiconductor package. In the first sub-model, the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is variable within a preset range. For each angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank within a preset range, the second sub-model, the third sub-model, and the fourth sub-model are controlled to perform thinning processing on the fifth sub-model located in the adsorption tank in sequence, so as to process thinning texture in the fifth sub-model. For each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, the stress of the chip in the fifth sub-model is obtained based on the thinning texture processed in the fifth sub-model and the third target thickness. Based on the comparison results between the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove is determined. In order to select the suction cup with the target angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove as the suction cup to be installed on the working plate.

[0008] Optionally, for each angle within a preset range between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the stress of the chip in the fifth sub-model is obtained based on the thinning texture processed in the fifth sub-model and the third target thickness, including: Based on the different angles between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank, a first correspondence is established between the angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank, and the thinning texture processed on the fifth sub-model. For each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, the stress of the chip in the fifth sub-model is obtained based on the first correspondence and the third target thickness. Accordingly, based on the comparison results between the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove is determined, including: Based on the stress of the chip corresponding to the different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, a second correspondence is constructed between the chip stress in the fifth sub-model after the simulated thinning process is completed and the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove. Based on the preset stress and the second correspondence, the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove is determined.

[0009] Optionally, according to preset first grinding parameters, the coarse grinding shaft on the thinning device is controlled to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the molded package is reduced to the first target thickness, including: Obtain a first initial height of the semiconductor package located on the chuck relative to the upper surface of the chuck, and a first initial distance between the upper surface of the semiconductor package located on the chuck and the coarse grinding shaft; Based on the first initial height and the first initial distance, and based on the first grinding parameters, the coarse grinding shaft is controlled to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the plastic package is reduced to the first target thickness. Accordingly, based on the preset second grinding parameters, the first fine grinding shaft on the thinning equipment is controlled to perform a first-stage fine grinding thinning on the semiconductor package that has been coarsely thinned and located on the chuck, so that the thickness of the chip is reduced to the second target thickness, including: Obtain the second initial height of the coarsely ground and thinned semiconductor package relative to the upper surface of the chuck, and the second initial distance between the upper surface of the coarsely ground and thinned semiconductor package and the first fine grinding axis; Based on the second initial height and the second initial distance, the first fine grinding shaft is controlled to perform a first-stage fine grinding thinning on the semiconductor package after coarse grinding thinning, so that the thickness of the chip is reduced to the second target thickness; Accordingly, based on the preset third grinding parameters, the second fine grinding shaft on the thinning equipment is controlled to perform a second-stage fine grinding thinning on the semiconductor package located on the chuck after the first-stage fine grinding thinning, so that the thickness of the chip is reduced to the third target thickness, including: Obtain the third initial height of the semiconductor package after primary fine grinding and thinning on the chuck relative to the upper surface of the chuck, and the third initial distance between the upper surface of the semiconductor package after primary fine grinding and thinning and the second fine grinding axis; Based on the third initial height and the third initial distance, the second fine grinding shaft is controlled to perform a second fine grinding thinning on the semiconductor package after the first-stage fine grinding thinning, so that the thickness of the chip is reduced to the third target thickness.

[0010] Optionally, based on a first initial height and a first initial distance, the coarse grinding shaft is controlled to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the molded package is reduced to a first target thickness, including: Based on the first initial height and the first initial distance, the coarse grinding shaft is controlled to move to a position that contacts the upper surface of the semiconductor package; After the coarse grinding shaft moves to contact the upper surface of the semiconductor package, and every time the coarse grinding shaft descends to a first preset height, the coarse grinding shaft stops coarse grinding and thinning of the semiconductor package, and the first current height of the semiconductor package relative to the upper surface of the chuck is obtained. When the coarse grinding shaft descends to the first preset height, it is determined whether the grinding height of the coarse grinding shaft on the semiconductor package needs to be corrected based on the first initial height, the first preset height and the first current height. If correction is required, a first correction value is calculated based on the first initial height, the first preset height, and the first current height, so that when the coarse grinding shaft descends to the next first preset height, the descent height of the coarse grinding shaft is controlled based on the first correction value and the first preset height. If no correction is required, the descent height of the coarse grinding shaft is controlled according to the first preset height when the coarse grinding shaft descends to the next first preset height.

[0011] Optionally, based on the second initial height and the second initial distance, the first fine grinding shaft is controlled to perform a first-stage fine grinding thinning on the semiconductor package after rough grinding thinning, so that the thickness of the chip is reduced to the second target thickness, including: Based on the second initial height and the second initial distance, the first fine grinding shaft is controlled to move to a position that contacts the upper surface of the semiconductor package after coarse grinding and thinning; After the first fine grinding shaft moves to contact the upper surface of the semiconductor package after coarse grinding and thinning, and every time the first fine grinding shaft descends to a second preset height, the first fine grinding shaft stops the first fine grinding and thinning of the semiconductor package, and the second current height of the semiconductor package relative to the upper surface of the suction cup is obtained. Each time the first fine grinding shaft descends to the second preset height, it is determined whether the grinding height of the first fine grinding shaft on the semiconductor package needs to be corrected based on the second initial height, the second preset height, and the second current height. If correction is required, a second correction value is calculated based on the second initial height, the second preset height, and the second current height, so that when the first fine grinding shaft descends to the next second preset height, the descent height of the first fine grinding shaft is controlled based on the second correction value and the second preset height. If no correction is required, the descent height of the first fine grinding shaft is controlled according to the second preset height when the first fine grinding shaft descends to the next second preset height.

[0012] Optionally, based on the third initial height and the third initial distance, the second fine grinding shaft is controlled to perform a second fine grinding thinning on the semiconductor package after the first-stage fine grinding thinning, so that the thickness of the chip is reduced to the third target thickness, including: Based on the third initial height and the third initial distance, control the second fine grinding shaft to move to a position that contacts the upper surface of the semiconductor package after the first-stage fine grinding and thinning; After the second fine grinding shaft moves to contact the upper surface of the semiconductor package after the first-stage fine grinding and thinning, and every time the second fine grinding shaft descends to the third preset height, the second fine grinding shaft stops the second-stage fine grinding and thinning of the semiconductor package, and obtains the third current height of the semiconductor package relative to the upper surface of the chuck on the chuck. When the second fine grinding shaft descends to the third preset height, it is determined whether the grinding height of the second fine grinding shaft on the semiconductor package needs to be corrected based on the third initial height, the third preset height and the third current height. If correction is required, a third correction value is calculated based on the third initial height, the third preset height, and the third current height, so that when the second fine grinding shaft descends to the next third preset height, the descent height of the second fine grinding shaft is controlled based on the third correction value and the third preset height. If no correction is required, the descent height of the second fine grinding shaft is controlled according to the third preset height when the second fine grinding shaft descends to the next third preset height.

[0013] Secondly, a thinning apparatus for a semiconductor package is provided, applied to a thinning device. The semiconductor package is a package formed by processing a semiconductor package workpiece using a cutting device. The semiconductor package includes a PCB board, a chip fixed on the PCB board, and a molding compound disposed on the upper surface and outer side of the chip to encapsulate the chip on the PCB board. The apparatus includes: The coarse grinding and thinning control module is used to control the coarse grinding shaft on the thinning equipment to perform coarse grinding and thinning on the plastic encapsulation in the semiconductor package located on the suction cup after the semiconductor package is placed on the suction cup, according to the preset first grinding parameters, so that the thickness of the plastic encapsulation is reduced to the first target thickness. The first-stage fine grinding and thinning control module is used to control the first fine grinding shaft on the thinning device to perform first-stage fine grinding and thinning on the semiconductor package that has been coarsely ground and thinned on the chuck, according to the preset second grinding parameters, so that the thickness of the chip is reduced to the second target thickness. The secondary fine grinding and thinning control module is used to control the second fine grinding shaft on the thinning equipment to perform secondary fine grinding and thinning on the semiconductor package that has been thinned by the primary fine grinding on the suction cup, according to the preset third grinding parameters, so that the thickness of the chip is reduced to the third target thickness, thereby completing the thinning process of the semiconductor package.

[0014] Thirdly, a thinning device is provided, comprising: a processor and a memory for storing a computer program, the processor for calling and running the computer program stored in the memory, and performing the methods as described in the first aspect or its various implementations.

[0015] Fourthly, a computer-readable storage medium is provided for storing a computer program that causes a computer to perform the methods described in the first aspect or its various implementations.

[0016] The technical solution provided in this application, after placing the semiconductor package onto the suction cup of the thinning equipment, sequentially controls the coarse grinding shaft, the first fine grinding shaft, and the second fine grinding shaft on the thinning equipment to thin the semiconductor package located on the suction cup according to the preset first grinding parameters, the second grinding parameters, and the third grinding parameters, thereby completing the thinning process of the semiconductor package. This solution enables precise thinning of individual discrete semiconductor packages after cutting and splitting, solves the industry problem that traditional processes cannot adapt to the thinning process of discrete semiconductor packages, and adapts to the thinning process requirements of small batches, high precision, and differentiated semiconductor packages.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 An application scenario diagram provided for an embodiment of this application; Figure 2 A flowchart illustrating a method for thinning a semiconductor package provided in this application embodiment; Figure 3 This is a schematic diagram of the structure of a semiconductor package provided in an embodiment of this application; Figure 4 A schematic diagram of the working disc, coarse grinding shaft, first fine grinding shaft, and second fine grinding shaft on the thinning device provided in the embodiments of this application; Figure 5 This is a schematic diagram of the suction cup structure provided in an embodiment of this application; Figure 6 This is a schematic diagram of the thinning texture obtained by thinning the fifth sub-model located on the first sub-model provided in the embodiments of this application; ((a) the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is 0°; (b) the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is 30°). Figure 7 A schematic diagram of a semiconductor package thinning device provided in an embodiment of this application; Figure 8 A schematic block diagram of a thinning device provided in an embodiment of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0022] Existing processing methods for thinning semiconductor devices are only suitable for thinning uncut whole semiconductor wafers as a whole, and there are no methods specifically for thinning individual discrete semiconductor packages formed after cutting and splitting.

[0023] However, traditional thinning methods can only thin the entire sheet of material by grinding, and cannot meet the thinning processing requirements of small, fragmented, and easily breakable discrete semiconductor packages after cutting.

[0024] To at least address one of the technical problems existing in the prior art or related technologies, the present invention provides a method, apparatus, and device for thinning a semiconductor package. The method includes: after placing the semiconductor package onto the suction cup of the thinning device, controlling the coarse grinding shaft on the thinning device to perform coarse grinding thinning on the semiconductor package located on the suction cup according to preset first grinding parameters, so that the thickness of the package is reduced to a first target thickness; controlling the first fine grinding shaft on the thinning device to perform first-stage fine grinding thinning on the semiconductor package located on the suction cup after coarse grinding thinning according to preset second grinding parameters, so that the thickness of the chip is reduced to a second target thickness; and controlling the second fine grinding shaft on the thinning device to perform second-stage fine grinding thinning on the semiconductor package located on the suction cup after first-stage fine grinding thinning according to preset third grinding parameters, so that the thickness of the chip is reduced to a third target thickness, thereby completing the thinning process of the semiconductor package. This application enables precise thinning of individual discrete semiconductor packages after cutting and splitting, solving the industry problem that traditional processes cannot adapt to the thinning of discrete semiconductor packages, and adapting to the thinning needs of small batches, high precision, and differentiated semiconductor packages.

[0025] It should be understood that the technical solution of this application can be applied to the following scenarios, but is not limited to: In some possible ways, Figure 1 An application scenario diagram provided for an embodiment of this application, such as... Figure 1As shown, this application scenario may include a thinning device 110 and a network device 120. The thinning device 110 can establish a connection with the network device 120 via a wired network or a wireless network.

[0026] For example, network device 120 may be a terminal device or a server, but is not limited thereto. In one embodiment of this application, thinning device 110 may send a request message to network device 120, which may be used to request the acquisition of preset first grinding parameters. Further, thinning device 110 may receive a response message sent by network device 120, which includes the acquisition of preset first grinding parameters.

[0027] also, Figure 1 An exemplary thinning device 110 and a network device 120 are provided, but other numbers of thinning devices and network devices may be included in practice, and this application does not limit this.

[0028] In other possible implementations, the technical solution of this application can also be implemented by the aforementioned thinning device 110, or by the aforementioned network device 120, and this application does not limit this.

[0029] After introducing the application scenarios of the embodiments of this application, the technical solution of this application will be described in detail below: Figure 2 The flowchart illustrates a method for thinning a semiconductor package as provided in this application embodiment, and can be derived from, as... Figure 1 The thinning device 110 shown is used for execution, but is not limited to it. This method is applied to the thinning device, and the semiconductor package is a package formed by processing a semiconductor package workpiece using a cutting device; the method may include the following steps: S210. After the semiconductor package is placed on the suction cup of the thinning device, the coarse grinding shaft on the thinning device is controlled to perform coarse grinding and thinning on the semiconductor package located on the suction cup according to the preset first grinding parameters, so that the thickness of the plastic package is reduced to the first target thickness.

[0030] like Figure 3 As shown, the semiconductor package includes a PCB board 1, a chip 2 fixed on the PCB board 1, and a molding compound 3 for molding the chip 2 onto the PCB board 1 on the upper surface and outer side of the chip 2.

[0031] After the individual discrete semiconductor package obtained from the cutting of the semiconductor package workpiece is placed on the suction cup of the thinning equipment, the semiconductor package is fixed by the suction cup to ensure that there is no deviation or shaking. Then, the preset first grinding parameters are called to control the operation of the coarse grinding shaft of the thinning equipment to perform overall coarse grinding on the plastic body of the semiconductor package, and finally the thickness of the plastic body on the semiconductor package is reduced to the preset first target thickness.

[0032] For example, the initial molding compound thickness in a discrete semiconductor package is 300 μm. The first grinding parameters are set as follows: coarse grinding wheel speed of 2500 rpm, grinding feed rate of 0.5 μm / s, and grinding pressure of 0.2 MPa. The preset first target thickness is 250 μm. Excess packaging material on the surface of the molding compound is quickly removed by the coarse grinding axis, rapidly reducing the overall thickness of the molding compound and eliminating defects such as protrusions, burrs, and packaging overflow on the surface, laying a smooth processing foundation for subsequent precise chip grinding.

[0033] It should be noted that step S210 only thins the plastic encapsulation on the semiconductor package and does not affect the chip structure inside the semiconductor package.

[0034] By adopting the above steps, the semiconductor package can be pre-ground by the coarse grinding shaft to remove impurities, protrusions, and hard lumps on the surface of the plastic package. This avoids the wear of hard defect particles on the high-precision first and second fine grinding shafts, effectively extending the service life of the fine grinding equipment. At the same time, the coarse grinding stage of the semiconductor package only processes the outer plastic package and does not contact the internal chip, which can completely avoid scratches, wear, chipping and other damage to the precision chip structure caused by the previous processing, and ensure the integrity of the chip body.

[0035] S220. According to the preset second grinding parameters, control the first fine grinding shaft on the thinning device to perform first-stage fine grinding on the semiconductor package that has been coarsely ground and thinned on the chuck, so that the thickness of the chip is reduced to the second target thickness.

[0036] After the rough grinding of the plastic package is completed, the semiconductor package is kept fixed on the chuck, and the preset second grinding parameters are called to control the first fine grinding axis of the thinning equipment to perform first-level fine grinding on the semiconductor package after rough grinding. After breaking through the plastic package layer, the internal chip is gradually thinned to reduce the chip thickness to the preset second target thickness.

[0037] Taking the example of the semiconductor package after rough grinding in step S210, the thickness of the molding compound has been stabilized at 250μm. The second grinding parameters are set as follows: fine grinding wheel speed 2000rpm, grinding feed speed 1.0μm / s, grinding pressure 0.1MPa, and the preset second target thickness of the chip is 180μm. The semiconductor package after rough grinding and thinning is subjected to first-stage fine grinding to grind the molding compound and chip material, gradually reducing the overall thickness of the chip and completing the initial thinning of the chip. At this time, the chip thickness is close to the finished product standard, with only a small amount of finishing allowance left for the chip.

[0038] Through the above steps, the semiconductor package that has been coarsely thinned can be subjected to first-stage fine thinning, which solves the defect that traditional whole-wafer thinning cannot adapt to the differentiated processing of individual semiconductor packages, so as to achieve precise control over the thickness of individual products.

[0039] S230. According to the preset third grinding parameters, control the second fine grinding shaft on the thinning device to perform a second fine grinding on the semiconductor package that has been thinned by the first-stage fine grinding on the suction cup, so that the thickness of the chip is reduced to the third target thickness, so as to complete the thinning process of the semiconductor package.

[0040] After completing the first-stage fine grinding and thinning of the semiconductor package, while keeping the semiconductor package fixed on the chuck, the preset third grinding parameters are called to control the second fine grinding axis of the thinning equipment to perform ultra-fine grinding on the semiconductor package. Finally, the thickness of the chip is precisely controlled to the third target thickness, thereby completing the entire thinning process of a single discrete semiconductor package.

[0041] Following the example of a semiconductor package with a chip thickness of 180μm after the first-stage fine grinding in step S230, the third grinding parameters are set as follows: grinding wheel speed 2700rpm, grinding feed speed 0.5μm / s, and grinding pressure 0.05MPa. The preset third target thickness of the finished chip is 175μm. By controlling the second fine grinding axis to perform a second-stage fine grinding on the semiconductor package, the fine processing stress and micro-scratches on the chip surface are removed, the thickness error is accurately corrected, and the chip thickness is finally stably controlled at a high precision of 175μm.

[0042] Through the above steps, a second-stage fine grinding thinning process can be performed on the semiconductor package after the first-stage fine grinding to perform micro-grinding of the chip, eliminate the thickness deviation of the previous processing, ensure extremely high consistency of the finished chip thickness, meet the high-precision dimensional requirements of high-end semiconductor devices, and ultimately achieve precise processing of discrete semiconductor packages to adapt to the personalized thinning needs of individual semiconductor packages.

[0043] Using the above method, after the semiconductor package is placed on the suction cup of the thinning equipment, the coarse grinding shaft, the first fine grinding shaft, and the second fine grinding shaft on the thinning equipment are sequentially controlled to thin the semiconductor package located on the suction cup according to the preset first grinding parameters, the second grinding parameters, and the third grinding parameters, thus completing the thinning process of the semiconductor package. This method can achieve precise thinning of individual discrete semiconductor packages after cutting and splitting, solving the industry problem that traditional processes cannot adapt to the thinning process of discrete semiconductor packages, and adapting to the thinning process requirements of small batches, high precision, and differentiated semiconductor packages.

[0044] In some possible implementations, the first grinding parameters include: a first spindle speed of 1700 rpm to 2700 rpm, a first longitudinal feed speed of 0.3 µm / s to 1.8 µm / s, and a first chuck axial speed of 70 rpm to 110 rpm.

[0045] Here, the first spindle speed can be one of 1700rpm, 1900rpm, 2100rpm, 2300rpm, 2500rpm, or 2700rpm, but is not limited to this; the first longitudinal feed speed can be one of 0.3µm / s, 0.6µm / s, 0.9µm / s, 1.2µm / s, 1.5µm / s, or 1.8µm / s, but is not limited to this; the first chuck axial speed can be one of 70rpm, 80rpm, 90rpm, 100rpm, or 110rpm, but is not limited to this.

[0046] Specifically, by using a first spindle speed with a constant range of 1700rpm to 2700rpm and a chuck with an axial speed of 70rpm to 110rpm, the contact surface between the coarse grinding shaft and the semiconductor package can be subjected to uniform force, avoiding over-grinding in certain areas. At the same time, by setting the relatively maximum first longitudinal feed speed (0.3µm / s to 1.8µm / s), the coarse grinding shaft and chuck can achieve the highest material removal efficiency for the semiconductor package under the action of the three sets of parameters, which can quickly remove excess material from the molded package and smooth the uneven surface.

[0047] The second grinding parameters include: the second spindle speed is 1700rpm~2700rpm, the second longitudinal feed speed is 0.2µm / s~1.2µm / s, and the second chuck axial speed is 70rpm~110rpm.

[0048] Here, the second spindle speed can be one of 1700rpm, 1900rpm, 2100rpm, 2300rpm, 2500rpm, or 2700rpm, but is not limited to this; the second longitudinal feed speed can be one of 0.2µm / s, 0.3µm / s, 0.6µm / s, 0.9µm / s, or 1.2µm / s, but is not limited to this; the second chuck axial speed can be one of 70rpm, 80rpm, 90rpm, 100rpm, or 110rpm, but is not limited to this.

[0049] By keeping the second spindle speed and the second chuck axial speed in the second grinding parameters consistent with the first spindle speed and the first chuck axial speed in the first grinding parameters, it is possible to ensure that the processing benchmarks for the first-stage fine grinding and thinning of the semiconductor package are consistent, and to avoid processing vibration and positional offset errors caused by speed switching.

[0050] By lowering the second longitudinal feed speed in the second grinding parameters compared to the first longitudinal feed speed in the first grinding parameters, it can adapt to the process switching requirements from molding compound grinding to chip surface grinding. The second longitudinal feed speed can slowly and stably control the first fine grinding axis to thin the chip in the semiconductor package, avoiding high-speed feeding from scratching the precision chip circuit, achieving preliminary and accurate thinning of the chip thickness, and reserving a uniform processing allowance for subsequent secondary fine grinding.

[0051] The third grinding parameters include: the third spindle speed is 1700rpm~2700rpm, the third longitudinal feed speed is 0.05µm / s~1.0µm / s, and the third chuck axial speed is 70rpm~110rpm.

[0052] The third longitudinal feed rate in the third grinding parameter is the lowest and most accurate range among the three sets of parameters. The ultra-low feed rate of 0.05µm / s enables minute thinning of the semiconductor package, accurately correcting thickness deviations from previous processing, and eliminating micro-scratches and surface processing stress. Simultaneously, the third spindle speed and third chuck axial speed in the third grinding parameter are consistent with the first spindle speed and first chuck axial speed in the first grinding parameter, and the second spindle speed and second chuck axial speed in the second grinding parameter throughout the process. This ensures zero speed fluctuation during the second-stage fine grinding and thinning of the semiconductor package, avoiding device vibration, warping, and uneven stress during the finishing process. Ultimately, this guarantees precise chip thickness while optimizing chip surface finish and structural stability.

[0053] In some possible implementations, such as Figure 4As shown, the thinning device has multiple suction cups 5, which are distributed on the working plate 6, and each suction cup 5 can rotate axially on the working plate 6. Figure 5 As shown, the suction cup 5 is provided with multiple adsorption grooves 4, which are evenly distributed in a ring around the axis of the suction cup 5. The angle between the line connecting the center point of the adsorption groove 4 to the center point of the suction cup 5 and the center line of the adsorption groove 4 is within a preset range. The adsorption grooves 4 are used to adsorb and fix the semiconductor package onto the suction cup 5.

[0054] Here, by distributing multiple independent suction cups 5 on the working plate 6 of the thinning equipment, each suction cup 5 can rotate independently along the axis, which can simultaneously complete the adsorption and fixation of multiple discrete semiconductor packages and synchronous thinning processing, thereby adapting to the mass production requirements of semiconductor packages. At the same time, because the independent rotation of a single suction cup 5 can also achieve independent adjustment of the processing angle of discrete semiconductor packages located on the same suction cup 5, without interference between them.

[0055] By setting multiple adsorption grooves 4 on each suction cup and arranging all the adsorption grooves 4 evenly in a ring around the axis of the suction cup, it can be ensured that the force on the suction cup is uniform after the semiconductor package is adsorbed and fixed on the suction cup, thus avoiding problems such as suction cup tilting, offset, and uneven force.

[0056] It should be noted that, as Figure 6 As shown, the different angles between the line connecting the center point of the adsorption groove 4 to the center point of the suction cup and the center line of the adsorption groove 4 correspond to different adsorption force postures of the semiconductor package on the suction cup and different thinning contact angles, thereby directly affecting the shape of the thinning texture formed on the chip in the semiconductor package and the stress distribution inside the chip.

[0057] Furthermore, the coarse grinding shaft 7, the first fine grinding shaft 8, and the second fine grinding shaft 9 are arranged sequentially along the circumferential direction of the working disk 6. Therefore, the working disk 6 can be controlled to rotate along its axial direction so that each suction cup 5 flows sequentially to the position corresponding to the coarse grinding shaft 7, the first fine grinding shaft 8, and the second fine grinding shaft 9 as the working disk 6 rotates.

[0058] Accordingly, before the semiconductor package is placed onto the suction cup of the thinning device, the following steps are also included: S310. Construct a three-dimensional simulation model corresponding to the thinning equipment.

[0059] The three-dimensional simulation model includes a first sub-model corresponding to the suction cup, a second sub-model corresponding to the coarse grinding axis, a third sub-model corresponding to the first fine grinding axis, a fourth sub-model corresponding to the second fine grinding axis, and a fifth sub-model corresponding to the semiconductor package. In the first sub-model, the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is variable within a preset range.

[0060] In this step, by constructing a three-dimensional simulation model corresponding to the thinning equipment, the repeated debugging and trial grinding of the semiconductor package can be replaced by the physical thinning equipment. This allows the target angle to be determined in subsequent steps without damaging the actual semiconductor package or wearing down the grinding wheel and suction cup. This is achieved by adjusting the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove in the first sub-model, thus eliminating external interference such as equipment vibration and manual placement deviation. This provides a complete data foundation for selecting the optimal target angle.

[0061] S320. For each angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank within a preset range, control the second sub-model, the third sub-model, and the fourth sub-model to perform thinning processing on the fifth sub-model located in the adsorption tank in sequence, so as to process thinning texture in the fifth sub-model.

[0062] For example, with a preset range of 0° to 60°, for five gradient angles of 0°, 15°, 30°, 45°, and 60°, the three-dimensional simulation model constructed in step S310 is used to simulate grinding, which is: rough grinding to remove the excess of the molding compound, first-stage fine thinning to reduce the chip thickness, and second-stage fine grinding to shape and level. Through this, the simulation results can intuitively show the skewing of the thinning texture and the unevenness of edge thinning at some angles, so as to distinguish the effect of thinning and forming of semiconductor package at different angles.

[0063] In this step, for each angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank within a preset range, the correspondence between the adsorption tank angle and the thinning texture can be directly established by simulating the grinding of the three-dimensional simulation model. This allows subsequent steps to select the target angle based on this correspondence.

[0064] S330. For each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, based on the thinning texture processed in the fifth sub-model and the third target thickness, the stress of the chip in the fifth sub-model is obtained.

[0065] For example, taking the target thickness of the finished chip of 7μm as a benchmark, stress analysis was performed on the simulated finished product at each included angle. The results are as follows: at an included angle of 0°, the chip edge stress is concentrated, with a maximum residual stress of 85MPa; at an included angle of 6°, the stress distribution is uniform, with a maximum residual stress of 32MPa; at an included angle of 45°, the local texture is too deep, with a stress peak of 78MPa.

[0066] As can be seen, this step can quantify data intuitively and compare the chip stress state at different angles. Therefore, this step can form a complete angle-stress database, so that the selection of the optimal angle in subsequent steps can be based on evidence, avoiding the subjectivity and error of manual experience selection.

[0067] S340. Based on the comparison results between the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, determine the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove, so as to select a suction cup with the target angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove as the suction cup to be installed on the working plate.

[0068] Specifically, using the preset stress as the evaluation benchmark, the stress of the chip corresponding to different angles between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank is compared with the preset stress. The angle with the smallest difference between the chip stress and the preset stress and the most uniform stress distribution is selected as the target angle. Then, the suction cups with the adsorption tank angle matching the target angle are finally selected in batches and assembled onto the working plate of the equipment for subsequent mass production thinning processing.

[0069] For example, with a preset stress of 40 MPa, comparing the data from different groups, the maximum chip stress corresponding to a 30° angle is 39.6 MPa, which is the smallest difference between the preset stress and the actual stress under all operating conditions. Furthermore, the stress distribution is uniform across the entire area, with no localized concentrations, and the thinning texture is smooth and uniform. Therefore, 30° is determined as the target angle, and suction cups with a uniform 30° angle are used for assembly into the equipment for mass production.

[0070] By employing the above method, a pre-optimization mode of 3D simulation modeling + virtual working condition iteration is used before the semiconductor package is thinned. This optimizes the stress state of the semiconductor package during thinning from the tooling structure of the suction groove on the suction cup, thereby solving the industry's hidden problem of chip stress concentration and significantly improving the long-term stability and reliability of the finished product.

[0071] In some possible embodiments, for each angle within a preset range between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the stress of the chip in the fifth sub-model is obtained based on the thinning texture processed in the fifth sub-model and the third target thickness, which may include the following steps: S410. Based on the different angles between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank, a first correspondence is established between the angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank, and the thinning texture processed on the fifth sub-model.

[0072] Specifically, the process involves iterating through all adjustable angles within a preset angle range, extracting the thinning texture features obtained from the simulation processing under each angle condition (including texture density, depth distribution, offset angle, uniformity, local overlapping areas, etc.), and establishing a one-to-one mapping relationship between the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, and the thinning texture morphology features of the package body, using this as the first correspondence to achieve a quantitative correlation between angle variables and the thinned surface morphology.

[0073] For example, continuing with the example of an adjustable angle range of 0° to 60°, five sets of working condition data were collected with a gradient of 15°: 0° corresponds to dense horizontal texture and deeper edge thinning; 15° corresponds to slight texture shift and local unevenness; 30° corresponds to uniform texture across the entire area, consistent depth, and no uneven wear; 45° corresponds to uniform texture across the entire area, consistent depth, and no uneven wear; and 60° corresponds to oblique texture shift and insufficient wear at the edges and corners. Each set of angles and the corresponding texture features were entered into the database, and a first correspondence curve was generated to clarify the pattern of how "angle changes directly affect the morphology of the thinned texture".

[0074] This step allows us to accurately establish the causal relationship between the angle and orientation of the adsorption tank and the thinning defects, clarify the core reasons for uneven wear, uneven texture, and differences in depth caused by different included angles, and provide accurate morphological input for subsequent stress calculations.

[0075] S420. For each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, the stress of the chip in the fifth sub-model is obtained according to the first correspondence and the third target thickness.

[0076] Specifically, based on the first correspondence established in step S410, the thinning texture corresponding to each included angle is retrieved. Combined with the third target thickness (final standard thickness of the finished product) corresponding to the chip, the surface stress difference, material removal amount, and thickness boundary conditions brought about by the thinning texture can be comprehensively considered to calculate the stress of the chip under different included angle conditions and obtain the accurate stress data corresponding to each set of included angles.

[0077] Taking the third target thickness of the chip of 75μm as a fixed boundary condition as an example, the texture characteristics of each group of angles in the first correspondence are retrieved: 30° angle with uniform texture, symmetrical thinning force and uniform material removal, the maximum residual stress of the chip is calculated to be 32MPa; 15° angle with deep grinding texture at the edge, excessive removal of corner material, obvious stress concentration, the maximum residual stress is 85MPa; 60° angle with oblique texture, asymmetrical force, the maximum residual stress is 78MPa. It can be seen that through this step, the chip stress value corresponding to each angle can be finally formed.

[0078] This step combines the real simulation of texture morphology and finished product thickness to simulate and solve the stress of the chip. This allows us to accurately reflect the stress state of the semiconductor package during the thinning process, thus ensuring that the final stress calculation results are accurate and reliable.

[0079] Accordingly, based on the comparison results between the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the adsorption groove to the center point of the chuck and the center line of the adsorption groove, the target angle between the line connecting the center point of the semiconductor package to the center point of the chuck and the center line of the adsorption groove can be determined, which may include the following steps: S510. Based on the stress of the chip corresponding to the different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, a second correspondence is constructed between the stress of the chip in the fifth sub-model after the simulated thinning process is completed and the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove.

[0080] In this step, by summarizing all included angles within the preset angle range and their corresponding chip stresses, a direct mapping relationship is established between the chip stress and the included angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove. This direct mapping relationship is used as the second correspondence relationship, which can intuitively present the influence law of angle variables on chip stress.

[0081] S520. Based on the preset stress and the second correspondence, determine the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove.

[0082] In this step, by using the preset chip safety stress threshold (preset stress) as the evaluation standard and combining the angle-stress change law presented by the second correspondence, the angle that meets the preset stress requirements and has the optimal stress is selected within the entire angle range. Finally, the target angle for mass production is determined, and the selection of tooling standardization for the suction cup is completed.

[0083] Using the above method, a two-layer correspondence model of "angle-texture and angle-stress" can be built, upgrading the traditional disordered and scattered simulation trial optimization method into a standardized optimization system with verifiable data and closed loop, thus solving the defects of low accuracy, high randomness, and lack of theoretical support in traditional simulation optimization. At the same time, by solving the stress under the dual conditions of accurate matching of texture morphology and finished product thickness benchmark constraint, the final stress calculation result obtained is more in line with the actual thinning conditions compared with the single thickness solution method. Furthermore, by fitting the angle-stress law of the whole domain, the single-point data deviation is avoided, and the selection accuracy of the target angle is optimized, thereby maximizing the optimization of the chip stress state.

[0084] In some possible embodiments, according to preset first grinding parameters, controlling the coarse grinding shaft on the thinning device to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the molded package is reduced to the first target thickness, may include the following steps: S610, Obtain a first initial height of the semiconductor package located on the chuck relative to the upper surface of the chuck, and a first initial distance between the upper surface of the semiconductor package located on the chuck and the coarse grinding shaft.

[0085] Before performing rough grinding and thinning of the molded package, two-dimensional height data acquisition is first completed: first, the initial height of the semiconductor package on the chuck relative to the upper surface of the chuck, i.e., the overall actual height of the semiconductor package; second, the initial distance between the upper surface of the semiconductor package and the rough grinding shaft, i.e., the initial gap between the grinding shaft and the surface to be processed.

[0086] S620. Based on the first initial height and the first initial distance, and based on the first grinding parameters, control the coarse grinding shaft to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the plastic package is reduced to the first target thickness.

[0087] Here, based on the first initial height and the first initial distance, and based on the first grinding parameters, the coarse grinding shaft is controlled to perform coarse grinding and thinning on the semiconductor package located on the chuck. This enables the height of the coarse grinding shaft to be measured and calibrated by using the height and distance obtained from the previous step, thus avoiding the problem of uneven grinding of the semiconductor package caused by uniformly fixed thinning amount.

[0088] Accordingly, based on the preset second grinding parameters, the first fine grinding shaft on the thinning device is controlled to perform a first-stage fine grinding thinning on the semiconductor package that has been coarsely thinned on the chuck, so that the thickness of the chip is reduced to the second target thickness. This may include the following steps: S710, Obtain the second initial height of the coarsely ground and thinned semiconductor package relative to the upper surface of the chuck, and the second initial distance between the upper surface of the coarsely ground and thinned semiconductor package and the first fine grinding shaft. S720. Based on the second initial height and the second initial distance, control the first fine grinding shaft to perform first-stage fine grinding on the semiconductor package after coarse grinding and thinning, so that the thickness of the chip is reduced to the second target thickness.

[0089] Here, after the rough grinding process of the semiconductor package is completed and before entering the first-stage fine grinding, real-time operating data is collected again, namely: the second initial height of the package relative to the upper surface of the chuck after rough grinding, and the second initial distance between the upper surface of the package and the first fine grinding axis; then, based on the measured second initial height and second initial distance, the feed of the first fine grinding axis is adaptively adjusted in combination with the second grinding parameters to accurately reduce the chip thickness, so that the chip thickness stably reaches the second target thickness, and the initial accurate thickness reduction of the chip is completed.

[0090] Accordingly, based on the preset third grinding parameters, the second fine grinding shaft on the thinning device is controlled to perform a second-stage fine grinding thinning on the semiconductor package located on the chuck after the first-stage fine grinding thinning, so that the thickness of the chip is reduced to the third target thickness. This may include the following steps: S810, obtain the third initial height of the semiconductor package after primary fine grinding and thinning on the chuck relative to the upper surface of the chuck, and the third initial distance between the upper surface of the semiconductor package after primary fine grinding and thinning and the second fine grinding axis. S820: Based on the third initial height and the third initial distance, control the second fine grinding shaft to perform a second fine grinding thinning on the semiconductor package after the first-stage fine grinding thinning, so that the thickness of the chip is reduced to the third target thickness.

[0091] Here, after the first-stage fine grinding of the semiconductor package is completed and before the final product is shaped, the third working condition data acquisition is performed, namely: to obtain the third initial height of the semiconductor package relative to the upper surface of the chuck after the first-stage fine grinding, and the third initial distance between the upper surface of the semiconductor package and the second fine grinding axis. Then, combined with the real-time third initial height and third initial distance, the micro-feed of the second fine grinding axis is adaptively adjusted to complete the final chip grinding, stress relief, and thickness calibration, so that the chip thickness accurately reaches the third target thickness, and the semiconductor package is thinned.

[0092] By adopting the above method, by setting up independent real-time detection links for initial height and initial distance at the front end of each process corresponding to rough grinding, first-level fine grinding and second-level fine grinding, a three-level closed-loop control of "detection-calculation-adaptive thinning" is formed, thereby enabling personalized and precise processing of discrete semiconductor packages.

[0093] Furthermore, based on the first initial height and the first initial distance, controlling the coarse grinding shaft to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the molded package is reduced to the first target thickness, may include the following steps: S910. Based on the first initial height and the first initial distance, control the coarse grinding shaft to move to a position that contacts the upper surface of the semiconductor package.

[0094] Here, based on the first initial height and the first initial distance, the reference displacement of the grinding shaft can be calculated. The rough grinding shaft is controlled to move downwards by the reference displacement until the end face of the grinding shaft is in complete contact with the upper surface of the plastic encapsulation of the semiconductor package, thus completing the thinning reference alignment of the grinding shaft and establishing the zero-error processing starting point for subsequent segmented thinning.

[0095] S920. After the coarse grinding shaft moves to contact the upper surface of the semiconductor package, and every time the coarse grinding shaft descends to a first preset height, the coarse grinding shaft stops coarse grinding and thinning of the semiconductor package, and the first current height of the semiconductor package relative to the upper surface of the suction cup is obtained.

[0096] After the coarse grinding shaft completes the contact and alignment with the surface of the semiconductor package, the coarse grinding shaft is controlled to descend in segments to thin it according to the first preset height. That is, each time the coarse grinding shaft descends to the first preset height position, the thinning action of the coarse grinding shaft is immediately paused, and the actual height of the semiconductor package relative to the upper surface of the chuck is collected in real time and recorded as the first current height.

[0097] For example: Set the first preset height (single-segment downward thinning amount) to 10μm, and the target total thinning amount to 60μm. When the coarse grinding shaft thins down by 10μm, the processing is paused and the current actual height of the semiconductor package is detected: The theoretical height after the first segment thinning should be 50μm, and the actual measured current height is 48μm. Record the 2μm thinning deviation of this segment to provide real data support for subsequent correction.

[0098] S930. When the coarse grinding shaft descends to a first preset height, determine whether the grinding height of the coarse grinding shaft on the semiconductor package needs to be corrected based on the first initial height, the first preset height and the first current height.

[0099] Specifically, after each segment of thinning is completed and the first current height is collected, three core parameters can be combined: the first initial height of the workpiece in its initial state, the first preset height (the theoretical thinning amount per segment), and the first current height after processing. By comparing the difference between the theoretical thinning thickness and the actual thinning thickness, it can be determined whether there is a deviation in the current thinning stroke, and then it can be determined whether the next segment of thinning needs to be corrected for the downward height.

[0100] For example: the initial height is 310μm, the preset thinning height per segment is 30μm, and the theoretical height after processing should be 280μm; the actual measured current height is 282μm, and the actual thinning amount is only 28μm, which is 2μm under-wearing deviation. Therefore, it can be determined that the current thinning stroke is insufficient and there is a processing deviation, so height correction needs to be performed; if the measured height is completely consistent with the theoretical height, then it is determined that no correction is needed.

[0101] S940. If correction is required, a first correction value is calculated based on the first initial height, the first preset height, and the first current height, so that when the coarse grinding shaft descends to the next first preset height, the descent height of the coarse grinding shaft is controlled based on the first correction value and the first preset height.

[0102] Specifically, if it is determined that there is a deviation in the current thinning and it needs to be corrected, the corresponding first correction value can be calculated based on the first initial height, the first preset height, and the first current height. In the next segmented thinning process, the standard downward movement of the first preset height is corrected in combination with the first correction value to compensate for the thinning deviation of the previous segment, so as to offset the previous under-wearing or over-wearing error and ensure that the overall thinning thickness continues to converge toward the target thickness.

[0103] For example, if there is a 2μm under-wear deviation in the previous section, the calculated first correction value is +2μm. Therefore, the original preset downward height of the next section is 30μm, and the actual downward height after correction is adjusted to 32μm. By thinning the next section by 2μm, the residual under-wear amount in the previous section is accurately compensated, the overall thickness deviation is gradually corrected, and the total thinning amount is accurately met.

[0104] As can be seen, step S940 enables real-time compensation for minute deviations caused by each thinning segment, preventing errors from being retained or accumulated, thereby achieving dynamic precision correction throughout the rough grinding process and ultimately ensuring that the thickness of the semiconductor molding compound accurately reaches the first target thickness.

[0105] S950. If no correction is required, when the coarse grinding shaft descends to the next first preset height, the descent height of the coarse grinding shaft is controlled according to the first preset height.

[0106] Specifically: if the measured height of the first segment is consistent with the theoretical height and there is no thinning deviation, then it is determined that no correction is needed. The downward height of the next segment of the rough grinding shaft shall be strictly executed according to the first preset height of the standard, maintaining the standard stepping thinning rhythm, and completing the remaining rough grinding process stably and efficiently.

[0107] For example: if the theoretical height of a certain section after coarse thinning is 250μm, and the actual measured height of the first section is also 250μm with no deviation, then there is no need to calculate the correction value. The next section can continue to be thinned according to the preset height of 30μm to maintain the processing efficiency and rhythm stability.

[0108] By using the above method, the process of controlling the coarse grinding shaft to coarsely thin the semiconductor package is broken down into a closed-loop process of "segmented descent, post-segment detection, deviation judgment, and dynamic compensation". This enables the monitoring, correction, and convergence of the coarse grinding process of the semiconductor package, thereby solving the problem of error accumulation in the coarse grinding process and improving the accuracy of the coarse grinding thickness of the plastic package.

[0109] Optionally, controlling the first fine grinding axis to perform a first-stage fine grinding thinning on the semiconductor package after rough grinding, based on the second initial height and the second initial distance, so that the chip thickness is reduced to the second target thickness, may include the following steps: S1010. Based on the second initial height and the second initial distance, control the first fine grinding shaft to move to a position that contacts the upper surface of the semiconductor package after coarse grinding and thinning.

[0110] Specifically: After the rough grinding process of the semiconductor package is completed and the reference of the semiconductor package is stable, the measured second initial height (the actual height of the package relative to the suction cup after rough grinding) and second initial distance (the initial gap between the upper surface of the semiconductor package and the first fine grinding shaft) are retrieved. The downward displacement of the first fine grinding shaft can be accurately calculated, thereby controlling the first fine grinding shaft to descend smoothly and making the end face of the first fine grinding shaft accurately fit the upper surface of the semiconductor package after rough grinding. This completes the zero-error reference alignment of the first-stage fine grinding, thus establishing the starting point for the standard fine grinding process of the chip.

[0111] S1020 After the first fine grinding shaft moves to contact the upper surface of the semiconductor package after coarse grinding and thinning, and every time the first fine grinding shaft descends to a second preset height, the first fine grinding shaft stops the first fine grinding and thinning of the semiconductor package, and the second current height of the semiconductor package relative to the upper surface of the suction cup is obtained.

[0112] Specifically: After the first fine grinding shaft completes the bonding and alignment between itself and the upper surface of the semiconductor package after coarse grinding and thinning, it descends in segments to thin it according to the preset second preset height (single-segment fine grinding step amount); each time the first fine grinding shaft descends to the second preset height position, the thinning action of the first fine grinding shaft is paused, and the actual height of the semiconductor package relative to the upper surface of the chuck is collected in real time and recorded as the second current height.

[0113] For example, considering the process characteristics of the first-stage fine grinding micro-thickness reduction, the second preset height (single-segment step-by-step thinning amount) is set to 10μm, and the target total fine grinding removal amount is 72μm. The machine is stopped immediately for detection when the first fine grinding axis thins by 10μm each time it moves down. If the theoretical workpiece height after the first segment thinning should be 142μm, but the actual measured second current height is 143μm, there is a 1μm under-grinding deviation. The single-segment thinning error is recorded to achieve real-time capture of the deviation.

[0114] S1030: When the first fine grinding shaft descends to the second preset height, determine whether the grinding height of the first fine grinding shaft on the semiconductor package needs to be corrected based on the second initial height, the second preset height and the second current height.

[0115] Specifically: After each pair of semiconductor packages completes a segment of fine grinding and collects the second current height, the system combines three core parameters: the second initial height measured after rough grinding, the second preset height preset by the process (the theoretical thinning amount per segment), and the second current height after processing. By comparing the difference between the theoretical remaining height and the actual remaining height, the system accurately determines whether there is a deviation in the current fine grinding stroke, and then determines whether the next segment of thinning needs to be height corrected and compensated.

[0116] For example: the second initial height is 152μm, the second preset height for a single segment is 10μm, and the theoretical remaining height after processing should be 142μm; the actual measured second current height is 143μm, and the actual thinning removal is only 9μm, which is 1μm under-wearing deviation. It can be determined that the current thinning stroke is insufficient and correction compensation needs to be performed; if the measured height is completely consistent with the theoretical height, it is determined that no correction is needed and the standard processing rhythm should be maintained.

[0117] S1040 If correction is required, a second correction value is calculated based on the second initial height, the second preset height, and the second current height, so that when the first fine grinding shaft descends to the next second preset height, the descent height of the first fine grinding shaft is controlled based on the second correction value and the second preset height.

[0118] Specifically: If a thinning deviation is determined in the current first-level fine grinding segment, a second correction value can be automatically calculated based on the second initial height, the second preset height, and the second current height; in the next segment thinning process, the downward amount of the standard second preset height is corrected in combination with the second correction value to specifically compensate for the under-grinding or over-grinding error remaining in the previous segment, so that the overall chip thinning thickness continues to converge toward the second target thickness, ensuring that the fine processing allowance is uniform and consistent.

[0119] For example, if there is a 1μm under-wear deviation in the previous segment, the second correction value can be calculated as +1μm. The second preset height of the next segment is 10μm. After correction, the actual downward height is adjusted to 11μm. By thinning the next segment by 1μm, the residual deviation of the previous segment is accurately compensated, and the overall thickness error is gradually corrected to ensure that the final chip thickness accurately converges to the second target thickness of 80μm.

[0120] S1050 If no correction is required, when the first fine grinding shaft descends to the next second preset height, the descent height of the first fine grinding shaft is controlled according to the second preset height.

[0121] Specifically: if the second current height is completely matched with the theoretical remaining height after the current segment fine grinding and there is no thinning deviation, then it is determined that no correction is needed; the downward height of the first fine grinding shaft in the next segment shall be strictly executed in accordance with the standard second preset height, so as to maintain the standardization and stability of the first-level fine grinding step processing and efficiently complete the remaining fine grinding process.

[0122] For example, after a certain segment of fine grinding, the theoretical remaining height is 132μm, and the actual measured second current height is also 132μm, indicating that the thinning amount fully meets the standard and has no deviation. The system does not need to calculate the second correction value, and the next segment continues to thin down according to the second preset height of 10μm, maintaining a stable and efficient processing rhythm.

[0123] By using the above method, the process of controlling the first fine grinding shaft to perform primary fine grinding on the semiconductor package is decomposed into a fully closed-loop process of "segmented descent, post-segment detection, deviation judgment, and dynamic compensation". This enables the monitoring, correction, and convergence of the primary fine grinding process of the semiconductor package, thereby solving the problem of error accumulation in the primary fine grinding process and improving the accuracy of the primary fine grinding thickness of the semiconductor package.

[0124] Optionally, based on the third initial height and the third initial distance, controlling the second fine grinding shaft to perform a second fine grinding thinning on the semiconductor package after the first-stage fine grinding thinning, so that the chip thickness is reduced to the third target thickness, may include the following steps: S1110. Based on the third initial height and the third initial distance, control the second fine grinding shaft to move to the position where it contacts the upper surface of the semiconductor package after the first-stage fine grinding and thinning.

[0125] S1120 After the second fine grinding shaft moves to contact the upper surface of the semiconductor package after the first-stage fine grinding and thinning, and every time the second fine grinding shaft descends to a third preset height, the second-stage fine grinding and thinning of the semiconductor package by the second fine grinding shaft is stopped, and the third current height of the semiconductor package on the suction cup relative to the upper surface of the suction cup is obtained.

[0126] S1130. When the second fine grinding shaft descends to the third preset height, determine whether the grinding height of the second fine grinding shaft on the semiconductor package needs to be corrected based on the third initial height, the third preset height and the third current height.

[0127] S1140. If correction is required, calculate the third correction value based on the third initial height, the third preset height, and the third current height, so as to control the descent height of the second fine grinding shaft based on the third correction value and the third preset height when the second fine grinding shaft descends to the next third preset height.

[0128] S1150 If no correction is required, when the second fine grinding shaft descends to the next third preset height, the descent height of the second fine grinding shaft is controlled according to the third preset height.

[0129] By using the above method, the process of controlling the second fine grinding shaft to perform secondary fine grinding on the semiconductor package is decomposed into a fully closed-loop process of "segmented descent, post-segment detection, deviation judgment, and dynamic compensation". This enables the monitoring, correction, and convergence of the secondary fine grinding process of the semiconductor package, thereby solving the problem of error accumulation in the secondary fine grinding process and improving the accuracy of the secondary fine grinding thickness of the semiconductor package.

[0130] Figure 7 This is a schematic diagram of a semiconductor package thinning device 1200 according to an embodiment of the present invention. The semiconductor package thinning device 1200 is applied to a thinning equipment. The semiconductor package is a package formed by processing a semiconductor packaged workpiece using a cutting equipment. The semiconductor package includes a PCB board, a chip fixed on the PCB board, and a molding compound for encapsulating the chip on the PCB board, with the chip's upper surface and outer side disposed thereon. The semiconductor package thinning device 1200 includes: The coarse grinding and thinning control module 1210 is used to control the coarse grinding shaft on the thinning equipment to perform coarse grinding and thinning on the plastic encapsulation in the semiconductor package located on the suction cup according to the preset first grinding parameters after the semiconductor package is placed on the suction cup, so that the thickness of the plastic encapsulation is reduced to the first target thickness. The first-stage fine grinding and thinning control module 1220 is used to control the first fine grinding shaft on the thinning device to perform first-stage fine grinding and thinning on the semiconductor package that has been coarsely ground and thinned on the chuck, according to the preset second grinding parameters, so that the thickness of the chip is reduced to the second target thickness. The secondary fine grinding and thinning control module 1230 is used to control the second fine grinding shaft on the thinning device to perform secondary fine grinding and thinning on the semiconductor package that has been thinned by the first-stage fine grinding on the suction cup according to the preset third grinding parameters, so that the thickness of the chip is reduced to the third target thickness, thereby completing the thinning process of the semiconductor package.

[0131] In some possible implementations, the first grinding parameters include: a first spindle speed of 1700 rpm to 2700 rpm, a first longitudinal feed speed of 0.3 µm / s to 1.8 µm / s, and a first chuck axial speed of 70 rpm to 110 rpm; The second grinding parameters include: the second spindle speed is 1700rpm~2700rpm, the second longitudinal feed speed is 0.2µm / s~1.2µm / s, and the second chuck axial speed is 70rpm~110rpm; The third grinding parameters include: the third spindle speed is 1700rpm~2700rpm, the third longitudinal feed speed is 0.05µm / s~1.0µm / s, and the third chuck axial speed is 70rpm~110rpm.

[0132] In some implementations, the thinning device has multiple suction cups, which are distributed on a working plate. Each suction cup can rotate axially on the working plate. Each suction cup has multiple adsorption grooves, which are evenly distributed in a ring around the axis of the suction cup. The angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is within a preset range. The adsorption grooves are used to adsorb and fix the semiconductor package onto the suction cup. Accordingly, the semiconductor package thinning device 1200 also includes: The three-dimensional simulation model construction module is used to construct a three-dimensional simulation model corresponding to the thinning equipment. The three-dimensional simulation model includes a first sub-model corresponding to the suction cup, a second sub-model corresponding to the coarse grinding shaft, a third sub-model corresponding to the first fine grinding shaft, a fourth sub-model corresponding to the second fine grinding shaft, and a fifth sub-model corresponding to the semiconductor package. In the first sub-model, the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is variable within a preset range. The simulated thinning process module is used to control the second, third, and fourth sub-models to perform thinning processes on the fifth sub-model located in the adsorption tank for each angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank within a preset range, so as to process thinning textures in the fifth sub-model. The stress calculation module is used to calculate the stress of the chip in the fifth sub-model for each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, based on the thinning texture processed in the fifth sub-model and the third target thickness. The suction cup selection module is used to determine the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the suction groove, based on the comparison results between the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the suction groove to the center point of the suction cup and the center line of the suction groove. This allows the selection of a suction cup with the target angle between the line connecting the center point of the suction groove to the center point of the suction cup and the center line of the suction groove as the suction cup to be mounted on the working plate.

[0133] In some implementations, the stress calculation module includes: The first correspondence construction unit is used to construct the first correspondence between the angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank and the thinning texture processed on the fifth sub-model, based on the different included angles between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank. The stress calculation unit is used to calculate the stress of the chip in the fifth sub-model based on the first correspondence and the third target thickness for each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range. Accordingly, the suction cup selection module includes: The second correspondence construction unit is used to construct a second correspondence between the stress of the chip in the fifth sub-model after the simulated thinning process and the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, based on the different included angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove. The target angle determination unit is used to determine the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove, based on the preset stress and the second correspondence.

[0134] In some implementations, the rough grinding thinning control module 1210 includes: The first acquisition unit is used to acquire the first initial height of the semiconductor package located on the chuck relative to the upper surface of the chuck, and the first initial distance between the upper surface of the semiconductor package located on the chuck and the coarse grinding shaft. The coarse grinding and thinning control unit is used to control the coarse grinding shaft to perform coarse grinding and thinning on the semiconductor package located on the chuck according to the first initial height and the first initial distance and according to the first grinding parameters, so that the thickness of the plastic package is reduced to the first target thickness; Accordingly, the primary fine grinding and thinning control module 1220 includes: The second acquisition unit is used to acquire the second initial height of the semiconductor package after rough grinding and thinning on the chuck relative to the upper surface of the chuck, and the second initial distance between the upper surface of the semiconductor package after rough grinding and thinning and the first fine grinding shaft. The first-stage fine grinding and thinning control unit is used to control the first fine grinding shaft to perform first-stage fine grinding and thinning on the semiconductor package after coarse grinding and thinning according to the second initial height and the second initial distance, so that the thickness of the chip is reduced to the second target thickness; Accordingly, the secondary fine grinding and thinning control module 1230 includes: The third acquisition unit is used to acquire the third initial height of the semiconductor package after primary fine grinding and thinning on the chuck relative to the upper surface of the chuck, and the third initial distance between the upper surface of the semiconductor package after primary fine grinding and thinning and the second fine grinding shaft. The secondary fine grinding and thinning control unit is used to control the second fine grinding shaft to perform secondary fine grinding and thinning on the semiconductor package after primary fine grinding and thinning, based on the third initial height and the third initial distance, so that the thickness of the chip is reduced to the third target thickness.

[0135] In some possible implementations, the rough grinding thinning control unit includes: The first control subunit is used to control the coarse grinding shaft to move to a position that contacts the upper surface of the semiconductor package based on the first initial height and the first initial distance. The first current height acquisition subunit is used to stop the coarse grinding shaft from coarsely grinding and thinning the semiconductor package after the coarse grinding shaft moves to contact the upper surface of the semiconductor package and every time the coarse grinding shaft descends to a first preset height, and to acquire the first current height of the semiconductor package relative to the upper surface of the suction cup. The first judgment subunit is used to determine whether the grinding height of the coarse grinding shaft on the semiconductor package needs to be corrected when the coarse grinding shaft descends to a first preset height, based on the first initial height, the first preset height and the first current height. The first coarse grinding shaft height control subunit is used to calculate a first correction value based on the first initial height, the first preset height and the first current height if correction is required, so as to control the descent height of the coarse grinding shaft based on the first correction value and the first preset height when the coarse grinding shaft descends to the next first preset height. The second coarse grinding shaft height control subunit is used to control the descent height of the coarse grinding shaft according to the first preset height when the coarse grinding shaft descends to the next first preset height if no correction is required.

[0136] In some possible implementations, the primary fine grinding and thinning control unit includes: The second control subunit is used to control the first fine grinding shaft to move to a position that contacts the upper surface of the semiconductor package after coarse grinding and thinning, based on the second initial height and the second initial distance. The second current height acquisition subunit is used to acquire the second current height of the semiconductor package relative to the upper surface of the chuck after the first fine grinding shaft moves to contact the upper surface of the semiconductor package after coarse grinding and thinning, and when the first fine grinding shaft descends to the second preset height, to stop the first fine grinding shaft from performing the first fine grinding and thinning of the semiconductor package. The second judgment subunit is used to determine whether the grinding height of the first fine grinding shaft on the semiconductor package needs to be corrected based on the second initial height, the second preset height and the second current height each time the first fine grinding shaft descends to the second preset height. The first fine grinding shaft height control subunit is used to calculate a second correction value based on the second initial height, the second preset height and the second current height if correction is required, so as to control the descent height of the first fine grinding shaft based on the second correction value and the second preset height when the first fine grinding shaft descends to the next second preset height. The second fine grinding shaft height control subunit is used to control the descent height of the first fine grinding shaft according to the second preset height when the first fine grinding shaft descends to the next second preset height if no correction is required.

[0137] In some possible implementations, the secondary fine grinding and thinning control unit includes: The third control subunit is used to control the second fine grinding shaft to move to the position where it contacts the upper surface of the semiconductor package after the first-stage fine grinding and thinning, based on the third initial height and the third initial distance. The third current height acquisition subunit is used to acquire the third current height of the semiconductor package relative to the upper surface of the chuck after the second fine grinding shaft moves to contact the upper surface of the semiconductor package after the first-stage fine grinding and thinning, and when the second fine grinding shaft descends to the third preset height. The third judgment subunit is used to determine whether the grinding height of the second fine grinding shaft on the semiconductor package needs to be corrected based on the third initial height, the third preset height and the third current height when the second fine grinding shaft descends to the third preset height. The third fine grinding shaft height control subunit is used to calculate a third correction value based on the third initial height, the third preset height and the third current height if correction is required, so as to control the descent height of the second fine grinding shaft based on the third correction value and the third preset height when the second fine grinding shaft descends to the next third preset height. The fourth fine grinding shaft height control subunit is used to control the descent height of the second fine grinding shaft according to the third preset height when the second fine grinding shaft descends to the next third preset height if no correction is required.

[0138] It should be understood that the embodiments of the semiconductor package thinning apparatus 1200 and the semiconductor package thinning method can correspond to each other, and similar descriptions can be found in the semiconductor package thinning method embodiments. To avoid repetition, further details are omitted here. Specifically, Figure 7The semiconductor package thinning device 1200 shown can execute the above-described semiconductor package thinning method embodiment, and the aforementioned and other operations and / or functions of each module in the semiconductor package thinning device 1200 are respectively for implementing the corresponding process in the above-described semiconductor package thinning method, which will not be described in detail here for the sake of brevity.

[0139] The semiconductor package thinning device 1200 of this invention, described above with reference to the accompanying drawings, is an example of a functional module. It should be understood that this functional module can be implemented in hardware, in software instructions, or in a combination of hardware and software modules. Specifically, each step of the semiconductor package thinning method embodiment of this invention can be completed by integrated logic circuits in the processor's hardware and / or by software instructions. The steps of the semiconductor package thinning method disclosed in this invention can be directly implemented by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. Optionally, the software module can be located in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the semiconductor package thinning method embodiment described above.

[0140] Figure 8 This is a schematic block diagram of a thinning device 110 according to an embodiment of the present invention.

[0141] like Figure 8 As shown, the thinning device 110 may include: The system includes a memory 111 and a processor 112. The memory 111 stores computer programs and transfers the program code to the processor 112. In other words, the processor 112 can retrieve and run the computer programs from the memory 111 to implement the methods described in the embodiments of the present invention.

[0142] For example, the processor 112 can be used to execute the above-described method embodiments according to instructions in the computer program.

[0143] In some embodiments of the present invention, the thinning device 110 may include, but is not limited to: General-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0144] In some embodiments of the present invention, the memory 111 includes, but is not limited to: Volatile memory and / or non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DR RAM).

[0145] In some embodiments of the present invention, the computer program may be divided into one or more modules, which are stored in the memory 111 and executed by the processor 112 to perform the method provided by the present invention. The one or more modules may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the controller.

[0146] like Figure 8 As shown, the thinning device 110 may further include: Transceiver 113, which can be connected to processor 112 or memory 111.

[0147] The processor 112 can control the transceiver 113 to communicate with other devices; specifically, it can send information or data to other devices or receive information or data sent by other devices. The transceiver 113 may include a transmitter and a receiver. The transceiver 113 may further include antennas, and the number of antennas may be one or more.

[0148] It should be understood that the various components in the thinning device are connected through a bus system, which includes a data bus, a power bus, a control bus, and a status signal bus.

[0149] The present invention also provides a thinning device, including the above-described semiconductor package thinning apparatus.

[0150] The present invention also provides a computer storage medium having a computer program stored thereon, which, when executed by a computer, enables the computer to perform the methods of the above-described method embodiments. Alternatively, one embodiment of the present invention also provides a computer program product containing instructions that, when executed by a computer, cause the computer to perform the methods of the above-described method embodiments.

[0151] When implemented using software, it can be implemented entirely or partially as a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the product follows the processes or functions described in the embodiments of this invention. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., Digital Video Disc (DVD)), or a semiconductor medium (e.g., Solid State Disk (SSD)).

[0152] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0153] In the several embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or modules may be electrical, mechanical, or other forms.

[0154] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. For example, the functional modules in the various embodiments of this application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0155] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for thinning a semiconductor package, applied to a thinning device, characterized in that, The semiconductor package is a package formed by processing a semiconductor packaged workpiece using a cutting device. The semiconductor package includes a PCB board, a chip fixed on the PCB board, and a molding compound disposed on the upper surface and outer side of the chip to encapsulate the chip on the PCB board. The method includes: After the semiconductor package is placed on the suction cup of the thinning device, the coarse grinding shaft on the thinning device is controlled to perform coarse grinding and thinning on the semiconductor package located on the suction cup according to the preset first grinding parameters, so that the thickness of the plastic package is reduced to the first target thickness. According to the preset second grinding parameters, the first fine grinding shaft on the thinning device is controlled to perform first-stage fine grinding on the semiconductor package that has been coarsely thinned on the suction cup, so that the thickness of the chip is reduced to the second target thickness. According to the preset third grinding parameters, the second fine grinding shaft on the thinning device is controlled to perform a second fine grinding on the semiconductor package that has been thinned by the first-stage fine grinding on the suction cup, so that the thickness of the chip is reduced to the third target thickness, thereby completing the thinning process of the semiconductor package. The thinning device comprises multiple suction cups, which are distributed on a working plate. Each suction cup is axially rotatable on the working plate. Each suction cup has multiple adsorption grooves, which are evenly distributed in a ring around the axis of the suction cup. The angle between the line connecting the center point of each adsorption groove to the center point of the suction cup and the center line of the adsorption groove is within a preset range. The adsorption grooves are used to adsorb and fix the semiconductor package onto the suction cup. Correspondingly, before the semiconductor package is placed onto the suction cup of the thinning device, the device further includes: A three-dimensional simulation model corresponding to the thinning device is constructed; the three-dimensional simulation model includes a first sub-model corresponding to the suction cup, a second sub-model corresponding to the coarse grinding shaft, a third sub-model corresponding to the first fine grinding shaft, a fourth sub-model corresponding to the second fine grinding shaft, and a fifth sub-model corresponding to the semiconductor package; wherein, in the first sub-model, the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is variable within a preset range; For each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, the second sub-model, the third sub-model, and the fourth sub-model are controlled to sequentially perform thinning processing on the fifth sub-model located in the adsorption groove, so as to process thinning texture in the fifth sub-model. For each angle within a preset range between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the stress of the chip in the fifth sub-model is obtained based on the thinning texture processed in the fifth sub-model and the third target thickness. Based on the comparison results between the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove is determined, so as to select a suction cup with the target angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove as the suction cup to be installed on the working plate.

2. The method for thinning a semiconductor package according to claim 1, characterized in that, The first grinding parameters include: a first spindle speed of 1700 rpm to 2700 rpm, a first longitudinal feed speed of 0.3 µm / s to 1.8 µm / s, and a first chuck axial speed of 70 rpm to 110 rpm; The second grinding parameters include: a second spindle speed of 1700 rpm to 2700 rpm, a second longitudinal feed speed of 0.2 µm / s to 1.2 µm / s, and a second chuck axial speed of 70 rpm to 110 rpm; The third grinding parameters include: a third spindle speed of 1700 rpm to 2700 rpm, a third longitudinal feed speed of 0.05 µm / s to 1.0 µm / s, and a third chuck axial speed of 70 rpm to 110 rpm.

3. The method for thinning a semiconductor package according to claim 1, characterized in that, The stress of the chip in the fifth sub-model is obtained based on the thinning texture processed in the fifth sub-model and the third target thickness, for each angle within a preset range between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, including: Based on the different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, a first correspondence is established between the angle between the line connecting the center point of the adsorption groove to the center line of the adsorption groove and the center line of the adsorption groove, and the thinning texture processed on the fifth sub-model. For each angle within a preset range between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, the stress of the chip in the fifth sub-model is obtained according to the first correspondence and the third target thickness. Accordingly, determining the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the suction cup, based on a comparison of the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the suction groove to the center point of the suction cup and the center line of the suction groove, includes: Based on the stress of the chip corresponding to the different angles between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove, a second correspondence is constructed between the stress of the chip in the fifth sub-model after the simulated thinning process is completed and the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove. Based on the preset stress and the second correspondence, the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the adsorption groove is determined.

4. The method for thinning a semiconductor package according to claim 1, characterized in that, The step of controlling the coarse grinding shaft on the thinning device to perform coarse grinding and thinning on the semiconductor package located on the chuck according to the preset first grinding parameters, so that the thickness of the molded package is reduced to the first target thickness, includes: Obtain a first initial height of the semiconductor package located on the chuck relative to the upper surface of the chuck, and a first initial distance between the upper surface of the semiconductor package located on the chuck and the coarse grinding shaft; Based on the first initial height and the first initial distance, and based on the first grinding parameters, the coarse grinding shaft is controlled to perform coarse grinding and thinning on the semiconductor package located on the chuck, so that the thickness of the plastic package is reduced to the first target thickness; Accordingly, controlling the first fine grinding shaft on the thinning device to perform primary fine grinding on the semiconductor package located on the chuck after coarse grinding and thinning, according to the preset second grinding parameters, so that the thickness of the chip is reduced to the second target thickness, includes: Obtain the second initial height of the coarsely ground and thinned semiconductor package relative to the upper surface of the chuck, and the second initial distance between the upper surface of the coarsely ground and thinned semiconductor package and the first fine grinding shaft; Based on the second initial height and the second initial distance, the first fine grinding shaft is controlled to perform a first-stage fine grinding thinning on the semiconductor package after coarse grinding thinning, so that the thickness of the chip is reduced to the second target thickness; Accordingly, the step of controlling the second fine grinding shaft on the thinning device to perform a second fine grinding thinning on the semiconductor package located on the chuck after the first-stage fine grinding thinning, according to the preset third grinding parameters, so that the thickness of the chip is reduced to the third target thickness, includes: Obtain the third initial height of the semiconductor package after primary fine grinding and thinning on the chuck relative to the upper surface of the chuck, and the third initial distance between the upper surface of the semiconductor package after primary fine grinding and thinning and the second fine grinding axis; Based on the third initial height and the third initial distance, the second fine grinding shaft is controlled to perform a second fine grinding thinning on the semiconductor package after the first-stage fine grinding thinning, so that the thickness of the chip is reduced to the third target thickness.

5. The method for thinning a semiconductor package according to claim 4, characterized in that, The step of controlling the coarse grinding shaft to perform coarse grinding and thinning on the semiconductor package located on the chuck, based on the first initial height and the first initial distance and according to the first grinding parameters, so that the thickness of the molded package is reduced to a first target thickness, includes: Based on the first initial height and the first initial distance, the coarse grinding shaft is controlled to move to a position that contacts the upper surface of the semiconductor package; After the coarse grinding shaft moves to contact the upper surface of the semiconductor package, and every time the coarse grinding shaft descends to a first preset height, the coarse grinding shaft stops coarsely grinding and thinning the semiconductor package, and the first current height of the semiconductor package relative to the upper surface of the suction cup is obtained. When the coarse grinding shaft descends to a first preset height, it is determined whether the grinding height of the coarse grinding shaft on the semiconductor package needs to be corrected based on the first initial height, the first preset height, and the first current height. If correction is required, a first correction value is calculated based on the first initial height, the first preset height, and the first current height, so that when the coarse grinding shaft descends to the next first preset height, the descent height of the coarse grinding shaft is controlled based on the first correction value and the first preset height. If no correction is required, the descent height of the coarse grinding shaft is controlled according to the first preset height when the coarse grinding shaft descends to the next first preset height.

6. The method for thinning a semiconductor package according to claim 4, characterized in that, The step of controlling the first fine grinding shaft to perform a first-stage fine grinding thinning on the semiconductor package after coarse grinding, based on the second initial height and the second initial distance, so that the thickness of the chip is reduced to the second target thickness, includes: Based on the second initial height and the second initial distance, the first fine grinding shaft is controlled to move to a position that contacts the upper surface of the semiconductor package after coarse grinding and thinning; After the first fine grinding shaft moves to contact the upper surface of the semiconductor package after coarse grinding and thinning, and every time the first fine grinding shaft descends to a second preset height, the first fine grinding shaft stops the first fine grinding and thinning of the semiconductor package, and the second current height of the semiconductor package relative to the upper surface of the suction cup is obtained. Each time the first fine grinding shaft descends to a second preset height, it is determined whether the grinding height of the first fine grinding shaft on the semiconductor package needs to be corrected based on the second initial height, the second preset height, and the second current height. If correction is required, a second correction value is calculated based on the second initial height, the second preset height, and the second current height, so that when the first fine grinding shaft descends to the next second preset height, the descent height of the first fine grinding shaft is controlled based on the second correction value and the second preset height; If no correction is required, the descent height of the first fine grinding shaft is controlled according to the second preset height when the first fine grinding shaft descends to the next second preset height.

7. The method for thinning a semiconductor package according to claim 4, characterized in that, The step of controlling the second fine grinding shaft to perform a second-stage fine grinding thinning on the semiconductor package after the first-stage fine grinding thinning, based on the third initial height and the third initial distance, so that the thickness of the chip is reduced to the third target thickness, includes: Based on the third initial height and the third initial distance, the second fine grinding shaft is controlled to move to a position that contacts the upper surface of the semiconductor package after primary fine grinding and thinning; After the second fine grinding shaft moves to contact the upper surface of the semiconductor package after the first-stage fine grinding and thinning, and every time the second fine grinding shaft descends to a third preset height, the second fine grinding shaft stops the second-stage fine grinding and thinning of the semiconductor package, and obtains the third current height of the semiconductor package relative to the upper surface of the suction cup. When the second fine grinding shaft descends to a third preset height, it is determined whether the grinding height of the second fine grinding shaft on the semiconductor package needs to be corrected based on the third initial height, the third preset height and the third current height. If correction is required, a third correction value is calculated based on the third initial height, the third preset height, and the third current height, so that when the second fine grinding shaft descends to the next third preset height, the descent height of the second fine grinding shaft is controlled based on the third correction value and the third preset height. If no correction is required, the descent height of the second fine grinding shaft is controlled according to the third preset height when the second fine grinding shaft descends to the next third preset height.

8. A semiconductor package thinning apparatus, used in thinning equipment, characterized in that, The semiconductor package is a package formed by processing a semiconductor packaged workpiece using a cutting device. The semiconductor package includes a PCB board, a chip fixed on the PCB board, and a molding compound disposed on the upper surface and outer side of the chip to encapsulate the chip on the PCB board. The device includes: The coarse grinding and thinning control module is used to control the coarse grinding shaft on the thinning device to perform coarse grinding and thinning on the plastic encapsulation in the semiconductor package located on the suction cup according to the preset first grinding parameters after the semiconductor package is placed on the suction cup, so that the thickness of the plastic encapsulation is reduced to the first target thickness. The first-stage fine grinding and thinning control module is used to control the first fine grinding shaft on the thinning device to perform first-stage fine grinding and thinning on the semiconductor package that has been coarsely ground and thinned on the suction cup, according to the preset second grinding parameters, so that the thickness of the chip is reduced to the second target thickness. The secondary fine grinding and thinning control module is used to control the second fine grinding shaft on the thinning device to perform secondary fine grinding and thinning on the semiconductor package that has been thinned by the first-stage fine grinding on the suction cup according to the preset third grinding parameters, so that the thickness of the chip is reduced to the third target thickness, thereby completing the thinning process of the semiconductor package. The thinning device comprises multiple suction cups, which are distributed on a working plate. Each suction cup is axially rotatable on the working plate. Each suction cup has multiple adsorption grooves, which are evenly distributed in a ring around the axis of the suction cup. The angle between the line connecting the center point of each adsorption groove to the center point of the suction cup and the center line of the adsorption groove is within a preset range. The adsorption grooves are used to adsorb and fix the semiconductor package onto the suction cup. Correspondingly, before the semiconductor package is placed onto the suction cup of the thinning device, the device further includes: A three-dimensional simulation model construction module is used to construct a three-dimensional simulation model corresponding to the thinning device; the three-dimensional simulation model includes a first sub-model corresponding to the suction cup, a second sub-model corresponding to the coarse grinding shaft, a third sub-model corresponding to the first fine grinding shaft, a fourth sub-model corresponding to the second fine grinding shaft, and a fifth sub-model corresponding to the semiconductor package; wherein, in the first sub-model, the angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove is variable within a preset range; The simulated thinning process module is used to control the second sub-model, the third sub-model, and the fourth sub-model to perform thinning process on the fifth sub-model located in the adsorption tank in sequence for each angle between the line connecting the center point of the adsorption tank to the center point of the suction cup and the center line of the adsorption tank within a preset range, so as to process thinning texture in the fifth sub-model. The stress calculation module is used to calculate the stress of the chip in the fifth sub-model for each angle between the line connecting the center point of the adsorption groove to the center point of the suction cup and the center line of the adsorption groove within a preset range, based on the thinning texture processed in the fifth sub-model and the third target thickness. The suction cup selection module is used to determine the target angle between the line connecting the center point of the semiconductor package to the center point of the suction cup and the center line of the suction groove, based on a comparison of the preset stress and the stress of the chip corresponding to different angles between the line connecting the center point of the suction groove to the center point of the suction cup and the center line of the suction groove. This allows the selection of a suction cup with the target angle between the line connecting the center point of the suction groove to the center point of the suction cup and the center line of the suction groove as the suction cup to be mounted on the working plate.

9. A thinning device, characterized in that, include: A processor and a memory, the memory being used to store a computer program, the processor being used to invoke and run the computer program stored in the memory to perform the method of any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, Used to store a computer program that causes a computer to perform the method as described in any one of claims 1-7.

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