The present invention belongs to the technical field of chip packaging, specifically, a chip packaging power distribution network electromagnetic modeling method and system.
With the continuous development of artificial intelligence, 5G and data centers, mass data are generated continually; CPUs of traditional infrastructures can no longer satisfy requirements of high performance computing (HPC). Advanced packaging technology represented by Heterogeneous Integration is an advanced technology in Post-Moore Era, and provides the possibility for realizing a higher computing ability, in the fields of FPGA, GPU, CPU, the heterogeneous integration technology is widely used, and typical examples include Fiji GPU by AMD, and Pascal GPU by Nvidia, wherein a GPU die is connected with surrounding four HBMs via a Si interposer. TSMC, Intel and Samsung are investing persistently in the advanced packaging field. 2.5D and 3D IC advanced packaging is to replace interconnection between chips via packaging substrates with interconnection via silicon substrates or chip stacking by through silicon via (TSV). The most significant advantage of 2.5D and 3D IC is heterogeneous integration, by involving heterogeneous hybrid fabrication can be realized with different process nodes. 2.5D and 3D IC can allocate two dies very close and connecting directly, routing density on the silicon interposer can be much higher than on traditional package, the size of the chip can be smaller, while higher signal performance can be obtained. This poses a new challenge to the electromagnetic field modeling, especially electromagnetic field modeling for power distribution networks. The electromagnetic modeling of power distribution networks is different from electromagnetic field modeling of signals, to this end, areas only containing signal networks among bulks of original data can be picked out according to signal traces, and by including appropriately more areas and conducting electromagnetic field modeling, the accuracy required for signal electromagnetic field model in a certain frequency range can be satisfied. For power distribution networks, during advanced packaging, the power distribution network is usually built by grid-shaped power routing, including via connections between multiple layers of routings. As the power distribution network routing covers basically a large range, it is difficult to pick out a small section for analysis as per trace routings just like what we do for the signal network, thus the electromagnetic field modeling of power distribution networks remains a difficulty in the field of advanced packaging. The current electromagnetic field modeling solution for the advanced packaging power distribution networks is to calculate equivalently with RLCK (resistance, inductance, capacitance and mutual inductance) circuits, the advantage of the algorithms is that a big bulk of data can be processed, however, the accuracy at high frequencies cannot be promised. If the electromagnetic field algorithms are used to model the entire power distribution network, the advantage is that the accuracy can be guaranteed, but the deficiency is that, it is difficult to provide time and machine resources required for solving the electromagnetic field with such a big bulk of data (hundreds of thousands of via and μbump connections) as per engineering need. It is thus desirable to have new technologies to solve electromagnetic fields quickly and precisely, and obtain the electromagnetic field model of the entire power distribution network.
For example, a Chinese patent filing no. CN2022100363508, with a publication date of May 27, 2022, discloses a chip packaging electromagnetic modeling system, method and device. A chip packaging electromagnetic modeling system, comprising a design module and a simulation module: the design module is configured to complete chip layout, build chip packaging and optimize and improve the chip packaging according to simulation results of chip packaging, and obtain a qualified chip packaging; the simulation module is configured to conduct simulation for the chip packaging in a design environment of the design module, and transmit the simulation results to the design module. The deficiency with the present technical solution is that: it is difficult to achieve both efficiency and accuracy.
For another example, a Chinese patent filing no. CN2017100006393 with a publication date of Jul. 10, 2018, discloses a method for building a 3D electromagnetic field parameterized simulation model, wherein by a complete method of extracting physical and geometrical parameters from physical layout, creating parameterized variants and 3D electromagnetic field parameterized simulation model, and improving design of the physical patterns after simulation and optimization, the modeling and simulation processes are simplified, modeling and simulation speed is improved and the time required for pattern design and simulation analysis is thus reduced. However, the defect with the technical solution is that, the accuracy is not guaranteed.
Targeting at the problem that for electromagnetic field modeling methods of large-scale power distribution networks currently available, it is not possible to promise both accuracy and speed, the present invention provides a chip packaging power distribution network electromagnetic modeling method and system. With the method proposed in the present invention, by decomposing and solving the power distribution network, time required for subsequent electromagnetic field modeling is substantially reduced, and by circuit connection of the decomposed and solved sub-magnetic field models, the large-scale electromagnetic field model in demand can be obtained and the accuracy is as desired. The system proposed in the present invention involves simple infrastructures, running of the modules is stable, while accuracy and speed of electromagnetic field modeling of large-scale power distribution network is promised simultaneously.
To address the foregoing problem, the present invention adopts the following technical solutions.
A chip packaging power distribution network electromagnetic modeling method, comprises:
Further still, obtaining the complete electromagnetic field model by circuit simulation of the complete circuit connection.
A system using the chip packaging power distribution network electromagnetic modeling method, comprises:
Compared with the prior art, the beneficial effects of the present invention are that:
Hereinafter a further description will be given to the present invention in conjunction with the embodiments and the drawings.
As shown in
As can be seen in Table 1, after decomposing, compared with direct solving of the original large-scale network, for solving each of the decomposed regions, the memory resource consumption is reduced for 6-9 times, and the time consumption is reduced for 10 times. The total time of solving the six decomposed regions is 1580 s, even in case the six decomposed regions are calculated in series, the total time consumption is reduced from original 2720 s for 42%. Given that the decomposed regions can be calculated in parallel, the solving time can be reduced exponentially.
S2: conducting electromagnetic field solving for each of the decomposed regions, and obtaining a plurality of sub-magnetic field models; herein it is to be noted that, for conventional electromagnetic simulation of large-scale designs, the required computation resource is huge, the solving time is long, and conventionally, when dividing and cascading, usually the solving method of finite element method (FEM) is used, and with this kind of solving method, the boundary shall be set, with the integral design or the decomposed design, the boundaries are different, which may affect the results, and if the boundary for decomposed design is configured to be the same as the integral design in size, the simulation efficiency cannot be improved. And for the FEM, a reference shall be provided for the port, when providing a power distribution network port at the decomposed plane, the ground network port can only be set as the reference, however, at the decomposed plane, it is necessary to set the ground network port to be the port to conduct circuit connection for the decomposed electromagnetic field models, and if the ground network port is set to be the reference, finally, the accuracy deviation can be big; specifically, step 2 comprises the following steps:
In the step S2, by solving with the MOM method, the limits of the conventional FEM method in decomposed region solving is efficiently avoided and it is no longer necessary to provide any boundary. More importantly, a power distribution network interface and a ground network interface are provided at the decomposed plane of each of the decomposed regions, and the ground network interface is not used as the reference. If the ground network is set to be the reference at the decomposed plane, when to cascade the circuit, that is, to conduct subsequent circuit connection, only the power distribution network is connected, the ground network serves directly as the reference, in this case, when combing the 20 micro bump ports to see the impedance of the entire chip packaging power distribution network design, it can be seen that, at 5 GHZ, the impedance of the entire network solving model is 0.03007, the impedance solved by region decomposition circuit cascading is 0.068721, the deviation is not acceptable, as shown in
In the present invention, by decomposing the large-scale initial power distribution network, conducting electromagnetic solving for each of the decomposed regions, the accuracy at high frequencies of equivalent RLCK circuits and the efficiency and consumption of electromagnetic field solving of the entire large-scale network is avoided; further, by providing the power distribution network interface and the ground network interface as nodes of subsequent circuit connection, the sub-magnetic field model of each of the decomposed regions is combined to be a final large-scale electromagnetic field model accurately, which is sufficient to meet engineering need. In the meanwhile, the present invention has done the following test: in the present invention, the electromagnetic field model obtained with the method offered in the present invention is compared with the electromagnetic field model obtained by direct solving of the initial power distribution network. As the electromagnetic field model concentrates on impedance, during comparison, the C4 bump port is short-circuited to check the self-impedance at the 20 micro bump ports, the accuracy result is shown in
As can be seen in Table 2, for the electromagnetic field model obtained in the present invention, even at the high frequency of 5 GHZ (usually the frequency range of power distribution network models is concentrated in 1-2 GHZ), the deviation is less than 10%, which meets the engineering need, which computation resources are remarkably saved. Therefore, compared with large-scale direct electromagnetic field solving of the initial power distribution network, the present invention has the higher efficiency and accuracy.
A system employing the chip packaging power distribution network electromagnetic modeling method, comprises:
A decomposition module: configured to decompose the initial power distribution network to be a plurality of decomposed regions; a standard of the decomposition module can be determined as per the magnitude of data and resource configurations, further, algorithms on decomposition of the initial power distribution network is relatively mature, therefore, in the present embodiment, the principle with regard to how to decompose with the decomposition module will not be elaborated on. The standard of decomposition shall promise that the decomposed planes are located where the routings are connected, so as to avoid via or flat structures in the decomposed planes and affect the subsequent connection, and the entire precision. An electromagnetic field solving module: configured to conduct electromagnetic field solving for each of the decomposed regions, and obtain sub-magnetic field models; the electromagnetic field solving module uses the MOM electromagnetic field simulation engine for solution, whereby avoiding restrictions of the conventional FEM method on decomposition and solution; further, the present electromagnetic field solving module will provide automatically a power distribution network interface and a ground network interface at the decomposed plane of each of the decomposed regions, and the power distribution network interface and the ground network interface serve as the nodes of subsequent circuit connection to promise accuracy and reduce deviation.
A circuit connection module: configured to conduct circuit connection for the sub-magnetic field models, and obtain the complete circuit connection; and for the circuit connection module, first of all, conducting circuit connection of the sub-magnetic fields based on actual physical connections, and connecting the neighboring sub-magnetic field models via the power distribution network interfaces and the ground network interfaces to obtain the complete circuit connection.
An electromagnetic model generation module: configured to solve the complete circuit connection by circuit simulation and obtain the complete electromagnetic field model.
With the system provided in the present invention, the large-scale power distribution network is divided into small regions for solving, the solving speed is expedited significantly, the computation resource required is reduced, furthermore, solving of the regions can be done in parallel, the solving speed is further improved, so is the working efficiency of the entire process; by converting the decomposed regions to be sub-magnetic field models with the electromagnetic field solving module, and obtaining the final electromagnetic model by circuit interconnection, compared with the conventional RLCK equivalent circuit solution, the accuracy at high frequencies can be met; the structures of the entire system are simple, running of the modules is stable, accuracy and speed of the electromagnetic field modeling of large-scale power distribution networks can be simultaneously satisfied.
The embodiments given in the present invention are only some preferable embodiments, and are not intended to limit the idea and spirit of the present invention, without departing from the idea of the present invention, all modifications and improvements made by those skilled in the art to the technical solutions of the present invention shall fall into the protection scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202211290070.6 | Oct 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2023/087432 | 4/11/2023 | WO |