JP2012003460A - Analyzing process for 3d mounting boards - Google Patents

Abstract

An object of the present invention is to reduce model generation processing time when analyzing the mechanical characteristics of a multilayer wiring board in which a three-dimensional mounting component such as PoP is mounted on the multilayer wiring board.
A step of generating a model of a package component by arranging a component and a joint at the center of the substrate and coupling the substrate, the component, and the joint (step S1), and a package component that is repeatedly generated in step S1. Use to select the upper and lower package component models to be stacked for a 3D mounting component, and align the lower package component joint lower surface with the lower package component upper substrate surface. A step of generating a model of a three-dimensional mounting component by combining the lower surface of the joint and the upper surface of the substrate (step S5), and a step of generating a model by combining the three-dimensional mounting component and the multilayer wiring board (step S7). And a step of calculating a deformation by giving a boundary condition to the model to be analyzed (step S8).
[Selection] Figure 2

Description

  The present invention is used in the construction of electronic circuits of various electronic devices, and is used for analysis of a three-dimensional mounting board for analyzing physical characteristics of a mounting board in a state where a three-dimensional mounting component is mounted on a multilayer wiring board. It is about the method.

  Recently, for the purpose of downsizing electronic devices, multilayer wiring boards (three-dimensional mounting boards) have been adopted in the construction of electronic circuits for high-density mounting of electronic components. As the wiring pattern of each layer of the multilayer wiring board, a multilayer wiring pattern satisfying electrical performance can be obtained by inputting circuit data to a computer aided design (CAD) of the computer-aided multilayer wiring board.

  However, the material of each layer of the multilayer wiring board, the width of the wiring pattern, the residual ratio of the copper foil part of the wiring pattern, the rigidity of the electronic components incorporated inside, the position and number of via holes, or mounted on the surface The mechanical performance of the completed component mounting board varies depending on the component and the mounting method of the component.

  Specifically, the substrate may be warped more than the limit due to the applied external force or temperature change, and a malfunction may occur in the multilayer wiring board.

  For this reason, conventional analysis methods for multilayer wiring boards with components mounted combine the model of the board and component created using laminated shell elements or solid elements based on the pattern and thickness data that are the outer shape of the board. Thus, a model of the entire multilayer wiring board on which components are mounted is created and analyzed (for example, see Patent Document 1). In the case of deformation exceeding the allowable range when the external force or temperature change is applied to the model of this laminated shell element or solid element, it is fed back to the design stage by CAD to satisfy the mechanical performance. Designed multilayer wiring board.

  FIG. 11 is an analysis model diagram showing a model generation procedure in the prior art described in Patent Document 1. In FIG.

  FIG. 11A shows a multilayer wiring board 111 on which a component 119 targeted by the prior art is mounted. As shown in FIG. 11B, the multilayer wiring board 111 includes a wiring layer and an insulating layer. Are generated as a single layer model 112 of the wiring layer and a single layer model 113 of the insulating layer, and then the generated single layer models 112 and 113 of each layer are stacked as shown in FIG. Further, as shown in FIG. 11 (d), a two-dimensional model of the substrate stacking shell model having the characteristics of the thickness information of the wiring layer and the insulating layer as a characteristic is generated on the neutral plane that is the center with respect to the thickness of the substrate outer shape. .

  As shown in FIG. 11E, the components mounted on the multilayer wiring board are divided into a first layer composed of a junction with the substrate, a second layer composed of IC120 and resin, and an IC120 as shown in FIG. It is a component composed of a third layer composed of resin to be molded. As shown in FIG. 11 (f), the first layer, the second layer, and the third layer are divided into layers, and each layer is generated by a single layer model. Then, as shown in FIG. Generate a two-dimensional model component stacking shell model with the characteristics of the first layer, second layer, third layer IC, resin material, and thickness information as the characteristics on the neutral plane that is the center with respect to the thickness of the outer shape. .

  FIG. 11H is a cross-sectional view of a state in which the generated component laminated shell model 129 is mounted on the board laminated shell model 114. The component laminated shell model 129 is arranged at an arrangement position determined by design within the plane of the board laminated shell model 114, and the model is generated on the neutral plane using the laminated shell model outside the plane. They are arranged at a distance of 1/2 of the thickness of the laminated shell model 114 and 1/2 of the thickness of the component laminated shell model 129.

  Further, the component laminated shell model 129 and the board laminated shell model 114 are coupled using the joining element 128 so that the degrees of freedom of the nodes are the same.

JP 2006-91939 A

  In the prior art, a multilayer shell model, which is a general idea of a multilayer wiring board and a component, is generated by modeling in a neutral plane, and the respective models are connected by joint elements.

  However, as shown in FIG. 12A, the actual components on the board are composed of the multilayer wiring board 111, the mold resin 139, the IC 120, and the underfill 135. The IC 120 is coupled to the lower surface of the multilayer wiring board 111 and the IC 120. Has been.

  When the model is generated by the component laminated shell model 129, the substrate laminated shell model 114, and the joining element 128 as in the prior art, as shown in FIG. Unlike the state of being coupled to the substrate and originally being coupled to the lower surface of the component, there is a problem that the structure cannot be accurately reflected.

  The prior art only provides an analysis method when a single component is mounted on a multilayer wiring board. For this reason, when analyzing the mechanical performance of a multilayer wiring board in which package parts are stacked in the out-of-plane direction of the multilayer wiring board, it is necessary to stack them while considering the component external shape of the package parts.

  The present invention solves the above-described problems of the prior art, accurately reflects the structure on the multilayer wiring board, and can reduce the model creation time of the three-dimensional mounting board. The purpose is to provide.

  In order to achieve the above object, the analysis method for a three-dimensional mounting board according to the present invention analyzes a characteristic of a three-dimensional mounting board configured by attaching a three-dimensional mounting part in which package parts are stacked on the surface of a multilayer wiring board. A package model generating step of generating a model of the package component by disposing a component and a package joint portion around the package substrate and combining the package substrate, the component and the package joint portion; and the package model Using a plurality of package component models generated by repeating the generation process, the upper and lower package component models are selected, the joint lower surface of the upper package component model, and the substrate upper surface of the lower package component model And joining the lower surface of the joint and the upper surface of the substrate, A three-dimensional mounting component model generation step for generating a three-dimensional mounting component model by combining the three-dimensional mounting component model and the multilayer wiring substrate model of the multilayer wiring substrate. And a characteristic calculation step of calculating a characteristic of the three-dimensional mounting board by giving a boundary condition to the three-dimensional mounting board model.

  According to the three-dimensional mounting board analysis method of the present invention, it is possible to accurately reflect the structure of a package component and to easily generate a three-dimensional mounting component model. Further, an arbitrary number of package part models can be stacked.

  In addition, even if the structure of a package part is changed due to the presence or absence of mold resin or the placement of joints, a package part model is generated without changing the subsequent model creation procedure by changing the corresponding part. And the model creation time can be shortened.

Configuration diagram showing an example of a PoP structure of a three-dimensional mounting component The flowchart which shows the general | schematic process of the analysis method for three-dimensional mounting boards in Embodiment 1 of this invention. Flow diagram of stress analysis of three-dimensional mounting board in the first embodiment (A), (b) Explanatory drawing of the package component laminated shell model in the first embodiment Explanatory drawing of a single unit model for explaining the first embodiment Explanatory drawing of the joint arrangement model for explaining the first embodiment Flowchart of package component model generation processing in the first embodiment Configuration diagram of package component model in the first embodiment generated in FIG. Flowchart of three-dimensional mounted component model generation process in the first embodiment Configuration diagram of the three-dimensional mounted component model in the first embodiment generated in FIG. (A)-(h) Explanatory drawing of the analysis model produced | generated by a prior art (A), (b) Explanatory drawing of the coupling state which is a problem in the prior art

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals, and description thereof is omitted as appropriate.

(Embodiment 1)
FIG. 1 is a structural diagram showing an example of a PoP structure of a three-dimensional mounting component which is a three-dimensional mounting board in Embodiment 1 of the present invention. In the present embodiment, the three-dimensional mounting board is obtained by joining the package component 140 and the interposer board 136 with a joining element.

  FIG. 2 is a flowchart showing a schematic process of the three-dimensional mounting board analysis method according to the first embodiment of the present invention. The outline of the analysis method according to the present embodiment will be described with reference to the flowchart of FIG.

In the present embodiment, an interposer substrate laminated shell model is generated (step S1),
A step (step S2) of generating a component stacking shell model based on a surface close to the interposer substrate based on a component outer shape composed of IC (integrated circuit), underfill, and mold resin;
A step of generating a joint model such as solder (step S3);
Using the interposer substrate laminated shell model, the component laminated shell model, and the joint model generated in steps S1 to S3, the neutral surface of the interposer substrate 136 and the lower surface that is the reference of the component laminated shell model are joined. A step of generating a package component model by combining the elements with each other, and further connecting the neutral surface of the interposer substrate 136 and the upper surface of the bonding portion model with the bonding elements;
Using a plurality of package component models generated by repeating steps S1 to S4, an upper or lower package component model is selected from these package component models to form a three-dimensional mounting component. The lower surface of the joint part of the upper package part model is formed on the board surface of the lower package part model on the basis of the plate thickness information of the lower surface of the joint part of the package part model and the substrate of the lower package part model. The three-dimensional mounting component model is obtained by connecting the interposer substrate laminated shell model of the lower package component model and the lower package component model with bonding elements. Generating step (step S5);
Generating a multilayer wiring board laminated shell model for mounting the three-dimensional mounting component model (step S6);
Based on the board thickness information of the multilayer wiring board multilayer shell model, the lower surface of the joint part of the three-dimensional mounting component model is on the board surface of the multilayer wiring board multilayer shell model. And a step of generating a three-dimensional mounting component mounting board model by joining the neutral planes of the multilayer wiring board stacking shell model with bonding elements (step S7),
And a step of calculating a deformation by giving a boundary condition to the three-dimensional mounting component mounting board model (step S8).

  FIG. 3 is a flow chart relating to stress analysis based on the multilayer wiring board analysis method of FIG. FIG. 3 shows a model generation procedure for the PoP structure shown in FIG.

  First, the production | generation process (step S1) of the lamination | stacking shell model of the interposer board | substrate 136 in FIG. 1 is demonstrated.

  At the start of processing, the board outline 1 of the interposer board 136 in the package 140 subjected to the analysis shown in FIG. 1, the board wiring pattern 2 of each layer, and the element size 3 required for dividing the elements with the finite element model are as follows. Prepare as file M1. For the file M1 of the package component 140, as many as the number of components to be stacked are prepared. Here, the element size is the length when the shape is divided into elements when generating a model by the finite element method.

  After preparing the file M1 of the package component 140, in step S101, which is a processing step of the electronic computer, the board outline 1 is divided into the same cells based on the designated element size 3, and the elements are divided into the layers. Material properties are assigned in accordance with the wiring pattern, and an interposer substrate laminated shell model file M2 is created as a laminated shell model.

  The interposer substrate laminate shell model is a two-dimensional model having information on each layer of the substrate as shown in FIG.

  Next, the production | generation process (step S2) of the component lamination | stacking shell model in FIG. 2 is demonstrated.

  Data of components arranged on the interposer substrate laminated shell model of the package component 140 in the electronic computer is obtained as IC shape 4, IC material properties 5, mold resin presence / absence information 6, mold resin shape 7, mold resin material properties 8, under After the file presence / absence information 9, underfill shape 10, underfill material properties 11, and element size 12 file M3 are prepared, a part model to be placed on the package substrate is generated in step S102, and the package part stacked shell model 13 is created. Saved as file M4.

  The IC shape, mold resin shape, and underfill shape in the package component multilayer shell model 13 indicate the dimensions of the IC 120, mold resin 139, and underfill 135 shown in FIG. 4, and the package component multilayer shell model is shown in FIG. 4 indicates a two-dimensional model shown in FIG. 4B having information on the structure of the IC 120, the underfill 135, and the mold resin 139. The reference surface of the package component laminated shell model 143 is generated so as to be the lower surface of the component shown in FIG.

  Next, the model generation process (step S3) of the joint in FIG. 2 will be described.

  The joints arranged in the interposer substrate laminated shell model of the package part are created by creating the joint part shape in step S103 based on the joint part shape 14, the joint part material property 15, and the file M5 of the joint part 16. The material properties 15 are assigned, and the joint unit model 17 is generated from the solid model and stored in the file M6.

  In step S104, based on the joint unit model 17, the joint arrangement information 18, the underfill presence / absence information 19, the underfill material property 20, and the underfill element size 21 composed of the distance, pitch, and number of rows from the substrate outer shape. If there is an underfill, the shape for modeling the underfill is determined from the pitch of the joint arrangement information and the shape of the joint unit model, and the element size of the joint unit model is determined when generating the underfill element. Based on this, a model is generated so that the underfill and the joint node are in the same position.

  Thereafter, the underfill and the joint unit model are copied based on the arrangement information, a model is generated, and an underfill part where there is no joint is generated based on the underfill element size 21, and the entire model is generated. The generated model is stored in the file M7 as a joint arrangement solid model. If there is no underfill in the underfill presence / absence information 19, the joint unit model is copied to the position information position based on the joint placement information 18, and the joint placement solid model is filed. Save as M7.

  The joint is a part for joining the substrates as shown in the joint 37 of FIG. 1, and the joint unit model is a solid element specified by the diameter and height as shown in FIG. Become a model. As shown in FIG. 6, a model generated based on the arrangement information specifying the X and Y distance intervals is used as the joint unit solid model.

  Next, the package component model generation step (step S4) in FIG. 2 will be described.

  Using the generated model data, the interposer substrate laminated shell model of the file M2, the package component laminated shell model of the file M4, and the joint arrangement solid model of the file M7, the process proceeds to step S105, which is a package component generation process. The package part model 22 is generated and stored in the file M8.

  The process of step S105 is executed according to the flow shown in FIG. FIG. 8 shows the positional relationship of the models in the flow of FIG.

  In FIG. 8, 141 is the outer shape of the package component, 142 is the outer shape of the interposer substrate 136, 143 is the package component laminated shell model, 144 is the interposer substrate laminated shell model, 145 is the joint arrangement model, and 146 is the thickness of the interposer substrate. A distance of / 2, 147 indicates the thickness of the package component.

  7 and 8, in step S9, the thickness information of the outer shape 142 of the interposer substrate 136 is extracted from the interposer substrate laminated shell model 144. Next, in step S10, the package component stacked shell model 143 is disposed above the thickness by a half with respect to the center of the interposer substrate 136.

  Next, in step S11, the package component laminated shell model 143 and the interposer substrate laminated shell model 144 are coupled. Thereby, the interposer substrate laminated shell model 144 and the package component laminated shell model 143 arranged on the neutral surface of the outer shape 142 of the interposer substrate 136 are coupled by the joining element.

  Next, in step S12, the joint arrangement model 145 is arranged 1/2 downward with respect to the center of the interposer substrate 136. Further, in step S13, the interposer substrate laminated shell model 144 and the joint arrangement model 145 are joined by joint elements. Data obtained by combining the component laminated shell model, the interposer substrate laminated shell model, and the joint arrangement model generated in step S105 is stored in the file M8 as the package component model 22.

  The above is the package component model generation step (step S4) in FIG.

  In the three-dimensional mounting component, the package component model 22 required for stacking the package components 140 is prepared by repeating the above procedure.

  Next, the generation process (step S5) of the three-dimensional mounting component model in FIG. 2 will be described.

  In step S106, which is the three-dimensional mounted component model generation process of FIG. 3, the package component model 22 is stacked using the generated package component model 22, and saved as a file M9 of the three-dimensional mounted component model 23. .

  Further, in step S106, not only the package component model 22 but also the three-dimensional mounting component model 23 can be stacked, and the package components 22 can be stacked on or below the three-dimensional mounting component model 23. Furthermore, it is possible to stack the three-dimensional mounting component models 23 by using the processing in step S106. The three-dimensional mounting component model 23 to be mounted on the multilayer wiring board 111 is generated by the above procedure.

  FIG. 9 shows a process flow of step S106. 9, in step S14, the upper package component model 22 or the three-dimensional mounting component model 23 is selected, and in step S15, the lower package component model 22 or the three-dimensional mounting component model 23 is selected. In step S16, the board thickness of the lower package part model 22 or the three-dimensional mounting part model 23 is extracted. In step S17, the board thickness center of the lower package part model 22 is set to 1 as a reference. / 2 The upper package component model 22 is disposed above, and in step S18, the joint portion of the upper package component model 22 and the interposer substrate 136 of the lower package component model 22 are coupled by the joint element.

  Thereby, the three-dimensional mounting component model 23 is generated. The required stacking can be performed by repeating the process of step S106 by the number of times of stacking.

  FIG. 20 is a configuration diagram of the three-dimensional mounting component model generated through the process of step S106. In FIG. 20, the upper package component stacked shell model 149, the upper interposer substrate stacked shell model 150, and the joint portion of the upper package component are shown. A model constituted by the placement model 152 is an upper package component model, a lower package component stacked shell model 154, a lower interposer substrate stacked shell model 156, and a lower package component joint placement model 157, Is a lower package part model.

  With respect to the neutral surface of the lower interposer substrate laminated shell model 156, the position above the distance 161 that is ½ of the substrate plate thickness and the lower surface of the joint arrangement model 152 of the upper package component coincide with each other. Joined with a joining element. Thereby, the generation process (step S5) of the three-dimensional mounting component model of FIG. 2 is performed.

  Next, the multilayer wiring board model generation step (step S6) in FIG. 2 will be described with reference to FIG.

  In FIG. 3, a file M10 comprising a multilayer wiring board outline 24, a wiring pattern 25 for each layer, and an element size 26 for mounting the three-dimensional mounting component model 23 is prepared, and in step S107, which is a board analysis model generation process, The board laminated shell model 27 and the component arrangement information 28 are stored as a file M11. Step S107 is the same process as step S101.

  Next, the process (step S7) of joining the lower surface of the joint portion of the three-dimensional mounting component and the neutral surface of the multilayer wiring board in FIG. 2 with a joint element will be described.

  In step S108, which is the component mounting board model generation process of FIG. 3, the three-dimensional mounting part model 23 is replaced with the board based on the stored three-dimensional mounting part model 23, board stacking shell model 27, and part arrangement information 28. By positioning in the plane and connecting the lower surface of the joint portion of the board stacking shell model 23 and the three-dimensional mounting part model with joining elements, a part mounting board model 29 is generated and stored as data.

  Next, the deformation calculation process (step S8) in the component mounting board model in FIG. 2 will be described.

  In analyzing the mechanical characteristics of the component mounting board model 29, boundary conditions 30 such as external force, temperature, and displacement and material properties 31 are prepared as a file M12 for the component mounting board model 29, and the analysis process proceeds to step S109. To analyze. Further, when changing the material physical property of each part of the package component or the material physical property of the substrate, the material physical property 31 is prepared and changed during the analysis process.

  As a result of step S109, which is an analysis process, warp (displacement) 32 and stress 33 within the given boundary condition 30 are obtained as a file M13.

  With the above procedure, it is possible to change each part independently in the generation of the package component stacking shell model during the PoP structure analysis model creation time shown in FIG. 1, and only the part changed in the structure is newly processed. By performing the process of joining the other parts by the joining elements, the working time can be shortened. Further, in the generation of the three-dimensional mounting component model, it is possible to generate the model only by selecting the upper and lower package components, so that the working time can be expected to be shortened.

  According to the present invention, a model of a multilayer wiring board on which a three-dimensional mounting component is mounted can be calculated in a short time by appropriately reflecting the structure of the package component model, and the mechanical performance can be calculated. It is effective for structural examination in

111 Multilayer Wiring Board 112,113 Single Layer Model 114 Board Stack Shell Model 119 Component 120 IC
128 Joint element 129 Component laminated shell model 135 Underfill 136 Interposer substrate 137 Joint portion 138 Multi-layer wiring substrate 139 Mold resin 140 Package component 141, 142 External shape 143 Package component laminate shell model 144 Interposer substrate laminate shell model 145 Joint arrangement model 146 Interposer Distance of 1/2 of substrate board thickness 147 Package component thickness 149 Upper package component laminate shell model 150 Upper interposer substrate laminate shell model 152 Upper package component joint arrangement model 154 Lower package component laminate shell model 156 Lower interposer substrate laminate Shell model 157 Joint arrangement model of lower package component 161 Interposer board thickness 1 of lower package component 2 of the distance

Claims (4)

When analyzing the characteristics of a 3D mounting board constructed by attaching 3D mounting parts with stacked package parts on the surface of a multilayer wiring board,
A package model generation step of arranging a component and a package joint around a package substrate, and generating a model of the package component by combining the package substrate, the component and the package joint;
Using a plurality of package component models generated by repeating the package model generation step, the upper and lower package component models are selected, the joint lower surface of the upper package component model, and the lower package component model A three-dimensional mounting component model generating step of aligning the upper surface of the substrate, combining the lower surface of the joint and the upper surface of the substrate, and generating the three-dimensional mounting component model;
A three-dimensional mounting component mounting board model generating step for generating a three-dimensional mounting board model by combining the three-dimensional mounting part model and the multilayer wiring board model of the multilayer wiring board;
A characteristic calculation step of calculating a characteristic of the three-dimensional mounting board by giving a boundary condition to the three-dimensional mounting board model. The package model generation step generates an interposer substrate laminate shell model, generates a component laminate shell model based on a component outer shape composed of an integrated circuit, an underfill, and a mold resin, with a surface close to the interposer substrate as a reference. After generating the part model, the neutral surface of the interposer substrate laminated shell model and the lower surface which is the reference of the component laminated shell model are coupled by a joining element, and the neutral surface of the interposer substrate laminated shell model and the joint The analysis method for a three-dimensional mounting board according to claim 1, wherein the package part model is generated by connecting the upper surface of the model with a joining element. The three-dimensional mounting component model generation step selects an upper and lower package component model from the plurality of generated package component models to form the three-dimensional mounting component, and joins the upper package component model. The lower surface of the joint portion of the upper package component model is arranged on the substrate surface of the lower package component model based on the plate thickness information between the lower surface of the portion and the substrate of the lower package component model And a three-dimensional mounting component model is generated by combining the lower surface of the joint portion of the upper package component model and the interposer substrate stacking shell model of the lower package component model with a joint element. The method for analyzing a three-dimensional mounting board according to claim 1 or 2. The three-dimensional mounting component mounting board model generation step generates a multilayer wiring board stacking shell model for mounting the three-dimensional mounting part model, and based on the board thickness information of the multilayer wiring board stacking shell model, the third order Alignment is performed so that the lower surface of the joint portion of the original mounting component model is disposed on the board surface of the multilayer wiring board laminated shell model, and the neutral surface of the multilayer wiring board laminated shell model is joined by a joining element 4. The three-dimensional mounting board analysis method according to claim 1, wherein a three-dimensional mounting component mounting board model is generated.

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