JP2010074085A - Design support system of electronic circuit board - Google Patents

Abstract

An electronic circuit board design support system that allows a designer to narrow down items to be examined when designing an electronic circuit board on which electronic components are mounted on the board.
In an electronic circuit board design support system 1 in which electronic components are mounted on a board, an initial state database 11 in which initial state information is stored, a transition state database 12 in which transition state information is stored, and electrical characteristic information Is stored in the electrical characteristic database 13. The initial state information is information regarding matters determined before starting the production of the electronic circuit board with respect to the substrate, electronic components, and manufacturing conditions, and the transition state information is information representing the result of appearance evaluation in the intermediate process. The electrical characteristic information is information indicating the electrical characteristics of the completed electronic circuit board. Then, based on the transition state information and the electrical characteristic information, there is provided a calculation means 14 that classifies the electronic components according to items that need to be examined in the initial state information.
[Selection] Figure 1

Description

  The present invention relates to an electronic circuit board design support system, and more particularly to a design support apparatus that supports the design of an electronic circuit board having electronic components mounted on the board.

  When manufacturing an electronic circuit board with electronic components mounted on the board, after printing the solder on the board, mounting the electronic parts on this board, and then melting and solidifying the solder, the electronic parts Is soldered to the board. Conventionally, for such an electronic circuit board, a system that predicts the quality of the electronic circuit board after completion at the design stage and supports the design so as to obtain an optimum quality has been proposed (for example, patents). Reference 1).

  However, there are many items that can affect the quality of the electronic circuit board, that is, items to be examined in designing, and there are several types of methods of study. For this reason, in order to efficiently design an electronic circuit board, it is necessary to narrow down a large number of combinations of items and methods to be examined to a small number of combinations that are considered to be effective, and to preferentially study them. However, such a narrowing-down depends on the personal knowledge and experience of the engineer and cannot always be narrowed down accurately.

Japanese Patent Laid-Open No. 11-175577

  An object of the present invention is to provide an electronic circuit board design support system that allows a designer to narrow down items to be examined when designing an electronic circuit board having electronic components mounted on the board.

  According to one aspect of the present invention, there is provided a design support system for an electronic circuit board in which an electronic component is mounted on the board, and the manufacturing of the electronic circuit board is performed with respect to the manufacturing conditions of the board, the electronic component, and the electronic circuit board. An initial state database in which initial state information relating to matters determined before starting is stored, a transition state database in which transition state information representing a result of appearance evaluation in an intermediate process of manufacturing the electronic circuit board is stored, Based on the electrical property database storing electrical property information indicating the electrical properties of the electronic circuit board on which the electronic component is mounted, the transition state information, and the electrical property information, the initial state information needs to be examined. There is provided a design support system for an electronic circuit board, comprising an arithmetic means for classifying the electronic components according to various items.

  ADVANTAGE OF THE INVENTION According to this invention, when designing the electronic circuit board by which the electronic component was mounted on the board | substrate, the design support system of the electronic circuit board which can make a designer narrow down the item which should be examined is realizable.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, an electronic circuit board design support system according to the present embodiment will be schematically described.
The design support system according to the present embodiment supports the design of an electronic circuit board. The electronic circuit board is an electronic component such as an LSI (Large Scale Integrated circuit) chip mounted on a board such as a printed board via solder. In such an electronic circuit board, solder is printed on the printed circuit board, the electronic component is mounted on the printed circuit board so that the electrode of the electronic component is in contact with the printed solder, and the printed solder is melted and re-applied. It is manufactured by joining the electronic component to a printed circuit board by solidifying.

  The design support system according to the present embodiment classifies each electronic component to be mounted on the electronic circuit board into a plurality of categories based on information during and after manufacture of the electronic circuit board. Depending on the classified category, items that need to be examined in the initial state determined before manufacturing and the examination method differ. Thereby, by classifying the electronic components, it is possible to narrow down items to be examined and examination methods for the electronic components.

Next, the design support system according to the present embodiment will be described in detail.
FIG. 1 is a block diagram illustrating an electronic circuit board design support system according to this embodiment.
FIG. 2 is a diagram illustrating information stored in the initial state database.
FIG. 3 is a diagram illustrating information stored in the transition state database.
FIG. 4 is a diagram illustrating information stored in the electrical characteristics database.
FIG. 5 is a diagram illustrating a method for classifying electronic components.
FIG. 6 is a diagram illustrating a correspondence relationship between classification results of electronic components and items that need to be examined among the initial state information and the examination method.

  As shown in FIG. 1, the electronic circuit board design support system 1 according to this embodiment includes an initial state database (DB) 11, a transition state database 12, and an electrical characteristic database 13. Information is input to these databases 11 to 13 at each stage of the product design stage 101, the process design stage 102, the manufacturing stage 103, and the market introduction stage 104 of the electronic circuit board.

  The initial state database 11 stores initial state information collected from the product design stage 101 and the process design stage 102 for the electronic circuit board. The initial state information is information regarding matters determined before starting the manufacture of the electronic circuit board with respect to the substrate, the electronic component, and the manufacturing conditions. As shown in FIG. 2, the initial state information is roughly classified into, for example, initial shape information, manufacturing condition information, and purchase information. The initial shape information includes information regarding the electronic component, the substrate, and the combination of the electronic component and the substrate. The manufacturing condition information includes printing conditions, mounting conditions, and reflow conditions. In addition to the process conditions, the manufacturing condition information includes information on a jig used for manufacturing. The purchase information includes information regarding the vendor and lot of the electronic component and information regarding the vendor and lot of the substrate.

  The transition state database 12 stores transition state information collected from the manufacturing stage 103 for the electronic circuit board. The transition state information is information representing the result of appearance evaluation in an intermediate process of manufacturing an electronic circuit board. As shown in FIG. 3, for example, the transition state information is roughly divided into print quality information indicating a print state when solder is printed on the board, and a mount state when electronic components are mounted on the board on which the solder is printed. And the appearance information after reflow indicating the appearance when the electronic component is soldered to the substrate by heating the solder. The print quality information includes the solder print height and the solder print volume, the mount quality information includes the shift amount of the mounting position of the electronic component, and the appearance information after reflow includes various defect mode information. The occurrence rate, for example, the occurrence rate of short-circuit defects and disconnection defects is included.

  Since the solder printing height and the solder printing volume are information in units of electrodes, it is desirable to convert them into information in units of electronic components and store them. The information for each electronic component is a basic statistic such as an average value, standard deviation, maximum value, minimum value, etc. of the solder printing height of all electrodes of a certain electronic component, or a feature value using the information for each electrode. The solder printing height and the solder printing volume may be stored as information in units of electrodes when data is stored, and may be converted into information in units of electronic components when determining an initial state to be described later. However, in this case, since the processing time becomes long, it is desirable to convert the information into electronic component units at the stage of storage in the transition state database 12.

  The electrical property database 13 stores electrical property information collected from the manufacturing stage 103 and the market launch stage 104 for the electronic circuit board. The electrical property information is information representing the electrical properties of the completed electronic circuit board. As shown in FIG. 4, the electrical characteristic information is, for example, information on the result of electrical inspection and operation test of an electronic circuit board performed in a factory, and the failure occurrence rate by failure mode within a certain period in the market. is there. The failure mode is a classification name given to the failure phenomenon. It is desirable that the failure mode names be unified for the failure phenomenon detected at any timing.

  In the initial state information, transition state information, and electrical characteristic information described above, in addition to the information on the electronic circuit board that is the design support target, the electronic component that is the target of the examination is other than the electronic circuit board that is the design support target. Information when mounted on other types of electronic circuit boards is also included. For example, if the electronic circuit board to be designed is a printed circuit board used in a personal computer and the electronic component to be examined is an LSI chip mounted on the printed circuit board, the same type of LSI chip is used. Information on mounting on other types of printed circuit boards used in liquid crystal display devices is also included. Further, specific items of the initial state information, the transition state information, and the electrical characteristic information are not limited to the items described above and shown in FIGS.

  As shown in FIG. 1, the design support system 1 is provided with a calculation means 14, a storage means 15, and an input / output means 16. The computing means 14 classifies the electronic component into one of a plurality of states based on the transition state information stored in the transition state database 12 and the electrical property information stored in the electrical property database 13. Specifically, as shown in FIG. 5, when the electronic component under consideration is mounted on another type of electronic circuit board, there are nine types depending on the necessity for improvement in electrical characteristics and necessity for improvement in transition state. Classify into categories. Details of this classification method will be described later.

  In addition, as shown in FIG. 6, the storage unit 15 stores a correspondence relationship between a plurality of states in which electronic parts are classified by the calculation unit 14 and items that need to be examined and examination methods in the initial state information. ing. The contents of this correspondence will also be described later. Then, the computing means 14 needs to be examined out of the initial state information of the electronic circuit board that is the design support target, based on the classification result of the electronic component that is the examination target and the correspondence relationship stored in the storage means 15. Output items and examination methods. The input / output unit 16 inputs an instruction to the calculation unit 14 and outputs information from the calculation unit 14.

  In one example, the calculation means 14 and the storage means 15 can be configured by a CPU (Central Processing Unit) and a built-in memory of a personal computer. The input / output means 16 can be constituted by a keyboard and a display connected to the personal computer. Furthermore, the initial state database 11, the transition state database 12, and the electrical characteristic database 13 can be configured by an external hard disk drive (HDD) connected to the personal computer. Note that the initial state database 11, the transition state database 12, and the electrical characteristic database 13 may be constructed in one common HDD.

Next, the operation of the design support system 1 according to the present embodiment, that is, the design support method according to the present embodiment will be described.
First, a method for storing initial state information, transition state information, and electrical characteristic information in the initial state database 11, the transition state database 12, and the electrical characteristic database 13, respectively, will be described.
As shown in FIG. 1, various electronic circuit boards are supplied to the market through a product design stage 101, a process design stage 102, a manufacturing stage 103, and a market introduction stage 104.

  In the product design stage 101, it is designed which electronic component is mounted on which board with which layout. At this stage, the substrate and electronic component to be used are selected, and the surface, position and direction for mounting the electronic component on the substrate are determined. At this time, initial shape information (see FIG. 2) relating to the selected substrate, electronic component, and combination of the substrate and the electronic component is input and stored in the initial state database 11.

  In the process design stage 102, it is determined by what process the electronic circuit board designed in the product design stage 101 is manufactured. Specifically, solder printing conditions, electronic component mounting conditions, and reflow conditions after mounting are determined. At this time, the manufacturing condition information (see FIG. 2) is input to the initial state database 11 and stored. Further, when actually planning a production plan, the purchase information of the boards and electronic parts to be used, that is, the vendor name and lot number, etc. are input to the initial state database 11 and stored.

  In the manufacturing stage 103, solder is printed on the substrate, the electronic component is mounted so that the electrode contacts the printed solder, and the electronic component is bonded to the substrate by melting and solidifying the solder by reflow. As a result, an electronic circuit board having electronic components mounted on the board is manufactured. At this time, quality is evaluated in each process of printing, mounting, and reflow. Then, transition state information (see FIG. 3) including print quality information, mount quality information, and appearance information after reflow is input to the transition state database 12 and stored. In addition, an electrical inspection and an operation test are performed on the completed electronic circuit board to evaluate electrical characteristics. Then, the result of this electrical characteristic is input and stored in the electrical characteristic database 13 as electrical characteristic information (see FIG. 4).

  In the market introduction stage 104, after the electronic circuit board is introduced into the market, information such as the occurrence rate of each defective mode in the market for a certain period is collected. Then, this information is input to the electrical property database 13 as electrical property information (see FIG. 4) and stored.

  As described above, by collecting information on various electronic circuit boards used for various applications in each of the above-described stages, initial state information before mounting on a large number of boards and electronic components and combinations thereof (FIG. 2). Reference state), transition state information during the mounting operation (see FIG. 3), and electrical characteristic information of the manufactured electronic circuit board (see FIG. 4) are stored in the databases 11 to 13, respectively.

Next, a design support method when designing a new electronic circuit board will be described.
FIG. 7 is a flowchart illustrating the design support method according to this embodiment.
First, as shown in step S <b> 1 of FIG. 7, the designer of the electronic circuit board sets electronic components to be studied (hereinafter also referred to as “reviewed components”). The considered component is one of the electronic components that are to be mounted on the electronic circuit board to be designed.

  Thereby, the calculating means 14 performs the process shown to following step S2-S6. These processes may be executed automatically by the calculation means 14 using, for example, a program stored in the storage means 15, and are executed step by step by sequentially inputting instructions to the calculation means 14 by the designer. May be.

  Next, as shown in step S2, the calculation means 14 searches the information stored in the databases 11 to 13 to determine whether the examined component is used in a plurality of existing models. The existing model refers to another type of electronic circuit board that is different from the electronic circuit board to be designed. If the examined part is not used in a plurality of existing models, the process is terminated because it is not a target of the design support method according to the present embodiment. If the examined part is used in a plurality of existing models, the process proceeds to step S3.

  Next, as shown in step S <b> 3, the computing means 14 extracts initial state information related to the studied part from the initial state database 11, extracts transition state information related to the considered part from the transition state database 12, and Electrical characteristic information on the examined part is extracted, and this information is linked to the considered part. For example, a copy of the extracted information is temporarily stored in the storage unit 15.

Next, as shown in step S4, the computing means 14 classifies the studied component based on the electrical characteristic information and the transition state information.
Specifically, the calculation means 14 determines that the necessity of improving the electrical characteristics is as follows (1) when the studied part is mounted on an existing electronic circuit board based on the electrical characteristic information linked to the studied part. -1), (1-2), and (1-3) classify the studied parts into three types depending on whether they are in the state.

(1-1) It is not necessary to improve electrical characteristics for all types of electronic circuit boards (all OK).
(1-2) Although it is not necessary to improve the electrical characteristics of some types of electronic circuit boards, it is necessary to improve the electrical characteristics of the remaining types of electronic circuit boards (partially OK).
(1-3) Electrical characteristics need to be improved for all types of electronic circuit boards (all NG).

  Whether or not the electrical characteristics of a certain electronic circuit board need to be improved is determined, for example, by comparing the defect rate of the electronic circuit component with a reference value. That is, if the defect rate is equal to or higher than the reference value, it is determined that improvement is necessary, and if the defect rate is less than the reference value, it is determined that improvement is not necessary.

  Next, based on the transition state information associated with the study component, the computing unit 14 determines that the need for improvement of the transition state is as follows (2-1) when the study component is mounted on an existing electronic circuit board. ), (2-2), and (2-3) are classified into three types according to the state.

(2-1) It is not necessary to improve the transition state for all types of electronic circuit boards (all OK).
(2-2) The transition state does not need to be improved for some types of electronic circuit boards, but the transition state needs to be improved for the remaining types of electronic circuit boards (partly OK).
(2-3) It is necessary to improve the transition state for all types of electronic circuit boards (all are NG).

  Whether or not the transition state of a certain electronic circuit board needs to be improved is determined by, for example, the quality of each stage. For example, in the print quality information, regarding the solder print height, it is judged that there is no need to improve if the average value of the print height is within a predetermined range, and if it is out of the predetermined range, improvement is necessary. Judge that there is.

  In this way, the computing means 14 classifies the studied parts into three types according to the necessity of improving the electrical characteristics, and classifies them into three types according to the necessity of improving the transition state. As a result, as shown in FIG. 5, the computing means 14 classifies the study parts into nine categories (Z, A, B, C, D, E, F, G, H) in total.

Next, as shown in step S5 of FIG. 7, the calculation means 14 corresponds to the correspondence relationship stored in the storage means 15, that is, the classification result of the examination part shown in FIG. 6 and the initial state associated with the examination part. Narrow down the items and methods that need to be reviewed by referring to the relationship between the items that need to be examined and the method of study. In the table shown in FIG. 6, columns represent categories, and rows represent items of initial state information. In each column of the table, “-” indicates that the item does not need to be considered in the category, and “Δ” and “◯” indicate that the item needs to be considered. The difference between “△” and “◯” represents the difference in the examination method. In other words, when there is a significant difference in electrical characteristics or transition state between different types of electronic circuit boards, “△” should adopt the initial state of the electronic circuit board with the better electrical characteristics or transition state. Represents that. On the other hand, “◯” indicates that the initial state of a specific type of electronic circuit board is not adopted, but an optimal initial state should be newly determined.
Hereinafter, the narrowing-down method will be described in detail with reference to FIGS.

(Category Z)
As shown in FIG. 5, (1-1) it is not necessary to improve the electrical characteristics of all types of electronic circuit boards, and (2-1) If there is no need to improve the transition state for a type of electronic circuit board, the component under consideration is classified into category “Z”. Then, as shown in FIG. 6, when the study part is classified into the category “Z”, it can be determined that there is no problem with the study part, so there is no item to be examined.

(Category A)
As shown in FIG. 5, (1-1) it is not necessary to improve the electrical characteristics of all types of electronic circuit boards, and (2-2) some of the existing electronic circuit boards on which the examination parts are mounted. If there is no need to improve the transition state for this type of electronic circuit board, but the transition state needs to be improved for the remaining types of electronic circuit boards, this component is classified as category “A”. The

  As shown in FIG. 6, when the studied part is classified into the category “A”, there is no problem with the electrical characteristics, and therefore it can be determined that there is no problem with the electronic part (the studied part) itself. On the other hand, since there is a problem with some electronic circuit boards regarding the transition state, among the initial states, items that may affect the transition state, that is, initial shapes of electronic components and boards, printing, mounting, and the like It is necessary to consider the items related to the appearance of electronic components and substrates for each vendor and lot in the reflow manufacturing conditions and purchase information. In addition, since there is no problem in the electrical characteristics of the electronic circuit board, it is considered unnecessary to examine the characteristics of the electronic component and the board in the purchase information. As for the examination method, since there is at least one type of electronic circuit board that does not need to improve the transition state, the initial state of the electronic circuit board may be adopted using this as an example.

This examination method will be described with a specific example.
8A is a plan view illustrating the mounting direction of the electronic component on the substrate, FIG. 8B is a partially enlarged plan view illustrating the region R illustrated in FIG. 8A, and FIG. Taking the mounting direction of electronic components, taking the incidence of short-circuit defects on the vertical axis, is a graph illustrating the effect of the mounting direction of electronic components on the incidence of short-circuit defects,
FIG. 9A is a graph illustrating the influence of the number of times of solder printing on the occurrence rate of short-circuit defects, with the horizontal axis representing the number of times of solder printing and the vertical axis representing the occurrence rate of short-circuit defects. (B) is a graph illustrating the influence of the number of times of solder printing on the occurrence rate of disconnection defects by taking the number of times of solder printing on the horizontal axis and the occurrence rate of disconnection defects on the vertical axis.
In FIG. 8C and FIGS. 9A and 9B, each plot represents a defect rate for each month, and the difference in the types of plots indicates the difference in the types of electronic circuit boards.

  As shown in FIG. 8A, when the electronic component 52 is mounted on the substrate 51, a method of mounting the electronic component 52 so that the longitudinal direction of the electronic component 52 is parallel to the printing direction of the solder, and the electronic component. There is a method of mounting so that the longitudinal direction of 52 is perpendicular to the printing direction of the solder. As shown in FIG. 8B, in the former case, the arrangement direction of the connectors 53 of the electronic component 52 is parallel to the printing direction, and in the latter case, the arrangement direction of the connectors 53 is relative to the printing direction. Become vertical. The mounting direction of such an electronic component is initial shape information regarding the combination of the board and the electronic component, and corresponds to the initial state information. On the other hand, in the reflow process, the electronic circuit board after the reflow is inspected for the presence of a short circuit and disconnection of the circuit. The result of this inspection corresponds to the appearance information after reflow and corresponds to the transition state information.

  As shown in FIG. 8C, as a result of investigating the correlation between the mounting direction of the electronic component and the short-circuit defect with respect to the existing electronic circuit board manufactured by the same type of printing apparatus, When mounted parallel to the printing direction, the incidence of short-circuit defects was stabilized in a range lower than when mounted vertically. For this reason, it is necessary to improve the transition state for an electronic circuit board on which electronic components are vertically mounted, and it is not necessary to improve the transition state for an electronic circuit board on which electronic components are mounted in parallel. As described above, when a significant difference is recognized in the transition state due to the difference in the initial state, and it is determined that there is no need to improve the transition state for at least one kind of electronic circuit board, it is a design target. For the electronic circuit board, the initial state of the electronic circuit board that does not need to improve the transition state is adopted. That is, this electronic component is mounted in parallel to the solder printing direction.

  Further, as shown in FIGS. 9A and 9B, when the number of times of solder printing is set to 2, compared to the case where the number of times of printing is set to 1, the occurrence rate of the short-circuit defect and the occurrence rate of the disconnection defect Both decreased. In this case, since the number of times of solder printing is a printing condition, it corresponds to initial state information, and the occurrence rate of short-circuit defects and disconnection defects corresponds to transition state information. When the number of times of printing is one, it is necessary to improve the transition state. When the number of times of printing is two, it is not necessary to improve the transition state. Therefore, the number of times of solder printing is two.

(Category B)
As shown in FIG. 5, (1-1) it is not necessary to improve the electrical characteristics of all types of electronic circuit boards, and (2-3) If the transition state needs to be improved for a type of electronic circuit board, the component under consideration is classified into category “B”.

  As shown in FIG. 6, when the study part is classified into the category “B”, there is no problem with the electrical characteristics as with the category “A”, and therefore there is no problem with the electronic part (the study part) itself. It can be judged. On the other hand, since there are problems for all electronic circuit boards with respect to the transition state, items that may affect the transition state among the initial states, that is, initial shapes of electronic components and boards, printing, mounting and the like It is necessary to consider the items related to the appearance of electronic components for each vendor and the appearance of the substrate for each vendor in the reflow manufacturing conditions and purchase information. Since there is no problem with the electrical characteristics of the electronic circuit board, it is considered unnecessary to examine the characteristics of the electronic component and the characteristics of the board in the purchase information. In addition, since a problem occurs in the transition state of all electronic circuit boards, it is difficult to think that the abnormality is in units of lots of electronic components or boards. And about the examination method, since the problem has occurred in the transition state of all the electronic circuit boards, and there is no electronic circuit board as a model, instead of adopting the initial state of a specific electronic circuit board, It is necessary to newly determine an optimal initial state.

The determination of the initial state may be performed by a statistical method such as multiple regression analysis or MT method (Mahalanobis-Taguchi method) using, for example, all the factors of the initial state information linked to the studied part. For example, the parameters of the items to be considered _{a 1, a 2,} ··· when the _{a n,} the function _f (a ₁ representing the fraction defective of the electronic circuit board using this study _component, a 2, · · · determined by multiple regression analysis of a _n), the function _{f (a 1,} a 2, · · · _a parameter, such as _n) takes the minimum value _{(a 1,} a 2, a combination of · · · _{a n)} decide.

(Category C)
As shown in FIG. 5, regarding the existing electronic circuit board on which the component to be examined is mounted, (1-2) it is not necessary to improve the electrical characteristics of some types of electronic circuit boards, but the remaining types of electronic circuits If it is necessary to improve the electrical characteristics of the board, and (2-1) it is not necessary to improve the transition state for all types of electronic circuit boards, the component under consideration is classified into the category “C”. The

  As shown in FIG. 6, when the part to be examined is classified into the category “C”, there is no problem with the transition state. Therefore, the items regarding the appearance of the electronic circuit board in the initial state information, that is, the electronic part and the board, etc. Of the initial shape information, printing, mounting and reflow manufacturing condition information, and purchase information, items relating to the appearance of the electronic component and the appearance of the substrate are not considered to be considered. On the other hand, there is a problem with some electronic circuit boards in terms of electrical characteristics. Therefore, there are items that may affect the electrical characteristics in the initial state, that is, the characteristics of electronic components for each vendor and lot, and board characteristics. The characteristics need to be considered. With regard to this examination method, there is at least one type of electronic circuit board that does not need to improve electrical characteristics. Therefore, the initial state of the electronic circuit board may be adopted using this as an example.

This examination method will be described with a specific example.
FIG. 10 is a graph illustrating the correlation between the electronic component vendor and the electronic circuit board defect rate, with the horizontal axis representing the electronic component vendor and the vertical axis representing the electronic circuit board defect rate.
In FIG. 10, each plot represents the defect rate for each month, and the difference in the type of plot represents the difference in the type of electronic circuit board.

  As shown in FIG. 10, when the electronic component vendor is company A, the electronic circuit board on which the electronic component is mounted has a large variation in the defect rate and the overall defect rate is high, and there is a need for improvement. It was. On the other hand, when the electronic component vendor is Company B, the defect rate of the electronic circuit board is low and stable, and no improvement is required. In this case, the vendor corresponds to the initial state, and the defect rate of the electronic circuit board corresponds to the electrical characteristics. And about the electronic circuit board used as a design object, the initial state of the electronic circuit board which does not need to improve an electrical property is employ | adopted. That is, the electronic component vendor is B company. In addition, you may perform a single regression analysis according to failure mode regarding the data shown in FIG.

(Category D)
As shown in FIG. 5, regarding the existing electronic circuit board on which the component to be examined is mounted, (1-2) it is not necessary to improve the electrical characteristics of some types of electronic circuit boards, but the remaining types of electronic circuits It is necessary to improve the electrical characteristics of the board, and (2-2) there is no need to improve the transition state for some types of electronic circuit boards, but the transition state for the remaining types of electronic circuit boards. If it is necessary to improve, the considered component is classified into the category “D”.

  As shown in FIG. 6, when the study parts are classified into the category “D”, the items and methods to be examined in the initial state are the items and methods to be examined in the case of the category “A” and the category “D”. This is the sum of items and methods to be considered in the case of “C”. In other words, with respect to the transition state, some electronic circuit boards do not need to be improved and the remaining electronic circuit boards need to be improved. For the shape, manufacturing conditions, appearance for each vendor, appearance for each lot), the initial state of the electronic circuit board that does not need to improve the transition state is adopted. As for electrical characteristics, some electronic circuit boards do not need to be improved, and the remaining electronic circuit boards need to be improved. For each characteristic and characteristic for each lot, the initial state of the electronic circuit board that does not require improvement of the electrical characteristics is adopted.

(Category E)
As shown in FIG. 5, regarding the existing electronic circuit board on which the component to be examined is mounted, (1-2) it is not necessary to improve the electrical characteristics of some types of electronic circuit boards, but the remaining types of electronic circuits If it is necessary to improve the electrical characteristics of the board, and (2-3) the transition state needs to be improved for all types of electronic circuit boards, the component under consideration is classified into category “E”. The

  As shown in FIG. 6, when the parts to be examined are classified into the category “E”, the items and methods to be examined in the initial state are the items and methods to be examined in the case of the category “B”, and the category “ This is the sum of items and methods to be considered in the case of “C”. In other words, because there are problems with all electronic circuit boards regarding the transition state, items that may affect the transition state in the initial state (initial shape, manufacturing conditions, appearance for each vendor) are subjected to multiple regression. It is necessary to newly determine an optimal initial state by analysis or the like. As for electrical characteristics, some electronic circuit boards do not need to be improved and the remaining electronic circuit boards need to be improved. The initial state of the electronic circuit board that does not need to improve the electrical characteristics is adopted for each characteristic and characteristic for each lot).

(Category F)
As shown in FIG. 5, (1-3) all types of electronic circuit boards need to be improved in electrical characteristics with respect to existing electronic circuit boards on which the investigation component is mounted, and (2-1) all If there is no need to improve the transition state for a type of electronic circuit board, the component under consideration is classified into category “F”.

  As shown in FIG. 6, when the studied part is classified into the category “F”, there is no problem with the transition state, and therefore items regarding the appearance of the electronic circuit board in the initial state (initial shape, manufacturing conditions, each vendor) The appearance of each item and the appearance of each lot are not considered. On the other hand, since there are problems with all electronic circuit boards regarding electrical characteristics, items that may affect the electrical characteristics (characteristics for each vendor and characteristics for each lot) in the initial state will be examined. There is a need. For this study method, there is a problem in the electrical characteristics of all electronic circuit boards, and there is no electronic circuit board as a model, so instead of adopting the initial state of a specific electronic circuit board. For example, it is necessary to newly determine an optimal initial state by multiple regression analysis or the like.

(Category G)
As shown in FIG. 5, (1-3) the electrical characteristics of all types of electronic circuit boards need to be improved for the existing electronic circuit boards on which the examination components are mounted, and (2-2) some If there is no need to improve the transition state for this type of electronic circuit board, but the transition state needs to be improved for the remaining types of electronic circuit boards, the component under consideration will be classified into category “G”. The

  As shown in FIG. 6, when the study parts are classified into the category “G”, the items and methods to be examined in the initial state are the items and methods to be examined in the case of the category “A”, and the category “ It is the sum of items and methods to be considered in the case of “F”. In other words, with respect to the transition state, some electronic circuit boards do not need to be improved and the remaining electronic circuit boards need to be improved. For the shape, manufacturing conditions, appearance for each vendor, appearance for each lot), the initial state of the electronic circuit board that does not need to improve the transition state is adopted. As for electrical characteristics, there are problems in all electronic circuit boards. For items that may affect the electrical characteristics in the initial state (characteristics per vendor, characteristics per lot), the optimal initial A new state is determined.

(Category H)
As shown in FIG. 5, for the existing electronic circuit board on which the component to be examined is mounted, (1-3) it is necessary to improve the electrical characteristics of all types of electronic circuit boards, and (2-3) all If the transition state needs to be improved for a type of electronic circuit board, the component under consideration falls into category “H”.

As shown in FIG. 6, when the part to be examined is classified into the category “H”, the items and methods to be examined in the initial state are the items and methods to be examined in the case of the category “B”, and the category “ It is the sum of items and methods to be considered in the case of “F”. In other words, because there is a problem with all electronic circuit boards regarding the transition state, items that may affect the transition state in the initial state (initial shape, manufacturing conditions, appearance for each vendor, appearance for each lot) For, the optimum initial state is newly determined. In addition, because there are problems with all electronic circuit boards in terms of electrical characteristics, the optimal initial stage for items that may affect the electrical characteristics in the initial state (characteristics per vendor, characteristics per lot) A new state is determined.
In this way, the computing means 14 classifies the studied parts into nine categories of categories “Z”, “A” to “H”.

  Next, as shown in step S6 of FIG. 7, the calculation means 14 inputs / outputs the items and the examination method that need to be examined for the examination part based on the above-described classification result and the correspondence shown in FIG. 16 is output. At this time, when the examination method is “Δ” shown in FIG. 6, that is, when the initial state of the electronic circuit board that does not require improvement is adopted as the initial state, the contents of the initial state to be adopted are also included. Output. For example, in the example shown in FIGS. 8 to 9 described above, the mounting direction of the electronic component is parallel to the solder printing direction, the number of times of solder printing is 2, and the vendor of the studied component is company B. Output.

  Based on the output result, the electronic circuit board designer grasps the items to be examined and the examination method for the electronic components to be mounted on the electronic circuit board, knows the initial state to be adopted, and designs the electronic circuit board. Useful for. Thus, according to the present embodiment, the design of the electronic circuit board can be supported.

Next, the effect of this embodiment will be described.
When designing an electronic circuit board, the design support system 1 according to the present embodiment uses initial state information for each electronic component to be mounted on the electronic circuit board to be designed based on the electrical characteristic information and the transition state information. The items to be examined and the method to be examined can be output. Thereby, the designer can narrow down the examination items and the examination method when designing the electronic circuit board. As a result, the time required for narrowing down can be omitted, and wasteful time due to examination of unnecessary items can be eliminated, and backtracking from the manufacturing stage to the design stage can be prevented by not examining the items to be examined. Can do. This makes it possible to improve the efficiency of the design of the electronic circuit board.

  In addition, according to the present embodiment, the examination items and the examination method are narrowed down by referring to not only the electrical characteristic information of the completed electronic circuit board but also the transition state information in the intermediate process, so that it is possible to narrow down with high accuracy. Become.

  Furthermore, according to the present embodiment, information on another type of electronic circuit board that is an electronic circuit board other than the electronic circuit board that is the design target and on which the electronic component to be examined (reviewed part) is mounted is used. Therefore, even when the electronic circuit board to be designed has not yet been manufactured, and there is no information regarding the electronic circuit board, it is possible to narrow down and support the design.

  The present invention has been described above with reference to the embodiment. However, the present invention is not limited to this embodiment. For example, those in which the person skilled in the art appropriately added, deleted, or changed a process or an apparatus with respect to the above-described embodiment are also included in the scope of the present invention as long as the gist of the present invention is included.

  For example, in the present embodiment, when the electronic circuit board that was the design target is designed and manufactured after a certain amount of manufacturing, when the design is reviewed, that is, the information about the electronic circuit board itself that is the design target, that is, In addition, the above-described design support may be performed by adding initial state information, transition state information, and electrical characteristic information.

  Further, in the present embodiment, the example in which the necessity of reviewing the electrical characteristics and the transition state is determined for each type of electronic circuit board has been described. However, in the same type of electronic circuit board, the determination is made for each initial state. May be. This increases the amount of computation, but enables more precise analysis.

  Further, in the present embodiment, information on an electronic circuit board on which an electronic component (consideration part) to be examined is mounted is used. In addition, information on an electronic circuit board on which an electronic part similar to the examination part is mounted. May be added. Thereby, since the amount of information to be analyzed can be increased, the accuracy of analysis can be increased when there is little information about the electronic circuit board on which the studied component is mounted.

  Furthermore, in the present embodiment, the storage unit 15 is provided in the design support system 1, and the storage unit 15 stores the correspondence (see FIG. 6) between the analysis result and the examination item / method. Although the design support system 1 shows an example in which the examination items / methods are output according to the analysis result, the design support system may not be provided with a storage unit that stores the correspondence relationship. In this case, for example, the designer holds a document on which the correspondence shown in FIG. 6 is printed. Then, the design support system outputs only the result of classification of the study parts, and the designer may determine the study item / method by looking at the document based on the classification result.

1 is a block diagram illustrating an electronic circuit board design support system according to an embodiment of the invention. It is a figure which illustrates the information memorized by the initial state database. It is a figure which illustrates the information memorized by transition state database. It is a figure which illustrates the information memorized by the electrical property database. It is a figure which illustrates the classification method of an electronic component. It is a figure which illustrates the correspondence of the classification result of electronic parts, the item which needs examination among initial state information, and the examination method. It is a flowchart figure which illustrates the design support method which concerns on this embodiment. (A) is a top view which illustrates the mounting direction of the electronic component with respect to a board | substrate, (b) is a partially expanded plan view which illustrates the area | region R shown to (a), (c) is an electronic component on a horizontal axis. 5 is a graph illustrating the influence of the mounting direction of an electronic component on the occurrence rate of a short-circuit defect, with the mounting direction of FIG. (A) is a graph illustrating the influence of the number of times of solder printing on the occurrence rate of short-circuit defects, with the horizontal axis representing the number of times of solder printing and the vertical axis representing the occurrence rate of short-circuit defects. ) Is a graph illustrating the influence of the number of times of solder printing on the occurrence rate of disconnection defects, with the horizontal axis indicating the number of times of solder printing and the vertical axis indicating the rate of occurrence of disconnection defects. FIG. 6 is a graph illustrating the correlation between the electronic component vendor and the electronic circuit board defect rate, with the horizontal axis representing the electronic component vendor and the vertical axis representing the electronic circuit board defect rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Design support system, 11 Initial state database, 12 Transition state database, 13 Electrical property database, 14 Computation means, 15 Storage means, 16 Input / output means, 51 Substrate, 52 Electronic component, 53 Connector, 101 Product design stage, 102 process Design stage, 103 manufacturing stage, 104 market introduction stage, R region

Claims (6)

An electronic circuit board design support system in which electronic components are mounted on a board,
For the manufacturing conditions of the substrate, the electronic component, and the electronic circuit board, an initial state database in which initial state information relating to matters determined before starting the manufacture of the electronic circuit board is stored;
Transition state database storing transition state information representing the result of appearance evaluation in an intermediate process of manufacturing the electronic circuit board;
An electrical property database storing electrical property information indicating electrical properties of an electronic circuit board on which the electronic component is mounted; and
Based on the transition state information and the electrical characteristic information, a computing means for classifying the electronic component according to an item that needs to be examined in the initial state information;
An electronic circuit board design support system comprising: The transition state information includes
Print quality information showing the print status when solder is printed on the board,
Mount quality information indicating a mounting state when the electronic component is mounted on a board on which the solder is printed,
Appearance information after reflow showing the appearance when the electronic component is soldered to the substrate by heating the solder,
The electronic circuit board design support system according to claim 1, wherein:   The initial state information, the transition state information, and the electrical characteristic information include information when the electronic component is mounted on another type of electronic circuit board other than the electronic circuit board that is the target of design support. The design support system for an electronic circuit board according to claim 1 or 2. The computing means is
Based on the electrical characteristic information, when the electronic component under consideration is mounted on the other type of electronic circuit board,
Whether all types of electronic circuit boards need improvement
There is no need for improvement for some types of electronic circuit boards, but there is a need for improvement for the remaining types of electronic circuit boards, or
Do you need to improve all types of electronic circuit boards?
Are classified into three types,
Based on the transition state information, when the electronic component being studied is mounted on the other type of electronic circuit board,
Whether all types of electronic circuit boards need improvement
There is no need for improvement for some types of electronic circuit boards, but there is a need for improvement for the remaining types of electronic circuit boards, or
Do you need to improve all types of electronic circuit boards?
The electronic circuit board design support system according to claim 3, wherein the electronic circuit board design support system is classified into the following three types. A storage means for storing a correspondence relationship between the classification result and the item in the initial state information that needs to be examined;
5. The calculation unit according to claim 1, wherein the calculation unit outputs an item that needs to be examined for the electronic component to be examined based on the classification result and the correspondence relationship. Design support system for electronic circuit boards described in 1. The storage means also describes a method for examining the item that needs to be examined,
6. The electronic circuit board design support system according to claim 5, wherein the calculation means also outputs the examination method.

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