Design device, design method and design program

Abstract

To contribute to a proper design of respective shapes and thicknesses of an opening part of a metal mask for mounting components to a substrate of an arbitrary thickness by a through-hole reflow.SOLUTION: For designing one or more opening parts respectively opened in a jig for applying a brazing raw material to a range including a through-hole in a circuit pattern, a processor is configured to: calculate a first volume of the brazing raw material filling the first through-hole on the basis of a first radius of a preliminarily prepared first through-hole, and a first thickness of a preliminarily prepared substrate; calculate a second volume of the brazing raw material filling the second through-hole on the basis of a second radius of a second through-hole formed in a printed substrate and a second thickness of the printed substrate; accept identifying a part or all of surroundings of the range; and change the identified part or all of the surroundings of the range so as to correspond to a differential between the first volume and the second volume.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a design apparatus, a design method, and a design program. [Background technology]

[0002] Printed circuit boards (hereinafter simply referred to as "boards") are widely used, in which circuit patterns and through-holes for electronic or electric circuits (hereinafter referred to as "electronic circuits") are formed on the surface of a single insulating board, or on the surface and inside of multiple insulating boards. Components whose terminals are connected to the circuit patterns of the board using the through-holes, and surface-mounted components whose terminals are connected to pads on the circuit patterns on the board surface, are connected by soldering.

[0003] Surface-mounted components, in which terminals are connected to pads on a circuit pattern on the surface of a board, are generally referred to as "SMD (Surface Mount Device) components." In this specification, components whose terminals are connected using through holes are referred to as "through-hole components," and SMD and through-hole components are collectively referred to as "components." In this specification, the portion of a circuit pattern formed near a through-hole, including the through-hole, and within the range to which the through-hole component is connected is referred to as the "through-hole portion." Examples of SMD components include chip resistors, chip capacitors, and small outline package (SOP) semiconductor elements. Examples of through-hole components include dual in-line package (DIP) semiconductor elements and board connectors. Connecting a component to a circuit pattern and attaching it to a board is generally referred to as "mounting."

[0004] Components are mounted on a board using a method known as "through-hole reflow." Mounting components on a board using through-hole reflow is performed as follows: First, solder paste is applied to each of the pads and through-holes of the circuit pattern by printing, in the volume required to connect the component terminals. Next, the terminals of the SMD component are properly aligned with the pads, and the terminals of the through-hole component are properly inserted into the through-holes, attaching the SMD and through-hole components to the board. The board with the components attached is then heated in a reflow oven or similar to melt the solder paste, electrically connecting the component terminals to the circuit pattern. The tool used to apply the solder paste to the pads and through-holes is generally called a "metal mask." Openings are also made in the metal mask to allow the solder paste to be applied to the pads and through-holes. Note that solder paste is sometimes referred to by other names, such as solder paste. In addition to cream solder, various materials can be used for soldering components to circuit patterns by through-hole reflow, including metals for brazing, which can be applied to a printed circuit board and heated after application to electrically connect the terminals of the components to the circuit pattern.

[0005] Mounting components on a board using through-hole reflow requires applying the appropriate volume of solder paste to each of the circuit pattern pads and through-holes on the board. To ensure that the appropriate volume of solder paste is applied to the circuit pattern pads and through-holes, component manufacturers recommend or define (hereafter referred to as "recommended") the board thickness and opening shape (area) and thickness before mounting the components on the board. The opening shape and opening thickness determine the solder paste volume required for proper mounting of SMD components, while the board thickness, opening shape (area), opening thickness, and board thickness determine the solder paste volume required for proper mounting of through-hole components. When the metal mask thickness is uniform throughout, the opening thickness of the metal mask is equal to the metal mask thickness.

[0006] The shapes of the terminals of SMD components and the pads for mounting SMD components are often known based on standards for semiconductor packages, etc., so designing the thickness and shape of openings in a metal mask that correspond to the pads is not difficult. For example, Patent Document 1 discloses a method for designing a metal mask that has pads for mounting SMD components and openings that correspond to the pads. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-073773 Summary of the Invention [Problem to be solved by the invention]

[0008] The disclosures of the above-mentioned prior art documents are incorporated herein by reference. The following analysis has been carried out by the present inventors.

[0009] However, the thickness of the board and the diameter of the through-holes vary depending on the product in which the board is used, etc. In other words, in order to properly mount through-hole components on a board, it is necessary to design the shape and thickness of each opening in the metal mask corresponding to the through-hole so that a sufficient volume of cream solder can be applied to electrically connect the terminal to the circuit pattern.

[0010] In view of the above-mentioned problems, the object of the present invention is to contribute to the appropriate design of the shape and thickness of each opening of a metal mask for mounting components to a substrate of any thickness by through-hole reflow. [Means for solving the problem]

[0011] In a first aspect of the present invention, there is provided a design device including one or more processors, wherein the one or more processors are configured to design one or more openings in a jig for applying brazing material to areas in the circuit pattern including the through holes in the printed circuit board by soldering, the one or more processors being configured to: calculate a first volume of the brazing material to fill the first through hole based on a first radius of the first through hole that is predetermined and a first thickness of the printed circuit board that is predetermined; calculate a second volume of the brazing material to fill the second through hole based on a second radius of the second through hole that is formed in the printed circuit board and a second thickness of the printed circuit board; accept specification of a portion or all of the perimeter of the area; and modify a portion or all of the perimeter of the specified area to correspond to a difference between the first volume and the second volume.

[0012] In a second aspect of the present invention, there is provided a design method for calculating one or more openings to be formed in a jig for applying brazing material to an area in a circuit pattern including through holes formed in the printed circuit board, in order to electrically connect terminals of a component to the circuit pattern by brazing using the through holes. The design method includes a first calculation step, a second calculation step, an acceptance step, and a modification step. The first calculation step calculates a first volume of the brazing material to fill a first through hole based on a first radius of the first through hole that is previously determined and a first thickness of the printed circuit board that is previously determined. The second calculation step calculates a second volume of the brazing material to fill a second through hole based on a second radius of a second through hole formed in the printed circuit board and a second thickness of the printed circuit board. The acceptance step accepts the identification of a portion or all of the perimeter of the area. The modification step modifies a portion or all of the perimeter of the identified area to correspond to the difference between the first volume and the second volume.

[0013] In a third aspect of the present invention, there is provided a design program for designing one or more openings formed in a jig for applying brazing material to an area in a circuit pattern including a through hole formed in the printed circuit board, in order to electrically connect a terminal of a component to the circuit pattern by brazing using the through hole formed in the printed circuit board. The design program includes a first calculation process for calculating a first volume of the brazing material to fill a first through hole based on a first radius of the first through hole prepared in advance and a first thickness of the printed circuit board prepared in advance, and a second calculation process for calculating a second volume of the brazing material to fill a second through hole based on a second radius of a second through hole formed in the printed circuit board and a second thickness of the printed circuit board. The processor is caused to execute an accepting process for accepting the identification of a portion or all of the perimeter of the range, and a modifying process for modifying a portion or all of the identified perimeter of the range to correspond to the difference between the first volume and the second volume. The program can be recorded on a computer-readable storage medium. The storage medium can be a non-transitory medium such as a semiconductor memory, a hard disk, a magnetic recording medium, an optical recording medium, etc. The present invention can be embodied as a computer program product. [Effects of the Invention]

[0014] Each aspect of the present invention can contribute to the appropriate design of the shape and thickness of each opening in a metal mask for mounting components on a substrate of any thickness by through-hole reflow. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating the shape of an opening in a metal mask corresponding to a portion of a circuit pattern on a substrate where pads and through-holes are mixed. [Figure 2A] FIG. 2A is a diagram illustrating a design process for partially changing the shape of the opening of the metal mask shown in FIG. [Figure 2B] FIG. 2B is a diagram illustrating a design process for partially changing the shape of the opening of the metal mask shown in FIG. [Figure 3] FIG. 3 is a diagram illustrating an example of the hardware configuration of an information processing device (computer) that realizes the metal mask opening design method according to the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of CAD software executed as a CAD program in the information processing device shown in FIG. [Figure 5] FIG. 5 is a flowchart showing a method (S10) for designing an opening in a metal mask using CAD software. [Figure 6]FIG. 6 is a flowchart showing the detailed process of S12 shown in FIG. [Figure 7] FIG. 7 is a diagram illustrating the shape of the opening in the metal mask changed by the processing shown in FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below. In addition, the same or corresponding elements in each drawing are appropriately designated by the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from the actual relationships. Furthermore, the dimensional relationships and ratios may differ between the drawings.

[0017] FIG. 1 is a diagram illustrating the shape of an opening in a metal mask (not shown) corresponding to a portion of a circuit pattern on a substrate where pads and through-holes are mixed. FIGS. 2A and 2B are diagrams illustrating a design process for partially modifying the shape of the opening in the metal mask shown in FIG. 1. Note that FIG. 2A illustrates the shape of the opening in the metal mask corresponding to the L-shaped through-hole portion shown in FIG. 1, and whose shape was determined in accordance with information recommended by a component manufacturer, and FIG. 2B illustrates the shape of the opening after the portions corresponding to the two sides around the L-shaped opening in the metal mask illustrated in FIGS. 1 and 2A have been modified (enlarged) by design.

[0018] 2A and 2B show an example in which the through-hole has a shape formed by combining rectangles. The lengths of the sides around the opening and the sides with lengths a to d (hereinafter referred to as "sides a to d"), and the lengths of the enlarged portions corresponding to the sides a and d of the opening, are defined as shown in FIG. 2B.

[0019] Designing the thickness and shape of the openings corresponding to the through-holes is difficult because the through-hole reflow process, which heats the board, provides a volume of solder paste that flows from the board's surface into the through-holes and fills them enough to connect the through-hole terminals to electronic circuits. On the other hand, designing the thickness and shape of the openings corresponding to the pads is not as difficult as designing the thickness and shape of the openings corresponding to the through-holes, since it only provides the amount of solder paste that connects the pads to the SMD component terminals. Therefore, the following discussion will primarily focus on the design of the thickness and shape (area) of the openings corresponding to the through-holes, and in the following discussion, unless otherwise specified, "opening" refers to the "opening corresponding to the through-hole."

[0020] The shape of each opening in the metal mask is designed, for example, by a designer operating a computer-aided design (CAD) program (described below with reference to FIG. 4) for designing metal masks that runs on an operating system (OS; not shown) executed on a computer (described below with reference to FIG. 3). Typically, such a CAD program includes a library of information that correlates the thickness of the substrate, the position of each of the multiple openings formed in the metal mask, and the shape and thickness of the openings.

[0021] The CAD program also has the ability to enlarge or reduce the entire shape of each opening in the library, as well as the shape of only the portion corresponding to one or more sides of each opening, according to the designer's design operations. However, when enlarging the shape of an opening, the sides of the opening to be enlarged must be selected so as to avoid interference with other openings and circuit patterns, including pads, located near the opening to be enlarged. Furthermore, if there are a large number of sides corresponding to the enlarged or reduced portions, the design work tends to become complicated. The metal mask opening design method disclosed herein is designed to simplify the design work, even when enlarging an opening to a portion corresponding to multiple sides.

[0022] Fig. 3 is a diagram illustrating an example of the hardware configuration of an information processing device (computer) 1 that realizes the metal mask opening design method according to the present disclosure. Fig. 4 is a diagram illustrating an example of the configuration of CAD software 2 that is executed as a CAD program in the information processing device 1 shown in Fig. 3. The metal mask opening design method according to the present disclosure is realized by the information processing device 1 executing the CAD software 2. However, the configuration of the information processing device 1 shown in Fig. 3 is an example of a hardware configuration that realizes each function for the opening creation method according to the present disclosure, and Fig. 3 does not limit the hardware configuration of the information processing device 1, and the information processing device 1 may include components not shown in Fig. 3.

[0023] As shown in FIG. 3, the information processing device 1 includes one or more CPUs (Central Processing Units; processors) 100, a main memory device 102, an auxiliary memory device 104, and an IF (Interface) unit 106, which are connected to each other via an internal bus so that data can be input and output.

[0024] The CPU 100 executes each command included in the CAD software 2 executed by the information processing device 1. The main memory device 102 includes memory elements such as RAM (Random Access Memory) and ROM (Read Only Memory), and temporarily stores the CAD software 2 executed by the information processing device 1 and data required for its execution. The IF 106 provides an interface function for inputting and outputting data required for editing and creating a metal mask and its openings between the CPU 100 and input devices such as a keyboard, mouse, and pen tablet, and output devices such as a display and printer (none of which are shown).

[0025] The auxiliary storage device 104 includes a nonvolatile storage device such as a hard disk drive (HDD), a solid state drive (SSD), or a flash memory (none of which are shown). The auxiliary storage device 104 stores the CAD software 2 executed by the information processing device 1 and data required for its execution over the medium to long term. A nonvolatile storage medium such as a USB memory stick is detachably connected to the auxiliary storage device 104, and the auxiliary storage device 104 can read information from and write information to the connected nonvolatile storage device. The CAD software 2 may be provided as a program product recorded on a non-transitory computer-readable storage medium such as a CD-ROM or DVD (none of which are shown). Alternatively, the CAD software 2 may be provided as a program product downloaded from a server device to a personal computer (PC) (none of which are shown) via a network.

[0026] 4, the CAD software 2 includes a CAD input unit 20, a calculation unit 24, and an output unit 26. The CAD input unit 20 includes an edge identification unit 200 and a recommended shape input unit 202. The information input unit 22 includes a recommended thickness input unit 220, a design information input unit 222, and a correction coefficient input unit 224. The calculation unit 24 includes a recommended volume calculation unit 240, a design volume calculation unit 242, and a change length calculation unit 244. The CAD output unit 26 includes an opening display unit 260 and a UI (User Interface) processing unit 262.

[0027] 4 omits the components that provide the library functions described above. As described above, the CAD software 2 is stored in the auxiliary storage device 104, loaded into the main storage device 102 in response to a startup operation by the designer, and executed by specifically utilizing the hardware components of the information processing device 1. Using these components, the CAD software 2 provides the designer with the function of designing the shape and thickness of a metal mask and each of its multiple openings.

[0028] These components of the CAD software 2 are realized, for example, as program modules including multiple instructions executed by the CPU 100. The CAD input unit 20, the information input unit 22, and the CAD output unit 26 accept input information from an input device such as a mouse of the information processing device 1 via the IF 106, and output information to an output device such as a display of the information processing device 1 via the IF 106. The opening display unit 260 and the UI processing unit 262 output information indicating the shape of the opening obtained as a result of the design to the output device of the information processing device 1 via the IF 106. For the sake of concreteness and clarity of the explanation below, an example will be given in which all of the cream solder applied to the through-hole portions of the circuit pattern fills and fills the through-holes into which the terminals of the through-hole component are inserted.

[0029] In the CAD input unit 20, the recommended shape input unit 202 accepts input of information indicating the shape of the opening recommended by the component manufacturer for each component (component manufacturer recommended information). Specifically, the component manufacturer recommended information includes information indicating the shape Am' (area Am) of the opening and information indicating the radius Rm of the through hole (first through hole; through hole corresponding to the opening shape recommended by the component manufacturer). The recommended shape input unit 202 can, for example, calculate the area Am (=πRm2) of the opening from the information indicating the shape Am' indicated by the component manufacturer recommended information. Therefore, the component manufacturer recommended information may include information that is not essential for calculating the shape and thickness of the opening. The recommended shape input unit 202 outputs the accepted component manufacturer recommended information and information indicating the calculated area Am of the opening to the recommended volume calculation unit 240.

[0030] Furthermore, the recommended shape input unit 202 reads information indicating the metal mask shape Am' corresponding to the received component manufacturer recommended information from the library, and displays the information on a display or the like of an output device of the information processing device 1, as shown in FIG. 2A . The recommended shape input unit 202 also outputs the received component manufacturer recommended information to the edge identifying unit 200 and the recommended volume calculation unit 240. The component manufacturer recommended information is input to the recommended shape input unit 202, for example, by a designer inputting it to an input device of the information processing device 1, by the information processing device 1 receiving it from a component manufacturer's server via a network, or by the CPU 100 reading it from a non-volatile storage medium connected to the auxiliary storage device 104. Note that information input to each component of the CAD input unit 20 and the information input unit 22 can also be input in a similar manner.

[0031] The side identifying unit 200 accepts, from the input device of the information processing device 1, an operation by the designer to specify one or more sides of the opening graphic displayed on the output device of the information processing device 1, and identifies one or more sides of the opening specified by the designer. Furthermore, the side identifying unit 200 displays, on the output device, an image showing the specified sides highlighted as shown in Fig. 2A, and outputs side information indicating the specified sides to the change length calculation unit 244. Note that Fig. 2A shows the case where a side of the opening with length a and a side of length d have been selected.

[0032] In information input unit 22, recommended thickness input unit 220 accepts input of information indicating the shape of the board and opening recommended by the component manufacturer for each component (component manufacturer recommended thickness information). Specifically, the component manufacturer recommended thickness information includes information indicating the thickness tp1 of the board and information indicating the thickness t1 of the opening. Recommended thickness input unit 220 outputs the input component manufacturer recommended thickness information to recommended volume calculation unit 240.

[0033] The design information input unit 222 accepts input of design information indicating the shape and thickness of the designed opening and the thickness of the board on which the component will actually be mounted, in response to operations by the designer. Specifically, the design information includes information indicating the designed opening shape A1', information indicating the radius R1 of the through-hole (second through-hole; the through-hole corresponding to the opening designed by CAD software 2), information indicating the opening thickness t1, and information indicating the thickness tp1 of the board on which the component will actually be mounted. Similar to the recommended shape input unit 202, the design information input unit 222 can also calculate the opening area A1 from the information indicating the designed opening shape A1'. The design information input unit 222 outputs the accepted design information and the calculated opening area to the design volume calculation unit 242.

[0034] The correction coefficient input unit 224 receives information indicating a correction coefficient k that is multiplied by the difference (ΔA; ΔA = A1 - Am) between the area Am of the opening recommended by the component manufacturer and the area A1 of the opening obtained by design, in order to correct the difference ΔA. The correction coefficient input unit 224 outputs the received information indicating the correction coefficient k to the design volume calculation unit 242. This correction coefficient k is determined based on information accumulated by the substrate manufacturer over many years, or is determined by simulation or experiment for optimal mounting on the component substrate. When an appropriate amount of cream solder given by the volume of the opening of the metal mask is applied to the through-hole portion and heated, and then the through-hole component is properly mounted in the through-hole and the through-hole is properly filled with solder, k = 1. That is, k = 1 when the amount of cream solder applied to the through-hole portion through the designed opening is appropriate. Also, when an appropriate amount of cream solder given by the volume of the opening of the metal mask is applied to the through-hole portion and heated, and there is a possibility that the solder will overflow from the through-hole, k < 1. That is, k < 1 when there is a possibility that the amount of cream solder applied to the through-hole portion through the designed opening is too much. Conversely, when an appropriate amount of cream solder given by the volume of the opening of the metal mask is applied to the through-hole portion and heated, and there is a possibility that the solder will not sufficiently fill the through-hole, 1 < k. That is, 1 < k when there is a possibility that the amount of cream solder applied to the through-hole portion through the designed opening is too little.

[0035] In the calculation unit 24, the recommended volume calculation unit 240 obtains a component manufacturer's recommended value (recommended volume Vm; Vm = Am × tm) of the volume of cream solder applied to the through-hole portion through the opening from the information indicating the area Am of the opening input from the recommended shape input unit 202 and the information indicating the thickness tm of the opening input from the recommended thickness input unit 220. The recommended volume calculation unit 240 outputs the recommended volume information indicating the recommended volume Vm and the information input from the recommended shape input unit 202 and the recommended volume calculation unit 240 to the design volume calculation unit 242.

[0036] Design volume calculation unit 242 calculates the change in the amount of cream solder that increases or decreases when an opening, the shape of which is determined based on component manufacturer recommendation information as shown in Fig. 2A, is changed in order to actually mount a component as shown in Fig. 2B. The value of this change in the amount of cream solder is equal to the value of the difference ΔV between the volume of the through-hole calculated based on the component manufacturer recommendation information and the volume of the through-hole provided in the board on which the component is actually mounted.

[0037] Based on the component manufacturer's recommended information, the recommended volume Vm of the through-hole is calculated by the following formula (1).

[0038] Vm = πRm2tp (1)

[0039] On the other hand, the volume V1 of the through-hole provided in the board on which the component is actually mounted is calculated by the following formula (2).

[0040] V1 = πR12tp1 (2)

[0041] Therefore, the difference ΔV is calculated by the following equation (3).

[0042] ΔV = π(R12tp1-Rm2tp) (3)

[0043] Design volume calculation unit 242 outputs information indicating value kΔV obtained by multiplying difference ΔV calculated in this way by correction coefficient k input from correction coefficient input unit 224 to change length calculation unit 244. When difference ΔV is a positive value, the shape of the opening is changed so that the area becomes larger as shown in Fig. 2B, and when difference ΔV is a negative value, the shape of the opening is changed so that the area becomes smaller (not shown).

[0044] Change length calculation unit 244 calculates the change amounts (X1 and X2) in the lengths of the sides (sides a and d in the example shown in FIG. 2B) identified by side identification unit 200 according to the change in the shape of the opening. For example, if difference kΔV obtained by multiplying difference ΔV by correction coefficient k is distributed equally, half to each of the portions corresponding to sides a and b, with the opening having a uniform thickness t1, X1 and X2 are given by the following equations (4) and (5).

[0045] X1={kΔV-Vm(t1-tm)} / (2at1) =kπ{(R12tp1-Rm2tp)-Vm(t1-tm)} / (2at1) (4)

[0046] Furthermore, the length of side d changes by X2 as shown in the following equation.

[0047] X2={kΔV-Vm(t1-tm)} / (2dt1) =kπ{(R12tp1-Rm2tp)-Vm(t1-tm)} / (2dt1) (5)

[0048] Change length calculation unit 244 outputs information indicating the amounts of change X1 and X2, and an image of the opening that has been read from the library and determined based on the component manufacturer's recommended information as shown in Fig. 2A, to opening display unit 260. Note that here, an example has been given in which two sides a and d have been identified by side identification unit 200. However, it goes without saying that if the number of sides identified by side identification unit 200 is other than two, or if a side other than sides a and d is identified, the number and value of the amounts of change will change depending on the lengths of the identified sides and the number of sides.

[0049] In CAD output unit 26, opening display unit 260 uses information indicating the amounts of change X1 and X2 and the opening shape shown in Fig. 2A to generate an image showing the opening shape as it changes before and after the change, as shown in Fig. 2B. Change length calculation unit 244 then superimposes the image showing the opening shape as it changes before and after the change on an image showing the shapes of other openings around the opening, and displays the resulting image on the output device of information processing device 1. By viewing the image of the opening displayed in this way, the designer can confirm whether, after the change in the opening shape, the opening will interfere with other openings and circuit patterns including pads, or will be so close that it will hinder proper component mounting.

[0050] The UI processing unit 262 accepts the designer's operation on the changed shape of the opening displayed on the output device of the information processing device 1, and, in response to the designer's operation, for example, lengthens or shortens the change amounts X1 and X2 in the opening display unit 260. For example, if the change amount X1 is shortened in response to the designer's operation, the CAD software 2 lengthens the change amount X2 because the volume corresponding to the shortened change amount X1 needs to be added to the change amount X2. Conversely, for example, if the change amount X2 is shortened in response to the designer's operation, the CAD software 2 lengthens the change amount X1 because the volume corresponding to the shortened change amount X2 needs to be added to the change amount X1. Furthermore, in response to the user's operation, the UI processing unit 262 displays a UI image (not shown) on the output device of the information processing device 1 that includes buttons for inputting, for example, "YES" and "NO," to prompt the designer to input whether or not the change to the changed shape of the opening is complete.

[0051] If the designer does not complete the change in the shape of the opening and operates the "NO" button on the input device of the information processing device 1, the UI processing unit 262 outputs information indicating the lengths of the change amounts X1 and X2 changed in response to the user's operation to the design information input unit 222. In this case, the processing of the design information input unit 222, design volume calculation unit 242, change length calculation unit 244, and opening display unit 260 is repeated, and the shape of the opening further changed in response to the user's operation is displayed on the output device of the information processing device 1.

[0052] When the designer completes the change in the shape of the opening and presses the "YES" button on the input device of the information processing device 1, the CAD software 2 repeats the above-described process for any other opening if it is necessary to change other openings, or stores information indicating the opening obtained by the design in the main memory device 102 and auxiliary memory device 104 of the information processing device 1 if it is not necessary to change other openings.

[0053] A method for designing openings in a metal mask using CAD software 2, which has been described with reference to FIGS. 3 and 4, will now be described. FIG. 5 is a flowchart showing the method for designing openings in a metal mask using CAD software 2 (S10). FIG. 6 is a flowchart showing detailed processing of S12 shown in FIG. 5. FIG. 7 is a diagram illustrating an example of the shape of an opening in a metal mask changed by the processing shown in FIGS. 5 and 6. The design method shown in FIG. 5 and the processing shown in FIG. 6 are performed for any of the many openings provided in the metal mask, and can be repeated for each of the multiple openings as necessary.

[0054] In S100 shown in FIG. 5, the designer first identifies the opening (through-hole portion) of the metal mask to be designed. The designer then checks the component manufacturer's recommended information for connecting the component to the through-hole portion corresponding to the opening in the metal mask. That is, the designer checks the recommended volume Vm of the opening in the metal mask, the shape Am' (area Am) of the metal mask, the thickness tm of the opening, the volume Vh of the cream solder filling the through-hole, the radius Rm of the through-hole, and the thickness tp of the board, all of which are included in the component manufacturer's recommended information. Note that, among the information included in the component manufacturer's recommended information, information that can be calculated using other numerical values, such as the recommended opening volume Vm (= kπRm²tp), may be omitted as appropriate.

[0055] In S102, the designer confirms the design information required for designing the mounting of the component into the opening in the metal mask. As with the component manufacturer's recommended information, the design information confirms the opening volume V1, the metal mask shape A1' (area A1), the opening thickness t1, the volume Vh1 of the cream solder filling the through-hole, the through-hole radius R1, and the board thickness tp1. Note that, as with the component manufacturer's recommended information, information that can be calculated from other numerical values ​​can be omitted from the design information as appropriate.

[0056] In S104, the designer inputs the component manufacturer recommended information and design information in S100 and S102 into the CAD software 2. The recommended volume calculation unit 240 and the design volume calculation unit 242 of the CAD software 2 calculate the volume of the through hole from the component manufacturer recommended information and the design information confirmed by the designer via the recommended shape input unit 202, for example. Furthermore, the change length calculation unit 244 calculates the difference ΔV between these volumes and displays the calculation result on the output device of the information processing device 1.

[0057] In S106, the designer checks the difference ΔV displayed on the output device and determines, for example, whether there is a difference ΔV in the volume of the through hole calculated from the component manufacturer recommended information and the design information (ΔV=0) or whether the difference is within the error range (ΔV≒0). If there is no difference or it is within the error range in the volume of the through hole calculated from the component manufacturer recommended information and the design information, the designer ends the design work for the opening identified in the process of S100 (N in S106). On the other hand, if there is a difference or it is outside the error range in the volume of the through hole calculated from the component manufacturer recommended information and the design information, the designer proceeds to the process of S12 and designs the opening using CAD software 2. Note that the information that the designer should check in S106 is not limited to the difference ΔV, and the designer may check other information as appropriate.

[0058] In S110, if the design work for the opening identified in the processing of S100 is completed, the designer operates the "YES" button displayed on the output device of the information processing device 1 and ends the design work (Y in the processing of S110). If the design work for the opening identified in the processing of S100 is not completed, the designer operates the "NO" button displayed on the output device of the information processing device 1 and returns to S12 (N in the processing of S110). Note that if the designer needs to design further openings in the metal mask, he or she may proceed to the processing of S100 as appropriate.

[0059] In the process of S12 shown in Fig. 6, the CAD software 2 first executes the processes of the CAD input unit 20 and the information input unit 22 shown in Fig. 4. That is, in S120, the recommended shape input unit 202 and the recommended thickness input unit 220 accept input of the component manufacturer recommended information confirmed by the designer in the process of S100. In S122, the design information input unit 222 accepts input of the design information confirmed by the designer in the process of S102.

[0060] In S124, the correction coefficient input unit 224 accepts input of the correction coefficient k in response to the designer's operation on the input device, etc. In S126, the side identification unit 200 generates an image of the through-hole portion shown in FIG. 2A based on the component manufacturer recommended information, accepts the user's identification of the sides surrounding the through-hole portion, and highlights the identified sides. Note that, in the process of S110, if the user operates the "NO" button to continue designing the opening, the processes included in S20 and S22 may be omitted as appropriate.

[0061] The CAD software 2 then performs processing of the calculation unit 24. In S128, the recommended volume calculation unit 240 reads information about the opening of the metal mask from the library using the component manufacturer recommended information received by the recommended shape input unit 202 and the recommended thickness input unit 220. The recommended volume calculation unit 240 generates an image of the through-hole portion shown in FIG. 2A based on the component manufacturer recommended information and outputs it to the opening display unit 260. Furthermore, the recommended volume calculation unit 240 calculates the recommended volume Vm of the through-hole based on the component manufacturer recommended information, as described above with reference to equation (1).

[0062] In S130, the design volume calculation unit 242 changes the image of the through-hole portion as shown in Fig. 2B based on the design information received by the design information input unit 222. Furthermore, the design volume calculation unit 242 calculates the volume V1 of the through-hole based on the design information, as described above with reference to equation (2).

[0063] In S132, the change length calculation unit 244 calculates the difference ΔV between the volume V of the through hole based on the component manufacturer recommended information and the volume V1 of the through hole based on the design information, as described above with reference to equation (3). Furthermore, the change length calculation unit 244 accepts an operation by the designer via the UI processing unit 262, and in accordance with the accepted operation, calculates the area of ​​the portion corresponding to the sides surrounding the opening (through hole portion) identified in the processing of S100, and displays the amounts of change X1 and X2 in the lengths of the sides surrounding the opening after the change, as shown in FIG. 2B.

[0064] In S134, the CAD software 2 then performs processing of the CAD output unit 26. The opening display unit 260 superimposes an image of the opening (through-hole portion) after the change on an image of the circuit pattern including other through-hole portions and pad portions, and displays the superimposed image on the output device of the information processing device 1. The UI processing unit 262 displays the image of the opening (through-hole portion) after the change and a UI image including "YES" and "NO" buttons on the output device of the information processing device 1. Furthermore, in S136, the UI processing unit 262 accepts operations on the displayed image of the opening (through-hole portion) after the change and the UI image, and proceeds to the processing of S110 (FIG. 5). Through the processing described above, the opening in the metal mask shown in FIG. 1 is changed to that shown in FIG. 7. [Example]

[0065] Below, we will explain an example of designing an opening in a through-hole portion of a metal mask using CAD software 2. First, component manufacturer recommended information is received by the recommended shape input unit 202 and recommended thickness input unit 220 of CAD software 2. The component manufacturer recommended information includes information indicating the recommended volume Vm of the opening, the shape Am' (area Am) of the metal mask, the thickness tp of the opening (metal mask), the volume Vh of the through-hole (the volume of cream solder in the through-hole), the radius Rm of the through-hole, and the thickness tp of the board.

[0066] Next, the design information is received by the design information input unit 222 of the CAD software 2. The design information includes information indicating the volume V1 of the opening, the shape A1' (area A1) of the metal mask, the thickness tp1 of the opening (metal mask), the volume V1 of the through-hole (the volume of the cream solder in the through-hole), the radius R1 of the through-hole, and the thickness tp1 of the board. Furthermore, the correction coefficient k is received by the correction coefficient input unit 224.

[0067] The recommended volume Vm of a through-hole based on the component manufacturer's recommended information is calculated as Vm = πRm2tp using formula (1). Here, the recommended volume Vm of cream solder required to mount a through-hole component on a board based on the component manufacturer's recommended information is calculated as kVm = πRm2tp. The volume V1 of a through-hole based on design information is calculated as V1 = πR12tp1 using formula (2). Here, the volume Vh of cream solder required to mount a through-hole component on a board based on the design information is calculated as kV1 = πR12tp1.

[0068] Therefore, the difference ΔV between the volume kVm of solder paste required to mount a through-hole component on a board based on the component manufacturer's recommended information and the volume kV1 of solder paste required to mount a through-hole component on a board based on the design information is calculated as ΔV = π(R12tp1 - Rm2tp) using equation (3). The volume corresponding to this difference ΔV is the change in volume of the part around the through-hole portion that corresponds to one or more sides specified by the designer.

[0069] Specifically, as shown in FIG. 2B, when the sides a and d around the through-hole are, for example, allocated such that the portion q (0≦q≦1) of the difference ΔV is allocated to the portion corresponding to side a, and the portion (1−q) is allocated to the portion corresponding to side a, the changes X1 and X2 can be calculated from equations (6) and (7), which are modified from equations (4) and (5).

[0070] X1=qkπ{(R12tp1-Rm2tp)-Vm(t1-tm)} / (at1) (6)

[0071] X2=(1-q)kπ{(R12tp1-Rm2tp)-Vm(t1-tm)} / (dt1) (7)

[0072] As explained above, by modifying equations (4) and (5), it is possible to determine the change in the other of the amounts of change X1 and X2 when the ratio of the difference ΔV is changed from 1 / 2, 1 / 2 to q, (1-q). Furthermore, even when the number of specified sides is increased or decreased, it is possible to obtain the appropriate shape and thickness of the opening by using equations similar to equations (4) and (5) as many times as the number of sides after the increase or decrease and modifying the contents of the equations appropriately.

[0073] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes. [Appendix 1] A design device including one or more processors, wherein the one or more processors are configured to design each of one or more openings in a jig for applying brazing material to an area in the circuit pattern including the through holes in the printed circuit board by soldering, the design device being configured to: calculate a first volume of brazing material to fill a first through hole based on a first radius of a first through hole that is prepared in advance and a first thickness of the printed circuit board that is prepared in advance; calculate a second volume of the brazing material to fill a second through hole based on a second radius of a second through hole formed in the printed circuit board and a second thickness of the printed circuit board; accept specification of a perimeter of part or all of the area; and change a perimeter of the specified area to correspond to a difference between the first volume and the second volume. [Appendix 2] 2. The design device according to claim 1, wherein the jig is a metal mask, and the opening allows the brazing material to pass through and be applied to the area. [Appendix 3] 3. The design device according to claim 1, wherein the brazing material is cream solder. [Appendix 4] 4. The design device according to any one of claims 1 to 3, wherein a correction coefficient to be multiplied by the difference is received, and the received correction coefficient is multiplied by the difference. [Appendix 5] 5. The design device according to any one of claims 1 to 4, wherein the circuit pattern and the terminal of the component are connected by through-hole reflow. [Appendix 6] The design device according to any one of appendices 1 to 5, wherein the brazing material is applied to the area, and the brazing material applied to the area fills the second through-hole. [Appendix 7] A design method for designing one or more openings in a jig for applying brazing material to an area in a circuit pattern including through holes formed in the printed circuit board, in order to electrically connect terminals of components to the circuit pattern by brazing using the through holes formed in the printed circuit board, includes a first calculation step, a second calculation step, an acceptance step, and a modification step. The first calculation step calculates a first volume of the brazing material to fill the first through hole based on a first radius of the first through hole that is previously determined and a first thickness of the printed circuit board that is previously determined. The second calculation step calculates a second volume of the brazing material to fill the second through hole based on a second radius of a second through hole formed in the printed circuit board and a second thickness of the printed circuit board. The acceptance step accepts the identification of a portion or all of the perimeter of the area. The modification step modifies a portion or all of the perimeter of the identified area to correspond to the difference between the first volume and the second volume. [Appendix 8] A design program for designing one or more openings in a jig for applying brazing material to an area in a circuit pattern including through holes formed in the printed circuit board, in order to electrically connect terminals of a component to the circuit pattern by brazing using the through holes formed in the printed circuit board, causes a processor to execute a first calculation process, a second calculation process, an acceptance process, and a modification process. The first calculation process calculates a first volume of the brazing material to fill a first through hole based on a first radius of the first through hole that is previously determined and a first thickness of the printed circuit board that is previously determined. The second calculation process calculates a second volume of the brazing material to fill a second through hole based on a second radius of a second through hole formed in the printed circuit board and a second thickness of the printed circuit board. The acceptance process accepts identification of a portion or all of the perimeter of the area. The modification process modifies a portion or all of the perimeter of the identified area to correspond to the difference between the first volume and the second volume. It goes without saying that combinations of the various forms described in the appendix of this disclosure, or any combination of the elements described in each aspect and embodiment (including the non-selection of some elements), can be made at any time by those skilled in the art in accordance with the basic concept of this disclosure.

[0074] The disclosures of the above-cited patent documents and other documents are incorporated herein by reference. Modifications and adjustments of the embodiments and examples are possible within the scope of the entire disclosure of the present invention (including the claims), and further based on the basic technical concept thereof. Furthermore, various combinations and selections (including partial deletions) of various disclosed elements (including elements of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible within the scope of the entire disclosure of the present invention. In other words, the present invention naturally embraces various modifications and alterations that would be possible by those skilled in the art in accordance with the entire disclosure and technical concept, including the claims. In particular, the numerical ranges set forth herein should be construed as specifically describing any numerical value or subrange within the range, even if not otherwise specified. Furthermore, the disclosures of the above-cited documents are deemed to be included in the disclosure of this application, in part or in whole, which may be used in combination with the disclosures herein, as part of the disclosure of the present invention, in accordance with the spirit of the present invention, as necessary. [Explanation of symbols]

[0075] 1. Information processing equipment 100 CPU 102 Main storage 104 Auxiliary storage 106 IF 2. CAD software 20 CAD input section 200 Side Identification Section 202 Recommended shape input section 22 Information input section 220 Recommended thickness input section 222 Design information input section 224 Correction coefficient input section 24 Calculation section 240 Recommended Volume Calculation Section 242 Design volume calculation section 244 Change length calculation section 26 CAD output section 260 Aperture display section 262 UI processing section

Claims

1. A design device comprising one or more processors, In order to electrically connect a terminal of a component to a circuit pattern formed on a printed circuit board by brazing using through holes formed in the printed circuit board, the one or more processors design each of one or more openings formed in a jig for applying a brazing material to an area of ​​the circuit pattern including the through holes, calculating a first volume of a brazing material to fill the first through-hole based on a first radius of the first through-hole prepared in advance and a first thickness of the substrate prepared in advance; calculating a second volume of the brazing material to fill the second through hole based on a second radius of the second through hole formed in the printed circuit board and a second thickness of the printed circuit board; Accepting specification of part or all of the perimeter of said range; A part or all of the periphery of the identified range is changed to correspond to the difference between the first volume and the second volume. It is configured as follows: Design equipment.

2. The jig is a metal mask, The opening allows the brazing material to pass through and be applied to the area. The design device according to claim 1 .

3. The brazing material is cream solder The design device according to claim 1 .

4. accepting a correction factor to be multiplied by the difference; Multiply the difference by the accepted correction factor. The design device according to claim 1 .

5. The circuit pattern and the terminals of the components are connected by through-hole reflow. The design device according to claim 1 .

6. The brazing material is applied to the area, The brazing material applied to the area fills the second through-hole. The design device according to claim 1 .

7. In order to electrically connect a terminal of a component to a circuit pattern formed on a printed circuit board by brazing using through holes formed in the printed circuit board, one or more openings are designed in a jig for applying a brazing material to an area of ​​the circuit pattern including the through holes, a first calculation step of calculating a first volume of a brazing material to fill the first through hole based on a first radius of the first through hole prepared in advance and a first thickness of the substrate prepared in advance; a second calculation step of calculating a second volume of the brazing material to fill the second through hole based on a second radius of the second through hole formed in the printed circuit board and a second thickness of the printed circuit board; an accepting step of accepting identification of part or all of the perimeter of said range; a modifying step of modifying a part or all of the periphery of the specified range so as to correspond to a difference between the first volume and the second volume; Design methods including:

8. In order to electrically connect a terminal of a component to a circuit pattern formed on a printed circuit board by brazing using through holes formed in the printed circuit board, one or more openings are designed in a jig for applying a brazing material to an area of ​​the circuit pattern including the through holes, a first calculation process for calculating a first volume of a brazing material to fill a first through-hole based on a first radius of the first through-hole and a first thickness of the substrate; a second calculation process for calculating a second volume of the brazing material to fill the second through hole based on a second radius of the second through hole formed in the printed circuit board and a second thickness of the printed circuit board; an acceptance process for accepting the identification of part or all of the perimeter of said range; a modification process for modifying a part or all of the periphery of the identified range to correspond to the difference between the first volume and the second volume; A design program that causes a processor to execute the following.

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