DESIGN APPARATUS, DESIGN METHOD, AND DESIGN PROGRAM

Abstract

This contributes to the appropriate design of the shape and thickness of each opening of a metal mask for mounting components to a board of any thickness by through-hole reflow. [Solution] In order to design each of one or more openings opened in a jig for applying brazing material to an area including a through hole in a circuit pattern, the system is 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 prepared in advance and a first thickness of a board prepared in advance, calculate a second volume of brazing material to fill a second through hole based on a second radius of a second through hole formed in the printed board and a second thickness of the printed board, accept identification of some or all of the perimeter of the area, and modify some or all of the perimeter of the identified area to correspond to the difference between the first volume and the second volume.

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 (hereafter simply referred to as "boards") are widely used, in which a circuit pattern and through-holes for an electronic or electric circuit (hereafter referred to as "electronic circuit") are formed on the surface of a single insulating board, or on the surface and inside of multiple insulating boards. Components with terminals connected via through-holes are connected to the circuit pattern of the board, and surface-mounted components with terminals connected to pads on the circuit pattern on the board surface are connected by soldering.

[0003] Surface mount components, whose terminals are connected to pads of a circuit pattern on the surface of a board, are generally called "SMD (Surface Mount Device) components." In this specification, components whose terminals are connected using through holes are described as "through-hole components," and SMD components and through-hole components are generally referred to as "components." In this specification, a portion of a circuit pattern that is formed in the vicinity of a through-hole in a circuit pattern, includes the through-hole, and is in a range where the through-hole component is connected is described as a "through-hole portion." Specific examples of SMD components include chip resistors, chip capacitors, and SOP (Small Outline Package) semiconductor elements. Specific examples of through-hole components include DIP (Dual In-line Package) semiconductor elements and board connectors. Connecting a component to a circuit pattern and attaching it to a board is generally called "mounting."

[0004] The mounting of components on a board is performed, for example, by a method called "through-hole reflow". The mounting of components on a board by through-hole reflow is performed as follows. First, cream solder is applied by printing to each of the pads and through-holes of the circuit pattern in a volume required for connecting the terminals of the components. Next, the terminals of the SMD components are correctly aligned with the pads, the terminals of the through-hole components are correctly inserted into the through-holes, and the SMD components and the through-hole components are attached to the board. Furthermore, the board on which the components are attached in this way is heated in a reflow furnace or the like to melt the cream solder and electrically connect the terminals of the components to the circuit pattern. The tool used to apply the cream solder to the pads and through-holes is generally called a "metal mask". In addition, "openings" are opened in the metal mask in order to apply the cream solder to each of the pads and through-holes. The cream solder may also be called by other names, such as solder paste. In addition, in order to solder a component to a circuit pattern by through-hole reflow, various materials can be used other than cream solder, which contain metals for brazing, can be applied to a printed circuit board, and can be heated after application to electrically connect the terminals of the component and the circuit pattern.

[0005] In order to mount components on a board by through-hole reflow, it is necessary to apply an appropriate volume of cream solder for soldering to each of the pads and through-holes of the circuit pattern on the board. In order to apply an appropriate volume of cream solder to the pads and through-holes of the circuit pattern, the component manufacturer prepares values ​​that recommend or define (hereinafter referred to as "recommended") the thickness of the board, the shape (area) and thickness of the opening before mounting the components on the board. The shape and thickness of the opening give the volume of cream solder for properly mounting SMD components, and the thickness of the board, the shape (area) of the opening, the thickness of the opening and the thickness of the board give the volume of cream solder for properly mounting through-hole components. When the thickness of the metal mask is uniform over the entire surface, the thickness of the opening of the metal mask is equal to the thickness of the metal mask.

[0006] The shapes of the terminals of SMD components and the pads for mounting SMD components are often known due to standards for semiconductor packages, etc., so designing the thickness and shape of the openings in the 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] JP 2006-073773 A 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 was conducted 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 a through-hole component 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 conductively connect the terminal to the circuit pattern.

[0010] In view of the above-mentioned problems, an 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 board of any thickness by through-hole reflow. [Means for solving the problem]

[0011] In a first aspect of the present invention, a design device including one or more processors is provided, in order to electrically connect a terminal of a component to a circuit pattern formed on a printed circuit board by brazing using a through hole formed on the printed circuit board, the one or more processors are configured to calculate a first volume of the brazing material to fill the first through hole based on a first radius of a first through hole prepared in advance and a first thickness of the printed circuit board prepared in advance, calculate a second volume of the brazing material to fill the second through hole based on a second radius of a second through hole formed on the printed circuit board and a second thickness of the printed circuit board, accept specification of a part or all of a perimeter of the range, and change a part or all of the perimeter of the specified range to correspond to a difference between the first volume and the second volume, in order to design each of one or more openings opened in a jig for applying a brazing material to an area in the circuit pattern including the through hole.

[0012] In a second aspect of the present invention, there is provided a design method for calculating one or more openings formed in a jig for applying a brazing material to a range including a through hole in a circuit pattern formed on a printed circuit board, in order to electrically connect a terminal of a component to the circuit pattern formed on the printed circuit board by brazing the through hole. The design method includes a first calculation step, a second calculation step, an acceptance step, and a change step. The first calculation step calculates a first volume of the brazing material filling the first through hole based on a first radius of a first through hole prepared in advance and a first thickness of the board prepared in advance. The second calculation step calculates a second volume of the brazing material filling the second through hole based on a second radius of a second through hole formed on the printed circuit board and a second thickness of the printed circuit board. The acceptance step accepts the specification of a part or all of the periphery of the range. The change step changes 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.

[0013] In a third aspect of the present invention, there is provided a design program for designing one or more openings in a jig for applying a brazing material to an area including a through hole in a circuit pattern formed on a printed circuit board, in order to electrically connect a terminal of a component to the circuit pattern formed on the printed circuit board by brazing the through hole. The design program includes a first calculation process for calculating a first volume of the brazing material filling the first through hole based on a first radius of the first through hole prepared in advance and a first thickness of the board prepared in advance, a second calculation process for calculating a second volume of the brazing material filling 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 processor is caused to execute an acceptance process for accepting the identification of some or all of the perimeter of the area, and a modification process for modifying some or all of the identified perimeter of the area to correspond to a difference between the first volume and the second volume. The program can be recorded in 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. Effect of the Invention

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

[0015] [Figure 1] FIG. 1 is a diagram illustrating an example of the shape of an opening in a metal mask that corresponds to a portion where pads and through-holes are mixed in a circuit pattern on a substrate. [Figure 2A] FIG. 2A is a diagram illustrating a design operation 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 operation for partially changing the shape of the opening of the metal mask shown in FIG. [Diagram 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 a configuration of CAD software executed as a CAD program in the information processing device shown in FIG. [Diagram 5] FIG. 5 is a flowchart showing a method (S10) of 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 an example of the shape of the opening of the metal mask changed by the processing shown in FIGS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment described below. In addition, in each drawing, the same or corresponding elements are appropriately assigned the same reference numerals. Furthermore, it should be noted that the drawings are schematic, and the dimensional relationship and ratio of each element may differ from the actual relationship and ratio of each element. In addition, the dimensional relationship and ratio 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 work illustrating a partial change in 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, which corresponds to the L-shaped through-hole portion shown in Fig. 1 and whose shape is determined according to 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 metal mask opening illustrated in Figs. 1 and 2A have been changed (enlarged) by design.

[0018] 2A and 2B show an example in which the through-hole has a shape formed by combining rectangles. The change amounts X1 and X2 in the length of the enlarged portion corresponding to the sides around the opening and the sides with lengths a to d (hereinafter referred to as "sides a to d"), and the sides a and d of the opening, are defined as shown in FIG. 2B.

[0019] It is difficult to design the thickness and shape of the opening corresponding to the through-hole portion because the process of heating the board for through-hole reflow provides a volume of cream solder that flows from the surface of the board into the through-hole and fills at least the terminal of the through-hole so that it can connect to an electronic circuit. On the other hand, it is not as difficult to design the thickness and shape of the opening corresponding to the pad as it only provides the amount of cream solder that can connect the pad and the terminal of the SMD component. Therefore, hereinafter, the design of the thickness and shape (area) of the opening corresponding to the through-hole portion will be mainly explained, and in the following explanation, unless otherwise specified, "opening" refers to "opening corresponding to the through-hole portion."

[0020] The shape of each opening in the metal mask is designed, for example, in response to the operation of a computer-aided design (CAD) program (described later with reference to FIG. 4) for designing metal masks, which runs on an operating system (OS; not shown) executed on a computer (described later with reference to FIG. 3). Generally, such a CAD program includes a library of information indicating the thickness of the substrate, the position of each of a number of openings formed in the metal mask, and the shape and thickness of the openings in association with each other.

[0021] The CAD program also has a function of enlarging or reducing the entire shape of each opening included in the library and the shape of only the part corresponding to one or more sides of each opening according to the design operation of the designer. However, when enlarging the shape of an opening, it is necessary to select the side of the opening to which the enlarged part is to be given so as to avoid interference with other openings in the vicinity of the opening to be enlarged and with circuit patterns including pads. In addition, if there are many sides corresponding to the parts to be enlarged or reduced, the design work tends to become complicated. The metal mask opening design method according to the present disclosure is devised to simplify the design work even when the opening is enlarged to a part corresponding to multiple sides.

[0022] Fig. 3 is a diagram illustrating an example of a 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 a configuration of CAD software 2 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 therebetween.

[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 a RAM (Random Access Memory) and a 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 input / output of 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 non-volatile storage device such as a hard disk drive (HDD), a solid state drive (SSD), and 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 the execution of the CAD software 2 on a medium to long-term basis. A non-volatile storage medium such as a USB memory is detachably connected to the auxiliary storage device 104, and the auxiliary storage device 104 can read information from the connected non-volatile storage device and write information to the connected non-volatile storage device. The CAD software 2 can 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 can 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, the components providing the above-mentioned library functions are omitted. 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 start-up operation by the designer, and executed by specifically utilizing the hardware components of the information processing device 1. With these components, the CAD software 2 provides the designer with the function of designing the shape and thickness of the metal mask and each of its multiple openings.

[0028] These components of the CAD software 2 are realized as program modules including a plurality of instruction commands executed by the CPU 100, for example. The CAD input unit 20, the information input unit 22, and the CAD output unit 26 receive 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. In the following, for the sake of concreteness and clarification of the explanation, a case is illustrated in which all of the cream solder applied to the through-hole portion of the circuit pattern fills and fills the through-hole into which the terminal of the through-hole component is inserted.

[0029] In the CAD input unit 20, the recommended shape input unit 202 accepts input of information (component manufacturer recommended information) indicating the shape of the opening recommended by the component manufacturer for each component. 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 shape of the opening recommended by the component manufacturer). The recommended shape input unit 202 can 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 can include information that is not essential for calculating the shape and thickness of the opening. The recommended shape input unit 202 outputs the received component manufacturer recommended information and information indicating the area Am of the opening calculated to the recommended volume calculation unit 240.

[0030] Furthermore, the recommended shape input unit 202 reads out information indicating the shape Am' of the metal mask corresponding to the received component manufacturer recommended information from the library, and displays it on the display 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 side 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 server of the component manufacturer 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 may 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 in an emphasized manner 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 a case where a side of the opening with length a and a side with length d are selected.

[0032] In the information input unit 22, the recommended thickness input unit 220 accepts input of information (component manufacturer recommended thickness information) indicating the shape of the board and openings recommended by the component manufacturer for each component. Specifically, the component manufacturer recommended thickness information includes information indicating the board thickness tp1 and information indicating the opening thickness t1. The recommended thickness input unit 220 outputs the inputted component manufacturer recommended thickness information to the 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 is actually mounted, in response to an operation by the designer. Specifically, the design information includes information indicating the shape A1' of the designed opening, information indicating the radius R1 of the through hole (second through hole; through hole corresponding to the opening designed by the CAD software 2), information indicating the thickness t1 of the opening, and information indicating the thickness tp1 of the board on which the component is actually mounted. Similarly to the recommended shape input unit 202, the design information input unit 222 can also calculate the area A1 of the opening from the information indicating the designed shape A1' of the opening. The design information input unit 222 outputs the accepted design information and the area of ​​the opening calculated 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 the years, or by simulation or experiment for optimal mounting on the component substrate. Note that when an appropriate amount of cream solder given by the volume of the opening of the metal mask is applied to the through-hole part 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 part 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 part and heated, and there is a possibility that the solder will overflow from the through-hole afterwards, k < 1. That is, k < 1 when there is a possibility that the amount of cream solder applied to the through-hole part 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 part and heated, and there is a possibility that the solder will not sufficiently fill the through-hole afterwards, 1 < k. That is, 1 < k when there is a possibility that the amount of cream solder applied to the through-hole part through the designed opening is too little.

[0035] In the calculation unit 24, the recommended volume calculation unit 240 obtains a component manufacturer 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 recommended 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 recommended 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 recommendation 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 a through-hole provided in a board on which a 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 a value kΔV obtained by multiplying the difference ΔV calculated in this way by the 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] The changed length calculation unit 244 calculates the change (X1, X2) in the length of the side (sides a, d in the example shown in FIG. 2B) identified by the side identification unit 200 in response to the change in the shape of the opening. For example, when the difference kΔV obtained by multiplying the difference ΔV by a correction coefficient k is equally distributed to the portions corresponding to the sides a, b with a uniform thickness t1 of the opening, X1 and X2 are given by the following formulas (4) and (5).

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

[0046] In addition, the length of side d changes by X2 as shown in the following formula.

[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 is read from the library and determined based on the parts manufacturer recommended information as shown in Fig. 2A, to opening display unit 260. Note that here, a case where two sides a and d are identified by side identification unit 200 is illustrated. 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 amount of change will change according to the length of the identified side and the number of sides.

[0049] In CAD output section 26, opening display section 260 uses information indicating the amounts of change X1 and X2 and the shape of the opening shown in Fig. 2A to generate an image showing the shape of the opening that changes before and after the change, as shown in Fig. 2B. Change length calculation section 244 further superimposes the image showing the shape of the opening that changes before and after the change on an image showing the shapes of other openings around this opening, and displays them on the output device of information processing device 1. By looking at the image of the opening displayed in this way, the designer can check whether or not, after the change in the shape of the opening, this opening will interfere with other openings and circuit patterns including pads, or will be too close to each other to cause problems in normal mounting of components.

[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, for example, lengthens or shortens the change amounts X1 and X2 of the opening display unit 260 in response to the designer's operation. For example, when the change amount X1 is shortened in response to the designer's operation, the CAD software 2 lengthens the change amount X2 because it is necessary to add the volume of the shortened change amount X1 to the change amount X2. Conversely, for example, when the change amount X2 is shortened in response to the designer's operation, the CAD software 2 lengthens the change amount X1 because it is necessary to add the volume of the shortened change amount X2 to the change amount X1. Furthermore, the UI processing unit 262 displays a UI image (not shown) including buttons for inputting, for example, "YES" and "NO" on the output device of the information processing device 1 in order to prompt the designer to input whether or not the change of the changed shape of the opening has been completed in response to the user's operation.

[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, the design volume calculation unit 242, the change length calculation unit 244 and the 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 has completed changing the shape of the opening and pressed the "YES" button on the input device of the information processing device 1, the CAD software 2 repeats the above-described process for any of the other openings if other openings need to be changed, or stores information indicating the openings obtained by the design in the main memory device 102 and auxiliary memory device 104 of the information processing device 1 if no other openings need to be changed.

[0053] A method for designing an opening in a metal mask using the CAD software 2 described with reference to Figs. 3 and 4 will be described below. Fig. 5 is a flowchart showing the method for designing an opening in a metal mask using the 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 one of a number of openings provided in a metal mask, and can be repeatedly performed 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. Furthermore, the designer checks the component manufacturer recommended information recommended by the component manufacturer to connect the component to the through-hole portion corresponding to the opening of the metal mask. That is, the designer checks the recommended volume Vm of the opening of 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, which are included in the component manufacturer recommended information. Note that, among the information included in the component manufacturer recommended information, information that can be calculated from other numerical values, such as the recommended volume Vm of the opening (=kπRm2tp), may be omitted as appropriate.

[0055] In S102, the designer confirms design information required for designing the mounting of the component in the opening of the metal mask. As with the component manufacturer recommended information, the design information confirms the volume V1 of the opening, the shape A1' (area A1) of the metal mask, the thickness t1 of the opening, the volume Vh1 of the cream solder filling the through hole, the radius R1 of the through hole, and the thickness tp1 of the board. As with the component manufacturer recommended information, information that can be calculated from other numerical values ​​may 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 to 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 judges, 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 in the volume of the through hole calculated from the component manufacturer recommended information and the design information or it is within the error range, 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 in the volume of the through hole calculated from the component manufacturer recommended information and the design information or it is outside the error range, the designer proceeds to the process of S12 and designs the opening using the 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 process 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 process of S110). If the design work for the opening identified in the process 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 process of S110). Note that if the designer needs to further design an opening in the metal mask, he or she will proceed to the process 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 the 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 the 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. In S126, the side identifying 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, when 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 on 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 formula (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 accepted 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 formula (2).

[0063] In S132, the change length calculation unit 244 calculates the difference ΔV between the through-hole volume V based on the component manufacturer recommended information and the through-hole volume V1 based on the design information, as described above with reference to formula (3). Furthermore, the change length calculation unit 244 accepts an operation by the designer via the UI processing unit 262, and in response to 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 change amounts 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 the image of the opening (through-hole portion) after the change on an image of a circuit pattern including other through-hole portions and pad portions, and displays them 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 the displayed image of the opening (through-hole portion) after the change and operations on the UI image, and proceeds to the processing of S110 (FIG. 5). Through the above-described processing, the opening of the metal mask shown in FIG. 1 is changed to that shown in FIG. 7. EXAMPLES

[0065] Hereinafter, an embodiment of designing an opening in a through-hole portion of a metal mask using CAD software 2 will be described. First, component manufacturer recommended information is received by 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 of the through-hole (volume of cream solder in the through-hole) Vh, 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 formula (3). The volume corresponding to this difference ΔV is the change in volume of the part corresponding to one or more sides specified by the designer around the through-hole part.

[0069] Specifically, as shown in FIG. 2B, when sides a and d around the through hole are allocated, for example, of the difference ΔV, q (0≦q≦1) portion is allocated to the portion corresponding to side a, and (1-q) portion is allocated to the portion corresponding to side a, the changes X1 and X2 can be calculated from equations (6) and (7) which are modifications of 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 obtain 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 an appropriate shape and thickness of the opening by using an equation similar to equations (4) and (5) for the number of sides after the increase or decrease and modifying the contents of the equation appropriately.

[0073] A part or all of the above-described embodiments may be described as, but is 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 a brazing material to an area in the circuit pattern including the through-holes in the printed circuit board by brazing a terminal of a component to the circuit pattern by using the through-holes in the printed circuit board, the one or more processors being configured to: calculate a first volume of a brazing material to fill the first through-hole based on a first radius of a first through-hole prepared in advance and a first thickness of the printed circuit board prepared in advance; calculate 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; accept specification of a part or all of a perimeter of the area; and change a part or all of the perimeter of the specified area to correspond to a difference between the first volume and the second volume. [Appendix 2] 2. The design device of 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 or 2, wherein the brazing material is cream solder. [Appendix 4] 4. The design device according to claim 1, further comprising: a correction coefficient to be multiplied by the difference; and a correction coefficient to be multiplied by the difference. [Appendix 5] 5. The design device according to claim 1, wherein the circuit pattern and the terminal of the component are connected by through-hole reflow. [Appendix 6] 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 opened in a jig for applying a brazing material to an area including a through hole in a circuit pattern formed on a 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 method includes a first calculation step, a second calculation step, an acceptance step, and a change 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 a first through hole prepared in advance and a first thickness of the board prepared in advance. 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 part or all of the periphery of the area. The change step changes a part or all of the periphery of the identified area to correspond to a 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 a brazing material to an area including a through hole in a circuit pattern formed on a printed circuit board 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 causes a processor to execute a first calculation process, a second calculation process, an acceptance process, and a change process. The first calculation process calculates a first volume of the brazing material filling the first through hole based on a first radius of a first through hole prepared in advance and a first thickness of the board prepared in advance. The second calculation process calculates a second volume of the brazing material filling 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 process accepts the identification of a part or all of the periphery of the area. The change process changes a part or all of the periphery of the identified area to correspond to a difference between the first volume and the second volume. It goes without saying that combinations of the various forms described in the appendix of the present disclosure, or any combination of the elements described in each aspect and embodiment (including the non-selection of some elements) can be made by those skilled in the art at any time in accordance with the basic concept of the present disclosure.

[0074] The disclosures of the above cited patent documents are incorporated herein by reference. Within the scope of the entire disclosure of the present invention (including the scope of claims), modifications and adjustments of the embodiments or examples are possible based on the basic technical ideas. Furthermore, within the scope of the entire disclosure of the present invention, various combinations or selections (including partial deletions) of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. In other words, the present invention naturally includes various modifications and corrections that a person skilled in the art would be able to make in accordance with the entire disclosure including the scope of claims and the technical ideas. In particular, the numerical ranges described in this specification should be interpreted as specifically describing any numerical value or small range included in the range, even if not otherwise specified. Furthermore, the disclosures of the above cited documents are deemed to be included in the disclosures of this application, which may be used in part or in whole in combination with the disclosures of this specification 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 device 100 CPU 102 Main storage 104 Auxiliary storage 106 IF 2. CAD Software 20 CAD input section 200 Side Specific Part 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 262 UI Processing Unit

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 a through hole formed in the printed circuit board, the one or more processors design each of one or more openings opened in a jig for applying a brazing material to an area of ​​the circuit pattern including the through hole, Calculating a first volume of a brazing material to fill the first through hole based on a first radius of the first through hole and a first thickness of the board; calculating 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; Accepting the specification of any 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 said 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. A design method for designing, by a design device having one or more processors, one or more openings in a jig for applying a brazing material to an area in a circuit pattern including a through hole in the printed circuit board so as to electrically connect a terminal of a component to a circuit pattern formed on the printed circuit board by soldering using the through hole, comprising: The one or more processors, 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 and a first thickness of the board; 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 a second through hole formed in the printed circuit board and a second thickness of the printed circuit board; an accepting step of accepting an identification of a part or all of the perimeter of said range; a modifying step of modifying a part or all of the periphery of the identified range so as to correspond to a difference between the first volume and the second volume; A design method to execute the above.

8. In order to electrically connect a terminal of a component to a circuit pattern formed on a printed circuit board by brazing using a through hole 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 hole, a first calculation process for calculating a first volume of a brazing material to fill the first through hole based on a first radius of the first through hole and a first thickness of the board; 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 some or all of the perimeter of said range; a modification process for modifying a portion or all of the perimeter of the identified area to correspond to a difference between the first volume and the second volume; A design program that causes a processor to execute the above.

Images