JP5121954B2 - Point solder NC data creation method - Google Patents

Description

  The present invention relates to an automatic soldering apparatus that performs soldering.

Patent Document 1 is known as an automatic soldering apparatus that automatically adjusts parameters related to soldering.
In this apparatus, when the component 2 is soldered to the printed circuit board 1 as shown in FIG. 8, the solder is supplied to the soldering portion by the solder feeding device 5a, and the temperature of the solder rod 3 is detected by the temperature sensor 4. The detected temperature is input to the arithmetic device 6 through the temperature sensor amplifier 4a, the arithmetic device 6 calculates the heat capacity of the component 2 from the temperature change at the tip of the soldering iron 3, and the arithmetic device 6 automatically sets the soldering conditions. Is determined.

JP-A-6-310845

  However, in this conventional automatic soldering apparatus, it is necessary to measure the temperature change at each soldering point, and there is a problem that the production time becomes long in the case of the printed circuit board 1 having a large number of soldering points or in mass production. In this patent document 1, the soldering iron 3 is pressed against a soldering location to perform soldering. However, in a jet type soldering apparatus in which a solder jet is applied to a soldering location to perform soldering, a soldering parameter is used. The current situation is that it is more difficult to determine automatically.

  An object of this invention is to determine the soldering conditions of point soldering in a short time.

The point solder NC data creation method of the present invention is a method of creating NC data for point soldering in which a component is mounted on a board by solder ejected from a nozzle. An information acquisition step for acquiring information and component information to be mounted; a heat capacity calculation step for calculating a heat capacity of the soldering location from the land information and the component information; and a soldering condition for calculating a soldering condition from the heat capacity The heat capacity calculation step includes obtaining a heat capacity from the heat capacity of the land, the heat capacity of the component, and the heat capacity of the component body.
Also, the point solder NC data creation method of the present invention is a method of creating NC data for point soldering in which a component is mounted on a substrate by solder ejected from a nozzle, and the soldering location is determined from the CAD data of the substrate. An information acquisition step of acquiring land information and component information to be mounted, a heat capacity calculation step of calculating a heat capacity of the soldering location from the land information and the component information, and a solder for calculating a soldering condition from the heat capacity A second correction step for measuring warpage of the substrate before and during soldering and correcting at least one of the nozzle height and the solder jet velocity based on the information. , Further including.

  According to this configuration, NC data creation time and soldering time can be shortened. Furthermore, high-quality point soldering can be realized by optimizing the NC data according to the state of the soldering location.

Configuration diagram of main part of automatic soldering apparatus for executing point solder NC data creating method of the present invention The figure which shows the example of each data used with the heat capacity calculation means 13 The figure which shows the example of the nozzle information used by the nozzle classification determination means 14, and the example of the information calculated by the solder jet velocity calculation means 15 The figure which shows the example of NC data produced | generated by the nozzle operation | movement determination means 16 Side view of soldering device Diagram explaining correction when solder is insufficient Diagram explaining correction when printed circuit board is warped Configuration diagram of conventional solder equipment

Hereinafter, the point solder NC data creation method of the present invention will be described based on specific embodiments.
FIG. 1 shows an automatic soldering apparatus including an arithmetic unit 10 that creates NC data based on input information. FIG. 5 shows a soldering device 25 that performs soldering by controlling the solder jet velocity and the height of the nozzle with respect to the printed circuit board based on the NC data determined by the arithmetic unit 10.

  The input of the arithmetic unit 10 mainly composed of a microcomputer includes information on a board design CAD system 21 used when designing and manufacturing a printed circuit board to be soldered, mounting positions and components mounted on the printed circuit board. A managed component information system 22 is connected. A soldering device 25 shown in FIG. 5 is connected to the output of the arithmetic unit 10. Further, a solder inspection machine 23 that inspects a printed circuit board that has been mounted by soldering and a substrate warpage sensor 24 that detects warpage of the printed circuit board before and during soldering are connected to the arithmetic device 10. .

The arithmetic device 10 is configured as follows.
The arithmetic unit 10 includes a land information acquisition unit 11, a component information acquisition unit 12, a heat capacity calculation unit 13, a nozzle type determination unit 14, a solder jet velocity calculation unit 15, a nozzle operation determination unit 16, a nozzle height correction unit 17, and NC data. Output means 18 is provided.

  The land information acquisition unit 11 acquires the land information D1 from the board design CAD system 21. FIG. 2A is an example of the land information D1 acquired by the land information acquisition unit 11. The land information D1 includes positions in the X direction and Y direction from the origin of the board, external dimensions in the X direction and Y direction, area, thickness, specific gravity, specific heat, and the like with respect to the land location of the soldering location. .

  The component information acquisition unit 12 acquires the component information D <b> 2 from the component information system 22. FIG. 2B is an example of the component information D2 acquired by the component information acquisition unit 12. The component information D2 includes the positions in the X direction and the Y direction from the board origin, the external dimensions in the X direction and the Y direction, the area, the length, the specific gravity, the specific heat, etc. with respect to the component location at the soldering location. Yes.

The heat capacity calculation unit 13 calculates the heat capacity of the soldering location from the land information D1 output from the land information acquisition unit 11 and the component information D2 output from the component information acquisition unit 12. For example, in FIG.
Heat capacity of soldering location = Land heat capacity + Heat capacity of component lead
Land heat capacity = area × thickness ÷ 1000 × specific gravity × heat capacity of lead part of specific heat component = area × length ÷ 1000 × specific gravity × specific heat. Here, the heat capacity of the component means the heat capacity of the lead portion of the component. Hereinafter, the heat capacity of the lead portion is referred to as component heat capacity.

Also, if you want to consider the heat capacity of the body information of parts,
Component body heat capacity = area x thickness ÷ 1000 x specific gravity x specific heat x coefficient can be calculated and added to the heat capacity of the soldering location. The component body heat capacity is the heat capacity of the component main body connected to the lead portion of the component. When not only the component heat capacity but also the component body heat capacity is included in the calculation, the heat capacity can be obtained more accurately.

On the other hand, if the component information D2 cannot be obtained, the component heat capacity can be calculated virtually by “component heat capacity = drill hole diameter of land information D1 × coefficient × virtual length ÷ 1000 × specific gravity × specific heat”. is there. FIG. 2C shows the result of the heat capacity calculation.

  The nozzle type determination unit 14 determines the nozzle type from the land shape dimensions obtained from the land information acquisition unit 11 and the nozzle information of the nozzles 51 that can be mounted on the solder device 25 shown in FIG. To decide. FIG. 3A shows an example of nozzle information. The nozzle information includes the shape, the dimension of the nozzle hole in the X direction (hole X dimension), the dimension of the nozzle hole in the Y direction (hole Y dimension), the area, the maximum jet velocity, and the jet flow rate versus heat quantity coefficient. As the nozzle type, for example, the nozzle having the smallest area is selected from the nozzles satisfying “maximum outer dimension of land information D1 ≦ hole size of nozzle information”.

  Also, the solder jet is smaller than the nozzle hole, and the land area to be soldered can be controlled within a certain range depending on the nozzle height. In the case of the land information D1 in FIG. 2A, since the maximum outer shape is 10 mm among the X and Y outer dimensions of the land, one of the X and Y hole dimensions has the smallest area among nozzles of 10 mm or more. -R1005 nozzle is selected. Here, the nozzle hole dimension X or Y may be 10 mm or more because the angle of the nozzle can be controlled.

The solder jet velocity calculating means 15 calculates the solder jet velocity and the soldering time from the heat capacity of the soldering location output from the heat capacity calculating means 13, the nozzle type output from the nozzle type determining means 14, and the preheat temperature. To do. For example,
Soldering temperature rise = Soldering temperature-Preheat temperature Amount of heat required for soldering = Soldering temperature rise × Heat capacity of soldering location
Solder jet velocity = Standard jet velocity coefficient × Maximum jet velocity Soldering time = Heat required for soldering ÷ (Solder jet velocity × jet flow rate vs. heat quantity coefficient)
Calculate with FIG. 3B is a calculation example of the solder jet velocity and the soldering time.

  Here, the standard jet velocity coefficient is the ratio of the jet velocity to the maximum jet velocity at which the jet can continue to flow constantly, and the maximum jet velocity is the maximum rotation speed of the motor that generates the jet.

  The nozzle operation determining unit 16 determines the operation of the nozzle that minimizes the soldering time while maintaining the quality from the land position obtained from the land information acquiring unit 11 and the soldering time output from the solder jet velocity calculating unit 15. . For example, the quality can be stabilized by soldering from a small heat capacity to a large heat capacity. That is, NC data is created so that soldering is performed from a soldering location having a short soldering time to a soldering location having a long soldering time. For example, in FIG. 3B, it is desirable to perform soldering in the order of soldering time of 0.40 seconds, 0.72 seconds, and 2.16 seconds. As a result, the difference in heat capacity required between the points is small, the amount of heat can be gradually applied, and the quality is stabilized.

  First, the soldering location X01-01 is soldered. It can be seen from the Y external dimension of the land information D1 that the land shape is a vertically long land. Since the land position is expressed by the land center coordinates, the position moved in the Y minus direction by Y outer dimension / 2 (5/2) = 2.5 mm is defined as the nozzle start position (X: 124 mm, Y46.5 mm). The position moved in the Y plus direction by 2.5 mm is defined as the nozzle end position (X: 124 mm, Y51.5 mm). The soldering height is set to soldering length (2 mm) of component information D2 + clearance (for example, 0.5 mm) = 2.5 mm. Here, the soldering length is the length from the position to the tip of a lead of a component that needs to be soldered, using the board surface as a reference. The moving speed is set as moving distance / soldering time = 5 mm / 0.4 s = 12.5 mm / s. Further, since the land X outer dimension is 3 mm and the short nozzle dimension is 5 mm in the Y direction, the nozzle angle is 90 degrees. Here, the nozzle angle is defined as 0 degrees as defined by the nozzle information. Since the nozzle has a rotation mechanism, the rotation angle with respect to 0 degrees is set as the nozzle angle. The X direction is the same as the direction in which the substrate flows.

  The nozzle angle is adjusted so that the land shape is within the nozzle shape when the dimensions of the nozzle shape in the X direction and the Y direction are different, or in the case of a square nozzle. In this example, since the land is vertically long and the nozzle is horizontally long, the nozzle is rotated 90 degrees to control the vertically long state. The height during movement is 2.5 mm. The next soldering location extracts the soldering location closest to X01-01 within the soldering time of 0.72 seconds, and solders the soldering location of CN02-02. From the external dimensions of the land information D1, the nozzle start position and the end position are the same. The soldering height is set to soldering length (2 mm) of component information D2 + clearance (for example, 0.5 mm) = 2.5 mm. No nozzle movement is required, so wait for the soldering time. Since the land XY outer dimension is 8 mm, the nozzle angle is 0 degree. The height during movement is 2.5 mm. Similarly, the soldering locations of CN02-01, R01-01, and R01-02 are soldered. FIG. 4 shows an example of NC data.

  Further, the nozzle operation determining means 16 obtains the inspection result obtained by inspecting the substrate soldered under the above-calculated conditions (NC data) by the solder inspection machine 23, and when the soldering location is determined to be defective, The nozzle operation is corrected according to the defective mode. For example, in the case of the solder bridge failure mode, the height at the time of movement is moved downward (for example, 4.0 mm) to suppress the influence of the solder jet at the time of moving the soldering location. On the other hand, in the case of the defective mode with a small amount of solder, the soldering nozzle movement from the soldering shape measurement data, which is the inspection result, to a portion with little solder is lengthened (for example, +1.0 mm), and the solder jet flow rate is increased.

Note that after the nozzle operation is corrected, it may be inspected and corrected again.
The nozzle height correcting unit 17 corrects the nozzle operation determined by the nozzle operation determining unit 16 based on the substrate warpage information acquired from the substrate warpage sensor 24. Specifically, the nozzle height determined by the nozzle operation determining unit 16 is corrected based on the substrate warpage information acquired from the substrate warpage sensor 24. For example, if the acquired board warpage information is soldering location R01-01, +1 mm, the soldering height is warped by 1 mm upward (= the height minus direction when the lower surface of the board 30 is the origin). Correction is made as 2.5 mm-1 mm = 1.5 mm.

The NC data output means 18 outputs the NC data created as described above in a format that can be read by the soldering device 25.
The configuration of the soldering device 25 operated based on the NC data output from the NC data output means 18 will be described with reference to FIGS. 5 (a) and 5 (b), FIG. 6, and FIG.

  In FIG. 5A, the nozzle 51 moves to the right with respect to the fixed printed circuit board 30 and is soldered. A lead portion 41 of a component 42 is inserted and set in a component hole formed in the land 31 of the printed circuit board 30. A lead portion 43 of a component 44 is inserted and set in a component hole formed in the land 32 of the printed circuit board 30. A lead portion 45 of a component 46 is inserted and set in a component hole formed in the land 33 of the printed circuit board 30.

  Soldering by the nozzle 51 that ejects the solder jet flow 52 from the tip is performed in ascending order of the NC data. Note that the speed of the solder jet 52 at each soldering point is controlled to an appropriate value based on the result of the solder jet speed calculation means 15 by the solder device 25.

  The nozzle 51 located at the origin is moved in the vertical and horizontal directions to move to the vicinity of the land 31 that is the soldering start position of the first soldering position, and then moved to the soldering height. As a result, the solder jet 52 is in contact with the land 31 and the lead 41 for a specified time, and soldering is performed. FIG. 5B shows the vertical movement and horizontal movement of the nozzle 51. In this case, since the size of the land 31 is the same as or smaller than the diameter of the nozzle 51 in use, the nozzle 51 that has arrived at the position below the land 31 rises toward the center position of the land 31, and rises. Then, the solder jet 52 is brought into contact with the land 31 and the lead 41 for a specified time, and then the nozzle 51 is lowered to a position where the solder jet 52 does not come into contact with the printed circuit board 30. The nozzle 51 heading to the next soldering position moves horizontally in this lowered state.

  Since the size of the land 32 at the next soldering location is larger than the diameter of the nozzle 51 in use and has a large heat capacity, the nozzle 51 moves to the soldering start position of the land 32 and the lead 43 and then solders. It rises to the height. Then, soldering is performed by moving horizontally at a designated moving speed toward the soldering end position while the nozzle 51 remains in the raised position. When the nozzle 51 arrives at the soldering end position, the nozzle 51 descends to a position where the solder jet 52 does not contact the printed circuit board 30. The nozzle 51 heading to the next soldering position moves horizontally in this lowered state.

  The size of the land 33 at the next soldering location is larger than the diameter of the nozzle 51 in use and has a large heat capacity. Therefore, after moving to the soldering start position between the land 33 and the lead 45, the soldering height is increased. Move to. Further, soldering is performed by moving to a soldering end position at a designated moving speed.

In this way, soldering is performed from a soldering part having a smaller heat capacity to a larger part in order, thereby stabilizing the solder jet and ensuring the soldering quality.
The operation in the case where a soldering failure due to lack of solder occurs in the soldering location between the land 32 and the lead 43 based on the inspection result obtained from the solder inspection machine 23 will be described with reference to FIG.

  When the nozzle operation determining means 16 reveals that the solder is low in the vicinity of the soldering end position from the soldering shape dimension measurement data which is the measurement result of the solder inspection machine 23, the next time soldering at the same location is performed. As shown in FIG. 6A, the nozzle operation determining means 16 raises the nozzle 51 to a position higher than the normal height indicated by the phantom line by a specified height (for example, 1.0 mm) as shown in FIG. The nozzle 51 is horizontally moved to the soldering end position while keeping the raised position higher than normal by 1.0 mm. Then, after the nozzle 51 is held at the soldering end position for a normal waiting time, the nozzle 51 starts to descend toward a position where the solder jet 52 does not contact the printed circuit board 30, thereby eliminating the soldering failure due to insufficient solder. Improve.

  Alternatively, as shown in FIG. 6B, at the next soldering of the same portion, the nozzle 51 is raised to the normal height indicated by the solid line at the soldering start position. Then, the nozzle 51 that has moved horizontally and arrived at the normal end position indicated by the phantom line is made to wait at the same position for a specified time (for example, +0.1 seconds) longer than the normal standby time, and then the solder jet 52 is printed. By starting the descent of the nozzle 51 toward the position where it does not contact the substrate 30, the soldering failure due to insufficient solder is improved.

  In the above description, when a soldering failure occurs due to insufficient solder, the nozzle 51 is raised higher than the normal height to prevent the solder failure, but the nozzle 51 remains at the normal height. By correcting the height of the solder jet 52 according to the solder measurement result that the nozzle operation determining means 16 can obtain from the solder inspection machine 23, it is possible to prevent the solder failure. More specifically, when the nozzle operation determining means 16 determines that the soldering failure is caused by insufficient solder, the solder jet flow 52 when the nozzle 51 is raised to the normal height for the same soldering location next time. The data is corrected so that the height is higher than the normal height depending on the degree of solder shortage. The nozzle 51 is horizontally moved to the soldering end position at the corrected height of the solder jet 52. Further, since the relationship between the solder jet height and the solder jet velocity is different for each nozzle, the nozzle operation determining means 16 prepares and calculates a conversion equation for each nozzle.

  In the above description, the height of the nozzle 51 or the height of the solder jet 52 is controlled according to the solder result to prevent the solder failure. However, the height of the nozzle 51 and the height of the solder jet 52 are determined according to the solder result. Both of them can be controlled appropriately to prevent solder failure.

The operation when the board warpage occurs at the soldered portion of the land 32 and the lead 43 will be described with reference to FIGS.
When the printed circuit board 30 is warped upward as shown in FIG. 7A, the solder jet 52, the land 32 and the lead 43 at the soldering location are maintained with the rising height of the nozzle 51 being normal. Lack of contact. Therefore, when the nozzle height correcting unit 17 determines that the substrate warpage information acquired from the substrate warpage sensor 24 is warped upward by 1.0 mm, the nozzle height correcting unit 17 determines the soldering start position. As shown in FIG. 7B, the nozzle 51 is raised by 1.0 mm in accordance with the amount of warpage of the printed circuit board 30 from the normal height, thereby preventing solder failure.

  In addition, when the board | substrate curvature sensor 24 is not attached to the arithmetic unit 10, it can also acquire and correct | amend the board | substrate curvature information from another apparatus. The best is to measure the warpage of the board at the position to be soldered by the board warpage sensor 24.

  As described above, based on the land information D1 and the component information D2, which are the design information acquired from the board design CAD system 21 and the component information system 22, the NC data serving as a reference can be created in a short time. did. Furthermore, by reflecting the results obtained from the measuring devices of the solder inspection machine 23 and the board warpage sensor 24 in the NC data, NC data that realizes high-quality soldering in a short time can be created, and the quality of the soldering point can be improved. Production time can be shortened while keeping high.

  In the above description, when it is determined that the printed circuit board 30 is warped upward, the nozzle 51 is raised higher than the normal height to prevent solder failure. Instead of inputting the warp information to the nozzle height correcting means 17 as indicated by the solid line in FIG. 1, the substrate warp information that can be obtained from the substrate warp sensor 24 is indicated by the phantom line in FIG. The solder failure can also be prevented in advance by correcting the height of the solder jet 52 according to the board warpage information that can be input to the determination means 16 and acquired by the nozzle operation determination means 16 from the board warpage sensor 24. Specifically, when the warpage information of the soldering portion acquired by the nozzle operation determining unit 16 from the substrate warpage sensor 24 is warped upward, or when the nozzle 51 is raised to the normal height The data is corrected so that the height of the solder jet 52 is higher than the normal height in accordance with the amount of substrate warpage acquired from the substrate warpage sensor 24. The nozzle 51 is horizontally moved to the soldering end position at the corrected height of the solder jet 52. Then, after the nozzle 51 is held at the soldering end position for the normal standby time, the solder jet velocity is returned to the specified speed while the nozzle 51 starts to descend toward the position where the solder jet 52 does not contact the printed circuit board 30. This improves the soldering failure due to insufficient solder. Further, since the relationship between the solder jet height and the solder jet velocity is different for each nozzle, a conversion equation is prepared for each nozzle operation determining means 16 and calculated. As described above, when the height of the nozzle 51 is controlled by the normal height regardless of the substrate warpage information, and the height of the solder jet 52 is controlled according to the substrate warpage information, the nozzle height shown in FIG. The correcting means 17 is unnecessary, and the output of the nozzle operation determining means 16 is supplied to the NC data output means 18.

  In the above description, the height of the nozzle 51 or the height of the solder jet 52 is controlled according to the board warpage information to prevent solder failure. However, the nozzle operation determining means 16 and the nozzle height correcting means 17 are used as the board warpage sensor. 24, and it is possible to appropriately control both the height of the nozzle 51 and the height of the solder jet 52 in accordance with the state of the substrate warp, thereby preventing a solder failure.

  As described above, based on the land information D1 and the component information D2, which are design information acquired from the board design CAD system 21 and the component information system 22, the reference NC data can be created in a short time. Furthermore, by reflecting the results obtained from the measuring devices of the solder inspection machine 23 and the board warpage sensor 24 in the NC data, NC data that realizes high-quality soldering in a short time can be created, and the quality of the soldering point can be improved. Production time can be shortened while keeping high.

  In the above description, when the nozzle 51 arriving at the soldering end position is moved to the next soldering location, the solder jet 52 is lowered so as not to come into contact with the printed circuit board 30 and then moved horizontally. In the case where there is no obstacle between the next soldering position and the next soldering position, the next soldering is performed without lowering the nozzle 51 when moving to the next soldering position. Faster soldering can be realized by horizontally moving to the soldering start position.

  In each of the above embodiments, the arithmetic unit 10 acquires the land information D1 from the board design CAD system 21 and the component information D2 from the component information system 22. However, the arithmetic device 10 acquires the land information D1 from the mounting engineering system. The component information D2 can also be acquired from the mounting engineering system, the mounting machine NC data, and the inspection machine data.

  Here, the mounting engineering system is a system that receives CAD data, checks board wiring rules, component adjacent interference, and the like, and extracts problems of the board and parts before production.

  The present invention can contribute to improvement in productivity of various electronic devices and high-quality soldering.

DESCRIPTION OF SYMBOLS 10 Arithmetic apparatus 11 Land information acquisition means 12 Parts information acquisition means 13 Heat capacity calculation means 14 Nozzle type determination means 15 Solder jet velocity calculation means 16 Nozzle operation determination means 17 Nozzle height correction means 18 NC data output means 21 Substrate design CAD system 22 Component information system 23 Solder inspection machine 24 Substrate warpage sensor 25 Solder device 30 Printed circuit board D1 Land information D2 Component information 31, 32, 33 Land 42, 44, 46 Components 41, 43, 45 Lead portion 51 Nozzle 52 Solder jet

Claims (8)

A method of creating NC data for point soldering by which a component is mounted on a substrate by solder ejected from a nozzle,
An information acquisition step of acquiring information on a land of a soldering point and component information to be mounted from CAD data of the substrate;
A heat capacity calculating step of calculating a heat capacity of the soldering location from the information of the land and the component information;
A soldering condition calculation step of calculating a soldering condition from the heat capacity,
In the heat capacity calculation step, a point solder NC data creation method for obtaining a heat capacity from the heat capacity of the land, the heat capacity of the component, and the heat capacity of the component body. 2. The point solder NC data creation method according to claim 1, wherein the heat capacity of the component body is calculated from information on the land on which the component is mounted for a component without the component information. A method of creating NC data for point soldering by which a component is mounted on a substrate by solder ejected from a nozzle,
An information acquisition step of acquiring information on a land of a soldering point and component information to be mounted from CAD data of the substrate;
A heat capacity calculating step of calculating a heat capacity of the soldering location from the information of the land and the component information;
A soldering condition calculation step of calculating a soldering condition from the heat capacity,
Point solder NC data generation further including a second correction step of measuring warpage of the substrate before and during soldering and correcting at least one of nozzle height and solder jet velocity based on the measured information Method. After soldering to the substrate under the soldering conditions calculated in the soldering condition calculation step, a first correction step of inspecting a soldering location and correcting the soldering conditions based on the inspection result, The point solder NC data creation method according to any one of claims 1 to 3, further comprising: The point solder NC data creation method according to claim 4, wherein the inspection results are classified according to a predetermined failure mode, and the first correction step corrects the soldering condition based on the failure mode. The point solder NC data creation according to any one of claims 1 to 5, wherein in the soldering condition calculation step, a solder jet velocity and a soldering time are calculated from the type of the nozzle, the heat capacity, and a preheat temperature. Method. The point solder NC data creation method according to any one of claims 1 to 6, wherein, in the soldering condition calculation step, the soldering order is determined in the order of the heat capacity.   The point solder NC data creation method according to claim 1, wherein, in the soldering condition calculation step, the nozzle angle is determined according to the shape of the land.

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