Application method, electronic component mounting machine, and circuit board manufacturing method

Abstract

To properly apply flux to an electronic component.SOLUTION: An application method according to the present disclosure comprises: a step of preparing in-tank flux held in a flux tank; A step of preparing an electronic component having an electrode portion and a non-electrode portion on a surface thereof; and an application step of bringing a portion of the electrode portion and a portion of the non-electrode portion into contact with the in-tank flux, and then separating the flux adhering to the electronic component from the in-tank flux. Therein the application step is performed so that the electronic component does not come into contact with the flux tank.SELECTED DRAWING: Figure 2B

Description

[Technical Field]

[0001] The present disclosure relates to a flux application method for electrically and mechanically joining electronic components to a wiring board using flux, an electronic component mounting machine, and a circuit board manufacturing method. [Background technology]

[0002] Patent Document 1 discloses an apparatus for applying flux to the electrodes of a semiconductor component by immersing the semiconductor component, which is held by a suction nozzle of a conveying device, up to the bottom of a liquid tank into which flux has been poured. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-285962 Summary of the Invention [Problem to be solved by the invention]

[0004] In the mounting method described in Patent Document 1, the viscous force of the flux causes the semiconductor components to stick to the bottom of the liquid tank, and there is a risk that the semiconductor components may fall off the suction nozzle when being pulled out of the flux in the liquid tank. In this case, the semiconductor components remain in the flux, making it impossible to apply flux to the electrodes of the semiconductor components with a good yield.

[0005] Therefore, an object of the present disclosure is to provide a flux application method, an electronic component mounting machine, and a circuit board manufacturing method that can appropriately apply flux to electronic components. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an applying method including the steps of: preparing in-tank flux held in a flux tank; preparing an electronic component having electrode portions and non-electrode portions on its surface; and bringing a portion of the electrode portions and a portion of the non-electrode portions into contact with the in-tank flux, and then separating the flux adhered to the electronic component from the in-tank flux, wherein the applying step is performed so that the electronic component does not come into contact with the flux tank. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a technique that is advantageous in appropriately applying flux to electronic components. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view showing a circuit board according to the first embodiment. [Figure 2A] 3A to 3C are diagrams illustrating a method for manufacturing the laminated structure of the electronic component according to the first embodiment. [Figure 2B] 3A to 3C are diagrams illustrating a method for manufacturing the laminated structure of the electronic component according to the first embodiment. [Figure 2C] 3A to 3C are diagrams illustrating a method for manufacturing the laminated structure of the electronic component according to the first embodiment. [Figure 3] 5 is a diagram for explaining the relationship between the speed at which the electronic component is moved and the state of flux attachment according to the first embodiment. FIG. [Figure 4] 3A to 3C are diagrams for explaining the flux transfer method of a reference example in comparison with the flux applying method according to the first embodiment. [Figure 5] FIG. 10 is a diagram showing the evaluation results of Example 2 of the flux application method according to the first embodiment. [Figure 6] FIG. 10 is a diagram showing the evaluation results of Example 3 of the flux application method according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing the evaluation results of Example 4 of the flux application method according to the first embodiment. [Figure 8A]10A and 10B are diagrams for explaining the structure of an electronic component mounter according to a second embodiment. [Figure 8B] 10A and 10B are diagrams for explaining the structure of an electronic component mounter according to a second embodiment. [Figure 9] 10 is a flowchart showing an example of the operation of the electronic component mounter according to the second embodiment. [Figure 10] 10A and 10B are diagrams for explaining the structure of an electronic component mounter according to a third embodiment. [Figure 11] 11 is a flowchart showing an example of the operation of the electronic component mounter according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiments and can be modified as appropriate without departing from the spirit of the present disclosure. In addition, in the drawings described below, parts having the same functions are given the same reference numerals, and their description may be omitted or simplified.

[0010] [First embodiment] Fig. 1 is a perspective view showing an electronic circuit 1 according to a first embodiment. In Fig. 1, the electronic circuit 1 is a circuit board including a printed wiring board 10, an electronic component (first electronic component) 11, an electronic component (second electronic component) 12, and a semiconductor device 13. A first wiring 14 and a second wiring 15 are formed on a main surface of the printed wiring board 10. Note that the wiring board used in the electronic circuit 1 is not limited to the printed wiring board 10. The wiring board may be a rigid wiring board or a flexible wiring board.

[0011] Electronic component 11 is disposed on the mounting surface of printed wiring board 10. Electronic component 12 is layered on electronic component 11. Electronic component 11 and electronic component 12 are, for example, passive components. Here, "passive components" refer to electronic components having two-terminal passive elements such as multilayer ceramic capacitors and chip resistors. For example, electronic component 11 and electronic component 12 are chip capacitors or chip resistors formed in a chip shape. In this embodiment, a case will be described in which electronic component 11 and electronic component 12 are multilayer ceramic capacitors.

[0012] The semiconductor device 13 is disposed on the main surface of the printed wiring board 10. The semiconductor device 13 also includes a power supply terminal 16 and a ground terminal 17. The power supply terminal 16 is connected to a first wiring 14 formed on the main surface of the printed wiring board 10. The ground terminal 17 is connected to a second wiring 15 formed on the main surface of the printed wiring board 10. Power (electricity) is supplied to the semiconductor device 13 from a power supply device (not shown) via the first wiring 14 and the second wiring 15. The power supply device that supplies power to the semiconductor device 13 may be a semiconductor device disposed on the printed wiring board 10. The power supply device may be mounted on the same main surface as the electronic components 11 and 12, or may be mounted on a different main surface from the electronic components 11 and 12. The power supply device may also be disposed outside the printed wiring board 10. In this embodiment, the first wiring 14 may be a power supply wiring and the second wiring 15 may be a ground wiring, but the polarities of the first wiring 14 and the second wiring 15 may be reversed.

[0013] 1, electronic components 11 and 12 are arranged on the main surface of printed wiring board 10 near semiconductor device 13, within a predetermined distance from semiconductor device 13. The predetermined distance is, for example, within 50 mm from semiconductor device 13. The centers of gravity of electronic components 11 and 12 stacked in two layers are aligned in a straight line in the stacking direction (vertical direction in the figure).

[0014] 2A to 2C are diagrams illustrating a method for manufacturing a laminated structure of an electronic component according to the first embodiment. The following describes the steps in the order shown in (a) to (j). FIG. 2A(a) is a diagram illustrating the step of supplying solder paste 4 onto first wiring 14 and second wiring 15 formed on the main surface of printed wiring board 10. Here, a metal mask 3 having openings is aligned with printed wiring board 10, and then the metal mask 3 is brought into close contact with printed wiring board 10. Furthermore, a squeegee 2 is moved along the top surface of metal mask 3, thereby filling the openings in the metal mask 3 with solder paste 4.

[0015] FIG. 2A(b) shows the state after the metal mask 3 is separated from the printed wiring board 10 and the solder paste 4 is supplied to the first wiring 14 and the second wiring 15 of the printed wiring board 10.

[0016] Next, as shown in FIG. 2A(c), the other end of the electronic component 11, which has an external electrode at one end, is suctioned by a suction nozzle 25. The suction nozzle 25 is a member for suctioning and holding electronic components by vacuum suction or the like, and is mounted on an electronic component mounting machine. The electronic component 11 has, on its surface, an electrode portion including a plurality of first external electrodes 111, 112 located at both ends of the bottom side, and a non-electrode portion 113 between the first external electrodes 111 and 112. The non-electrode portion 113 is typically made of an insulator, but may also be made of a conductor insulated from the electrode portion. In this state, the first external electrodes 111, 112 of the electronic component 11 are aligned with the solder paste 4 covering the first wiring 14 and second wiring 15 provided on the printed wiring board 10.

[0017] Next, the electronic component 11 held by the suction nozzle 25 is moved vertically downward, and the electronic component 11 is placed on the solder paste 4. Fig. 2A(d) shows a state in which the electronic component 11 in the first layer of the stacked structure of electronic components has been placed on the printed wiring board 10.

[0018] Next, with reference to FIGS. 2B(e) to (g), a process for stacking a second-layer electronic component 12 on a first-layer electronic component 11 in a stacked structure of electronic components will be described. As shown in FIG. 2B(e), the electronic component 12 has, on its surface, an electrode portion including a plurality of second external electrodes 121 and 122, and a non-electrode portion 123 between the second external electrodes 121 and 122. The non-electrode portion 123 is typically made of an insulator, but may also be made of a conductor insulated from the electrode portion. The flux tank 27 is a container for holding the flux 5. As shown in FIG. 2B(e), the flux 5 is poured into the flux tank 27 to a predetermined thickness t. Hereinafter, the flux 5 poured into the flux tank 27 will also be referred to as "flux in the tank." The flux 5 is a flux containing, for example, rosin, epoxy resin, or the like. The flux 5 may contain other components besides the flux. For example, the flux 5 may be a solder paste containing flux. Also, as shown in FIG. 2B(e), a suction nozzle 25 of an electronic component mounter suction-holds an electronic component 12 above a flux tank 27. The viscosity of the flux 5 is, for example, 10 Pa·sec or more and 50 Pa·sec or less, and preferably 20 Pa·sec or more and 40 Pa·sec or less. It is more preferable that the viscosity of the flux 5 is approximately 30 Pa·sec.

[0019] 2B(f) shows a state in which the electronic component 12 is lowered toward the flux tank 27 at a predetermined lowering speed until the height from the bottom of the flux tank 27 to the lower surface of the electronic component 12 reaches a predetermined height h. In other words, the electronic component 12 is immersed in the flux tank 27 to a depth (th) in the vertical direction. The electronic component 12 is also spaced apart from the bottom of the flux tank 27. In this specification, the term "immersed" means that the electrode and non-electrode portions of the electronic component are brought into contact with the flux in the tank.

[0020] FIG. 2B(g) shows a state in which the electronic component 12 is lifted from the flux bath 27 at a predetermined lifting speed, thereby applying the flux 5 to the second external electrodes 121, 122 at both ends of the electronic component 12. The electronic component 12, which is suctioned and held by the suction nozzle 25, does not fall into the flux bath 27, and the flux 5 is applied to portions of the second external electrodes 121, 122 and portions of the non-electrode portions at both ends of the electronic component 12. However, the flux 5 is not applied to the remaining portions of the second external electrodes 121, 122 and portions of the non-electrode portions at both ends of the electronic component 12. In other words, the flux 5 is not applied to all of the electrode portions of the electronic component 12, nor is the flux 5 applied to all of the non-electrode portions of the electronic component 12. Hereinafter, in this specification, the flux 5 applied to portions of the electrode portions and portions of the non-electrode portions of the electronic component by the above-described application method is also referred to as "adhered flux" and is distinguished from "flux in the bath." After the electronic component 12 is immersed in the flux 5 as shown in FIG. 2B(f), it is preferable to immediately lift the electronic component 12 out as shown in FIG. 2B(g). The time for which the component 12 is left immersed may be changed as appropriate. This allows the amount of flux 5 supplied to the electronic component 12 to be appropriate.

[0021] Here, we will explain why electronic components held by the suction nozzle 25 do not fall into the flux bath 27. When an electronic component rises from the flux bath 27, the suction nozzle 25 exerts an upward force P holding the electronic component. At this time, a viscous force F (= μ·dv / dh) of the flux 5 acts on the electronic component. Furthermore, the rapid rise of the electronic component causes the flux 5 to flow toward the location where the electronic component was immersed. This is thought to generate a downward force due to a decrease in the pressure of the flux 5. The inventors of this application experimentally found that the combined force of the viscous force F of the flux 5 and the downward force generated by the flow of the flux 5 decreases as the height h from the bottom of the flux bath 27 to the underside of the electronic component increases.

[0022] In other words, the greater the height h from the bottom of the flux tank 27 to the underside of the electronic components, the less likely the electronic components will fall out of the flux tank 27 when they are pulled out of the tank. We checked whether electronic components had fallen out of the flux tank 27 for sizes of approximately 0.6 mm × 0.3 mm (hereinafter referred to as the "first component size") and approximately 1.6 mm × 0.8 mm (hereinafter referred to as the "second component size"). We found that, for both the first and second component sizes, the electronic components did not fall out of the flux tank 27 when they were pulled out of the flux tank 27. In other words, assuming that the height h from the bottom of the flux tank 27 to the underside of the electronic components is h and the thickness of the flux 5 in the flux tank 27 is t, the relationship 4t / 5≦h≦t must be satisfied. This relationship is not affected by the size of the electronic components. The value of t that satisfies 4t / 5≦h≦t is preferably 150 μm or more, more preferably 200 μm or more, and is preferably 1000 μm or less, more preferably 500 μm or less.

[0023] Furthermore, the depth (th) to which the electronic components are immersed in the flux 5 is preferably 100 μm or less, and more preferably 50 μm or less, which makes it possible to apply (transfer) a small amount of flux to the electronic components, thereby enabling a stacked structure of electronic components to be mounted adjacent to each other in a narrow area on the printed wiring board 10.

[0024] In the explanation of Figures 2B(f) and 2B(g), it is assumed that the inner bottom surface of the flux tank 27, i.e., the surface in contact with the flux in the tank, is horizontal. However, the surface may not be horizontal. Below, we will explain the case where the shape of the surface in contact with the flux in the tank is taken into consideration. In Figure 2B(f), the surface in contact with the flux in the tank of the flux tank 27 can be divided into a first region and a second region. The first region is the region facing the electronic components in the vertical direction. The second region is the region outside the first region and faces the liquid surface of the flux in the tank in the vertical direction.

[0025] Let h be the minimum vertical distance between the first area and the electronic components, and t be the vertical distance between the second area and the liquid surface of the flux in the bath. 4t / 5≦h <t The following relationship shall be satisfied.

[0026] Furthermore, the distance from the second region to the liquid surface of the flux in the tank is preferably 1000 μm or less. The distance from the second region to the liquid surface of the flux in the tank is preferably 500 μm or less. The distance from the second region to the liquid surface of the flux in the tank is preferably 100 μm or more. The distance from the second region to the liquid surface of the flux in the tank is preferably 200 μm or more.

[0027] 2B(f) and 2B(g), the minimum distance between the first region and the electronic component is preferably 150 μm or more and 500 μm or less. Furthermore, the difference between the minimum distance between the first region and the electronic component and the distance between the second region and the flux liquid surface in the tank is preferably 100 μm or less, and more preferably 50 μm or less.

[0028] 2C(h) shows a state in which electronic component 12 is positioned relative to electronic component 11 in order to stack electronic component 12 in a second layer on electronic component 11 already mounted on printed wiring board 10. In this manner, with flux 5 applied to second external electrodes 121, 122 on both ends of electronic component 12, electronic component 12 picked up by suction nozzle 25 is stacked on electronic component 11 in the first layer.

[0029] 2C(i) shows a state in which electronic component 12 is stacked on electronic component 11. Electronic component 12 on the second layer is adhered to electronic component 11 with flux 5, and therefore is unlikely to fall off electronic component 11 when conveyed to a reflow furnace, which will be described later.

[0030] FIG. 2C(j) shows a stacked structure 19 of electronic components in which the solder paste 4 is melted in a reflow furnace (not shown) to electrically and mechanically bond the electronic components 11 and 12 to the first wiring 14 and second wiring 15 of the printed wiring board 10. The solder paste 4 supplied to the printed wiring board 10, the first external electrodes 111 and 112 of the electronic component 11, and the second external electrodes 121 and 122 of the electronic component 12 each contain tin (Sn). Therefore, by melting the solder paste 4 in a reflow furnace, the printed wiring board 10, the electronic components 11, and the electronic components 12 can be electrically and mechanically bonded. Furthermore, when the solder paste 4 melts, the solder 6, which has a higher surface tension than the flux 5, aggregates, forming a structure in which the flux 5 is expelled outside the solder 6.

[0031] 3A and 3B are diagrams illustrating the relationship between the speed at which an electronic component is moved and the state of adhesion of flux 5 in this embodiment. Fig. 3A shows the state immediately after electronic component 12, which has been picked up by suction nozzle 25, is immersed vertically downward into flux bath 27 at relative speed (lowering speed) S1. Because flux 5 has viscosity, increasing the relative speed (lowering speed) S1 at which electronic component 12 is immersed causes a phenomenon in which flux 5 is pushed out by electronic component 12. FIG. 3(b) shows a state in which the electronic component 12 is being pulled up vertically from the flux tank 27 at a second relative speed (rising speed) S2. The relative speeds S1 and S2 are now described in detail. The relative speed S1 is the relative speed between the flux tank 27 and the electronic component when the electronic component begins to come into contact with the flux in the tank as the distance between the electronic component 12 and the flux tank 27 decreases. The relative speed S2 is the relative speed of the electronic component with respect to the liquid surface of the flux in the tank when the applied flux begins to separate from the flux in the tank as the distance between the electronic component and the flux tank 27 increases. The minimum value h of the vertical distance between the first region and the electronic component corresponds to the distance at which the vertical relative speed between the electronic component and the flux tank 27 becomes zero. As shown in Figure 3(b), the flux 5 is stringy on the underside of the electronic component 12. It was found that the length of the stringy flux 5 becomes shorter when the relative speed S2 is slower than the relative speed S1 and longer when the relative speed S2 is faster than the relative speed S1. Therefore, by satisfying the relationship S1 > S2, stringy flux 5 can be suppressed and the amount of flux 5 supplied to the electronic component can be reduced and set to an appropriate amount. As a result, when stacked electronic components are arranged closely adjacent on the main surface of the printed wiring board 10, the flux 5 does not come into contact with adjacent electronic components, thereby reducing short circuits caused by reflow heating. Figure 3(c) shows the state in which the electronic component 12 is further raised from the state shown in Figure 3(b), with the flux 5 attached to the underside of the electronic component 12 and separated from the flux in the bath (a state in which the flux is depleted).

[0032] When reducing the distance between the electronic component and the flux bath 27, the relative speed S3 between the flux bath 27 and the electronic component before the electronic component begins to contact the flux in the bath may be the same as the relative speed S1 (S1 = S3) or may be faster than the relative speed S1 (S1 < S3). Also, the relative speed S4 between the flux bath 27 and the electronic component before reaching the relative speed S3 may be faster than the relative speed S3 (S3 < S4). Note that the relative speed S3 and the relative speed S4 are typically the maximum value of the relative speed between the flux bath 27 and the electronic component or the relative speed when the flux bath 27 and the electronic component are moving at a constant speed. For example, the electronic component is moved horizontally at a high relative speed S4 to place the electronic component above the flux bath 27. Then, the electronic component is moved vertically at a medium relative speed S3 to approach the flux bath 27, decelerated from the relative speed S3, and the electronic component is stopped at the position where the minimum value h is reached. The relative speed S1 may coincide with the relative speed S3 (S1 = S3) if the start of deceleration is after the electronic component begins to contact the flux in the bath. The relative speed S1 is slower than the relative speed S3 (S1 < S3) if the start of deceleration is before the electronic component begins to contact the flux in the bath. When increasing the distance between the electronic component and the flux bath 27, the relative speed S5 of the electronic component with respect to the liquid level of the flux in the bath after the applied flux separates from the flux in the bath may be the same as the relative speed S2 (S5 = S2) or may be faster than the relative speed S2 (S5 > S2). The relative speed S6 between the flux bath 27 and the electronic component after reaching the relative speed S5 may be faster than the relative speed S5 (S5 < S6). Note that the relative speed S5 and the relative speed S6 are typically the maximum value of the relative speed between the flux bath 27 and the electronic component or the relative speed when the flux bath 27 and the electronic component are moving at a constant speed. For example, the electronic component that has stopped at the position where the minimum value h is reached is accelerated to a low relative speed S5 and moved vertically to move away from the flux bath 27. Thereafter, the electronic component is moved vertically and horizontally at a high relative speed S6 to move the electronic component outside the flux bath 27. The relative speed S2 may coincide with the relative speed S5 (S2 = S5) if the relative speed S5 is reached before the applied flux separates from the flux in the bath.If the relative velocity S2 reaches the relative velocity S5 after the applied flux separates from the flux in the tank, the relative velocity S2 is slower than the relative velocity S5 (S2 <S5)。

[0033] In order to improve the tact time, the relative speeds S1 and S3 are preferably 1 mm / s or more, preferably 8 mm / s or more, preferably 10 mm / s or more, preferably 20 mm / s or more, and may be 40 mm / s or more. Taking into account the distance required for deceleration, the relative speeds S1 and S3 are preferably 400 mm / s or less, preferably 100 mm / s or less, and may be 80 mm / s or less. Taking stringiness into consideration, the relative speeds S2 and S5 are preferably 100 mm / s or less, preferably 80 mm / s or less, preferably 40 mm / s or less, preferably 20 mm / s or less, and may be 10 mm / s or less. In order to improve tact time, the relative speed S2 is preferably 1 mm / s or more, preferably 2 mm / s or more, preferably 4 mm / s or more, and preferably 8 mm / s or more. In order to improve the tact time, the relative speeds S4 and S6 are preferably 100 mm / s or more, more preferably 100 mm / s or more, and even more preferably 400 mm / s or more. The relative speeds S4 and S6 may be 1000 mm / s or less. Acceleration and deceleration depend on the mechanical performance of the component mounter, but for example, 1 x 10 4 mm / s 2 That's it, 2 x 10 4 mm / s 2 That's it, 3 x 10 4 mm / s 2 This can be done with, for example, 1 x 10 5 mm / s 2 Below, 7 x 10 4 mm / s 2 Below, 6 x 10 4 mm / s 2This can be done as follows. The relative speeds S1, S2, S3, and S5 can be set based on acceleration and deceleration performance so that they are faster (S3, S5) outside the vicinity of the liquid surface, are appropriate speeds (S1, S2) near the liquid surface, and can be stopped at the depth (th). For example, if the relative speed S3 is made larger, it is necessary to start deceleration at a position farther away from the liquid surface.

[0034] While the present embodiment has described a method for manufacturing a laminate structure in which electronic components are stacked in two layers, the same conditions apply to stacking electronic components in three or four layers, such as the immersion process order, lowering speed, and ascent speed. For example, when stacking electronic components in three layers, a third electronic component (the third layer) is immersed in a flux tank 27 into which flux 5 has been poured to a thickness t, until the height from the bottom of the flux tank 27 to the underside of the third electronic component reaches a predetermined height h, and flux 5 is applied to the external electrodes at both ends of the third electronic component. Next, the third electronic component (the third layer) is stacked on top of the two-layer stack of electronic components already mounted on the printed wiring board 10. This results in a laminate structure in which electronic components are stacked in three layers.

[0035] It should be noted that the greater the number of stacked electronic components, the greater the possibility that the solder paste 4 supplied to the printed wiring board 10 will be insufficient. In such cases, it is advisable to use a solder paste containing flux as the flux 5. Then, by using the method described above, the amount of solder necessary to connect the printed wiring board 10 and the multiple electronic components may be ensured by supplying the solder paste containing flux to the external electrodes on both ends of the electronic components.

[0036] As described above, according to this embodiment, unlike conventional mounting lines that use a dispenser to apply conductive connecting material to electronic components, there is no need to change the configuration of the manufacturing equipment depending on the number of layers of electronic components to be stacked. Therefore, it is possible to build a mounting line at low cost and produce stacked structures of electronic components. Furthermore, by immersing electronic components in flux bath 27, flux can be easily and reliably applied to the external electrodes of the electronic components. Furthermore, unlike when using a dispenser, there is no need to replace worn components or clean up after the end of a day's production.

[0037] Furthermore, in conventional mounting lines, it was difficult to inspect whether the conductive connecting material was properly applied to the electronic components below after being applied with a dispenser. Therefore, for example, if the conductive connecting material clogged the path to the dispenser's outlet, the conductive connecting material could not be supplied, resulting in the mass production of defective products. In contrast, in this embodiment, electronic components are immersed in flux tank 27, and flux is applied to a portion of the electrode portions and a portion of the non-electrode portions of the electronic components. Therefore, it is easy to determine whether the flux was properly applied to the electronic components.

[0038] Furthermore, since conductive connecting materials generally vary in physical properties such as viscosity, when a dispenser is used, it is necessary to fine-tune the discharge conditions of the conductive connecting material. In contrast, in this embodiment, the amount of flux supplied to the external electrodes of the electronic component is adjusted based on the thickness t of the flux and the height h from the bottom of the flux tank 27 to the lower surface of the electronic component. Therefore, even if the viscosity of the flux 5 varies depending on the lot, a constant amount of flux 5 can be applied to the external electrodes of the electronic component.

[0039] Example 1 Example 1 corresponding to the first embodiment will be described. In order to confirm the effects of the first embodiment, a two-tiered stacked structure of electronic components was mounted on a printed wiring board 10. A multilayer ceramic capacitor 0603 (product number: GRM033B31H102KA12D) manufactured by Murata Manufacturing Co., Ltd. was used as the electronic component.

[0040] First, solder paste 4 was applied by screen printing to printed wiring board 10. M705-GRN360-CNS2-Type5 manufactured by Senju Metal Industry Co., Ltd. was used as the solder paste 4. Next, an electronic component mounter NXTR manufactured by FUJI CORPORATION was used to mount electronic component 0603C, which would be the first layer, on printed wiring board 10 to which the solder paste had been applied.

[0041] Next, we will explain the process of stacking the second electronic component (0603C) on the first electronic component (0603C). A high-speed rotary dipping unit manufactured by FUJI Corporation was used to apply flux to the second electronic component (0603C). Furthermore, DELTALUX GTN-68 (HF) manufactured by Senju Metal Industry Co., Ltd. was used as flux 5. The viscosity of flux 5 was approximately 30 Pa·sec. In the flux tank 27 of the high-speed rotary dipping unit, the thickness t of flux 5 was adjusted to 200 μm. The height h from the bottom of the flux tank 27 to the underside of the electronic component (0603C) was set to 160 μm. In other words, the electronic component (0603C) was immersed in flux 5 to a depth of 40 μm.

[0042] A wide range nozzle S manufactured by FUJI Corporation was used as the suction nozzle 25. After the electronic component 0603C was picked up by the suction nozzle 25, the nozzle was rotated from a speed of 80 mm / s (relative speed S3) to a speed of 3×10 4 mm / s 2 The electronic component 0603C was then decelerated at a rate of 3×10 to 8.0 mm / s (relative speed S5) and lowered until the height from the bottom of the flux bath 27 to the bottom surface of the electronic component 0603C reached 160 μm, and the electronic component 0603C was immersed in the flux in the bath. 4The flux was accelerated at 80 mm / s and raised from the flux in the bath. This allowed the flux to be applied to the external electrodes on both ends of the electronic component 0603C. From a speed of 80 mm / s, the flux was 3 x 10 4 mm / s 2 Therefore, the object is moved at a constant speed of 80 mm / s to a position about 0.07 mm above the liquid surface, and then the object is moved from the position about 0.07 mm above the liquid surface to a distance of 3 × 10 4 mm / s 2 If the speed starts to decelerate at , it will be 50 mm / s when it contacts the liquid surface. After contacting the liquid surface, it will drop 0.04 mm and stop. In other words, the relative speed S1 can be estimated as 50 mm / s. From a stopped state, 4 mm / s 2 To accelerate to 8 mm / s, a distance of approximately 0.001 mm is required. Since this position is below the liquid surface, the relative velocity S2 can be estimated to be 8 mm / s.

[0043] (Reference example) Next, as a reference example, the results of an attempt to apply flux to the external electrodes of electronic component 100 using another transfer method will be described with reference to FIG.

[0044] In the reference example, the electronic component 100, flux 5, suction nozzle 25, and flux tank 27 used were the same as those in Example 1. The electronic component mounter was made to acquire information indicating the position of the bottom surface of the flux tank 27 (height H from the bottom surface to the edge of the flux tank 27 and the position of the edge), and was controlled to move the electronic component 100 based on the position of the bottom surface of the flux tank 27. Note that the thickness t of the flux 5 in the flux tank 27 was adjusted to 30 μm, but the electronic component mounter did not acquire information indicating the position of the liquid surface of the flux 5, such as the thickness t of the flux 5.

[0045] FIG. 4(a) shows a state in which an electronic component 100 of a first component size is sucked and held by the suction nozzle 25 of the electronic component mounter and moved above the flux bath 27. FIG. 4(b) shows a state in which the electronic component is immersed in the flux bath 27 from the state in FIG. 4(a) so that the external electrodes of the electronic component are pressed against the bottom surface of the flux bath 27. The liquid level of the flux 5 rises slightly as the electronic component 100 is immersed, but the depth to which the electronic component is immersed is roughly the same as the thickness (30 μm) of the flux 5 adjusted in the flux bath 27. After the electronic component 100 is sucked by the suction nozzle 25, it is lowered at a speed of 80 mm / s, and is then lowered by 3×10 4 The speed was reduced at a rate of mm / s, and the electronic component 100 was immersed until the lower surface of the electronic component 100 reached the bottom surface of the flux bath 27. Thereafter, the electronic component 100 was removed from the flux bath 27 by 3×10 4 When the electronic component 100 was raised at a speed of 80 mm / s, the electronic component 100 came off the suction nozzle 25 and dropped into the flux bath 27 as shown in FIG. 4(c).

[0046] As shown in FIG. 4(b), if the lower surface of the electronic component 100 is pressed against the bottom surface of the flux bath 27, the viscous force F (= μ·dv / dh) of the flux may become greater than the suction force of the suction nozzle 25 when the electronic component 100 rises from the flux bath 27. In this case, as shown in FIG. 4(c), the electronic component 100 may come off the suction nozzle 25 and fall into the flux bath 27. Here, μ is the viscosity of the flux, dv is the speed at which the electronic component 100 is raised, and dh is the height from the bottom surface of the flux bath 27 to the lower surface of the electronic component 100.

[0047] Next, Examples 2 to 4 corresponding to the first embodiment will be described. In Examples 2 to 4, whether or not an electronic component falls into the flux tank 27 was experimentally confirmed using the following parameters: height h from the bottom of the flux tank 27 to the lower surface of the electronic component, thickness t of the flux 5 in the flux tank 27, component size of the electronic component, and speed at which the electronic component is raised from the flux tank 27. The same flux 5, electronic component mounter, suction nozzle 25, and flux tank 27 as in Example 1 were used in Examples 2 to 4. Evaluations were performed 20 times (n=20) under each condition, and a case in which no component fell into the flux tank 27 in any of the 20 times was evaluated as "P." Conversely, a case in which an electronic component fell into the flux tank 27 even once was evaluated as "N."

[0048] Example 2 FIG. 5 shows the evaluation results when applying flux to an electronic component of the first component size. The height h (set value) from the bottom of the flux tank 27 to the underside of the electronic component was varied within a range of 150 μm or more and 500 μm or less. The thickness t of the flux in the flux tank 27 was set to a value obtained by adding 50 μm to the height h from the bottom of the flux tank 27 to the underside of the electronic component (h + 50 μm). In other words, the electronic component of the first component size was immersed to a depth of 50 μm from the liquid surface of the flux 5. The speed at which the electronic component was raised from the flux tank 27 (relative speed S5) was varied within a range of 8 mm / s or more and 80 mm / s or less. The speed was varied from a stopped state to 3×10 4 mm / s 2 When accelerating at 1000 rpm, a distance of approximately 0.001 mm is required to reach 8 mm / s, and a distance of approximately 0.11 mm is required to reach 80 mm / s.

[0049] 5, it can be seen that the greater the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component, the more successfully the flux 5 was applied to the external electrodes on both ends of the electronic component without the electronic component falling off into the flux tank 27. Furthermore, when the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component was 200 μm or greater, the flux 5 was successfully applied to the external electrodes on both ends of the electronic component.

[0050] Example 3 FIG. 6 shows the evaluation results when flux was applied to an electronic component having a component size of approximately 1.0 mm x approximately 0.5 mm (hereinafter referred to as the "third component size"). The thickness t of the flux 5 in the flux bath 27 was set to a value obtained by adding 50 μm to the height h from the bottom of the flux bath 27 to the underside of the electronic component (h + 50 μm). In other words, the electronic component of the third component size was immersed to a depth of 50 μm from the liquid surface of the flux 5. The speed at which the electronic component was raised from the flux bath 27 was varied within a range of 8 mm / s to 80 mm / s.

[0051] In Example 3, similarly to Example 2, the greater the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component, the more easily the flux 5 was applied to the external electrodes on both ends of the electronic component without the electronic component falling off into the flux tank 27. Furthermore, when the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component was 200 μm or greater, the flux 5 was able to be applied to the external electrodes on both ends of the electronic component.

[0052] Example 4 Figure 7 shows the evaluation results when applying flux to electronic components of the second component size. The thickness t of the flux in the flux tank 27 was set to a value obtained by adding 50 μm to the height h from the bottom of the flux tank 27 to the underside of the electronic component (h + 50 μm). In other words, the electronic component of the second component size was immersed to a depth of 50 μm from the liquid surface of the flux 5. The speed at which the electronic component was raised from the flux tank 27 was varied within a range of 8 mm / s to 80 mm / s.

[0053] In Example 4, similarly to Example 2, the greater the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component, the more easily the flux 5 was applied to the external electrodes on both ends of the electronic component without the electronic component falling off into the flux tank 27. Furthermore, when the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component was 200 μm or greater, the flux 5 was able to be applied to the external electrodes on both ends of the electronic component.

[0054] Thus, in the range where the height h from the bottom surface of the flux tank 27 to the bottom surface of the electronic component is 200 μm or more, by immersing the electronic components of the first component size, the second component size, and the third component size in the flux tank 27 respectively, the flux 5 can be applied to the external electrodes at both ends of the electronic component.

[0055] From the above evaluation results, when the volume of the electronic component immersed in the flux tank 27 is V1 and the volume of the flux 5 in the region sandwiched between the bottom surface of the flux tank 27 and the bottom surface of the electronic component is V2, it was confirmed that the electronic component does not fall off the flux tank 27 when the condition 4V1 < V2 is satisfied. Here, when V1 and V2 are obtained with the area of the bottom surface of the electronic component as A, V1 = A×(t - h) and V2 = A×h. Therefore, when 4V1 < V2 is expanded, the relationship 4t / 5 < h can be derived. Also, in order to apply the flux 5 to the electronic component, the condition h < t must be satisfied. From the above, the relationship 4t / 5 < h < t was derived as the condition for applying the flux 5 to the external electrodes at both ends of the electronic component.

[0056] According to this embodiment, the electronic component is immersed in the flux tank 2,7 until the height from the bottom surface of the flux tank 27 to the bottom surface of the electronic component reaches the set value (height h) corresponding to the thickness t of the flux 5 in the flux tank 27, and then the electronic component is pulled up from the flux tank 27. Thereby, the flux 5 can be surely applied to the external electrodes of the electronic component.

[0057] Furthermore, since the flux application method according to this embodiment applies flux 5 to the external electrodes of electronic components by immersing the electronic components in flux bath 27, a flux dispenser is not required for the mounting line. This makes it possible to build a mounting line at low cost for mounting multiple electronic components on printed wiring board 10. Specifically, for example, when stacking electronic components in two layers on printed wiring board 10, a conventional mounting line requires at least a mounter for mounting the electronic components in the first layer, a dispenser for supplying conductive connecting material to the electrodes of the electronic components in the first layer, and a mounter for mounting the electronic components in the second layer. In other words, two mounters and one dispenser are required to stack electronic components in two layers. Furthermore, when stacking electronic components in three layers, three mounters and two dispensers are required, since a dispenser for supplying conductive connecting material to the electrodes of the electronic components in the second layer and a mounter for mounting the electronic components in the third layer are added. In other words, equipment corresponding to the number of layers is required. In contrast, according to this embodiment, a dispenser is not required, and therefore a significant cost reduction can be expected.

[0058] In this embodiment, the thickness of the flux 5 in the flux tank 27 is set to a predetermined thickness t, and the electronic component is immersed in the flux tank 27 until the height from the bottom surface of the electronic component reaches a set value (height h) corresponding to the thickness t. Therefore, even if the viscosity of the flux 5 varies depending on the lot, the flux 5 can be reliably applied to the external electrodes of the electronic component.

[0059] Furthermore, it is also possible to control the amount of flux 5 supplied to the electronic components by appropriately changing the depth to which the electronic components are immersed and the speed at which they are lowered in the flux 5. For example, if the viscosity of the flux 5 is high, adjustments can be easily made, such as reducing the depth to which the electronic components are immersed in the flux 5 and reducing the amount supplied.

[0060] [Second embodiment] In the second embodiment, an apparatus for applying flux to external electrodes on both ends of an electronic component will be described, in order to automatically realize the method described in the first embodiment.

[0061] 8A and 8B are diagrams illustrating the structure of an electronic component mounter 20 according to this embodiment. As shown in Fig. 8A(a), the electronic component mounter 20 includes a head 21, a head holding member 22, an XY-axis direction moving mechanism 23, a Z-axis direction moving mechanism 24, a suction nozzle 25, a bottom surface detection unit 26, and a flux tank 27. Note that the left-right direction in the figure is the XY-axis direction, and the up-down direction is the Z-axis direction.

[0062] The head 21 is connected to one end of a head holding member 22. An XY-axis direction moving mechanism 23 is connected to the other end of the head holding member 22. A Z-axis direction moving mechanism 24 is provided inside the head 21. The XY-axis direction moving mechanism 23 moves the head 21 held by the head holding member 22 in the X and Y axis directions. The Z-axis direction moving mechanism 24 moves a suction nozzle 25 attached to the tip of the shaft member in the Z axis direction (vertical direction). A bottom surface detecting unit 26 is provided in the head 21 and has the function of detecting the position of the bottom surface of the electronic component sucked and held by the suction nozzle 25. The bottom surface detecting unit 26 is, for example, a camera or a line laser.

[0063] The head 21 further includes a displacement sensor (not shown) or a load sensor (not shown). The displacement sensor (or load sensor) has the function of detecting that an electronic component has been mounted on the printed wiring board 10. A flux tank 27 is disposed below the head 21 and the suction nozzle 25. Flux 5 is poured into the flux tank 27 to a predetermined thickness t. The height from the bottom surface of the flux tank 27 to the edge is assumed to be height H.

[0064] 8A(b) shows a state in which the tip of the suction nozzle 25 is brought into contact with the edge of the flux tank 27 by moving the head 21 above the edge of the flux tank 27 using the XY-axis movement mechanism 23 and the Z-axis movement mechanism 24. In this way, the electronic component mounter 20 detects the position of the edge of the flux tank 27. The value of the height H from the bottom surface of the flux tank 27 to the edge can be acquired from processing drawings of the flux tank 27, facility information, etc., that are stored in advance in a storage device (not shown) of the electronic component mounter 20. Therefore, by detecting the position of the edge of the flux tank 27, the electronic component mounter 20 can determine the position of the bottom surface of the flux tank 27.

[0065] FIG. 8A(c) shows a state in which electronic component 100 is sucked by suction nozzle 25. The electrode portion of electronic component 100 includes outer electrode 111, which is a first electrode, and outer electrode 112, which is a second electrode. In addition, non-electrode portion 113 is provided between outer electrode 111 and outer electrode 112. Bottom surface detection unit 26 detects the position of the bottom surface of electronic component 100 sucked and held by suction nozzle 25. Bottom surface detection unit 26 is an optical device such as a camera or line laser, and optically detects the position of electronic component 100. It is preferable to select a sensor as bottom surface detection unit 26 that can detect the position of the bottom surface of electronic component 100 with high accuracy.

[0066] 8A(b) and 8A(c), the electronic component mounter 20 grasps the positions of the bottom surface of the flux bath 27 and the bottom surface of the electronic component 100. Furthermore, the thickness t of the flux 5 in the flux bath 27 is set before production begins and is a known value. Therefore, the electronic component mounter 20 can immerse the electronic component 100 so that the height from the bottom surface of the flux bath 27 to the bottom surface of the electronic component 100 is a predetermined height h (set value). However, in order to apply the flux 5 to the external electrodes on both ends of the electronic component 100, it is also necessary that t>h. In other words, the bottom surface of the electronic component 100 is spaced apart from the bottom surface of the flux bath 27.

[0067] Fig. 8B(d) shows a state in which electronic component 100 is immersed until the height from the bottom surface of flux tank 27 to the lower surface of the electronic component reaches a set value (height h). Fig. 8B(e) shows a state in which electronic component 100 is raised from flux tank 27 from the state in Fig. 8B(d) so that flux 5 is applied to the lower surface side of electronic component 100.

[0068] 9 is a flowchart showing an example of the operation of the electronic component mounter 20 according to this embodiment. This process is executed by a computer (not shown) that functions as a control unit in the electronic component mounter 20.

[0069] First, the value of the thickness t of the flux 5 to be poured into the flux tank 27 is set based on an external input operation (S101). That is, the thickness of the flux in the flux tank 27 is instructed to be a predetermined thickness t before the start of production. Once the setting is complete, the flux 5 is poured into the flux tank 27. In this way, the in-tank flux held in the flux tank 27 is prepared. Note that if the flux 5 has already been poured into the flux tank 27, the value of the thickness t of the flux 5 can be obtained from the computer.

[0070] Next, the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component 100 (passive component) is specified based on an external input operation (S102). The specified information on the height h is stored in the storage device of the computer.

[0071] Next, the position of the edge of the flux tank 27 is detected by moving the suction nozzle 25 to above the edge of the flux tank 27 using the XY-axis direction moving mechanism 23 and the Z-axis direction moving mechanism 24 (S103). The position information of the edge is stored in the storage device of the computer.

[0072] Next, the position of the bottom surface of the flux tank 27 is calculated based on the position of the edge of the flux tank 27 and the size information of the flux tank 27 stored in advance in the storage device (S104).

[0073] Next, an electronic component 100 is prepared as an electronic component having an electrode portion and a non-electrode portion on its surface, and an suction nozzle 25 is moved onto the electronic component 100 by an XY-axis direction moving mechanism 23 and a Z-axis direction moving mechanism 24, and the electronic component 100 (a passive component) is suctioned by the suction nozzle 25 (S105).

[0074] Next, suction nozzle 25 is moved upward by Z-axis direction movement mechanism 24, and bottom surface detection unit 26 detects the position of the bottom surface of a passive component as electronic component 100 (S106). Information about the detected position of the bottom surface of electronic component 100 is stored in the storage device of the computer.

[0075] Next, the Z-axis direction moving mechanism 24 is controlled based on the thickness t of the flux 5 stored in the storage device, the predetermined height h, the position of the lower surface of the electronic component 100, and the position of the bottom surface of the flux bath 27, and the passive component as the electronic component 100 is immersed until the height from the bottom surface of the flux bath 27 to the lower surface of the electronic component 100 reaches the predetermined height h (set value) (S107). Note that the computer (controller) of the electronic component mounter 20 performs the step of applying the flux 5 to the electronic component 100 so that the electronic component 100 does not come into contact with the flux bath 27. Therefore, in this step, a portion of the first external electrode 111, a portion of the second external electrode 112, and a portion of the non-electrode portion 113 of the electronic component 100 are brought into contact with the flux in the bath.

[0076] Then, the Z-axis direction moving mechanism 24 moves the head 21 upward, thereby lifting the electronic component 100 (passive component) from the flux bath 27 (S108). By performing steps S107 and S108, a portion of the electrode portion and a portion of the non-electrode portion of the electronic component 100 are brought into contact with the flux in the bath, and then the flux adhering to the electronic component 100 is separated from the flux in the bath. This separation is achieved by increasing the distance between the flux bath 27 and the electronic component.

[0077] With such an apparatus configuration and operation, electronic component 100 does not fall off into flux bath 27, and flux can be applied to the external electrodes on both ends of electronic component 100 with a stable yield.

[0078] [Third embodiment] 10 is a diagram illustrating the structure of an electronic component mounter 20 according to this embodiment. As shown in FIG. 10, the electronic component mounter 20 according to this embodiment differs from the electronic component mounter 20 according to the second embodiment in that it further includes a liquid level detector 29 below the head 21.

[0079] The liquid level detection unit 29 has a function of detecting the liquid level of the flux 5 poured into the flux tank 27. A laser displacement meter capable of detecting the liquid level of the flux 5 in a non-contact manner is preferably used as the liquid level detection unit 29. While FIG. 10 shows an example of a laser displacement meter using the principle of triangulation, a laser displacement meter using the principle of confocal measurement may also be used. The liquid level detection unit 29 may also have a function of detecting the edge of the flux tank 27.

[0080] 11 is a flowchart showing an example of the operation of the electronic component mounter 20 according to this embodiment. This process is executed by a computer (not shown) installed in the electronic component mounter 20.

[0081] First, the value of the thickness t of the flux 5 to be poured into the flux tank 27 is set based on an external input operation (S201).

[0082] Next, the value of the thickness t of the flux 5 is stored in a storage device (not shown) of the computer (S202).

[0083] Next, the height h from the bottom surface of the flux tank 27 to the lower surface of the electronic component 100 (passive component) is specified based on an external input operation (S203). The input information on the specified height h is stored in the storage device of the computer.

[0084] Next, the suction nozzle 25 is moved onto the electronic component 100 by the XY-axis direction movement mechanism 23 and the Z-axis direction movement mechanism 24, and the electronic component 100 (passive component) is adsorbed by the suction nozzle 25 (S204).

[0085] Next, the suction nozzle 25 is moved upward by the Z-axis direction movement mechanism 24, and the position of the lower surface of the electronic component 100 is detected by the lower surface detection unit 26 (S205). The position information of the lower surface of the detected electronic component 100 is stored in the storage device of the computer.

[0086] Next, the liquid level detection unit 29 detects the position of the liquid level of the flux 5 in the flux tank 27 (S206). The position information of the liquid level of the flux in the detected tank is stored in the storage device of the computer.

[0087] Next, based on the thickness t, height h, position of the lower surface of the electronic component, and position of the liquid level of the flux 5 stored in the storage device, the Z-axis direction movement mechanism 24 is controlled to immerse the lower surface of the electronic component 100 (passive component) from the liquid level of the flux 5 to a position with a depth of (t - h) (S207). The immersion depth (t - h) is determined based on the thickness t, height h, position of the lower surface of the electronic component 100, and position of the liquid level of the flux 5.

[0088] The height h corresponds to the distance in the vertical direction between the electronic component 100 and the flux tank 27 when the relative speed in the vertical direction between the electronic component 100 and the flux tank​​​​​​​​​Here, the relative velocity between the electronic component and the flux tank 27 in the vertical direction when the distance between the electronic component and the bottom surface of the flux tank 27 becomes a predetermined distance D while the distance between the electronic component and the bottom surface of the flux tank 27 is being reduced is defined as S13. The predetermined distance D is typically the thickness t of the flux in the tank. However, the predetermined distance D may be greater or less than the thickness t. The predetermined distance D may be within 2 mm above the liquid surface. This is because stringing and liquid breakdown typically occur within 2 mm above the liquid surface. Furthermore, the relative velocity between the electronic component and the flux tank 27 in the vertical direction when the distance between the suction nozzle 25 and the bottom surface of the flux tank 27 becomes the predetermined distance D while the distance between the suction nozzle 25 and the bottom surface of the flux tank 27 is being increased is defined as S25. Here, the relative velocity S1 and the relative velocity S25 satisfy the relationship S13 > S25. The relative velocity S13 is preferably 1 mm / s or greater. Furthermore, it is preferable that the relative speed S25 is 100 mm / s or less. The relative speed S13 is, for example, equal to or less than the above-mentioned relative speed S3, and may be equal to, for example, the above-mentioned relative speed S1. The relative speed S25 is, for example, equal to or less than the above-mentioned relative speed S5, and may be approximately the same as, for example, the above-mentioned relative speed S2.

[0091] In this manner, the electronic component mounter 20 (controller) according to this embodiment controls the Z-axis direction movement mechanism 24 based on the position of the bottom surface of the flux bath 27 and the position of the liquid surface of the flux held in the flux bath 27 to apply flux to the electronic component. That is, the electronic component mounter 20 according to this embodiment specifies the thickness t of the flux 5 in the flux bath 27 and the height h from the bottom surface of the flux bath 27 to the bottom surface of the electronic component 100, and detects the position of the liquid surface of the flux bath 27. Based on this information, the electronic component mounter 20 controls the Z-axis direction movement mechanism 24 to immerse the bottom surface of the electronic component 100 to a desired depth (th), thereby applying flux 5 to the external electrodes on both ends of the electronic component 100. Furthermore, the electronic component mounter 20 (controller) controls the Z-axis direction movement mechanism 24 so that the electronic component 100, which is sucked and held by the suction nozzle, does not come into contact with the flux bath 27. This prevents the electronic component from falling off the suction nozzle and remaining in the flux in the tank when the electronic component is moved vertically.

[0092] [Modified embodiment] The present disclosure is not limited to the above-described embodiments and various modifications are possible. For example, an example in which part of the configuration of one embodiment is added to another embodiment, or an example in which part of the configuration of another embodiment is replaced with another embodiment, is also an embodiment of the present disclosure.

[0093] Although the above-described embodiments have described methods for applying flux 5 to the external electrodes of electronic components, the flux application method of the present disclosure can be applied to any electronic component. For example, flux can be applied to active components such as diodes and transistors in a similar manner. Flux can also be applied to integrated circuit components in a similar manner. The electronic component may or may not be a semiconductor component.

[0094] In the above-described embodiments, the method of setting the thickness t of the flux 5 in the flux tank 27 has been described. However, the thickness t of the flux may be obtained by another method without setting the thickness t at the start of production. For example, the actual thickness of the flux 5 may be measured by a sensor, or thickness information of the flux 5 stored in a computer may be obtained.

[0095] In each of the above-described embodiments, the flux tank 27 is stationary, and the electronic components are moved up and down relative to the flux tank 27. However, the electronic components may be stationary, and the flux tank 27 may be moved up and down relative to the electronic components. That is, the electronic components and the flux tank 27 may move relatively. Furthermore, the configuration for applying flux to the electronic components is not limited to a configuration in which the electronic components and the flux tank 27 move relatively. Both the electronic components and the flux tank 27 may be stationary. In this case, the amount of flux in the flux tank 27 (in-tank flux) may be adjusted to change the liquid level, and the flux may be applied to the electronic components.

[0096] In the above-described embodiments, two electronic components (chip components) are stacked. However, it is not necessary to stack multiple electronic components. For example, flux 5 may be applied to electronic component 11 using the same application method as in the above-described embodiments, and this electronic component (first electronic component) 11 may be mounted directly on a wiring board. Alternatively, solder paste may be applied to the wiring board, and electronic component 11 to which flux 5 has been applied may be soldered using the solder paste. Furthermore, solder paste may be applied to the wiring board, electronic component 11 may be mounted on the solder paste, and electronic component (second electronic component) 12 with applied flux attached may be mounted on electronic component 11, and electronic component 12 may be soldered to electronic component 11 using solder paste. The attached flux attached to electronic component 12 adheres to electronic component 12.

[0097] The present disclosure includes the following configurations and methods. (Method 1) providing a flux held in a flux tank; providing an electronic component having an electrode portion and a non-electrode portion on a surface thereof; an applying step of bringing a part of the electrode portion and a part of the non-electrode portion into contact with the flux in the tank, and then separating the flux adhered to the electronic component from the flux in the tank; Equipped with The applying step is performed so that the electronic component does not come into contact with the flux bath. (Method 2) The separation is performed by increasing the distance between the flux bath and the electronic component. The method of application according to method 1, characterized in that (Method 3) the electrode portion includes a first electrode and a second electrode, and in the applying step, a portion of the first electrode, a portion of the second electrode, and a portion of the non-electrode portion are brought into contact with the flux in the vessel; 3. The method of applying according to method 1 or 2. (Method 4) In the applying step, a first region of a contact surface of the flux tank with the flux in the tank faces the electronic component in a vertical direction, and a second region of the contact surface of the flux tank with the flux in the tank faces a liquid surface of the flux in the tank in a vertical direction, When the minimum value of the distance between the first region and the electronic component in the vertical direction is h and the distance between the second region and the liquid surface of the flux in the tank in the vertical direction is t, 4t / 5≦h <t Satisfy the relationship of 4. The method of applying described in any one of Methods 1 to 3. (Method 5) The distance from the second region to the liquid surface of the flux in the tank is 1000 μm or less. 5. The method of application according to method 4. (Method 6) The distance from the second region to the liquid surface of the flux in the tank is 100 μm or more. 6. The method of applying according to method 4 or 5. (Method 7) In the applying step, the minimum distance between the first region and the electronic component is 150 μm or more and 500 μm or less. 7. The method of applying according to any one of methods 4 to 6. (Method 8) a difference between a minimum distance between the first region and the electronic component and a distance between the second region and the liquid surface of the flux in the tank is 100 μm or less; 8. The method of applying according to any one of methods 4 to 7. (Method 9) When the distance between the electronic component and the flux bath is reduced, the relative speed between the electronic component and the flux bath when the electronic component starts to come into contact with the flux in the bath is defined as S1, and when the distance between the electronic component and the flux bath is increased, the relative speed of the electronic component with respect to the liquid surface of the flux in the bath when the applied flux applied to the electronic component starts to separate from the flux in the bath is defined as S2. S1>S2 Satisfy the relationship of 9. The method of applying described in any one of Methods 1 to 8. (Method 10) The S1 is 1 mm / s or more. 10. The method of claim 9, wherein (Method 11) The S2 is 100 mm / s or less. 11. The method of applying according to Method 9 or 10. (Method 12) detecting the position of the electronic component using an optical device; 12. The method of any one of methods 1 to 11, further comprising: (Method 13) The viscosity of the flux in the tank is 10 Pa·sec or more and 50 Pa·sec or less. 13. The method of applying according to any one of methods 1 to 12. (Method 14) The electronic component is a passive component. 14. The method of applying according to any one of methods 1 to 13. (Method 15) The electronic component is a chip capacitor. 15. The method of applying according to any one of methods 1 to 14. (Method 16) Mounting a first electronic component to which flux has been applied using any one of the methods 1 to 15 on a wiring board; A method for manufacturing a circuit board, comprising: (Method 17) applying a solder paste onto the wiring board; soldering the first electronic component using the solder paste; 17. The method for producing a circuit board according to method 16, comprising: (Method 18) Mounting a second electronic component on the solder paste; Mounting the first electronic component on the second electronic component; Including, soldering the first electronic component to the second electronic component using the solder paste; 18. The method for producing a circuit board according to method 17. (Method 19) The flux adhered to the first electronic component adheres to the second electronic component. 19. The method for producing a circuit board according to method 18. (Configuration 20) a flux tank for holding flux; a suction nozzle for suctioning an electronic component; a moving mechanism that moves the suction nozzle and the flux tank relative to each other in a vertical direction; a control unit that controls the movement mechanism; Equipped with the control unit controls the movement mechanism based on the position of a bottom surface of the flux bath and the position of a liquid surface of the flux held in the flux bath, thereby applying the flux to the electronic components. (Configuration 21) a bottom surface detection unit for detecting the position of the bottom surface of the electronic component; the control unit controls the movement mechanism based on the position of the lower surface of the electronic component to apply the flux to the electronic component. 21. The electronic component mounter according to configuration 20. (Configuration 22) When the relative velocity between the electronic component and the flux tank in the vertical direction becomes zero, the distance between the electronic component and the flux tank in the vertical direction is defined as h, and the distance between the bottom surface and the liquid surface is defined as t, 4t / 5≦h <t Satisfy the relationship of 22. The electronic component mounter according to configuration 20 or 21. (Configuration 23) When the relative speed in the vertical direction between the electronic component and the flux tank when the distance between the electronic component and the flux tank reaches a predetermined distance while the distance between the electronic component and the bottom surface is reduced is S13, and the relative speed in the vertical direction between the electronic component and the flux tank when the distance between the suction nozzle and the bottom surface is increased is S25, S13>S25 Satisfy the relationship of 23. The electronic component mounter according to any one of configurations 20 to 22. (Configuration 24) The S13 is 1 mm / s or more, The S25 is 100 mm / s or less. 24. The electronic component mounter according to configuration 23. (Configuration 25) a liquid level detector for detecting the position of the liquid level of the flux; 25. The electronic component mounter according to any one of configurations 20 to 24. (Configuration 26) The liquid level detection unit is a laser displacement meter. 26. The electronic component mounter according to configuration 25. (Configuration 27) The lower surface detection unit is a camera or a line laser. 22. The electronic component mounter according to configuration 21. (Configuration 28) the control unit controls the moving mechanism so that the electronic component does not come into contact with the flux bath. 28. The electronic component mounter according to any one of configurations 20 to 27. [Explanation of symbols]

[0098] 1...Electronic circuit 2...Squeegee 3...Metal mask 4...Solder paste 5...Flux 6...Solder 10...Printed wiring board 11...Electronic components 12...Electronic components 13...Semiconductor device 14...1st wiring 15…Second wiring 16…Power terminal 17...Ground terminal 20...Electronic component mounting machine 21...Head 22...Head holding member 23…XY-axis direction movement mechanism 24…Z-axis direction movement mechanism 25...Suction nozzle 26...Bottom detection unit 27...Flux tank 29...Liquid level detector 100...Electronic components 111,112...First external electrode 121,122…Second external electrode

Claims

1. providing a flux held in a flux tank; providing an electronic component having an electrode portion and a non-electrode portion on a surface thereof; an applying step of bringing a part of the electrode portion and a part of the non-electrode portion into contact with the flux in the tank, and then separating the flux adhered to the electronic component from the flux in the tank; Equipped with The applying step is performed so that the electronic component does not come into contact with the flux bath.

2. The separation is performed by increasing the distance between the flux bath and the electronic component. The method of claim 1 .

3. the electrode portion includes a first electrode and a second electrode, and in the applying step, a portion of the first electrode, a portion of the second electrode, and a portion of the non-electrode portion are brought into contact with the flux in the tank; The method of claim 1 .

4. In the applying step, a first region of a contact surface of the flux tank with the flux in the tank faces the electronic component in a vertical direction, and a second region of the contact surface of the flux tank with the flux in the tank faces a liquid surface of the flux in the tank in a vertical direction, When a minimum value of the distance between the first region and the electronic component in the vertical direction is h and a distance between the second region and the liquid surface of the flux in the tank in the vertical direction is t, 4t / 5≦h<t Satisfy the relationship of The method of claim 1 .

5. a distance from the second region to the liquid surface of the flux in the tank is 1000 μm or less; 5. The method of claim 4.

6. a distance from the second region to the liquid surface of the flux in the tank is 100 μm or more; 6. The method of claim 5.

7. In the applying step, a minimum value of the distance between the first region and the electronic component is 150 μm or more and 500 μm or less.

5. The method of claim 4.

8. a difference between a minimum distance between the first region and the electronic component and a distance between the second region and the liquid surface of the flux in the tank is 100 μm or less; 5. The method of claim 4.

9. When the distance between the electronic component and the flux tank is reduced, a relative speed between the electronic component and the flux tank when the electronic component starts to come into contact with the flux in the tank is defined as S1, and when the distance between the electronic component and the flux tank is increased, a relative speed between the electronic component and the liquid surface of the flux in the tank when the applied flux applied to the electronic component starts to separate from the flux in the tank is defined as S2. S1>S2 Satisfy the relationship of The method of claim 1 .

10. The S1 is 1 mm / s or more.

10. The method of claim 9.

11. The S2 is 100 mm / s or less.

10. The method of claim 9.

12. detecting the position of the electronic component using an optical device; 2. The method of claim 1, further comprising:

13. The viscosity of the flux in the tank is 10 Pa sec or more and 50 Pa sec or less. The method of claim 1 .

14. The electronic component is a passive component. The method of claim 1 .

15. The electronic component is a chip capacitor. The method of claim 1 .

16. a first electronic component to which flux has been applied using the application method of claim 1, the first electronic component being mounted on a wiring board; A method for manufacturing a circuit board, comprising:

17. applying a solder paste onto the wiring board; soldering the first electronic component using the solder paste; 17. The method of claim 16, further comprising:

18. Mounting a second electronic component on the solder paste; Mounting the first electronic component on the second electronic component; Including, soldering the first electronic component to the second electronic component using the solder paste; 18. The method of claim 17, wherein the circuit board is made of a polyimide.

19. the deposited flux attached to the first electronic component is then deposited on the second electronic component; 20. The method of claim 18, wherein the circuit board is made of a polyimide.

20. a flux tank for holding flux; a suction nozzle for suctioning an electronic component; a moving mechanism that moves the suction nozzle and the flux tank relative to each other in a vertical direction; a control unit that controls the movement mechanism; Equipped with the control unit controls the movement mechanism based on the position of a bottom surface of the flux bath and the position of a liquid surface of the flux held in the flux bath, thereby applying the flux to the electronic components.

21. a bottom surface detection unit for detecting the position of the bottom surface of the electronic component; the control unit controls the movement mechanism based on the position of the lower surface of the electronic component to apply the flux to the electronic component.

21. The electronic component mounting machine according to claim 20.

22. When the relative velocity between the electronic component and the flux tank in the vertical direction becomes zero, the distance between the electronic component and the flux tank in the vertical direction is defined as h, and the distance between the bottom surface and the liquid surface is defined as t, 4t / 5≦h<t Satisfy the relationship of 22. The electronic component mounting machine according to claim 20 or 21.

23. When the relative speed in the vertical direction between the electronic component and the flux tank when the distance between the electronic component and the flux tank reaches a predetermined distance while the distance between the electronic component and the bottom surface is reduced is S13, and the relative speed in the vertical direction between the electronic component and the flux tank when the distance between the suction nozzle and the bottom surface is increased is S25, S13>S25 Satisfy the relationship of 21. The electronic component mounting machine according to claim 20.

24. The S13 is 1 mm / s or more, The S25 is 100 mm / s or less.

24. The electronic component mounting machine according to claim 23.

25. a liquid level detector for detecting the position of the liquid level of the flux; 21. The electronic component mounting machine according to claim 20.

26. The liquid level detection unit is a laser displacement meter.

26. The electronic component mounting machine according to claim 25.

27. The lower surface detection unit is a camera or a line laser.

22. The electronic component mounting machine according to claim 21.

28. the control unit controls the moving mechanism so that the electronic component does not come into contact with the flux bath.

21. The electronic component mounting machine according to claim 20.

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