JP5126887B2 - Flow soldering mask and flow soldering method - Google Patents

Description

  The present invention relates to a flow soldering mask and a flow soldering method, and more particularly to a flow soldering mask and a flow soldering method used when an electronic component is soldered by an automatic soldering apparatus.

  The flow soldering mask used in the flow soldering process for printed wiring boards in which the part to be soldered for surface mounting parts and the part to be soldered for insertion mounting parts coexist on the same surface is the solder for the printed wiring board. It has a size that covers the entire surface to be soldered, and has a structure in which a portion to be flow soldered is selectively opened. As such a technique, there is a solder dip mask disclosed in Japanese Patent No. 2872715 (Patent Document 1). A solder dip mask according to Patent Document 1 is a frame body made of a heat-resistant material, a window portion on which a printed wiring board to be soldered to the flow formed on the frame body is installed, and a print attached to the window portion. Heat resistance that has a recess in which an electronic component protruding on the surface to be soldered of a wiring board is embedded, and that has an opening that covers the surface to be soldered and selectively exposes the portion to be soldered And a thin plate made of material. This dip mask is characterized in that it is in close contact with the surface to be soldered in the printed wiring board and selectively covers the surface to be soldered.

According to Patent Document 1, an unnecessary portion of the surface to be soldered on the printed wiring board is covered, and a portion to be soldered is selectively exposed from the opening. For this reason, it is disclosed that the electronic component in the opening can be flow soldered.
Japanese Patent No. 2872715

  However, in the method using the dip mask of Patent Document 1, since the opening is larger than the part to be soldered in the printed wiring board, the flux is applied to the part other than the part to be soldered and soldering is performed. . For this reason, impurities such as excessive flux, a large amount of residue, solder dross called dross float on the liquid surface of the molten solder, and flow into the opening of the dip mask together with the molten solder and adhere to the printed circuit board. End up. When such impurities adhere to the soldered part of the printed wiring board, the impurities adhere to areas other than the part to be soldered between the surface mounting component and the insertion mounting component, thereby causing a short circuit between the electronic components and between the electronic components and the leads. There was a problem that occurred. Further, when impurities adhere to the printed wiring board, there is a problem that the appearance of the printed wiring board becomes poor.

  An object of the present invention is to provide a flow soldering mask and a flow soldering method that suppress short-circuiting due to adhesion of impurities and suppress appearance defects.

  The flow soldering mask of the present invention is a flow soldering mask for performing flow soldering on a substrate surface, and includes a main body portion and an impurity trapping portion. The main body portion has first and second surfaces, covers the substrate with the first surface and the substrate facing each other, and exposes a portion to be soldered on the substrate from the first surface to the second surface. An opening penetrating the surface is formed. The impurity trapping part includes at least one of a concave part and a convex part provided close to the opening part on the second surface. The recess has a wall surface which is a part of the recess and has an acute angle or a right angle with the second surface on the side close to the opening. The convex part is a part of the convex part, and has a wall surface with an acute angle formed with the second surface on the side opposite to the side close to the opening.

  The flow soldering mask of the present invention can be used for flow soldering in a state in which a portion to be soldered is exposed and a portion other than the portion to be soldered is covered. Impurities such as excess flux, flux residue, and soldering iron have a lighter specific gravity than molten solder, so that the impurities float in the molten solder liquid. When the flow soldering mask is transported so that the impurity trapping portion is located upstream of the opening in the transport direction of the substrate, impurities are trapped on the side walls of the recesses and the side walls of the protrusions. For this reason, since it can suppress that an impurity flows into an opening part from an impurity capture part, the part to be soldered of the board | substrate exposed from the opening part can be soldered using the solder which suppressed the contained impurity. . Therefore, since it can suppress that an impurity adheres to a board | substrate, while being able to suppress the short circuit by an impurity adhering to a board | substrate, it can suppress that a board | substrate becomes the appearance defect.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic diagram showing a flow soldering mask according to the present embodiment. As shown in FIG. 1, the flow soldering mask 1a in the present embodiment is a flow soldering mask for performing flow soldering on the surface of a substrate 50 (see FIG. 6). The main body part 10 having the surfaces 11 and 12 and the impurity trapping part 20 including at least one of the concave part 30 and the convex part 40 are provided. The impurity trap 20 is provided near the opening 13 in the second surface 12.

  The main body 10 covers the substrate 50 with the first surface 11 and the substrate 50 facing each other. In order to hold the substrate 50 in a covered state, the end portion of the main body portion 10 is bent so that the first surface 11 is located on the inner periphery.

  The main body 10 is formed with an opening 13 that penetrates from the first surface 11 to the second surface 12 in order to expose a portion to be soldered in the substrate 50. The first surface 11 and the second surface 12 are positioned so as to face each other. For example, the opening 13 has a tapered shape in which a region opening from the first surface 11 toward the second surface 12 increases.

  The area of the opening 13 is not particularly limited, and covers the mounting component 51 mounted on the surface of the substrate 50 so that only the electrode pattern 55 of the substrate 50 is selectively soldered in the opening 13. If there is no problem, the larger the better.

  On the first surface 11 of the main body 10, an opening 11 a for covering the mounting component 51 already mounted on the surface of the substrate 50 is formed. The opening 11 a has substantially the same depth as the thickness of the mounting component 51.

  The thermal conductivity of the material constituting the main body 10, the heat resistance temperature of the parts to be soldered on the substrate 50 (in this embodiment, the mounting component 52 and the lead 54), the temperature of the molten solder that is contacted when transported, the molten solder It is preferable to appropriately determine the material and thickness H of the main body 10 depending on the contact time between the solder and the flow soldering mask. The flow soldering mask 1a is preferably not deformed during flow soldering, and the thickness H is preferably 6 mm or less, and the material is preferably ABS resin, for example. In addition, the material which comprises the main-body part 10 is not specifically limited to resin, For example, metal materials, such as aluminum and stainless steel, and inorganic materials, such as ceramics, may be sufficient. The thickness H of the main body 10 is the distance between the first surface 11 and the second surface 12 in the portion where the opening 13 is formed. The upper limit of the thickness H is, for example, a thickness that can protect the mounting component 51 formed on the substrate 50, and a thickness that does not hinder the conveyance of the flow soldering mask 1a by the flow soldering apparatus.

  The impurity trap 20 is formed on the second surface 12 and is disposed around the opening 13. The impurity capturing unit 20 includes at least one of the concave portion 30 and the convex portion 40.

  FIG. 2 is a schematic cross-sectional view schematically showing a concave portion in the present embodiment. As shown in FIG. 2, the recess 30 is a part of the recess 30 and has a side wall 31 as a wall surface on the side close to the opening 13. The side wall 31 extends from the second surface 12 toward the first surface 11 and is positioned on the side close to the opening 13. An angle θ30 formed by the side wall 31 and the second surface 12 is an acute angle or a right angle. In other words, when flow soldering is performed using the flow soldering mask 1a, the angle formed between the conveyance direction of the flow soldering mask 1a and the side wall 31 is the same as the substrate conveyance direction in a sectional view (see FIG. Acute or right-angled (in cross section). The recess 30 is groove-shaped and does not penetrate from the second surface 12 constituting the recess 30 to the first surface 11.

  FIG. 3 is a schematic cross-sectional view schematically showing another concave portion in the present embodiment. The recess 30 further has a side wall 32 on the side opposite to the side close to the opening 13. The side wall 32 extends from the second surface 12 toward the first surface 11 and is located on the side far from the opening 13. The angle formed by the side wall 32 and the second surface may be an obtuse angle as shown in FIG. 2, an acute angle as shown in FIG. 3, or a right angle.

  Recess 30 has, for example, a depth H30 of 0.5 mm or more and a width W30 of 2 mm or more. In the present embodiment, for example, the depth H30 of the recessed portion 30 is 3 mm, and the width W30 of the recessed portion 30 is approximately 3 mm.

  Here, the depth H of the concave portion 30 is the largest of the second surface 12 and the side wall 32 on the side of the opening 13 extending from the second surface 12 in the concave portion 30 (the wall surface on the side close to the opening 13). It is a big distance.

  The thickness of impurities such as flux residue and dross floating on the molten solder surface in the solder bath of the flow soldering apparatus is generally about 0.5 mm, and the width is generally about 2 mm. For this reason, by making the depth H and the width W30 of the concave portion 30 as described above, impurities can be selectively invaded into the concave portion 30 and captured.

  In addition, the recessed part 30 will not be specifically limited if it is a magnitude | size which can capture | acquire an impurity. From the viewpoint of selectively trapping the impurities into the recesses 30 and effectively capturing them, the depth H and the width W30 of the recesses 30 are preferably greater than or equal to the size of the impurities. Further, the cross-sectional shape of the recess 30 is not limited to a square. For example, the closer to the opening 13 (toward the rear in the transport direction of the substrate 50), the depth H30 becomes larger, and the bottom surface of the recess 30 is increased. An angle may be added to the. Moreover, the connection part of the bottom face of the recessed part 30 and the side walls 31 and 32 may have an angular shape, or may have a rounded shape.

  Such a recess 30 is formed by cutting, for example. Further, the bottom of the recess 30 may be smooth as shown in FIG. 3, or the notch 12 may be provided in the bottom of the recess 30 as shown in FIGS. It is preferable that the notch 12 has an uneven shape that can prevent impurities from flowing into the opening 13.

  FIG. 4 is a schematic cross-sectional view schematically showing a convex portion in the present embodiment. As shown in FIG. 4, the convex portion 40 is a part of the convex portion 40 and has a side wall 42 as a wall surface on the side opposite to the side close to the opening portion 13. The side wall 42 extends so as to protrude from the second surface 12, and is located on the side far from the opening 13. An angle θ40 formed by the side wall 42 and the second surface 12 is an acute angle. In other words, when performing flow soldering using the flow soldering mask 1a, the angle formed between the conveyance direction of the flow soldering mask 1a and the side wall 42 is an acute angle in a cross-sectional view. The convex portion 40 has a bank shape.

  The convex part 40 has a side wall 41 on the side close to the opening part 13. The side wall 41 extends so as to protrude from the second surface and is located on the side close to the opening 13. The angle formed by the side wall 41 and the second surface 12 may be a right angle in a cross-sectional view as shown in FIG. 4, or may be an acute angle or an obtuse angle.

  The convex part 40 has, for example, a height H40 of 0.5 mm or more and 6 mm or less and a width W40 of 2 mm or more. In the present embodiment, for example, the height H40 of the convex portion 40 is 3 mm, the width W40 of the convex portion 40 is 3 mm, and the depth D40 of the convex portion 40 is 3 mm.

  Here, the height H of the convex portion 40 refers to the side wall 41 opposite to the opening 13 extending from the second surface 12 in the convex portion 40 (the wall surface on the opposite side to the side close to the opening 13). , The largest distance from the second surface 12.

  The thickness of impurities such as flux residue and dross floating on the molten solder surface in the solder bath of the flow soldering apparatus is generally about 0.5 mm as described above, and the width is generally about 2 mm. It is. For this reason, it can suppress that an impurity is captured by the convex part 40 and flows into the opening part 13.

  In addition, when the flow soldering mask 1a is used in a flow soldering apparatus, the distance between the member for jetting solder (in this embodiment, the solder jet nozzle 14 in FIG. 6) and the second surface 12 is as follows. Since it is generally about 6 mm, the height H40 of the convex portion 40 is preferably 6 mm or less.

  From the viewpoint of preventing the flux applied to the surface of the convex portion 40 that contacts the solder from flowing into the opening portion 13, the width W40 of the convex portion 40 is preferably as small as possible. In addition, from the viewpoint of suppressing the flow of impurities into the opening 13, the depth D 40 of the protrusion 40 is preferably large enough to block the front of the opening 13.

  In addition, if the convex part 40 is a magnitude | size which can capture | acquire an impurity, it will not specifically limit to these. From the viewpoint of selectively capturing the impurities by selectively intruding into the convex portions 40, the depth H and the width W30 of the convex portions 40 are preferably equal to or larger than the size of the impurities. In addition, the cross-sectional shape of the convex portion 40 is not particularly limited to a substantially square shape. For example, the closer to the opening portion 13 (toward the back of the transport direction of the substrate 50), the height 41 of the convex portion 40 is the convex portion. An angle may be given toward the tip of 40. Moreover, the connection part of the front-end | tip of the convex part 40 and the side walls 41 and 42 may be a square shape, and the shape which gave the roundness may be sufficient as it.

  Further, as the material of the convex portion 40, for example, an ABS resin, a metal material such as aluminum or stainless steel, an inorganic material such as ceramics, or the like can be used. The convex portion 40 may be the same material as the main body portion 10 or a different material. The convex portion 40 is preferably solid in order to capture impurities.

  Such a convex part 40 is formed, for example, by preparing the convex part 40 separately from the main body part 10 and screwing it at a predetermined position or by an adhesive. Moreover, you may form by cutting out from the plate-shaped material which comprises a main-body part at the time of preparation of the main-body part 10. FIG.

  FIG. 5 is a schematic cross-sectional view schematically showing another convex portion in the present embodiment. As shown in FIG. 5, the side wall 31 on the opening 13 side extending from the second surface 12 in the concave portion 30 and the side wall 42 on the opposite side to the opening 13 extending from the second surface 12 in the convex portion 40 are continuous. It is preferable.

  In addition, although the impurity capture | acquisition part 20 in this Embodiment contains both the recessed part 30 and the convex part 40, the impurity capture part 20 should just contain at least one of the recessed part 30 and the convex part 40. FIG.

  FIG. 6 is a schematic diagram showing flow soldering when the flow soldering mask according to the present embodiment is used. Next, a flow soldering method using the flow soldering mask 1a in the present embodiment will be described.

  First, the substrate 50 is prepared. As the substrate 50, for example, a printed wiring board can be used. As shown in FIG. 6, a mounting component 52 having leads 54 is formed on one surface of the substrate 50, and an electrode pattern 55 and a plurality of mounting components 51 already mounted are formed on the other surface. ing. A lead 54 of the mounting component 52 is inserted into a through hole 53 penetrating from one surface of the substrate 50 to the other surface. The mounting component 52 may be connected to the substrate 50 with a conductive adhesive or the like. In the present embodiment, the lead 54 and the electrode pattern 55 are soldered on the substrate 50.

  Next, the substrate 50 and the flow soldering mask 1a are overlapped so that the soldering portion of the substrate 50 is exposed from the opening 13 of the flow soldering mask 1a and the portion other than this portion of the substrate 50 is covered. Match.

  Specifically, the surface side of the substrate 50 on which the electrode pattern 55 is formed is placed on the first surface 11 of the flow soldering mask 1a. As a result, the lead 54 is inserted from the first surface 11 toward the second surface 12, and the tip of the lead 54 is disposed in the opening 13 that is a through hole for soldering. In addition, the mounting part 51 already mounted by soldering or the like is covered with the opening 11a formed in the first surface 11 of the flow soldering mask 1a.

  Next, in a state where the flow soldering mask 1a and the substrate 50 are overlapped, the solder 15 is transferred to a solder bath (in this embodiment, a solder jet nozzle 14) and exposed from the opening 13. Soldering board 50 is soldered. At this time, the impurity capturing unit 20 is located upstream of the opening 13 in the transport direction of the substrate 50. Moreover, the impurity capture | acquisition part 20 is located in the side which contacts the solder 15 in a flow soldering apparatus.

  Specifically, the flux is applied to the side in contact with the solder 15 in the flow soldering mask using, for example, a spray atomizing fluxer. Thereafter, the substrate 50 passes over the solder jet nozzle 14 in which the solder 15 is melted by using a conveyor means such as a belt conveyor, so that the lead 54 and the electrode pattern 55 in which the melted solder 15 is exposed from the opening portion 13. The electrode pattern 55 exposed from the opening 13 and the lead 54 are selectively soldered.

  At the time of this soldering, the flux 60 applied to the soldering side of the flow soldering mask, its residue, and impurities 60 such as dross generated when the solder spouts on the molten solder 15 liquid surface. Float. Since the impurity 60 has a lower specific gravity than the molten solder 15, the impurity 60 floats above the molten solder 15 and selectively flows into the impurity capturing unit 20 including at least one of the concave portion 30 and the convex portion 40. The impurity trap 20 prevents the impurity 60 from entering the recess 13 and the protrusion 40 and flowing into the opening 13.

  In FIG. 6, an arrow 61 indicates a normal flow direction in the solder 15 in which the impurity 60 is melted. In the present embodiment, the impurities 60 are prevented from being trapped by the impurity trapping portion 20 and flowing into the opening 13.

  As a result, the impurity 60 can be prevented from flowing into the opening 13, and the impurity 60 can be prevented from adhering to portions to be soldered such as the electrode pattern 55 and the lead 54 exposed from the opening 13. Therefore, the product (soldered substrate 50) obtained by this flow soldering method has a good appearance because the adhesion of the impurities 60 is suppressed, and other than the portion connecting the lead 54 and the electrode pattern 55. A short circuit due to the adhesion of the impurity 60 can be prevented.

  As described above, the flow soldering mask 1a in the present embodiment is a flow soldering mask for performing flow soldering on the surface of the substrate 50, and includes the main body portion 10 and the impurity trapping portion 20. I have. The main body 10 has first and second surfaces 11 and 12 for covering the substrate 50 with the first surface 11 and the substrate 50 facing each other, and for exposing a portion to be soldered on the substrate 50. In addition, an opening 13 penetrating from the first surface 11 to the second surface 12 is formed. The impurity trapping portion 20 includes at least one of a concave portion 30 and a convex portion 40 that are provided close to the opening portion 13 in the second surface 12. The concave portion 30 is a part of the concave portion 30 and has a wall surface (side wall 31) whose angle θ30 formed with the second surface 12 is an acute angle or a right angle on the side close to the opening portion 13. The convex portion 40 is a part of the convex portion 40 and has a wall surface (side wall 42) having an acute angle θ40 formed with the second surface 12 on the side opposite to the side close to the opening 13. ing.

  According to the flow soldering mask 1a in the present embodiment, the portion to be soldered (in this embodiment, the lead 54 and the electrode pattern 55) is exposed, and the flow is performed with the portion other than the portion to be soldered covered. It can be used in a soldering method and apparatus. Impurities 60 such as excess flux, flux residue, solder dregs and the like have lighter specific gravity than the melted solder 15, so that the impurities 60 float on the liquid surface of the solder 15. When the flow soldering mask 1a is transported with respect to the opening 13 of the flow soldering mask 1a so that the impurity capturing portion 20 is located upstream in the transport direction of the substrate 50, the side walls 31 and the convex portions of the recess 30 are formed. Impurities are trapped in the side walls 42 of 40. Even if the flow soldering mask 1a is transported, it is possible to suppress the impurities 60 trapped by the impurity trapping portion 20 from entering the opening portion 13 through the side walls 31 of the concave portions 30 and the side walls 42 of the convex portions 40. For this reason, the impurity 60 contained in the solder which solders the part to solder in the board | substrate 50 exposed from the opening part 13 can be reduced. Therefore, since it can suppress that the impurity 60 adheres to the part soldered in the board | substrate 50 exposed from the opening part 13, while suppressing the short circuit by the impurity 60 adhering, it can suppress that it becomes an external appearance defect. be able to.

  Furthermore, since it can suppress that the impurity 60 adheres to the part to which the board | substrate 50 is soldered, even if it is a case where the impurity 60 does not have favorable electroconductivity, soldering is carried out by the impurity 60 adhering. It is possible to suppress the occurrence of defective soldering such as occurrence of a portion that has not been performed.

  Furthermore, since it can suppress that the impurity 60 adheres to the part to solder, it can suppress that the insulation resistance between the mounting components 51 and 52 of the board | substrate, the lead | read | reed 54, and the electrode pattern 55 is reduced by a migration phenomenon.

  In the flow soldering mask 1a, the convex portion 40 preferably has a height H40 of 6 mm or less.

  When the flow soldering mask 1a is used in a flow soldering apparatus, the distance between the member (in this embodiment, the solder jet nozzle 14 in FIG. 6) for ejecting the solder 15 and the second surface 12 is generally 6 mm. Degree. For this reason, the versatility of the mask 1a for flow soldering can be improved by setting the height H40 of the convex part 40 to 6 mm or less.

  The flow soldering method according to the present embodiment is a flow soldering method for soldering the substrate 50 using the flow soldering mask 1a, and includes the following steps. First, the substrate 50 and the flow soldering mask 1a are overlapped so that the portion to be soldered of the substrate 50 is exposed from the opening 13 of the flow soldering mask 1a and the portion other than the portion of the substrate 50 is covered. Then, in a state where the flow soldering mask 1a and the substrate 50 are overlapped, the solder 15 is transferred to a solder bath disposed therein, and the substrate 50 exposed from the opening 13 is soldered. The impurity trap 20 is positioned upstream of the opening 13 in the transport direction of the substrate 50.

  According to the flow soldering method in the present embodiment, impurities 60 such as excess flux, flux residue, solder slag and the like have a lighter specific gravity than the melted solder 15, so that the openings 13 of the flow soldering mask 1 a are not filled. On the other hand, when the flow soldering mask 1a is transported so that the impurity capturing part 20 is located upstream in the transport direction of the substrate 50, the impurity capturing part 20 can capture the impurities 60. For this reason, even if the flow soldering mask 1 a covering the substrate 50 is transported, the impurities 60 trapped by the impurity trapping part 20 sink into the side wall 31 of the concave part 30 and the side wall 42 of the convex part 40 and enter the opening part 13. Inflow can be suppressed. As a result, the portion to be soldered in the substrate 50 exposed from the opening 13 can be soldered by the solder 15 in which the impurities 60 contained are suppressed. Therefore, it is possible to suppress a short circuit due to the adhesion of the impurity 60 and to suppress appearance defects.

(Embodiment 2)
FIG. 7 is a plan view schematically showing a flow soldering mask in the present embodiment. FIG. 7 is a diagram when viewed from the second surface 12 in a state where the substrate 50 is disposed on the flow soldering mask 1b in the present embodiment. With reference to FIG. 7, the flow soldering mask 1b in the present embodiment will be described. As shown in FIG. 7, the flow soldering mask 1b in the present embodiment has the same configuration as the flow soldering mask 1a in the first embodiment, but there are a plurality of portions to be soldered in the substrate 50. Yes, a plurality of openings 13 are formed, and convex portions 40a, 40b, 40c and a concave portion 30d constituting the impurity trapping portion are formed.

  The convex portions 40a, 40b, and 40c have a wall surface that has an acute angle with the second surface 12 on the side opposite to the side close to the openings 13a, 13b, and 13c.

  The convex part 40a is formed so as to surround the long side of the opening part 13a. The size of the opening 13a in plan view (when viewed from above) is, for example, a long side of 50 mm and a short side of 30 mm, and the size of the convex portion 40a in plan view is larger than that of the long side of the opening 13a. For example, the long side is 70 mm and the short side is 3 mm.

  Moreover, the convex part 40b is formed so that about 1/2 of the outer periphery of the opening part 13b may be enclosed. Moreover, the convex part 40c is formed so that it may extend in the direction which cross | intersects the direction where the long side of the opening part 13c extends.

  The concave portion 30d has a wall surface whose angle formed with the second surface 12 is an acute angle or a right angle on the side close to the opening portion 13d.

  Next, a flow soldering method using the flow soldering mask 1b will be described with reference to FIG.

  First, the substrate 50 is prepared. A plurality of portions to be soldered are formed on the substrate 50. Next, the substrate 50 and the flow soldering mask 1b are overlapped so that the portion to be soldered of the substrate 50 is exposed from the opening 13 of the flow soldering mask 1b and the portion other than this portion of the substrate 50 is covered. Match. Since a plurality of portions to be soldered are formed on the substrate 50, a plurality of openings 13 are formed in the flow soldering mask.

  Next, in a state where the flow soldering mask 1b and the substrate 50 are overlapped, the solder 15 is transferred to a solder bath disposed therein, and the substrate 50 exposed from the opening 13 is soldered. In this step, the flow soldering mask 1b shown in FIG. 7 is transported in the transport direction indicated by the arrow.

  When the flow soldering mask 1b is transported to the solder bath, the convex portions 40a, 40b, 40c and the concave portion 30d are positioned in front of the openings 13a, 13b, 13c, respectively, in the transport direction of the flow soldering mask 1b. ing. The convex portion 40b and the concave portion 30d are positioned so as to surround the front and side portions of the openings 13b and 13d in the transport direction of the flow soldering mask 1b. The convex portions 40a, 40b, 40c and the concave portion 30d may be strip-shaped or wave-shaped.

  Further, the convex portions 40a, 40b, 40c and the concave portion 30d of the flow soldering mask 1b are the widths of the openings 13a, 13b, 13c, 13d when the flow soldering mask is viewed from the upstream in the transport direction of the substrate 50. Has a larger width. In addition, it is preferable that the convex parts 40a, 40b, 40c and the concave part 30d have a shape that does not inhibit the molten solder 15 from flowing into the openings 13a, 13b, 13c, 13d.

  Moreover, like the convex part 40a, the normal line of the wall surface of the convex part 40a may have a direction parallel to the transport direction of the substrate 50 (the longitudinal direction of the convex part 40a and the transport direction are orthogonal to each other). . Further, like the convex portions 40b and 40c, the normal line of the wall surface of the convex portions 40b and 40c has a direction that is not parallel to the transport direction of the substrate 50 (the angle between the transport direction of the substrate 50 in plan view is an acute angle and It may include a portion formed so as to be at least one of an obtuse angle). Further, like the recess 30d, the recess 30d may include a portion extending in the same direction as the transport direction of the substrate 50 in plan view. In other words, the angle formed by the convex portions 40b and 40c and the concave portion 30d and the transport direction of the substrate 50 may not be a right angle in a plan view.

  The convex portions 40a, 40b, and 40c may be concave portions, or at least one of the upstream and downstream sides of the convex portions 40a, 40b, and 40c in the direction intersecting the transport direction, A recess may be further formed on the upstream side of the portions 13a, 13b, and 13c. The concave portion 30d may be a convex portion, or a convex portion is further formed on at least one of the upstream side and the downstream side of the concave portion 30d in the direction intersecting the transport direction and upstream of the opening portion 13d. Also good. A plurality of recesses and projections may be formed for one opening 13a, 13b, 13c, 13d.

  The distances between the convex portions 40a, 40b, 40c and the concave portion 30d and the openings 13a, 13b, 13c, 13d are, for example, 10 mm. The distance between the protrusions 40a, 40b, 40c and the recess 30d and the openings 13a, 13b, 13c, 13d is preferably as short as possible when solder flows into the openings 13a, 13b, 13c, 13d. As a result, the flux applied between the protrusions 40a, 40b, 40c and the recess 30d side tip and the protrusions 40a, 40b, 40c and the recess 30d in the openings 13a, 13b, 13c, and 13d is soldered. Sometimes it can be prevented from flowing into the openings 13a, 13b, 13c, 13d.

  As described above, in the flow soldering method according to the present embodiment, the flow soldering has a direction in which at least one normal line of the wall surface of the recess 30d and the wall surfaces of the protrusions 40b and 40c is not parallel to the conveyance direction of the substrate 50. Use an attachment mask.

  Thereby, the freedom degree of arrangement | positioning of the recessed part 30d and convex part 40a, 40b, 40c becomes high, and the impurity trap part 20 for trapping an impurity can be arrange | positioned efficiently. For this reason, the impurity which flows into opening part 13a, 13b, 13c, 13d can be suppressed.

  Further, in the flow soldering method according to the present embodiment, at least one of the convex portions 40a, 40b, 40c and the concave portion 30d of the flow soldering mask 1b is viewed from the upstream in the conveying direction of the substrate 50. The opening portions 13a, 13b, 13c and 13d have a width larger than that of the opening.

  Thereby, the impurities flowing into the openings 13a, 13b, 13c, and 13d can be effectively captured by the convex portions 40a, 40b, and 40c and the concave portion 30d. For this reason, the impurity which flows into opening part 13a, 13b, 13c, 13d can be suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

It is a schematic diagram which shows the mask for flow soldering in Embodiment 1 of this invention. It is a schematic sectional drawing which shows typically the recessed part in Embodiment 1 of this invention. It is a schematic sectional drawing which shows typically another recessed part in Embodiment 1 of this invention. It is a schematic sectional drawing which shows typically the convex part in Embodiment 1 of this invention. It is a schematic sectional drawing which shows typically another convex part in Embodiment 1 of this invention. It is a schematic diagram which shows the flow soldering at the time of using the flow soldering mask in Embodiment 1 of this invention. It is a top view which shows roughly the mask for flow soldering in Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b Flow soldering mask, 10 Main-body part, 11 1st surface, 11a, 13, 13a, 13b, 13c, 13d Opening part, 12 2nd surface, 14 Jet nozzle, 20 Impurity capture | acquisition part, 30, 30d Recess, 31, 32, 41, 42 Side wall, 40, 40a, 40b, 40c Protrusion, 50 Substrate, 51, 52 Mounted part, 53 Through hole, 54 Lead, 55 Electrode pattern, 60 Impurity, 61 Arrow, W30, W40 width, θ30, θ40 angle.

Claims (5)

A flow soldering mask for performing flow soldering on a substrate surface,
A first surface and a second surface, the first surface and the substrate facing each other to cover the substrate and to expose a portion to be soldered on the substrate from the first surface; A main body formed with an opening penetrating the second surface;
An impurity capturing part including a concave part and a convex part provided near the opening in the second surface;
The recess has a wall surface that is a part of the recess and has an acute angle or a right angle with the second surface on the side close to the opening.
The flow soldering mask, wherein the convex part has a wall surface that is a part of the convex part and has an acute angle with the second surface on the side opposite to the side close to the opening. .   The flow soldering mask according to claim 1, wherein the convex portion has a height of 6 mm or less. A flow soldering method for soldering the substrate using the flow soldering mask according to claim 1 or 2,
Superimposing the substrate and the flow soldering mask so as to expose a portion to be soldered of the substrate from the opening of the flow soldering mask and to cover the portion other than the portion of the substrate; ,
In a state where the flow soldering mask and the substrate are superposed, the solder is transferred to a solder bath disposed therein, and the substrate exposed from the opening is soldered.
The flow soldering method, wherein the impurity trapping portion is positioned upstream of the opening in the transport direction of the substrate.   The flow soldering method according to claim 3, wherein the flow soldering mask has a direction in which at least one of the wall surface of the concave portion and the wall surface of the convex portion is not parallel to the transport direction of the substrate. .   At least one of the convex portion and the concave portion of the flow soldering mask has a width larger than a width of the opening when the flow soldering mask is viewed from upstream in the transport direction of the substrate. Item 5. A soldering method according to item 3 or 4.

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