JP5195701B2 - Soldering method and soldering apparatus - Google Patents

Description

  The present invention relates to a soldering method and a soldering apparatus.

  In patent document 1, the mounting method of the flat member for adhere | attaching a flat member on the base material for mounting is disclosed. Specifically, as shown in FIG. 16, the mounting jig (mounting table) 100 for the flat plate member 103 includes two concave portions 101 and 102 for mounting the flat plate member 103 and the mounting base material 105. . The first recess 101 has an opening for mounting the mounting substrate 105 in a face-down posture. The second recess 102 opened at the bottom of the first recess 101 positions the flat plate member 103 in a face-down posture and the adhesive member 104 placed on the flat plate member 103 at the bonding position of the mounting substrate 105. The thickness of the adhesive member 104 at the time of mounting is deeper than the thickness of the opening for mounting and the flat plate member 103. Then, the flat plate member 103 is mounted in the second recess 102 in a face-down posture, the adhesive member 104 is mounted on the flat plate member 103, and the mounting substrate 105 is mounted on the first recess 101. Next, by heating the mounting jig 100 on which the mounting base material 105 and the flat plate member 103 are placed, the adhesive member 104 is melted, and the flat plate member 103 is bonded to the mounting base material 105.

JP 2006-93205 A

  However, it was not possible to cope with variations in the thickness dimension of the flat plate member 103. In order to cope with this, it is necessary to prepare a large number of mounting jigs (mounting tables) 100 having different depths for the second recess 102.

  On the other hand, it is conceivable to use the method shown in FIG. In FIG. 17A, the electronic component 112 and the solder 113 are placed on the recess 111 formed on the upper surface of the jig 110, and the substrate 114 is disposed on the upper surface of the jig 110 in a state where a gap AG is formed between the electronic device 112 and the solder 113. To do. When the solder 113 is melted by heating, as shown in FIG. 17B, the solder 113a comes into contact with the substrate 114 due to the aggregation of the solder 113a, and the surface tension of the solder 113a causes the solder 113a to show as shown in FIG. The electronic component 112 is lifted to solder the electronic component 112 to the lower surface 114 a of the substrate 114.

  However, since the dimensions of the positioning jig 110 for the electronic component 112 are fixed, if the dimensional tolerance of the electronic component 112 is large, it may not be possible to join well. This is because the dimension L10 of the gap between the solder 113 and the substrate 114 (see FIG. 17A) fluctuates, and thus the height of the solder 113a in which the dimension L10 of the gap between the solder 113 and the substrate 114 is melted. When it is larger than H (see FIG. 17B), there is a case where the lifting force does not work and soldering is not performed, or the gap dimension L10 is less than zero and the solder 113a protrudes due to the pressing state.

  In particular, other electronic components have a larger dimensional tolerance than the semiconductor element, and the dimensional tolerance of the thickness of the electronic component 112 is larger than the gap dimension L10. Therefore, soldering on the lower surface 114a of the substrate 114 becomes difficult.

  The present invention has been made under such a background, and an object thereof is a soldering method capable of reliably soldering a component to the lower surface of a base material without being affected by the thickness of the component, and It is to provide a soldering apparatus.

The invention according to claim 1 is a soldering method for soldering a component to the lower surface of a base material,
By lowering the solder before melting and the part by a specified amount with respect to the base material, which is controlled to move downward, from a state in which the solder before melting disposed on the upper surface of the part is in contact with the lower surface of the base material. A first step of separating the lower surface of the base material and the solder before melting by a specified amount; and by melting the solder, the solder is brought into contact with the lower surface of the base material by agglomeration of the solder. And a second step of lifting the component to the lower surface side of the substrate by surface tension.

  According to the first aspect of the present invention, in the first step, the solder before melting is applied to the base material whose downward movement is regulated from the state where the solder before melting disposed on the upper surface of the component is in contact with the lower surface of the base material. When the component is moved down by a specified amount, the lower surface of the base material and the solder before melting are separated by a specified amount. In the second step, by melting the solder, the solder is brought into contact with the lower surface of the base material due to the aggregation of the solder, and the component is lifted to the lower surface side of the base material by the surface tension of the melted solder.

  As a result, even if the thickness of the component varies, the solder before melting is separated from the lower surface of the base material by a specified amount, and the solder can be brought into contact with the lower surface of the base material by melting the solder. The component can be reliably soldered to the lower surface of the substrate without being affected by the thickness.

  The invention according to claim 2 is a soldering method in which a plurality of components are laminated and soldered on the lower surface of the base material, and the plurality of components are laminated such that the solder before melting is positioned on the components. The solder and the parts before melting with respect to the base material in which the downward movement is regulated from the state in which all the solder before melting and the parts located above the solder before melting and the lower surface of the base material are in contact with each other First step of separating at least one of the lower surface of the base material and the uppermost solder before melting, and the lower surface of the component and the solder immediately before melting by a predetermined amount, by lowering the base material by a predetermined amount; And a second step of lifting the component by the surface tension of the melted solder by bringing the solder into contact with at least one of the lower surface of the base material and the lower surface of the component by agglomerating the solder by melting the solder. Abstract

  According to the second aspect of the present invention, in the first step, a plurality of components are laminated and disposed so that the unmelted solder is positioned on the components, and all the unmelted solder is melted. When the solder and parts before melting are moved down by a specified amount from the state in which the parts located above the previous solder and the lower surface of the base material are in contact with the base material whose downward movement is regulated, At least one of the solder before melting of the uppermost layer and the lower surface of the component and the solder before melting immediately below is separated by a specified amount. In the second step, by melting the solder, the solder is brought into contact with at least one of the lower surface of the substrate and the lower surface of the component due to the aggregation of the solder, and the component is lifted by the surface tension of the molten solder.

  As a result, even if the thickness of the component varies, the solder before melting is between the lower surface of the base material and the solder before melting of the uppermost layer, and between the lower surface of the component and the solder before melting immediately below it. Since at least one of them is separated by a specified amount, the solder can be brought into contact with at least one of the lower surface of the substrate and the lower surface of the component by melting the solder, so that the lower surface of the substrate is not affected by the thickness of the component. The parts can be securely soldered to the solder.

According to a third aspect of the present invention, in the soldering method according to the first or second aspect, the parts may be simultaneously soldered to the lower surface and the upper surface of the base material.
The invention according to claim 4 is a soldering apparatus for soldering a component to a lower surface of a base material, wherein a concave portion in which the component is disposed is formed on an upper surface on which the base material is mounted, and A pedestal having a through-hole extending vertically on the bottom surface of the recess, a cylindrical member that slides through the through-hole of the pedestal, and slides in the cylindrical member, with the upper end protruding from the upper end of the cylindrical member by a specified amount In this state, the part disposed in the recess and the solder for melting the solder before being pushed up to bring the solder before melting into contact with the lower surface of the base material, and the upper end of the rod as the upper end of the cylindrical member The cylindrical member is fixed to the pedestal in a state of protruding from the base, and the lower end of the component is brought into contact with the upper end of the cylindrical member by retracting the upper end of the rod from the upper end of the cylindrical member. Cylinder material with a specified distance from A heating means for lifting the component to the lower surface side of the base material by the surface tension of the molten solder by bringing the solder into contact with the lower surface of the base material by agglomerating the solder by melting the solder; The main point is that

  According to the fourth aspect of the present invention, the cylindrical member can slide in the through hole of the pedestal, the rod can slide in the cylindrical member, and the upper end of the rod protrudes from the upper end of the cylindrical member by a specified amount. The parts disposed in the recesses and the solder before melting thereon are pushed up, and the solder before melting contacts the lower surface of the substrate. The tubular member is fixed to the base with the upper end of the rod projecting from the upper end of the tubular member by the tubular member fixing means, and the upper end of the rod is retracted from the upper end of the tubular member to retract the part to the upper end of the tubular member. The lower surface comes into contact and the distance between the solder and the base material is set to a specified amount. The solder is melted by the heating means, and the component is lifted to the lower surface side of the base material by the surface tension of the solder which is melted by contact of the solder with the lower surface of the base material due to the aggregation of the solder.

  Thereby, even when the thickness of components differs, the distance of a solder and a base material can be made into rod protrusion amount. Therefore, even if the thickness of the component varies, the solder before melting is separated from the lower surface of the base material by a specified amount, and the solder can be brought into contact with the lower surface of the base material by melting the solder. The component can be reliably soldered to the lower surface of the base material without being affected by the above.

  The invention according to claim 5 is a soldering apparatus for laminating and soldering a plurality of components on the lower surface of the base material, wherein the first recess in which the components are arranged is provided on the upper surface on which the base material is mounted. A pedestal formed with a second recess formed on the bottom surface of the first recess and having a through-hole extending vertically on the bottom surface of the second recess; and the penetration of the pedestal A cylindrical member that slides in a hole, and a slide inside the cylindrical member, with the upper end protruding from the upper end of the cylindrical member by a specified amount, and laminated so that the solder before melting is positioned on the part A rod for pushing up a plurality of parts and bringing all the unmelted solder into contact with the parts on the unmelted solder and the lower surface of the base material, and the upper end of the rod projecting from the upper end of the tubular member The tubular member is fixed to the pedestal in the By retracting from the upper end of the cylindrical material, the lower surface of the lowermost component is brought into contact with the upper end of the cylindrical material, the distance between the lower surface of the base material and the solder before melting of the uppermost layer, and the lower surface of the component and immediately below it Cylindrical member fixing means for setting at least one of the distance to the solder before melting to a specified amount, and at least one of the lower surface of the base and the lower surface of the component by aggregating the solder by melting the solder And heating means for lifting the component by the surface tension of the solder which is brought into contact with and melted.

  According to the invention described in claim 5, in the state where the cylindrical material can slide through the through hole of the pedestal, the rod can slide in the cylindrical material, and the upper end of the rod protrudes from the upper end of the cylindrical material by a specified amount, A plurality of laminated parts are pushed up so that the unmelted solder is positioned on the parts, and all the unmelted solder contacts the parts on the unmelted solder and the lower surface of the substrate. The cylindrical material is fixed to the pedestal with the upper end of the rod protruding from the upper end of the cylindrical material by the cylindrical material fixing means, and the uppermost layer of the rod is retracted from the upper end of the cylindrical material to lower the bottom of the cylindrical material. At least one of the distance between the lower surface of the substrate and the unmelted solder of the uppermost layer, and the distance between the lower surface of the component and the unmelted solder immediately below is defined as the specified amount. . The solder is melted by the heating means, and the component is lifted by the surface tension of the solder melted by contacting the solder with at least one of the lower surface of the substrate and the lower surface of the component due to the aggregation of the solder.

  This defines at least one of the distance between the lower surface of the substrate and the solder before melting of the uppermost layer and the distance between the lower surface of the component and the solder before melting just below it even when the thickness of the components is different It can be an amount. Therefore, even if the thickness of the component varies, the solder before melting is separated from the lower surface of the base material and at least one of the lower surface of the component by a specified amount. Since it can be brought into contact with at least one of the lower surfaces, the component can be reliably soldered to the lower surface of the substrate without being affected by the thickness of the component.

According to a sixth aspect of the present invention, in the soldering apparatus according to the fourth or fifth aspect, when the cylindrical material fixing means is a set screw, the cylindrical material can be easily fixed by screwing in the screw.
As described in claim 7, in the soldering apparatus according to claim 6, the set screw has a cylindrical material that is open at one end and cuts a spiral groove on the outer surface, and the inside of the cylindrical material. When the pressing member is urged toward the opening of the cylindrical member by the compression coil spring, the cylindrical member can be stably fixed even when the diameter of the through hole is easily changed by heat.

  According to the present invention, a component can be reliably soldered to the lower surface of the substrate without being affected by the thickness of the component.

The exploded view of the soldering apparatus in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. Sectional drawing for demonstrating the soldering method in 1st Embodiment. The exploded view of the soldering apparatus in 2nd Embodiment. Sectional drawing for demonstrating the soldering method in 2nd Embodiment. Sectional drawing for demonstrating the soldering method in 2nd Embodiment. Sectional drawing for demonstrating the soldering method in 2nd Embodiment. Sectional drawing for demonstrating the soldering method in 2nd Embodiment. Sectional drawing for demonstrating the soldering method in 2nd Embodiment. Sectional drawing for demonstrating the soldering method in 2nd Embodiment. Sectional drawing for demonstrating the mounting method of the flat member in background art. (A), (b), (c) is sectional drawing for demonstrating the soldering method.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, the exploded view of the soldering apparatus 20 in this embodiment is shown. 2-5 is sectional drawing for demonstrating the soldering method in this embodiment. Using the soldering device 20, the electronic component 11 can be soldered to the lower surface 10b of the substrate 10 as a base material as shown in FIG. That is, the electronic component 11 is soldered to the lower surface 10b that is the back surface of the upper surface 10a of the substrate 10.

  As shown in FIG. 1, a soldering apparatus 20 includes a pedestal (block) 30 as an electronic component soldering jig, a collar 40 as a cylinder, a rod 45, and a plunger 34 as a cylinder fixing means. And a heat plate 50 as a heating means. The base 30 has the substrate 10 mounted on the upper surface 30a. A recess 32 is formed in the upper surface 30 a of the pedestal 30. The electronic component 11 can be placed inside the recess 32 and the electronic component 11 can move up and down inside the recess 32. A through hole 33 is formed in the bottom surface 32a of the recess 32 of the pedestal 30, and the through hole 33 extends vertically.

  The collar 40 as a cylindrical material has a cylindrical shape and slides through the through hole 33 of the pedestal 30. A cylindrical main body 46 of the rod 45 is slidable on the inner peripheral surface of the collar 40. A rod 47 is provided at the lower end of the main body 46 of the rod 45, and when the rod 47 comes into contact with the lower surface of the collar 40, the rod 45 can no longer move up. When the collar 47 is in contact with the lower surface of the collar 40, the upper end 45a of the rod 45 protrudes from the upper end 40a of the collar 40 by a specified amount D0.

  A plunger 34 as a set screw is disposed on the side wall of the through hole 33 in the base 30. The plunger 34 has a cylindrical material 34a. One end of the cylindrical member 34a is opened, and a spiral groove is cut on the outer surface. A cylindrical material 34 a is screwed into a screw hole 31 formed in the pedestal 30. A pressing member 34b is slidably disposed on the opening side (the left end side in FIG. 1) inside the cylindrical member 34a. A compression coil spring 34c is disposed inside the cylindrical member 34a, and the pressing member 34b is urged toward the opening (left side in FIG. 1) by the compression coil spring 34c. The base end (right end in FIG. 1) of the cylindrical member 34a is closed, and a hexagonal hole 34d is formed on the end surface.

  Further, the heat plate 50 is a plate-like heating element that generates heat when energized, and the plate solder 60 can be melted by heating the pedestal 30, the substrate 10 and the like by the heat plate 50.

Next, a soldering method will be described.
As shown in FIG. 2, the electronic component 11 is disposed in the recess 32 of the pedestal 30, and the sheet solder 60 before melting is disposed on the upper surface 11 a of the electronic component 11. Further, the substrate 10 is disposed on the upper surface 30 a of the pedestal 30 so as to close the recess 32. Then, the collar 40 in which the rod 45 protrudes from the upper end 40a by the specified amount D0 is inserted into the through hole 33 of the pedestal 30, and the electronic component 11 is pushed up by the upper end 45a of the rod 45 to bring the sheet solder 60 into contact with the lower surface 10b of the substrate 10. (Contact). That is, the collar 40 and the rod 45 provided with the prescribed rod protrusion amount (D0) are simultaneously pressed to bring the sheet solder 60 into contact with the lower surface 10b of the substrate 10.

  Further, as shown in FIG. 3, the plunger 34 is screwed into the screw hole 31 of the base 30 to fix the collar 40 with screws. Then, the rod 45 is slid downward to remove the rod 45 from the collar 40 so that the rod 45 does not protrude from the upper end 40a of the collar 40. As a result, the collar 40 is fixed to the pedestal 30 with the lower surface 11b of the electronic component 11 in contact (contact) with the upper end 40a of the collar 40, and the distance D1 between the plate solder 60 and the lower surface 10b of the substrate 10 is the rod protrusion amount. (D0).

  Thus, as a first step, the unmelted plate solder 60 disposed on the upper surface 11a of the electronic component 11 is in contact with the lower surface 10b of the substrate 10 and then the unmelted plate 10 with respect to the substrate 10 whose downward movement is restricted. By lowering the solder 60 and the electronic component 11 by a specified amount, the lower surface 10b of the substrate 10 and the plate solder 60 before melting are separated by a specified amount.

  Then, the heat plate 50 is heated by the operation (energization) of the heat plate 50 to melt the sheet solder 60 by heating, and the molten solder 60a is agglomerated by the molten solder 60a as shown in FIG. Contact. Further, the electronic component 11 is lifted (moved upward) as shown in FIG. 5 by the surface tension of the molten solder 60a.

  In this way, as a second step, by melting the plate solder 60, the solder is brought into contact with the lower surface 10b of the substrate 10 by agglomeration of the solder, and the electronic component 11 is attached to the lower surface 10b of the substrate 10 by the surface tension of the molten solder. Lift to the side.

  The pedestal 30 is heated to melt the plate solder 60, but the cylindrical member fixing means is a set screw, and the set screw is stable because the holding member 34b is the plunger 34 biased by the compression coil spring 34c. Thus, the collar 40 can be fixed to the base 30. That is, even if the inner diameter of the through-hole 33 formed in the pedestal 30 is expanded by heat, the collar 40 is urged by the compression coil spring 34c and the pressing member 34b, so that the collar 40 can be fixed securely.

Thereafter, when cooled, as shown in FIG. 6, the electronic component 11 is joined (soldered) to the lower surface 10b of the substrate 10 by the solder 60b.
A case where the thickness of the electronic component 11 varies will be described with reference to FIGS.

  When the thickness of the electronic component 11 is reduced by Δt as shown in FIG. 7 as compared with FIG. 2, the collar 40 is positioned upward by Δt in FIG. 7 as compared with FIG. The collar 40 is fixed to the pedestal 30. Then, when the rod 45 is removed from the collar 40, it becomes as shown in FIG. In FIG. 8, the distance D1 between the sheet solder 60 and the substrate 10 is the rod protrusion amount (D0).

  2 and 3 and FIGS. 7 and 8 are compared in this way, in any case, the distance D1 between the sheet solder 60 and the substrate 10 becomes the rod protrusion amount (D0). That is, even if the thickness of the electronic component 11 varies, the distance D1 between the sheet solder 60 and the substrate 10 can be a constant value (rod protrusion amount (D0)) before the solder is melted.

  In other words, the gap size (rod protrusion (D0)) that is always made of two parts composed of the collar 40 and the rod 45 is to press the collar 40 and the rod 45 at the same time, and then fix only the collar 40 and then the rod. By pulling out 45, the gap dimension (D1) between the solder and the substrate is obtained. Since D0 = D1, it is possible to always give a constant gap size regardless of the thickness direction of the electronic component 11 or the pedestal (jig) 30, and when soldering by heating, the surface tension of the solder The lifting force can be greater than the weight of the electronic component 11, and the electronic component 11 can be lifted by surface tension and soldered to the lower surface 10 b of the substrate 10.

  Thus, by using two parts (rod 45 and collar 40) that can give a constant gap dimension, a constant gap dimension is always given regardless of the dimensions of the electronic component 11 and the base (jig) 30. Therefore, the range in which soldering on the lower surface 10b of the substrate 10 can be adopted is expanded.

As described above, according to the present embodiment, the following effects can be obtained.
(1) As a soldering method, as shown in FIGS. 2 and 3, the plate solder 60 and the electronic component 11 before melting are lowered by a specified amount with respect to the lower surface 10b of the substrate 10 using a collar 40, a rod 45 and a plunger 34. By moving, the lower surface 10b of the substrate 10 and the sheet solder 60 before melting are separated by a specified amount D0. 4 and 5, the sheet solder 60 is melted to lift the electronic component 11 to the lower surface 10b side of the substrate 10 by the surface tension of the solder.

  Therefore, even if the thickness of the electronic component 11 varies, the unmelted plate solder 60 is separated from the lower surface 10b of the substrate 10 by a specified amount, and the solder is brought into contact with the lower surface 10b of the substrate 10 by melting the plate solder 60. Therefore, the electronic component 11 can be reliably soldered to the lower surface 10b of the substrate 10 as a base material without being affected by the thickness of the electronic component 11. That is, the influence of the dimensional tolerance of the electronic component 11 is eliminated, and the dimensional tolerance (dimensional variation) of the electronic component 11 can be dealt with.

  (2) As a configuration of the soldering apparatus 20, the electronic component 11 disposed in the concave portion 32 with the rod 45 sliding inside the collar 40 and the upper end 45a protruding from the upper end 40a of the collar 40 by a specified amount and above The plate solder 60 before melting can be pushed up to bring the plate solder 60 into contact with the lower surface 10 b of the substrate 10. The collar 40 is fixed to the base 30 with the upper end 45a of the rod 45 protruding from the upper end 40a of the collar 40 by the plunger 34 as a cylinder fixing means, and the upper end 45a of the rod 45 is retracted from the upper end 40a of the collar 40. Thus, the lower surface 11b of the electronic component 11 is brought into contact with the upper end 40a of the collar 40, and the distance between the sheet solder 60 and the substrate 10 can be set to a specified amount. With the heat plate 50 as a heating means, the solder is melted to bring the solder into contact with the lower surface 10b of the substrate 10 by agglomeration of the solder, and the electronic component 11 is lifted to the lower surface 10b side of the substrate 10 by the surface tension of the melted solder. be able to. Thereby, even when the thicknesses of the components are different, the distance between the solder and the substrate 10 can be set as the rod protrusion amount.

Using this apparatus, the soldering method (1) can be performed.
(3) Since the cylindrical material fixing means (34) is a set screw, the collar 40 can be easily fixed by screwing in the screw.

(4) The set screw has a cylindrical member 34a which is open at one end and cuts a spiral groove on the outer surface, and a holding member 34b is placed inside the cylindrical member 34a on the opening side of the cylindrical member 34a by a compression coil spring 34c. Since it is biased, the collar 40 can be stably fixed even when the diameter of the through hole 33 is easily changed by heat.
(Second Embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment.

  In FIG. 9, the exploded view of the soldering apparatus 21 in this embodiment is shown. 10 to 13 are cross-sectional views for explaining the soldering method in the present embodiment. Using the soldering device 21, the components (semiconductor element 74 and heat mass 75) of the power module Mp can be soldered to the lower surface 70b of the insulating substrate 70 as a base material as shown in FIG. That is, a plurality of components can be stacked and soldered to the lower surface 70b of the insulating substrate 70 as a base material (multiple steps of back surface soldering can be performed).

  In FIG. 14, the power module Mp is mounted and used in a vehicle. In particular, the present invention is applied to a power module that constitutes an inverter for driving a traveling motor in a hybrid vehicle. This inverter includes a semiconductor switching element, and the semiconductor switching element constitutes an arm. Specifically, an IGBT or a power MOSFET that is a vertical element is used as the semiconductor switching element.

As shown in FIG. 14, in the power module Mp, a semiconductor element 74 that is a power device constituting an arm of an inverter is mounted on an insulating substrate 70 as a base material.
The insulating substrate 70 is formed by forming metal layers 72 and 73 on both surfaces of a ceramic substrate 71 which is an insulating substrate. Specifically, the first metal layer 72 is formed on one surface (upper surface) of the ceramic substrate 71, and the second metal layer 73 is formed on the other surface (lower surface) of the ceramic substrate 71. The ceramic substrate 71 is made of, for example, aluminum nitride, alumina, silicon nitride, or the like. The metal layers 72 and 73 are made of aluminum.

The upper surface 70 a of the insulating substrate 70 is the front surface, the lower surface 70 b is the back surface, and the semiconductor element (chip) 74 is soldered to the lower surface 70 b of the insulating substrate 70.
A heat mass 75 is soldered to the lower surface 74 a of the semiconductor element 74. The heat mass 75 has a predetermined heat capacity to receive the heat of the semiconductor element 74 when the temperature of the thermally coupled semiconductor element 74 rises above the temperature of the heat mass 75. The heat mass 75 temporarily absorbs the heat generated in the semiconductor element 74 and then releases it. The heat capacity of the heat mass 75 temporarily absorbs a part of the heat generated in the semiconductor element 74 when the semiconductor element 74 generates heat larger than the normal heat generation state due to overload or the like and the cooling function by the heat sink becomes insufficient. Thus, the value is set to a value necessary for suppressing the semiconductor element 74 from being overheated. For example, in the case of an inverter used for controlling a driving motor of a hybrid vehicle, when sudden acceleration or sudden stop is caused from a steady operation state, the heat generated from the semiconductor element 74 is rated 3-5 in a short time of less than 1 second. Double heat loss is generated. In this embodiment, the temperature of the semiconductor element 74 is set so as not to exceed the upper limit of the operating temperature. The excessive heat loss is generated in the case of a sudden stop because a large current flows because the regenerative operation is performed.

  As shown in FIG. 9, the pedestal (block) 90 is formed on the upper surface 90 a on which the insulating substrate 70 is mounted, on the first concave portion 92 where the components are arranged, and on the bottom surface 92 a of the first concave portion 92. A second recess 93 in which components are arranged is formed, and a through hole 94 extending vertically is formed in the bottom surface 93a of the second recess 93. The collar 40 as a cylindrical member slides through the through hole 94 of the base 90.

  A plunger 34 as a set screw is disposed on the side wall of the through hole 94 in the base 90. The rod 45 is slidable in the inner hole of the cylindrical collar 40, and the rod 47 of the rod 45 protrudes by a specified amount D0 in a state where it contacts the lower surface of the collar 40.

Next, a soldering method will be described.
As shown in FIG. 10, the heat mass 75 is arranged in the second recess 93 of the pedestal 90 and the plate solder 81 is arranged on the heat mass 75. Further, the semiconductor element 74 is disposed in the first recess 92 of the pedestal 90 and the plate solder 80 is disposed on the semiconductor element 74. Further, the base 90 is pressed against the fixing ceiling surface 82 with the insulating substrate 70 interposed therebetween. Then, the collar 40 in which the rod 45 protrudes from the upper end 40a by a predetermined amount D0 is inserted into the through hole 94 of the base 90, and the heat mass 75, the plate solder 81, the semiconductor element 74, and the plate solder 80 are pushed up by the upper end 45a of the rod 45. Then, the plate solder 80 is brought into contact (contact) with the lower surface 70b of the insulating substrate 70. In other words, with the upper end 45a of the rod 45 protruding from the upper end 40a of the collar 40 by a specified amount D0, the plurality of parts (74, 75) stacked so that the solder before melting is positioned on the part are pushed up. The plate solder 81 is brought into contact with the semiconductor element 74 and the plate solder 80 is brought into contact with the lower surface 70 b of the insulating substrate 70. That is, with the upper end 45a of the rod 45 protruding from the upper end 40a of the collar 40 by a specified amount D0, a plurality of parts (74, 75) stacked so that the solder before melting is positioned on the part are pushed up. All the unmelted solder (80, 81) is brought into contact with the component (74) on the unmelted solder (80, 81) and the lower surface 70b of the insulating substrate 70.

  Then, as shown in FIG. 11, the plunger 34 is screwed into the screw hole 91 of the base 90 and the collar 40 is screwed by the plunger 34. Then, the rod 45 is slid downward and extracted from the collar 40 so that the rod 45 does not protrude from the upper end 40a of the collar 40. At this time, the lower surface 75 a of the heat mass 75 is in contact with the upper end 40 a of the collar 40. The semiconductor element 74 is placed on the bottom surface 92 a of the first recess 92 of the pedestal 90, and the lower surface 74 a of the semiconductor element 74 and the sheet solder 81 are separated from each other.

  In the state of FIG. 11, the distance between the sheet solder 80 and the lower surface 70b of the insulating substrate 70 is D10. Further, the distance between the lower surface 74a of the semiconductor element 74 and the sheet solder 81 is D11. The sum of the distance D10 and the distance D11 (= D10 + D11) is the rod protrusion amount (D0).

  Then, the plate solders 80 and 81 are melted by heating with the heat plate 50, and the solder 80a is brought into contact with the lower surface 70b of the insulating substrate 70 by aggregation of the solder as shown in FIG. As shown in FIG. 13, the semiconductor element 74 and the heat mass 75 are lifted (moved upward) by the surface tension of the solder.

  Here, instead of FIG. 11, as shown in FIG. 15, the lower surface 74a of the semiconductor element 74 and the bottom surface 92a of the first recess 92 may be in a non-contact state. That is, the distance between the sheet solder 80 and the lower surface 70b of the insulating substrate 70 is D20, and the lower surface 74a of the semiconductor element 74 and the sheet solder 81 are in contact with each other, and the distance D20 becomes the rod protrusion amount (D0). Yes. Alternatively, in FIG. 11, the sheet solder 80 and the lower surface 70b of the insulating substrate 70 may be in contact (D10 = 0, D11 = D0).

  Then, when cooled, the semiconductor element 74 is bonded to the lower surface 70b of the insulating substrate 70 by the solder 80b and the heat mass 75 is bonded to the lower surface 74a of the semiconductor element 74 by the solder 81b, as shown in FIG. That is, the semiconductor element 74 can be soldered to the insulating substrate 70 by melting the solder, and at the same time, the heat mass 75 can be soldered to the semiconductor element 74.

  As described above, in the soldering method of the present embodiment, as a first step, a plurality of components (semiconductors) are arranged such that the unmelted solder (80, 81) is positioned on the components (semiconductor element 74, heat mass 75). The element 74 and the heat mass 75) are stacked and arranged from the state where the solder 81 is in contact with the semiconductor element 74 and the solder 80 is in contact with the lower surface 70b of the insulating substrate 70, that is, all the unmelted solder is melted. The solder (80, 81) and components (semiconductor element 74, heat mass 75) before melting with respect to the insulating substrate 70 in which the downward movement is controlled from the state in which the component located on the previous solder and the lower surface 70b of the insulating substrate 70 are in contact. ) Is moved downward by a specified amount, the lower surface 70b of the insulating substrate 70 and the solder 80 before melting the uppermost layer, and the lower surface of the component (the lower surface 74a of the semiconductor element 74) and immediately below it. It is separated by a predetermined amount of at least one of the solder before fusion (81). Then, as a second step, the solder surface is melted by bringing the solder into contact with at least one of the lower surface 70b of the insulating substrate 70 and the lower surface of the component (the lower surface 74a of the semiconductor element 74) by melting the solder. The component (semiconductor element 74, heat mass 75) is lifted by tension.

  Thereby, even if the thickness of the heat mass 75 as a component varies, the solder before melting is melted immediately below the lower surface 70b of the insulating substrate 70 and the solder 80 before melting of the uppermost layer and the lower surface 74a of the semiconductor element 74. At least one of the previous solders 81 is separated by a specified amount, and the solder can be brought into contact with at least one of the lower surface 70b of the insulating substrate 70 and the lower surface 74a of the semiconductor element 74 by melting the solder. The components can be reliably soldered to the lower surface 70b of the insulating substrate 70 without being affected by the above.

  Further, as a configuration of the soldering device 21 of the present embodiment, the collar 40 is fixed to the pedestal 90 in a state where the upper end 45a of the rod 45 protrudes from the upper end 40a of the collar 40 by the plunger 34 as the cylindrical member fixing means. By retracting the upper end 45a of the rod 45 from the upper end 40a of the collar 40, the lower surface of the lowermost component (the lower surface 75a of the heat mass) is brought into contact with the upper end 40a of the collar 40, and the lower surface 70b of the insulating substrate 70 and the uppermost layer before melting. At least one of the distance from the solder 80 and the distance between the lower surface of the component (the lower surface 74a of the semiconductor element) and the solder (81) before melting immediately below is defined as a specified amount. By melting the solder by the heat plate 50 as a heating means, the solder is brought into contact with at least one of the lower surface 70b of the insulating substrate 70 and the lower surface of the component (the lower surface 74a of the semiconductor element) by the aggregation of the solder. Lift the part by surface tension. As a result, even when the thicknesses of the components are different, the distance between the lower surface 70b of the insulating substrate 70 and the solder 80 before melting of the uppermost layer, and the lower surface of the component (the lower surface 74a of the semiconductor element) and the melting point immediately below it. At least one of the distances to the solder (81) can be a specified amount. Therefore, even if the thickness of the component varies, the solder before melting is separated from the lower surface 70b of the insulating substrate 70 and at least one of the lower surface of the component (the lower surface 74a of the semiconductor element) by a predetermined amount. Since the solder can be brought into contact with at least one of the lower surface 70b of the insulating substrate 70 and the lower surface of the component (the lower surface 74a of the semiconductor element), the component can be securely attached to the lower surface 70b of the insulating substrate 70 without being affected by the thickness of the component. Can be soldered to.

The embodiment is not limited to the above, and may be embodied as follows, for example.
○ Although a heat plate 50 (a plate-like heating element that generates heat when energized) is used as a heating means, the present invention is not limited to this, and other places where light and infrared rays should be heated by a high-frequency induction heating device or a lamp, for example It may be a heating apparatus that irradiates and heats, or a device that heats the entire interior of the heating furnace.

  As shown in phantom lines in FIG. 1, the electronic component 15 may be placed on the upper surface 10a of the substrate 10 via the plate solder 65, and the upper surface 10a may be soldered simultaneously with the lower surface 10b of the substrate 10 by heating. . That is, the components (11, 15) may be soldered to the lower surface 10b and the upper surface 10a of the substrate 10 at the same time. Similarly, in the second embodiment, components may be soldered simultaneously to the lower surface 70b and the upper surface 70a of the insulating substrate 70 as a base material.

  ○ The base material was the substrate 10 or the insulating substrate 70. However, the present invention is not limited to this. For example, it is applied to a case where a heat radiating member (heat radiating plate) such as a heat sink is used as a base material and components are soldered to the heat radiating member. May be.

  O Although the thing which has the pressing member 34b and the compression coil spring 34c was used as a cylinder fixing means, you may use the set screw of a structure without the pressing member 34b and the compression coil spring 34c.

○ Although a screw (set screw) is used as the cylinder fixing means, other means may be used without being limited thereto.
The rod 45 is extracted from the collar 40, but the upper end 45a of the rod 45 may not protrude from the upper end 40a of the collar 40 without being extracted.

  In the second embodiment, the case where two components are stacked and soldered on the lower surface 70b of the insulating substrate 70 has been described. However, the case where three or more components are stacked and soldered on the lower surface 70b of the insulating substrate 70 is described. You may apply to.

  DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 10a ... Upper surface, 10b ... Lower surface, 11 ... Electronic component, 11a ... Upper surface, 11b ... Lower surface, 15 ... Electronic component, 20 ... Soldering device, 21 ... Soldering device, 30 ... Base, 30a ... Upper surface, 32 ... Recess, 32a ... Bottom, 33 ... Through hole, 34 ... Plunger, 34a ... Cylindrical material, 34b ... Holding member, 34c ... Compression coil spring, 40 ... Collar, 40a ... Upper end, 45 ... Rod, 45a ... Upper end, 50 ... Heat plate, 60 ... plate solder, 65 ... plate solder, 70 ... insulating substrate, 70a ... upper surface, 70b ... lower surface, 74 ... semiconductor element, 74a ... lower surface, 75 ... heat mass, 75a ... lower surface, 80 ... plate solder, 81 ... Plate solder, 90 ... pedestal, 90a ... upper surface, 92 ... first recess, 92a ... bottom surface, 93 ... second recess, 93a ... bottom surface, 94 ... through hole.

Claims (7)

A soldering method for soldering a component to the lower surface of a substrate,
By lowering the solder before melting and the part by a specified amount with respect to the base material, which is controlled to move downward, from a state in which the solder before melting disposed on the upper surface of the part is in contact with the lower surface of the base material. A first step of separating the lower surface of the base material and the solder before melting by a specified amount;
A second step in which the solder is brought into contact with the lower surface of the base material by aggregating the solder by melting the solder and the component is lifted to the lower surface side of the base material by the surface tension of the melted solder;
A soldering method characterized by comprising: A soldering method for laminating and soldering a plurality of components on the lower surface of a base material,
A plurality of components are stacked and arranged so that the unmelted solder is positioned on the components, and all the unmelted solder contacts the components positioned on the unmelted solder and the lower surface of the base material. In this state, by lowering the solder and the parts before melting by a specified amount with respect to the base material, the lower surface of the base material and the uppermost layer of solder before melting, A first step of separating at least one of the solder before melting immediately below by a specified amount;
A second step in which the solder is brought into contact with at least one of the lower surface of the base material and the lower surface of the component by melting the solder and the component is lifted by the surface tension of the melted solder;
A soldering method characterized by comprising:   The soldering method according to claim 1 or 2, wherein parts are simultaneously soldered to the lower surface and the upper surface of the base material. A soldering device for soldering a component to the lower surface of a substrate,
On the upper surface on which the base material is mounted, a recess in which the component is disposed is formed, and a pedestal in which a through hole extending vertically is formed on the bottom surface of the recess;
A cylinder that slides through the through hole of the pedestal;
The part that slides in the cylindrical member and the upper end protrudes from the upper end of the cylindrical member by a specified amount and pushes up the component placed in the recess and the unmelted solder thereon to use the unmelted solder as the base. A rod for contacting the lower surface of the material;
The cylindrical member is fixed to the pedestal with the upper end of the rod projecting from the upper end of the cylindrical member, and the upper end of the rod is retracted from the upper end of the cylindrical member, thereby lowering the lower surface of the part to the upper end of the cylindrical member. A cylindrical member fixing means for bringing a distance between the solder and the base material into a prescribed amount by contacting
Heating means for lifting the component to the lower surface side of the base material by the surface tension of the molten solder by bringing the solder into contact with the lower surface of the base material by agglomerating the solder by melting the solder;
A soldering apparatus comprising: A soldering device for laminating and soldering a plurality of components on the lower surface of a substrate,
A first recess in which the component is disposed is formed on the upper surface on which the base material is mounted, and a second recess in which the component is disposed is formed on the bottom surface of the first recess. A pedestal formed with a through hole extending vertically on the bottom surface of the recess,
A cylinder that slides through the through hole of the pedestal;
Sliding through the cylinder, with the upper end protruding from the upper end of the cylinder by a specified amount, push the stacked parts so that the pre-melting solder is positioned on the part to melt all A rod for bringing the previous solder into contact with the part on the solder before the melting and the lower surface of the substrate;
The tubular member is fixed to the pedestal with the upper end of the rod protruding from the upper end of the tubular member, and the uppermost part of the tubular member is retracted from the upper end of the tubular member so that the lowermost part is placed on the upper end of the tubular member. The lower surface of the base material and the distance between the lower surface of the substrate and the solder before melting of the uppermost layer, and at least one of the distance between the lower surface of the component and the solder before melting immediately below the specified amount A cylinder fixing means;
Heating means for lifting the component by the surface tension of the molten solder by bringing the solder into contact with at least one of the lower surface of the base and the lower surface of the component by agglomerating the solder by melting the solder;
A soldering apparatus comprising:   The soldering apparatus according to claim 4 or 5, wherein the cylindrical member fixing means is a set screw.   The set screw has a cylindrical material which is open at one end and cuts a spiral groove on the outer surface, and a pressing member is urged toward the opening of the cylindrical material by a compression coil spring inside the cylindrical material. The soldering apparatus according to claim 6.

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