JP4541327B2 - Conveying jig and processing device - Google Patents

Description

  The present invention relates to a printed circuit board conveying jig, and more particularly to a conveying jig for conveying a printed circuit board onto a molten solder jet during soldering of a component and a processing apparatus for processing the printed circuit board using the same. .

  In order to improve productivity and workability when manufacturing printed circuit board units (circuit boards) on which circuit components are mounted, a soldering device especially for soldering electrodes and leads of circuit components placed on printed circuit boards Is widely used.

  For example, in Patent Document 1, a printed circuit board on which circuit components are arranged is transported to a molten solder jet and soldered. In addition, the solder jet tank of patent document 1 spouts inert gas from the nozzle provided in the jet tank upper part, makes the solder jet surface the inert gas atmosphere, and suppresses oxidation.

  In a conventional solder jet bath, when solder is filled into a through-hole formed in a printed circuit board, the solder is first filled in the through-hole by immersing in a static jet bath, and then in an inclined jet bath Finish soldering is performed by contacting the molten solder jetted obliquely.

JP-A-7-185790

  In the conventional solder jet tank, the circuit component is soldered to the printed circuit board by immersing the back surface of the printed circuit board on which the circuit component is disposed in a molten jet of molten solder. For this reason, when the wettability of the material itself is small like lead-free solder, there is a problem that the solder cannot be sufficiently filled in the through hole (the solder finish is poor).

  For example, if there is a factor that hinders good soldering into the through hole, such as when the printed board is thick, the number of layers is large, or electronic components with large heat capacity are mounted, etc. When soldering with a static jet, the through hole cannot be filled with sufficient solder, and good soldering is difficult. When a soldering failure occurs, the correction work is necessary, which not only complicates the manufacture of the circuit board but also requires a large amount of cost.

  The present invention has been made to solve the above-described problems. In manufacturing a circuit board using a printed circuit board, in particular, the efficiency of filling a through-hole formed in the printed circuit board with a fluid member such as molten solder. It is an object of the present invention to obtain a conveying jig capable of dramatically improving the quality and a processing apparatus for processing a printed circuit board using the conveying jig.

Conveying jig according to the present invention is a conveying jig for transporting the printed circuit board on the flow member, supports the printed circuit board on one side, a portion of the printed circuit board to flow member on the other side A support plate provided with an opening to be exposed, and provided on the other surface side of the support plate, when the printed circuit board is conveyed onto the flow member, the opening is opposed to at least the flow direction of the flow member from three directions. And a surrounding current plate.

  According to the present invention, in the above-described transport jig, the printed circuit board is transported while being immersed in the flow member so that the rectifying plate faces the flow direction of the flow member. There is an effect that the efficiency of filling the formed through hole can be dramatically improved. As a result, when the present invention is applied to soldering, a good soldering state can be stably provided on a circuit board mounted on a product group requiring high reliability. In addition, the correction work for the soldering failure can be omitted, and it is possible to suppress the generation of a large expense required for this work.

Embodiment 1 FIG.
FIG. 1 is a view showing a conveying jig according to Embodiment 1 of the present invention, and shows a cross section cut in a direction perpendicular to a current plate. 2 is a view of the conveying jig in FIG. 1 as viewed from the surface side to which the current plate is attached, and FIG. 3 is a side view of the conveying jig in FIG. As shown in FIG. 1, the conveyance jig 3 according to Embodiment 1 includes a support plate 3a that supports the printed circuit board 2, and a rectifying plate 4 provided on the support plate 3a.

  The printed circuit board 2 has a circuit board on which the electronic component 1 is mounted, and a through-hole penetrating the front and back surfaces is formed. In the first embodiment, the electrode terminal of the electronic component 1 arranged on one surface of the printed circuit board 2 is inserted into the through hole, and the molten solder (fluid member) 7 is inserted into the through hole from the other surface. The process of filling and soldering will be described as an example.

  As shown in FIG. 2, the support plate 3 a has a rectangular shape that matches the shape of the printed circuit board 2, and is a through hole for exposing a soldered portion of the electronic component 1 disposed on the printed circuit board 2. A soldering opening (opening) 5 is formed. The rectifying plate 4 is attached in three directions of the support plate 3 a so as to surround the soldering opening 5. In particular, the rectifying plate 4 attached to one end connecting both side surfaces is arranged so as to be positioned in the flow direction of the molten solder 7.

  As will be described later, the conveying jig 3 according to the first embodiment changes the flow direction of the molten solder in the portion surrounding the soldering opening 5 by the rectifying plate 4 and solders into the through hole provided in the printed circuit board 2. Improve the rise. The width a of the rectifying plate 4 shown in FIG. 2 is 300 mm or less, the distance b from the rectifying plate 4 to the farthest soldering opening 5 is 150 mm or less, and the longitudinal dimension c of the side rectifying plate 4 is at least the distance b. It is confirmed that when the dimension d in the vertical direction of the rectifying plate 4 immersed in the molten solder is 5 to 20 mm, a good solder finish can be obtained. The plate thickness of the rectifying plate 4 does not particularly affect the soldering effect.

  FIG. 4 is a diagram showing a processing apparatus using the transport jig according to the first embodiment, and FIG. 4A shows a state in which the printed circuit board is immersed in the static flow solder bath by the transport jig in FIG. FIG. 4B is a diagram showing the flow direction of the solder in the static flow solder bath in FIG. The processing apparatus 6 shown in FIG. 4 includes a stationary flow solder tank (jet tank) 8 filled with, for example, molten solder 7 of lead-free solder.

  The stationary flow solder tank 8 has a double structure in which an internal tank 9 is provided. As shown in FIG. 4 (b), the molten solder 7 flows in the internal tank 9 in the direction of the arrow in the figure by the rotation of the propeller 10, and when it overflows from the internal tank 9, the molten solder 7 accumulates outside it. It circulates in the internal tank 9 through the inflow hole 11 provided in. For this reason, the molten solder 7 overflowing from the internal tank 9 flows in a horizontal direction on the surface layer of the molten solder 7 as indicated by an arrow in FIG.

  When soldering is performed with the processing device 6 shown in FIG. 4, the printed circuit board 2 is placed on the support plate 3 a so that the soldering target portion where the electronic component 1 is disposed is located in the soldering opening 5, and the current plate 4 is immersed in molten solder 7 from the surface side to which 4 is attached.

  In addition, as a direction to immerse, in addition to immersing perpendicularly to the surface layer of the molten solder 7 in the static flow solder bath 8, so that the flow direction of the molten solder 7 changes in a portion surrounded by the rectifying plate 4, The immersion may be performed while moving in the horizontal direction with respect to the surface layer of the molten solder 7. Further, when immersed in the molten solder 7, a part of the printed circuit board 2 may be fixed to the support plate 3a so that the printed circuit board 2 does not float from the support plate 3a.

Next, an outline of soldering using the conveying jig according to the first embodiment will be described.
FIG. 5 is a cross-sectional view showing a state in which a conventional conveying jig without a current plate is immersed in molten solder. As shown in FIG. 5, the conventional conveying jig 3 </ b> A is only a flat support plate 3 b that supports the printed circuit board 2 on which the electronic component 1 is arranged. For this reason, in the conventional conveying jig 3A, when the molten solder 7 is flowing in the horizontal direction (the direction indicated by the arrow in FIG. 5) like the static flow solder tank 8 described above, it is formed on the printed circuit board 2. There is no flow in the direction in which the molten solder 7 rises inside the through hole.

  Accordingly, when conditions that inhibit good soldering such as a thick printed board 2, a large number of layers, and mounting of an electronic component having a large heat capacity overlap, the molten solder 7 is formed inside the through hole. Not fully filled, resulting in poor soldering.

  On the other hand, in the conveying jig 3 according to the first embodiment, as shown in FIG. 6, the molten solder 7 that flows in the horizontal direction is blocked by the rectifying plate 4 that opposes the flowing direction, and the molten solder 7 is in the reverse direction. It turns into a flow that wraps around. At the same time, the flow of the molten solder 7 turned back is blocked by the rectifying plates 4 attached to both side surfaces.

  As a result, the molten solder 7 flows in a spiral shape in the space surrounded by the rectifying plate 4, and the flow direction of the molten solder 7 extends in the vertical direction from the horizontal direction toward the printed circuit board 2 as indicated by an arrow in FIG. 6. It changes locally. At this time, since the pressure of the molten solder 7 in the space surrounded by the rectifying plate 4 temporarily rises, the filling of the molten solder 7 into the through hole is promoted.

  FIG. 7 is a diagram showing the evaluation results of the solder finish, FIG. 7 (a) shows the degree of solder filling into the through hole, and FIG. 7 (b) shows the conventional board specifications for the printed circuit board. The solder rise evaluation result in the conveyance jig and the conveyance jig of the present invention is shown. In FIG. 7A, the filling degree of the solder into the through hole is shown at three levels A, B, and C. Level C where the solder is filled only up to the vicinity of the opening of the through hole is shown in FIG. Levels A and B in which solder is sufficiently filled in the through holes are evaluated as good solder finishes.

  FIG. 7B shows a printed circuit board 2 having a four-layer glass epoxy board having a thickness t = 1.6 mm, a six-layer glass epoxy board having a thickness t = 1.6 mm, and a thickness t = 2.4 mm. In this example, a 12-layer glass epoxy substrate and a 24-layer glass epoxy substrate having a thickness t = 2.4 mm are used. Using the printed circuit board 2 of each specification, the sheet is conveyed by the conventional conveying jig 3A shown in FIG. 5 and the conveying jig 3 according to the first embodiment shown in FIG. 6 in the static flow solder bath 8 shown in FIG. The soldering process was performed under the same conditions.

  When the plate thickness t = 1.6 mm and the number of laminated layers is as small as 4 or 6, even in the conventional transfer jig 3A, 80% of the total soldered amount is in a level A solder-up state. % Exceeded. On the other hand, in the case of the conveying jig 3 according to the first embodiment, soldering can be performed in the state of level A at a rate of 100%.

  Furthermore, as a condition that hinders good solder rising into the through hole, when the plate thickness is t = 2.4 mm and the number of laminations is increased to 12 layers and 24 layers, the conventional transfer jig 3A has a level A level. The amount of solder that has risen is extremely reduced, accounting for 28% and 12% of the total. Further, when the most severe plate thickness t = 2.4 mm and the number of laminated layers is 24, the level C, which is a poor solder rise, reaches 60% of the total.

  On the other hand, in the conveyance jig 3 according to the first embodiment, when the plate thickness t = 2.4 mm and the number of laminated layers is 12, the soldering is still possible in the level A state at a rate of 100%. Even in the case where the most severe plate thickness t = 2.4 mm and the number of laminated layers is 24, soldering in the level A state can be performed at a rate exceeding 80%.

  As described above, according to the first embodiment, the rectifying plate 4 is provided on the conveying jig 3, and the flow direction of the molten solder 7 is locally changed by the rectifying plate 4, thereby being surrounded by the rectifying plate 4. The pressure of the molten solder 7 in the remaining space temporarily rises. Thereby, the solder rising state to a through-hole part can be improved dramatically. Therefore, it is possible to stably provide a good soldering state in a mounting board used for a product group that requires high reliability. In addition, it is possible to suppress a large amount of expenses due to correction work or the like.

Embodiment 2. FIG.
FIG. 8 is a view showing a machining apparatus according to Embodiment 2 of the present invention, and shows a cross section so that the internal structure can be visually recognized. The processing apparatus 6A according to the second embodiment includes an inclined flow solder bath (jet bath) 8A filled with molten solder (fluid member) 7 such as lead-free solder and a transport rail for transporting the transport jig 3 onto the molten solder 7. 12 is provided.

  The inclined flow solder tank 8A has a double structure in which an internal tank 9 is provided, and the internal tank 9 is provided with two nozzles 13a and 13b having different opening diameters and heights. As shown in FIG. 8, the molten solder 7 flows in the inner tank 9 in the direction of the arrow in the drawing by the rotation of the propeller 10, and has a large nozzle 13 a having a large height and a nozzle 13 b having a small diameter and a small height. Each erupts from.

  The molten solder 7 overflowing from the internal tank 9 accumulates outside the internal tank 9 and circulates in the internal tank 9 via an inflow hole 11 provided in the lower part of the internal tank 9. The molten solder 7 overflowing from the internal tank 9 flows in a horizontal direction on the surface layer of the molten solder 7 as indicated by an arrow in FIG.

  Further, in the small-diameter nozzle 13b, the pressure at which the molten solder 7 is ejected is higher than that of the nozzle 13a, but the area of the surface layer formed by the ejected molten solder 7 is small. On the other hand, in the large-diameter nozzle 13a, the pressure at which the molten solder 7 is ejected is smaller than that of the nozzle 13b, but the surface layer area formed by the ejected molten solder 7 is larger than the nozzle 13b.

  The conveyance rail 12 is provided at an appropriate inclination angle so that the lower part of the conveyance jig 3 is in contact with the molten solder 7 ejected from the nozzles 13a and 13b, and the conveyance jig 3 is directed from the nozzle 13b toward the nozzle 13a (in the drawing). In the direction indicated by the white arrow).

  When soldering is performed with the processing apparatus 6A shown in FIG. 8, the printed circuit board 2 is attached to the support plate 3a so that the through hole into which the electrode terminal of the electronic component 1 is inserted is located in the soldering opening 5, and the rectifying plate 4 Installed on the transport rail 12 with the mounting surface down. At this time, as shown in FIG. 8, it installs so that the baffle plate 4 may be located in the opposite side to the conveyance direction in the conveyance rail 12. FIG.

  Thereafter, the transport jig 3 is moved onto the transport rail 12 and the lower part of the transport jig 3 is immersed so as to be in contact with the surface of the molten solder 7 ejected from the nozzles 13a and 13b. FIG. 9 is a cross-sectional view showing a state in which the conveying jig is immersed in molten solder by the processing apparatus in FIG. When the transport jig 3 is moved on the transport rail 12 in the direction from the nozzle 13b toward the nozzle 13a (the direction indicated by the white arrow in FIG. 9), the melt flows in the direction opposite to the transport direction and in the horizontal direction. The solder 7 flows.

  As in the first embodiment, the flow of the molten solder 7 is blocked by the rectifying plate 4 facing the flow direction of the molten solder 7 and changes to a flow in which the molten solder 7 turns back in the reverse direction. At the same time, the flow of the folded molten solder 7 on both sides of the conveying jig 3 is blocked by the rectifying plates 4 attached to both side surfaces.

  As a result, the molten solder 7 flows in a spiral shape in the space surrounded by the current plate 4, and the flow direction of the molten solder 7 extends in the vertical direction from the horizontal direction toward the printed circuit board 2 as indicated by an arrow in FIG. 9. It changes locally. At this time, since the pressure of the molten solder 7 in the space surrounded by the rectifying plate 4 temporarily rises, the filling of the molten solder 7 into the through hole is promoted.

  In the processing apparatus 6A according to the second embodiment, not only the flow of the molten solder 7 caused by the rotation of the propeller 10, but also the molten solder 7 is caused to flow by being conveyed on the conveyance rail 12. For this reason, in the case of the processing apparatus 6A according to the second embodiment, if the force in the conveying direction on the conveying rail 12 is controlled, the pressure of the molten solder 7 in the space surrounded by the rectifying plate 4 can be increased more greatly. Can do.

  Thereby, in the said Embodiment 1, although the case where the dimension a of the depth direction of the baffle plate 4 shown in FIG. 3 was 5-20 mm was preferable, in the processing apparatus 6A by Embodiment 2, rectification | straightening is carried out. Even if the dimension a in the depth direction of the plate 4 is about 2 to 10 mm, the same effect as in the first embodiment can be obtained.

  As described above, according to the second embodiment, by using the conveyance rail 12, the conveyance jig 3 is moved so that the rectification plate 4 faces the flow direction of the molten solder 7. The pressure of the molten solder 7 in the enclosed space temporarily rises. Thereby, the solder rising state to a through-hole part can be improved dramatically. Therefore, it is possible to stably provide a good soldering state in a mounting board used for a product group that requires high reliability. In addition, it is possible to suppress a large amount of expenses due to correction work or the like.

  In the first embodiment and the second embodiment, lead-free solder is used as the molten solder. However, eutectic solder may be used, and equivalent effects can be obtained.

  In the first embodiment and the second embodiment, the process of filling the through-hole with molten solder and fixing the electronic component 1 has been described. However, filling the through-hole with a fluid resin It can be applied to the processing to be performed, and an equivalent effect can be obtained.

  Furthermore, in the second embodiment, various processes can be executed by controlling the conveyance of the conveyance jig 3 on the conveyance rail 12 and appropriately adjusting the amount of the flow member introduced into the through hole. For example, the inner wall surface of the through hole can be coated by so-called hot dipping by using a metal fluid member and adjusting the amount of the fluid member introduced into the through hole.

It is a figure which shows the conveyance jig by Embodiment 1 of this invention. It is the figure which looked at the conveyance jig in FIG. 1 from the surface side which attached the baffle plate. It is a side view of the conveyance jig in FIG. It is a figure which shows the processing apparatus using the conveyance jig by Embodiment 1. FIG. It is sectional drawing which shows the state which the conventional conveyance jig was immersed in the molten solder. It is sectional drawing which shows the state which immersed the conveyance jig in FIG. 1 in the molten solder. It is a figure which shows the evaluation result of a solder finish. It is a figure which shows the processing apparatus by Embodiment 2 of this invention. FIG. 9 is a cross-sectional view illustrating a state in which a conveying jig is immersed in molten solder by the processing apparatus in FIG. 8.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Electronic component, 2 Printed circuit board, 3,3A Conveying jig, 3a, 3b Support plate, 4 Current plate, 5 Soldering opening (opening), 6,6A Processing apparatus, 7 Molten solder (fluid member), 8 Static flow solder bath (jet bath), 8A inclined flow solder bath (jet bath), 9 internal bath, 10 propeller, 11 inflow hole, 12 transport rail, 13a, 13b nozzle.

Claims (3)

A transport jig for transporting a printed circuit board onto a fluid member ,
A support plate that supports the printed circuit board on one side, and has an opening that exposes a part of the printed circuit board to the fluid member on the other side;
A rectifying plate that is provided on the other surface side of the support plate and surrounds the opening from three sides at least when facing the flow direction of the flow member when the printed board is conveyed onto the flow member. Transporting jig. In a processing apparatus comprising a jet tank in which a fluid member flows and processing a printed circuit board placed on a conveying jig in contact with the fluid member of the jet tank,
The processing apparatus according to claim 1, wherein the transport jig is the transport jig according to claim 1.   The processing apparatus according to claim 2, further comprising a conveyance rail provided on the jet tank.

Images