JP4558660B2 - Coating agent application device for soldering part of circuit board - Google Patents

Description

The present invention is a component such as a lead in the circuit board in the soldered portion, it relates to equipment you applying the coating agent to solder migration prevention.

  Conventionally, as a method for applying a coating agent to a soldered portion of a circuit board, a metering pump nozzle method and a curtain coating method are known.

  In the metering pump nozzle system, as shown in FIG. 5A, the coating agent is quantitatively supplied from the tank and metering pump 10 to the nozzle 12, and the nozzle 12 is supplied to the soldering portion 16 of the circuit board 14 by an XY robot. This is a system in which the coating agent 18 is applied linearly by moving at a constant speed along the array line.

  As shown in FIG. 5B, the curtain coating method is a method in which the coating agent 18 is applied in a planar shape using a slit die 20 that can discharge the coating agent 18 in a strip shape. Other than that, it is the same as that of the said system (patent document 1).

JP 2005-194392 A

  However, the conventional coating method has the following problems. That is, since the metering pump nozzle system is linearly applied, the accuracy of application to each soldering part is accurate and the application amount is relatively stable, but there is a problem that the application speed is slow. On the other hand, the curtain coating method has a problem that the coating speed is fast because of the surface coating, but it is difficult to improve the coating accuracy due to scattering of the coating agent, and the amount of coating on the individual soldering parts is not stable. is there.

In view of the above-mentioned problems of the prior art, the object of the present invention is to coat a circuit board soldering part, which has a high coating speed, accurate coating accuracy, and a stable coating amount on each soldering part. to provide a mixture coating NunoSo location.

The coating agent application device to the circuit board soldering part according to the present invention is:
A tank for storing a coating agent to be applied to the soldering portion of the circuit board;
A plurality of nozzles provided in a one-to-one correspondence with a plurality of soldering portions of the circuit board on the bottom plate of the tank;
A shutter installed on a bottom plate in the tank and having a plurality of conduction holes that correspond one-to-one with the plurality of nozzles;
A cylinder plate installed on the shutter and having a plurality of cylinders corresponding one-to-one with the plurality of nozzles;
The lower end portion is inserted into a plurality of cylinders of the cylinder plate, and the upper end portion is provided with a plurality of pistons held together by a piston holder so as to be movable up and down.
In the shutter, a common rail for supplying a coating agent to each cylinder is formed at a position separated from each conduction hole by a reciprocating distance of the shutter, and this common rail is formed in an area other than the cylinder forming area of the cylinder plate. The coating agent in the tank is supplied through the made opening,
The cylinder plate is installed so that it cannot move in the tank, and the shutter is installed so that each conduction hole can reciprocate between the position where the corresponding cylinder and nozzle connect and the position where each common rail coincides with the cylinder . It is characterized by this.

  According to the present invention, since the coating agent can be applied simultaneously to a large number of soldered portions of the circuit board, the time required for applying the coating agent can be greatly shortened. In addition, since the application is performed without moving the relative position of the nozzle and the circuit board, not only the application accuracy becomes accurate, but also the air bites into the coating agent, the non-wetting that the coating agent is not applied, or the coating misalignment, etc. There is no risk of defects. Furthermore, since the coating agent measured by the cylinder is applied to each soldering portion, the amount applied to each soldering portion is constant, and a stable application state without variations can be obtained.

Figure 1 shows an embodiment of a coating agent coating NunoSo location on the circuit board soldering portion in accordance with the present invention. This coating device includes a tank 22 for storing a coating agent. The coating agent flows into the tank 22 from the inlet pipe 24A, and excess coating agent flows out of the outlet pipe 24B so that fresh coating agent is always stored. The tank 22 is covered with a hermetic cover 26 to prevent deterioration of the coating agent.

  A large number of nozzles 28 are provided on the bottom plate of the tank 22. These nozzles 28 correspond one-to-one with the numerous soldering portions 16 of the circuit board 14. Reference numeral 30 denotes a lead of a component soldered to the circuit board 14.

  A shutter 32 is installed on the bottom plate in the tank 22, and a cylinder plate 34 is installed on the shutter 32. A number of cylinders 36 are formed on the cylinder plate 34 so as to correspond to the number of nozzles 28 on a one-to-one basis. The cylinder 36 includes a hole that penetrates the cylinder plate 34 in the vertical direction. The shutter 32 is formed with a large number of conducting holes 38 for conducting each cylinder 36 and the nozzle 28. The shutter 32 can reciprocate in one direction (left and right in the drawing) between the bottom plate of the tank 22 and the cylinder plate 34, but the cylinder plate 34 cannot move in the tank 22 (the cylinder 36 and the nozzle 28). It is installed so that the position does not shift.

  Further, a common rail 40 that opens upward is formed in the shutter 32 at a position separated from each conduction hole 38 by a reciprocating movement stroke of the shutter 32 (a distance that is half the arrangement pitch of the cylinders 36). The common rail 40 communicates with the coating agent reservoir in the tank 22 through an opening (not shown) formed in a region other than the cylinder forming region of the cylinder plate 34. Thereby, the coating agent in the tank 22 is supplied to the common rail 40 through the opening of the cylinder plate 34 and is supplied from the common rail 40 to the cylinder 36 (details will be described later).

  A lower end portion of a piston 42 is inserted into each cylinder 36 of the cylinder plate 34. Each piston 42 penetrates the sealing cover 26, and the upper end portion of each piston 42 is collectively held by a piston holder 44 outside the sealing cover 26. That is, all the pistons 42 are moved up and down collectively by moving the piston holder 44 up and down.

  Next, a method for applying the coating agent to the soldering portion of the circuit board using the coating apparatus configured as described above will be described with reference to FIGS. First, as shown in FIG. 2A, the coating agent 18 is supplied into the tank 22 from the inlet pipe 24A, and the excess coating agent 18 is discharged from the outlet pipe 24B, so that the amount of the coating agent 18 in the tank 22 is increased. Is kept constant.

  In the initial state of FIG. 2A, the piston 42 is in the lowered position, and no coating agent is contained in the cylinder 36. The shutter 32 is at a position where the common rail 40 coincides with the cylinder 36 (a position where the conduction between the cylinder 36 and the nozzle 28 is cut off). The common rail 40 is supplied with the coating agent 18 in the tank 22 through an opening (not shown) of the cylinder plate 34. Under the tank 22, the circuit board 14 is positioned so that each soldering portion 16 is positioned directly below the corresponding nozzle 28.

  From this state, as shown in FIG. 2 (B), all the pistons 42 are raised to a predetermined raised position. As a result, the coating agent 18 in the common rail 40 is sucked (supplied) into the cylinder 36. The volume of the cylinder 36 is set so that when the piston 42 rises to a predetermined ascending position, the amount of the coating agent sucked into the cylinder 36 becomes the application amount for one time.

  Next, the shutter 32 is moved to the left on the paper by a predetermined distance. Then, as shown in FIG. 3A, the cylinder 36 and the nozzle 28 are brought into conduction through the conduction hole 38 of the shutter 32.

  If all the pistons 42 are lowered in this state, as shown in FIG. 3 (B), the coating agent 18 weighed in each cylinder 36 is simultaneously discharged from the nozzle 28 and applied to each soldering portion 16 at the same time. .

  As shown in FIG. 4B, the conventional coating method is a method in which the coating agent 18 is applied while moving the nozzle 12 (or the slit die 20) with respect to the circuit board 14, and therefore the soldering portion 16 ( There is a problem that non-wetting f in which the coating agent is not applied to the down slope of the solder fillet) in the nozzle traveling direction is likely to occur, or air entrainment e in which the applied coating agent 18 entraps air is likely to occur. On the other hand, the coating method of the present invention is a system in which the coating agent 18 is applied from the top of the solder fillet without moving the nozzle 28 as shown in FIG. In addition, since a prescribed amount of the coating agent measured by the cylinder is applied, uniform and stable application can be performed on a large number of soldering portions 16 in both position and amount.

  In the above application device, when the piston 42 is raised or lowered, the cylinder plate 34 is not lifted (so as not to be separated from the shutter 32), and a spring or the like (not shown) is provided on the cylinder plate 34. It is preferable to apply a pressing force from above.

Sectional drawing which shows one Embodiment of the coating agent application | coating apparatus to the circuit board soldering part which concerns on this invention. (A) is sectional drawing which shows the initial stage of the coating agent application | coating method using the coating device of FIG. 1, (B) is sectional drawing which shows the next step. FIG. 3A is a cross-sectional view showing the next stage of FIG. 2B, and FIG. (A) is explanatory drawing of the coating method by the coating device of this invention, (B) is explanatory drawing of the conventional coating method. (A), (B) is a perspective view which shows the conventional application | coating method, respectively.

Explanation of symbols

14: Circuit board 16: Soldering part 18: Coating agent 22: Tank 24A, 24B: Pipe 26: Sealing cover 28: Nozzle 32: Shutter 34: Cylinder plate 36: Cylinder 38: Conduction hole 40: Common rail 42: Piston 44: Piston holder

Claims (1)

A tank for storing a coating agent to be applied to the soldering portion of the circuit board;
A plurality of nozzles provided in a one-to-one correspondence with a plurality of soldering portions of the circuit board on the bottom plate of the tank;
A shutter installed on a bottom plate in the tank and having a plurality of conduction holes that correspond one-to-one with the plurality of nozzles;
A cylinder plate installed on the shutter and having a plurality of cylinders corresponding one-to-one with the plurality of nozzles;
The lower end portion is inserted into a plurality of cylinders of the cylinder plate, and the upper end portion is provided with a plurality of pistons held together by a piston holder so as to be movable up and down.
In the shutter, a common rail for supplying a coating agent to each cylinder is formed at a position separated from each conduction hole by a reciprocating distance of the shutter, and this common rail is formed in an area other than the cylinder forming area of the cylinder plate. The coating agent in the tank is supplied through the made opening,
The cylinder plate is installed so that it cannot move in the tank, and the shutter is installed so that each conduction hole can reciprocate between the position where the corresponding cylinder and nozzle connect and the position where each common rail matches the cylinder . An apparatus for applying a coating agent to a soldered portion of a circuit board.

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