JPS63303681A - Cream solder applicator - Google Patents

Abstract

PURPOSE:To accurately regulate the quantity of application and to uniformalize the thickness of application of solder by forming discharge openings in accordance with a lead pattern on one end of a cylinder member for applying the solder and arranging an elastic member projecting somewhat in the vicinity of the discharge openings. CONSTITUTION:The discharge openings 6, 6, 6, 6 in accordance with the lead pattern of a circuit substrate are formed on one end of the cylinder 1 to store the cream solder. A lid member 4 is fitted freely attachably and detachably to the other end of the cylinder 1 and a piston 2 is airtightly inserted therein via the screwing of a screw 3. The cream solder is filled in the cylinder 1 and the piston 2 is inserted therein and a knob 5 is turned to push down it. Since an antislipping plate 8 having the elasticity is provided at the center of the discharge opening 6, the discharge openings 6, 6... abuts on the substrate without slipping and the quantity of application of the solder is accurately regulated with the quantity of clearance. By this method, the quantity of application of the solder is accurately regulated and the thickness of its application is uninformalized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a method for applying cream solder that is used when surface mounting electronic components onto a printed circuit board. This invention relates to a device that applies only 1.

(Prior art) When electronic components are surface mounted on a printed circuit board (in this case, cream solder is applied to a pattern on the printed circuit board formed to match the lead arrangement of the electronic components, and the electronic components are mounted on top of this). Cream solder is heated and melted in a heated state.

In this case, if the gap between the leads is extremely narrow, about 0.5 mm, such as Flat Pack Doe C, if too much cream solder is applied, it will bridge the leads and cause a short circuit. On the other hand, if it is too small, it will cause connection failure, so it is necessary to accurately control the amount of application.

For this reason, as shown in FIG. 4, a mask plate M, which is made of a plate material having a certain thickness and through holes Ht formed in accordance with the lead pattern P, is usually superimposed on the printed circuit board K (by the same figure). , apply cream solder R on top of this
According to this method, it is possible to apply a certain amount of cream solder R' depending on the area and thickness of the through hole H of the mask plate M (■).
), due to the need to prepare a large amount of cream solder during application, the excess cream solder R'' (n) not only adheres to the mask board M and is wasted, but even if this excess cream solder Even if it is collected, it may be exposed to air,
There is a problem in that because it adsorbs dust on the surface of the mask plate, it tends to deteriorate.

In order to solve this problem, there is an apparatus that uses a dispenser such as a syringe to apply a fixed amount to each pattern point, but there is a problem that the application takes time and effort.

(Purpose) The present invention was made in view of these problems, and its purpose is to discharge only a necessary and sufficient amount of cream solder from a storage container and apply it at once in accordance with a pattern. Our goal is to provide you with the equipment you need.

(Summary of the Invention) That is, the present invention is characterized by forming a discharge port in accordance with a circuit pattern at the other end of a cylinder member into which a piston member that is moved forward and backward in the axial direction by external operation is fitted. , the elastic member is attached near the discharge port so as to slightly protrude from the tip of the discharge port.

(Structure) Therefore, details of the present invention will be described below based on illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, and the reference numeral 1 in the figure is a cylinder forming a container for storing cream solder, and one end is fixed to a piston 2 that is fitted into the cylinder. A lid member 4 formed at the center of a screw hole 4a% that is screwed into the screw 3 is detachably attached, and a discharge port 6.6.6. that matches the lead pattern of the circuit board is provided at the other end.
6 is formed. This discharge port 6 is formed by providing a rectangular through hole %N on the outer periphery of the substrate 7 in accordance with the pattern to be coated, as shown in FIG. An anti-slip plate 8 such as a rubber plate is protruded and fixed to ensure the coating thickness d from the tip.

In addition, the reference numeral 5 in the figure indicates the knob fixed to the screw, and 10
○ is the air vent, and 11 is fitted to the piston 2.
Each ring is shown.

In this embodiment, the cylinder 1 is filled with cream solder R, the piston 2 is inserted, and the discharge ports 6,6,6...
Turn the knob 5 to push down the piston 2 until the cream solder is discharged (see the second drawing).

After completing these preparations, the discharge port 6.6.6...
When the cylinder 1 is pressed against the circuit board K so that it matches the pattern P on the printed circuit board, it will come into contact with the circuit board K through the anti-slip plate 8, so it will be fixed to the circuit board K without slipping. At the same time, a certain gap d is formed between the circuit board surface and the tip of the ejection port (II).

When the knob is rotated in this state, the piston 2 moves relative to the discharge ports 6.6.6 and 6.6.6 in the cylinder 1 in the axial direction.
...Move to the side and push out the cream solder inside the cylinder (■). As a result, the cream solder will be in a shape that is completely different from the shape of the discharge port 6, 6, 6'... As a result, the amount determined by the amount of rotation of the knob 5 is discharged, and the amount is applied onto the pattern of the printed circuit board P with a thickness that approximately corresponds to the gap length d (■).

In this state, when the electronic components to be mounted are arranged in accordance with the pattern of the circuit board and heated, the cream solder that had been attached to bridge the two lead patterns that are in contact with each other will melt due to surface tension. It is attracted to the pattern P and separated, and after wetting the lead of the electronic component and the pattern, both are fixed when cooled.

FIG. 3 shows an embodiment of a stand suitable for holding the above-mentioned applicator at 1, in which a plurality of protrusions 21, 21, 21, . . . are formed on the surface of a synthetic resin plate 2o. In addition to forming a concave portion 2418 that matches the shape of the bottom surface of the applicator 23 described above.

According to this embodiment, when not in use, the applicator 23 is moved to the recess 2.
To 4! ! By leaving the applicator 23 open, it is possible to prevent the cream solder from deteriorating by cutting off contact with air as much as possible, and at the beginning of use, the bottom of the applicator 23 is lined with convex stripes 2], 21.2.
1. Residues can be easily removed by pressing it against the surface.

In this example, separation by the surface tension of cream solder during melting is actively used to make the discharge ports on each side continuous ports, but independent holes or elongated holes may be provided according to the circuit pattern. It is clear that the same effect can be obtained even if the tank is divided into several tanks.

Further, in this embodiment, the piston is moved in the axial direction by rotating the knob, but the drive screw may also be rotated by a trigger mechanism or a button, or by a click that controls the amount of rotation. By providing a mechanism, the amount of application can be controlled more accurately.

Further, in this embodiment, the knob is moved manually, but it is clear that the same effect can be achieved even if it is connected to a power source such as a pulse motor or a pressure air limit. Further, in this embodiment, the screw member is constructed integrally with the piston, but they may be rotatably fixed between them. It is clear that the same effect can be achieved even if the two are provided and rotated relative to each other.

(Effects) As explained above, a discharge port is formed at one end of the cylinder in accordance with the lead pattern of the electronic component, and a piston that advances and retracts with a thread is provided, so the cream solder is kept as airtight as possible. While stocking, it is possible not only to reliably supply cream solder by applying strong pressure from the thread, but also to precisely adjust the stroke length and the amount of application.

In addition, an anti-slip plate is provided at the bottom so that the surface slightly protrudes from the discharge port, so it not only can be securely fixed in place on the circuit board when it comes into contact, but also prevents slippage between the surface of the circuit board and the surface of the circuit board. With a constant gap length, the coating thickness can be controlled to a constant value.

[Brief explanation of drawings]

FIGS. 1(A) and 1(B) are explanatory diagrams showing one embodiment of the solder coating method of the present invention, respectively. 1...Cylinder 2...Piston 3...
・Screw 4... Lid member 6. 6... Discharge port 7... Board 8... Anti-slip plate

Claims (1)

[Claims] A discharge port that matches the lead pattern of the electronic component is formed at the other end of the cylinder member into which a piston member that is moved forward and backward in the axial direction by external operation is formed, and an elastic member is formed so as to slightly protrude from the tip of the discharge port. A cream solder applicator comprising a member attached near the discharge port.