JP2669406B2 - Through-hole heating type flow soldering apparatus and flow soldering method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering apparatus and a soldering method, and more particularly to a flow soldering apparatus and a flow soldering method.

[0002]

2. Description of the Related Art As this kind of technology conventionally used, for example, as disclosed in Japanese Patent Application Laid-Open No. 04-151897, reflow soldering is performed by heating from the upper surface of a printed circuit board, and at the same time, from the lower surface. There is a method of performing flow soldering.

In this method, a printed circuit board preheated by a preheater is subjected to flow soldering from a lower surface by a flow soldering device, and at the same time, reflow soldering is performed by applying hot air from an upper surface.

[0004]

According to the above technique,
The defect rate of soldering is lower than that of flow soldering only from the bottom, but when soldering to the through hole of a multi-layer printed circuit board with a large number of layers and large heat capacity, the problem may still occur. There was a point.

[0005] This is because the multilayer printed circuit board has a large heat capacity, so that much heat is radiated from the solder sucked into the through-hole. That's why.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flow soldering apparatus and a flow soldering method capable of performing reliable flow soldering on through holes of a multilayer printed circuit board having a large number of layers and a large heat capacity.

[0007]

A flow soldering apparatus of the present invention has a printed circuit board positioning portion for holding a printed circuit board to be soldered and a flow solder bath for jetting molten solder onto the lower surface of the printed circuit board. In the flow soldering apparatus, a plurality of heating pins are provided, and a heating mechanism capable of bringing a desired heating pin down into contact with the upper surface of the printed board held by the positioning section is provided.

The heating pin may be arranged so as to come into contact with the vicinity of the mounting through hole of the mounting component arranged on the printed board.

A flow soldering method according to the present invention is directed to a flow soldering method for soldering a component mounted on an upper surface of a printed circuit board to a printed circuit board held by a printed circuit board positioning section of a flow soldering apparatus.
The heating pin heated by the heater is brought into contact with a desired position on the printed circuit board, and the heating of the contact portion raises the temperature of the conductive portion on the inner surface of the through hole, which is the connection portion with the mounting component. The molten solder is jetted onto the lower surface of the printed circuit board from the jet outlet to connect the mounting portion of the mounted component and the through-hole conductive portion of the printed circuit board.

The contact portion of the heating pin with the printed circuit board is
It may be in the vicinity of the mounting through-hole of the mounted component arranged on the printed circuit board, or may be a land portion connected to the mounting through-hole of the mounted component mounted on the printed circuit board.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is directed to a flow soldering apparatus having a flow solder bath and a printed circuit board positioning section, in which a desired heating pin is brought into contact with the upper surface of a printed circuit board held by the positioning section by descent contact. The heating mechanism is provided with a plurality of heating pins capable of being driven.

The heating pin heated by the heater is brought into contact with the vicinity of a desired through-hole on a printed circuit board on which mounted components are held, which is held at a predetermined position above the flow solder bath of the flow soldering apparatus, and heat conduction is performed. After the temperature of the conductive layer on the inner surface of the through hole is increased, molten solder is jetted from the flow solder bath to the lower surface of the printed circuit board to perform flow soldering.

The heat of the heated pin is transmitted to the conductive portion on the inner surface of the through-hole, and the temperature of the conductive portion rises, so that the solder by the flow soldering sucked into the through-hole is hard to be cooled. Does not deteriorate, and enters into a fine void to securely bond the mounting portion of the mounted component to a predetermined position on the printed circuit board.

According to the information from the line to which the flow soldering apparatus belongs, only the heating pins at the required positions are automatically projected downward by the control of the built-in controller, and only the necessary heating pins are located at the predetermined positions. And heating. Although the outside diameter of the heating pin is small to make contact with a small area, the heat capacity for heating the conductive portion on the inner surface of the through hole is ensured by arranging the heater as close to the tip of the pin as possible.

The contact position of the heating pin is preferably the land portion of the through hole if possible. The land of the through-hole is connected to the conductive part on the inner surface of the through-hole. Since the thermal conductivity is higher than that of the surrounding insulator, the heat of the heating pin is easily transferred to the conductive part on the inner surface of the through-hole. , The temperature rises quickly.

Next, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of a flow soldering apparatus according to an embodiment of the present invention, FIG. 2 is a schematic partial front view near a heating mechanism, and FIG. 3 is a partial front sectional view near a through hole.

In the drawing, reference numeral 1 denotes a flow solder tank for storing, heating and melting the solder and sending it out to the jet port 3 to collect the excess solder, 2 denotes a drain for collecting the excess solder, and 3 denotes a printed circuit board support 4 Jet holes 4 for jetting solder on the lower surface of the printed circuit board 5 are printed circuit board supports for holding the printed circuit board at a predetermined position,
5 is a printed board, 6 is a heating pin attached to a heating mechanism 7 for heating the land 12 of the through hole 10 of the printed board 5, 7 is a heating mechanism incorporating a controller of the heating pin 6 and the heater 9, Reference numeral 8 is a mounted component arranged on the printed circuit board 5, 9 is a heater for the heating pin 6, 10 is a through hole of the printed circuit board 5, 11 is a conductive portion on the inner surface of the through hole, 12 is a land portion of the through hole 10, and 13
Is a solder jet.

The flow solder bath 1 has a solder jet 13 on its upper surface.
Has a jet port 3 for carrying out, and a drain 2 for receiving the jetted solder is arranged around the jet port. Further, a printed circuit board support 4 for holding a printed circuit board 5 to be soldered at a predetermined position is arranged above the jet port 3.

A heating mechanism 7 that can move up and down is provided above the printed board support 4, and a plurality of heating pins 6 for heating the upper surface of the printed board are arranged on the heating mechanism 7 in a grid pattern. The pin 6 can move up and down independently. Heaters 9 are provided at the bases of the heating pins 6, respectively. The raising and lowering of the heating mechanism 7, the raising and lowering of the heating pins 6 and the heating of the heater 9 are performed by a controller (not shown) built in the heating mechanism 7.
Is controlled by

The printed circuit board 5 on which the mounting components 8 are arranged is conveyed to a predetermined position of the printed circuit board support 4 by a transfer mechanism (not shown) and held by the substrate support 4, and the heating mechanism 7 moves to a predetermined heating position. And heating mechanism 7 based on information from the assembly line to which the flow soldering device belongs.
Controller lowers the heatable pin 6 at a desired position,
It is heated by the heater 9. The lowered heating pin 6 contacts the vicinity of the mounting portion of the mounting component 8 arranged on the printed board 5, and heats the printed board 5. The heating position is preferably the land portion 12 connected to the conductive portion 11 on the inner surface of the through hole 10, which is the main heating target.

After the vicinity of the mounting portion of the mounting component 8 is heated,
When the molten solder is jetted from the jet port 3 of the flow solder tank 1, the temperature drop in the through hole is small, so that the flowability of the solder is prevented from lowering. As shown in FIG. The mounting portion of the mounting component 8 and the conductive portion 11 of the through hole 10 are securely connected to each other.

The heating pin 6 is formed to have a small outer diameter in order to make contact with a small area. However, as shown in FIG. 2, the heater 9 is arranged as close to the tip of the heating pin 6 as possible for heating. Heat capacity is secured.

[0023]

As described above, according to the present invention, the conductive portion of the through hole of the printed circuit board connected to the mounting portion of the mounting component can be heated from the vicinity thereof and heated in advance, so that the through hole can be formed. Since the cooling of the sucked solder is suppressed and the flowability of the solder does not decrease, the solder is sufficiently filled in the through hole, and the mounting part of the mounted component inserted inside the through hole is securely connected to the conductive part of the through hole. Therefore, even in a multilayer printed circuit board having a large number of layers and a large heat capacity, it is possible to reduce solder defects in flow soldering.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a flow soldering apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic partial front view near a heating mechanism.

FIG. 3 is a partial front sectional view near a through hole.

[Explanation of symbols]

 1 Flow Solder Tank 2 Drain 3 Jet Port 4 Printed Circuit Board Support 5 Printed Circuit Board 6 Heating Pin 7 Heating Mechanism 8 Mounted Parts 9 Heater 10 Through Hole 11 Conductive Part 12 Land Part 13 Solder Jet

Claims (5)

(57) [Claims] 1. A flow soldering apparatus having a printed circuit board positioning portion for holding a printed circuit board to be soldered, and a flow solder bath for jetting molten solder onto a lower surface of the printed circuit board, wherein a plurality of heating pins are provided. A flow soldering apparatus, comprising: a heating mechanism that is provided and that allows a desired one of the heating pins to descend and contact the upper surface of the printed circuit board held by the positioning part. 2. The flow soldering apparatus according to claim 1, wherein the heating pin is disposed so as to contact a vicinity of a through hole for mounting a component mounted on the printed circuit board. Characterized by flow soldering equipment. 3. A flow soldering method for soldering a mounted component disposed on an upper surface of a printed circuit board to a printed circuit board held by a printed circuit board positioning section of a flow soldering apparatus, wherein the heating method comprises the steps of: The pin is brought into contact with a desired position on the printed circuit board, and the heating of the contact portion raises the temperature of the conductive portion on the inner surface of the through hole, which is the connection portion with the mounting component. A flow soldering method, comprising: ejecting solder to a lower surface of the printed circuit board to connect a mounting portion of the mounted component to the through-hole conductive portion of the printed circuit board. 4. The flow soldering method according to claim 3, wherein a contact portion of the heating pin with the printed board is in the vicinity of a through hole for mounting a mounted component arranged on the printed board. Characteristic flow soldering method. 5. The flow soldering method according to claim 4, wherein a contact portion of the heating pin with the printed circuit board is a land portion connected to a mounting through hole of a mounted component arranged on the printed circuit board. A flow soldering method characterized in that there is.