JPS58125895A - Method of soldering printed board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention provides a method for soldering printed board mounted component terminals to a printed board. It is something to do.

(2) Background of the technology Electronic components that are mounted on printed boards that make up various electronic devices have terminals 9 and A protruding from the back through the through-holes of the printed board, and O terminals printed on the back of the printed board. It is soldered to the board. S products installed on printed boards in various electronic devices in recent years and! With the increase in the number of ICs*1 and the increasing complexity of circuits due to diversification of functions, there is a growing outlook for highly reliable solder joints that provide reliable connections with good quality and do not cause WA contact with other parts. It's getting stronger.

(3) Conventional technology and problems Conventionally, the method for soldering component terminals protruding from the back side of a printed board is to pour molten solder as a jet and place the back side of the printed board in the jet to adhere the solder to the component terminals. Flow soldering method and! Lin) 41111! A ring soldering method is used in which a ring-shaped solder is attached to each component terminal protruding from a surface, and the entire solder is heated to melt the solder and join the component terminals by soldering. However, in the flow soldering method, due to the turbulent flow of the molten solder jet, the state of solder adhesion to each component terminal is not constant, and there is a case where the solder crosses between the Due to the agitation effect of the jet stream with the air, the solder tends to densify, resulting in a decrease in the quality of the solder and the reliability of the bond. Further, in the ring soldering method, the solder must be prepared in advance in the form of a ring, and the ring solder must be manually attached to the trench can component terminal, making the work tedious.

(4) Purpose of the Invention The present invention solves the drawbacks of the prior art described above, and provides a highly reliable print that is of good quality, easily and securely connects, and does not cause erroneous contact with other parts. Board soldering aims to provide a method.

(5) Structure of the Invention In order to achieve this object, the present invention provides a method for soldering terminals of components mounted on the front surface of a printed board from the back surface of the printed board by protruding from the back surface of the printed board. After wiping to remove the surface staining layer O, remove the soldering of the component terminals protruding from the printed board lk side by floating the printed board to be soldered with its back side facing down on the molten solder. There is.

(6) Embodiment of the Invention The drawing is a sectional view showing an example of a soldering apparatus for carrying out the method of the invention. Molten solder 3 is stored in a rectangular solder tank 2 with a heater 71 fixed at the bottom. This solder tank 2 can be moved up and down by a hydraulic cylinder 4 in the direction of the υ arrow. Guide rods 5 are provided on both side edges of this rectangular solder tank 20. A transverse piece 6 for wiping the molten solder surface is slidably attached to both guide rods 5. This horizontal piece 6#'i is provided across the solder tank 2 in a direction perpendicular to the drawing. An oxidized solder receiving tank 7 is provided on the side edge of the solder tank 20 . When the horizontal piece 6 slides along the guide rod 5 in the direction of arrow B, its tip is held in a vertical state with its tip slightly immersed in the molten solder, and as it moves in the direction of arrow B, the oxidized solder layer on the surface is removed as shown in the drawing. Push it to the left and move it to the oxidized solder receiving tank 7.
Put it inside.

When the horizontal piece 6 moves to the right in the drawing, the horizontal piece 6 rotates freely around its upper hinge portion and is not immersed in the f6M solder, and e) the half-exposed surface (3) is not glued.

A support frame 8 is provided above the solder 41II2 in a direction perpendicular to the drawing. A printed board 10 to be soldered is attached to the support frame 8 in a suspended state from wires 9. Connector IIO electronic component 11 is connected to the 6100 fitting surface, and O terminal 12 is connected to LK.
It protrudes in the opposite direction.

In this type of soldering, when soldering a printed circuit board 100 using a device, first, the horizontal piece 6 is slid in the direction of arrow B along the guide rod 5 to oxidize the surface of the molten solder 30 in the solder tank 2. Wipe away the solder.

Next, the hydraulic cylinder 4 is actuated so that the printed circuit board 10 is completely floating on the molten solder 3, that is, the wire 9 is completely suspended! The solder bath 2 is raised until the lint plate 10 is not supported and is in a slack state. Printed board 100 imperial side (bottom side) by pressing like this
The protruding component terminal 12 is dipped into the molten solder 3 to adhere the solder, and then the solder cylinder 2 is lowered again by the action of the hydraulic cylinder 40.

(7) As a detailed explanation of the invention, in the present invention, molten solder is stored in a solder bath, and the surface of the molten solder is once wiped to remove the surface plated layer, and then the printed board is placed in the bath. Soldering is performed by completely floating the component terminals on the melted solder and protruding into the printed board 1 by immersing them in the bath melted solder. Therefore, the molten solder surface is kept in a horizontal shape with uniformity, and high quality molten solder with less oxidized solder and less unevenness is applied to the entire terminal on the back of the printed board. A highly reliable solder joint with uniform adhesion can be obtained. In addition, since the molten solder surface acts on each terminal in an extremely quiet and stable manner without turbulent flow, reliable solder joints with less solder icicles, blisters, and jigs are achieved. Since the terminals protruding downward from the printed board are immersed in the molten solder while the printed board is completely floating above the molten solder, the rise 1 of the solder bath is adjusted according to the length of the terminal protruding downward from the printed board. Good, uniform and reliable bulk solder joints can easily be achieved with a single up and down movement of the solder bath for terminals of any length.

Note that the printed board may be moved up and down instead of moving the solder tank up and down.

[Brief explanation of drawings]

The drawing is a sectional view of a soldering device for carrying out the method of the invention. 2... Semicircular tank, 3... Molten solder, 6... Horizontal fragment,
9... Wire, 10... Printed board, ll... Parts, 12... Terminal. Patent Applicant: Fujitsu Limited Patent Application Agent Patent Attorneys: Akira Aomizu, Patent Attorney Kazuyuki Nishidate, Patent Attorney 1) Yukio Patent Attorney, Anyuki Yamaguchi

Claims (1)

[Claims] 1. In the method of soldering the mounted component terminals on the back side of the printed circuit board with 9 glints on the backside of the glint board, wipe the surface of the molten solder in the solder bath to remove the surface oxidation layer.
Soldering of printed circuit boards is characterized in that component terminals protruding from the back of the print board are soldered by floating the printed board to be soldered with the back side facing down on a mill solder. Method.