JP2005223230A - Printing method of solder and printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method whereby, when repairing a surface mounting component having many pins and narrowly pitched terminals after detaching the component therefrom, solders are printed accurately and without using any devoted mechanical equipment. <P>SOLUTION: The printing of solders is performed by using a metal mask 1 having aligning holes, and by using a printed board 3 having lands for forming protrusions for aligning references. The aligning holes 2 of the metal mask are aligned with the aligning protrusions 4 present on the printed board which are formed previously of solders. Consequently, the openings of the metal mask are aligned simply and accurately with the solder printing positions of the printed board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solder printing method at the time of repairing a mounted component, and more particularly to a method and jig for easily performing alignment.

  When a mounting part with multiple pins and narrow pitch terminals, such as a BGA type package or QFP type package, is removed from a printed circuit board once soldered and replaced with a new part, it is printed because other parts are mounted. It is necessary to supply solder partially to the land on the board or to supply solder to the component side.

  As a method of supplying the solder to the land, for example, a solder wire having a required length is placed on the board land as disclosed in Japanese Patent Application Laid-Open No. 07-074458, and the solder is melted by non-contact heating to be soldered on the land. And a method of transferring solder onto a substrate land after supplying solder by screen printing to a solder supply jig as disclosed in JP-A-2002-57453 (Patent Document 2).

As a method for supplying solder to the component side, a method of transferring solder to terminals of a mounted component by screen printing as disclosed in Japanese Patent No. 3039543 (Patent Document 3) is disclosed.
JP 07-074458 JP2002-57453 Special registration 3039543

  The solder supply process in the conventional mounting component repair method performs solder printing by manually aligning the metal mask, so printing can be performed with high accuracy, especially for mounting components with multiple pins or narrow pitch leads. It was difficult.

  In the method of placing the solder wire on the substrate land and heating it to melt the solder and transfer the solder onto the land, it is expected that a solder bridge will be generated between the lands depending on the heating method. Further, there is a concern that the adhesion strength of the land to the substrate may be reduced by increasing the number of times of heating.

  In addition, in the method of transferring solder onto the board land after the solder is once supplied to the jig for supplying solder by screen printing, capital investment is required to transfer it to the board land position with high accuracy.

  In addition, in the method of transferring solder to the terminals of the mounted component, there is a problem that even if the flatness of the lead terminals varies in the QFP type package, uniform solder transfer cannot be performed for each lead terminal. Furthermore, when the lead terminal is thin and weak, there is also a problem that the lead terminal is bent due to stress at the time of solder transfer.

  The present invention solves the above problems and provides a method for performing solder printing with ease and accuracy.

  The present invention provides a metal mask having a positioning hole in addition to a pattern hole corresponding to a solder application position of a mounted component and a land having a land for forming a positioning reference projection when performing solder printing. A substrate is used.

  According to the present invention, by aligning the alignment hole of the metal mask with the alignment protrusion on the printed circuit board formed in advance by solder, the metal mask opening is manually placed at the solder printing position of the printed circuit board. Can be combined easily and accurately.

  According to the first aspect of the present invention, it is possible to easily and accurately perform solder printing without using a special dedicated machine when repairing a surface mount component having multiple pins and a narrow pitch terminal.

  According to the second aspect of the present invention, since it is only necessary to make a hole necessary for the metal mask, a printing jig can be created easily and at low cost.

  According to the third aspect of the present invention, it is possible to form the alignment protrusion easily and at low cost, and it is possible to perform solder printing with high accuracy by using the protrusion.

  In the present invention, solder printing is performed using a metal mask 1 having alignment holes and a printed circuit board 3 having lands for forming alignment reference protrusions. The purpose of aligning the opening of the metal mask with the solder printing position of the printed circuit board easily and accurately by aligning the alignment hole 2 of the metal mask with the alignment protrusion 4 formed on the printed circuit board in advance by soldering. It is said.

  Embodiments of the present invention will be described in detail. FIG. 1 is a perspective view of a solder printing jig (metal mask 1) and a printed board to which the present invention is applied. The alignment protrusions 4 of the printed circuit board 3 are formed by performing solder printing simultaneously with normal soldering, or are formed by manual soldering after removing components during repair. FIG. 2 is a plan view of the metal mask 1. The alignment hole 2 of the metal mask 1 and the hole position of the metal mask opening 5 are mounted on the printed circuit board when the alignment hole 2 is aligned with the alignment protrusion 4 on the printed circuit board. It is designed to fit the component mounting land 8. Further, when solder printing is performed using a squeegee, the alignment hole 2 is placed at the corner of the metal mask 1 so that the squeegee and the alignment protrusion 4 do not interfere with each other. Moreover, since the dimension of the metal mask 1 can be reduced by reducing the hole diameter of the alignment hole 2, the metal mask 1 and the like can be used even when there are other mounting parts around the mounting part to be repaired. Solder printing can be performed without interference of the mounted parts.

  In order to perform solder printing according to the present invention, after mounting components are removed and unnecessary solder remaining on the lands 8 is removed, a metal mask is placed so that the alignment holes 2 are aligned with the alignment protrusions 4 as shown in FIG. The cream solder 7 is printed using a squeegee 6 placed on a printed circuit board.

The perspective view of the jig for solder printing and the printed circuit board to which the present invention is applied. The top view of the jig for solder printing to which the present invention is applied. The solder printing process sectional drawing to which this invention is applied.

Explanation of symbols

1 Metal mask 2 Alignment hole 3 Printed circuit board 4 Alignment protrusion 5 Metal mask opening 6 Squeegee 7 Cream solder 8 Land

Claims (3)

  In a solder printing method for repairing a mounting component mounted on a printed circuit board, a solder protrusion different from that for connecting the mounting component in the vicinity of the mounting position of the mounting component on the printed circuit board from which the mounting component is removed A solder printing method, wherein solder is printed on a land for connection of a mounted component by providing at least two lands made of and positioning a metal mask on the land made of the solder protrusion.   The solder printing method according to claim 1, wherein an alignment hole is provided in a part of the metal mask.   At least two lands made of solder protrusions different from those used for connecting the mounted parts are formed in the vicinity of the mounted parts mounted on the printed circuit board on the printed circuit board. A printed circuit board characterized by being used for positioning a metal mask that prints solder on a land for connecting a mounted component when repairing the component.

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