JP2013016765A - Solder absorbing sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solder absorbing sheet which removes solder at once in a short time.SOLUTION: A solder absorbing sheet is composed of multiple copper wire net layers and is formed by pressure welding the respective wire net layers so that the wire net layers closely contact with each other. Further, the respective wire net layers are engaged with each other by multiple engagement parts.

Description

  The present invention relates to a solder blotting sheet used when removing solder remaining on a pad surface of a printed circuit board.

  When a defect occurs in the printed circuit board or a soldered component mounted thereon, repair or rework work is performed. For example, a BGA component is removed and a new BGA component is mounted on the printed circuit board. It is necessary to remove the solder remaining on the printed circuit board after removing the components. The removal of the residual solder needs to minimize the thermal stress on the printed circuit board. In particular, damage such as peeling of the pad due to thermal stress must be prevented.

  Patent Document 1 describes a technique for removing solder remaining on a pad surface using a wick. According to this technology, the tip of the soldering iron formed on the curved surface is moved in an arc, the solder is melted by the heat supplied from the iron, and the wick width and length are divided at once using the capillary phenomenon. Only the solder can be removed.

JP 2008-172179 A

  When the electronic component is removed from the printed circuit board, a lot of solder remains. In order to mount a new electronic component, it is necessary to remove the remaining solder cleanly. When removing this residual solder, it is desirable to finish it clean in a short time in order to minimize the peeling of the pad and the thermal damage to the substrate. However, the above-mentioned prior art document 1 does not clearly indicate the desirable configuration and structure of the wick.

  Moreover, various electronic parts are used for soldering areas of electronic parts from large to small. For this reason, it is strongly desired to supply not only a standard size solder sucking sheet, but also a free size cut type solder sucking sheet that can be cut out by an operator with an arbitrary size.

  An object of the present invention is to provide a solder blotting sheet that can solve the above-described problems. Therefore, the present inventor paid attention to the configuration and structure of the solder blotting sheet.

  That is, the solder blotting sheet according to claim 1 is a solder blotting sheet that sucks solder by a capillary phenomenon, and is composed of a plurality of copper metal meshes, and is press-contacted so that the metal mesh layers are in close contact with each other.

  The solder blotting sheet according to claim 2 is composed of a plurality of copper wire meshes, each wire mesh layer is press-contacted so as to be in close contact with each other, and each wire mesh layer is locked by a plurality of locking portions. It is characterized by.

  According to the solder blotting sheet according to claim 1, as a result of the press-contact of a plurality of copper wire meshes, the distance between the wire meshes and the copper wire constituting the wire mesh are compressed, the gaps are made finer and the capillary phenomenon is activated and melted. It is possible to further increase the solder sucking effect. In addition, according to the solder blotting sheet of the second aspect, the plurality of layers of copper metal mesh are pressed together and a plurality of locking portions are provided, so that the above-described operation and a plurality of layers can be freely cut out with any size. It is possible to prevent the wire mesh from separating apart.

The top view which shows the partial expansion of the copper metal mesh which comprises the solder blotting sheet by this invention. 1 is a front view showing a state in which the copper wire mesh is folded into three layers. Sectional drawing cut | disconnected by the AA line in the state which bent the copper metal mesh in three layers. The side view which shows the model of the press molding process by a press. Sectional drawing of the solder blotting sheet after pressure molding. Sectional drawing of the solder blotting sheet which bent and crimped the extension part of the edge part. The solder blotting sheet which shows 2nd Example by invention is shown, (a) is the top view, (b) is the side view cut | disconnected by the BB line. The perspective view which shows the relationship between the solder blotting sheet by this invention, and the heating block located in the front-end | tip of a iron.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is an enlarged front view of a copper wire mesh constituting a solder blotting sheet. The copper wire mesh 1 is manufactured by plain weaving of copper wire, and the wire diameter (thickness) and weaving density of the copper wire can be selected from various ones. The recommended range is φ0.08 with a weaving density of 120 mesh and φ0.05 with a weaving density of 150 mesh.

  FIG. 2 is a front view of a solder sucking sheet 2 cut out from a copper wire mesh 1 in a laterally long size three times the solder sucking area of an electronic component generally used, and folded in three steps and lightly pressed. FIG. It is a side view.

  FIG. 4 is a side view for explaining a process of pressure-molding the solder blotting sheet 2 shown in FIG. The solder blotting sheet 2 set between the press dies 3 and 4 is pressed with an appropriate pressure. By this crimping, the copper wire is deformed from a round shape to a flat shape, and a mutual biting deformation occurs between the layers. As a result, the adhesion between the three layers is improved and each layer is prevented from spreading, and the mesh is deformed into a small area. This activates the capillary phenomenon that sucks up the melted solder and improves the efficiency of the solder removal operation. Further, in addition to the solder holding of the metal mesh layer itself, the metal mesh layer is brought into close contact, so that the solder holding capacity is increased, and more solder can be absorbed and removed by one removal operation. The press dies 3 and 4 have curved surfaces with the same curvature, and when the pressing process is completed, the solder sucking sheet 2 is obtained in a curved shape along the press die as a whole as shown in FIG.

  In FIG. 6, the end 7 of the copper wire mesh is bent inside the curved surface, and the caulking stopper 7 a is formed so that the three-layer wire mesh is not separated.

  7A and 7B show a solder blotting sheet 20 showing a second embodiment according to the invention, in which FIG. 7A is a front view thereof and FIG. 7B is a right side view thereof. The solder blotting sheet 20 is used after being cut into an arbitrary size and shape by an operator. The construction and the production method are the same as those of the solder blotting sheet 2 shown in FIGS. 1 to 6, and are composed of a plurality of layers of wire mesh woven with copper wire, and are pressed so that the wire mesh layers are in close contact with each other. It is formed into a curve.

  Here, an example of a method for forming the locking portion 8 will be described. The material constituting the locking portion 8 is cream solder, and a certain amount is applied on the solder blotting sheet surface at regular intervals. For this reason, a stainless steel metal mask was used. For example, small holes of φ1 mm and φ0.8 mm are formed vertically and horizontally at intervals of 10 mm in the metal mask, and an appropriate amount of cream solder is placed on the metal mask surface and the squeegee is operated to print on the copper wire mesh surface. The thickness of the metal mask is 0.1 to 0.3 mm, and is selected according to the type of copper wire mesh to be processed. After the cream solder is printed, the engaging portion 8 is completed by heating and soldering in a heating furnace.

  The locking portion 8 can be a guide for cutting the sheet into an arbitrary size and shape, and can prevent the copper wire mesh layers from being separated.

  It is recommended that the solder blotting sheets 2 and 20 be treated to prevent oil removal and discoloration of the copper wire mesh during the manufacturing process in order to further increase the blotting effect. Thereafter, a solder paste is applied. This solder paste promotes the wettability of the molten solder and further increases the solder sucking efficiency by capillary action. Moreover, the application of the solder paste further strengthens the integration of each wire mesh layer. Therefore, the layers are prevented from being separated.

  As shown in FIG. 8, the curved solder sucking sheets 2 and 20 are arranged between a heating block 9 having a curved heating pressing surface and a printed circuit board (not shown), and the heating block is used as a solder sucking sheet. 2 and 20 are pressed against the printed circuit board and oscillated, so that the solder can be removed at once in a short time.

1 Copper wire mesh 2,20 Solder blotting sheet 8 Locking part 9 Heating block

Claims (2)

  A solder absorbing sheet for absorbing solder by a capillary phenomenon, comprising a plurality of copper wire meshes, wherein the wire mesh layers are pressed against each other so as to be in close contact with each other.   A solder blotting sheet that absorbs solder by capillary action, consisting of multiple layers of copper wire mesh, pressed against each other so that each wire mesh layer is in close contact with each other, and each wire mesh layer is locked by a plurality of locking portions A solder blotting sheet characterized by comprising:

Images