JP2010212591A - Circuit board and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circuit board for improving yield by covering a through-hole with a mask to prevent the through-hole from being closed by first solder in a reflow soldering. <P>SOLUTION: The method for manufacturing a circuit board 1 includes: providing first and second land portions 11, 21 by exposing a part of a conductor portion 4 formed on an insulating substrate 2, soldering a chip component 10 on the first land portion 11, and soldering an insertion component 20 to the second land portion 21 having the through-hole 21a. The manufacturing method further includes: a reflow soldering step of covering a predetermined position with a mask 6 and applying a paste-like first solder 12 on the first and second land portions 11, 21, a chip component mounting step of soldering the chip component 10 to the first land portion 11, a flow soldering step of providing a second solder 22 on the second land portion 21 by immersing the insulating substrate 2 into a solder bath, and an insertion component mounting step of soldering an insertion component 20 inserted into the through-hole 21a to the second land portion 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a circuit board on which a chip part and an insertion part are mounted, and a manufacturing method thereof.

  A conventional circuit board is disclosed in Patent Document 1. In this circuit board, solder is provided by a reflow soldering process and a flow soldering process on a land part where a part of a conductor part provided on an insulating substrate is exposed. In the reflow soldering process, paste solder such as cream solder is applied to the land portion. A chip component such as an IC is placed on the solder provided in the reflow soldering process, and is heated to a predetermined temperature in a constant temperature bath and soldered.

  In the flow process, the insulating substrate is immersed in a solder bath and solder is provided on the land portion having a through hole. An insertion component such as a capacitor is inserted into the through hole and soldered by solder provided on a land portion around the through hole.

JP 2008-60327 A (pages 4-5, FIG. 5)

  However, according to the conventional circuit board, since the insulating substrate is placed in the thermostatic bath in the reflow soldering process, the land portion on which the insertion component is arranged is easily oxidized. For this reason, there is a problem that the solder is difficult to be attached to the land portion in the flow soldering process, the soldering failure of the inserted component occurs, and the yield of the circuit board is lowered.

  An object of this invention is to provide the circuit board which can improve a yield, and its manufacturing method.

  In order to achieve the above object, the present invention provides first and second land portions exposing a part of a conductor portion formed on an insulating substrate, soldering a chip component to the first land portion, and through holes A reflow soldering process in which a paste-like first solder is applied to the first and second land portions so as to cover a predetermined position with a mask; A chip component mounting step of soldering the chip component to one land portion, a flow soldering step of immersing the insulating substrate in a solder bath to provide a second solder in the second land portion, and the insertion inserted into the through hole And an insertion component mounting step of soldering the component to the second land portion.

  According to this configuration, the conductor portion having a predetermined pattern is formed on the insulating substrate, and the first and second land portions are provided by exposing a part of the conductor portion. In the reflow soldering process, the first and second land portions are exposed, the insulating substrate is covered with a mask, and paste-like first solder such as cream solder is applied on the first and second land portions. In the chip component mounting step, the chip component is placed on the first solder of the first land portion, and the chip component is soldered by placing the insulating substrate in a constant temperature bath. In the flow soldering process, the insulating substrate is immersed in the solder bath, and the second solder adheres to the first solder on the second land portion. At this time, the insulating substrate may be immersed in a solder bath covering the chip component. In the insertion component mounting step, the insertion component is inserted into the through hole of the second land portion, and the insertion component is soldered by the second solder.

  According to the present invention, in the method for manufacturing a circuit board having the above configuration, the through hole is covered with the mask. According to this configuration, the through hole is covered with the mask in the reflow soldering process, and the blocking of the through hole by the first solder is prevented.

  According to the present invention, in the method for manufacturing a circuit board having the above-described configuration, the chip component is mounted by providing the first land portions on both surfaces of the insulating substrate, and the second solder is provided on the second land portion on one surface. The reflow soldering process on one surface is performed before the chip component mounting process on the other surface.

  According to this configuration, for example, the first solder is applied to the first land portion on the surface of the insulating substrate by the reflow solder process, and then the first solder is applied to the first and second land portions on the back surface by the reflow solder process. The Then, after the chip components are mounted on the first land portions on both sides by the chip component mounting step, the second solder is provided on the second land portions on the back surface by the flow solder process. After the chip component is mounted on the first land portion on the back surface, a reflow soldering process for the first land portion on the front surface may be performed.

  According to the present invention, the first land portion and the second land portion having the through hole are exposed on the insulating substrate, and the chip component is soldered by applying the paste-like first solder to the first land portion. In the circuit board in which the second land is provided in the second land portion by immersing the insulating substrate in the solder bath and the inserted component is soldered, the second solder is applied after the first solder is applied to the second land portion. It is characterized by providing.

  According to this configuration, the chip component is soldered on the first land portion to which the first solder is applied. First and second solders are stacked on the second land portion, and an insertion component inserted into the through hole of the second land portion is soldered.

  According to the present invention, the paste-like first solder is applied to the second land portion to which the insert component is attached, and the second solder is provided on the first solder of the second land portion by immersing the insulating substrate in the solder bath. Further, oxidation of the second land portion can be prevented without requiring an expensive plating process or the like. Therefore, it is possible to reduce the soldering failure of the inserted part and improve the yield of the circuit board. In addition, the second solder is easily attached by the flux component contained in the first solder, and the soldering time can be shortened to reduce the thermal stress on the electronic component.

Side surface sectional drawing which shows the circuit board of embodiment of this invention Side surface sectional drawing which shows the surface reflow soldering process of the circuit board of embodiment of this invention Side surface sectional drawing which shows the surface chip component mounting process of the circuit board of embodiment of this invention Side surface sectional drawing which shows the back surface reflow soldering process of the circuit board of embodiment of this invention The top view which shows the mask of the back surface reflow soldering process of the circuit board of embodiment of this invention Part A and part B enlarged view of FIG. The top view which shows the 2nd land part of the back surface reflow soldering process of the circuit board of embodiment of this invention Side surface sectional drawing which shows the back surface chip component mounting process of the circuit board of embodiment of this invention Side surface sectional drawing which shows the flow soldering process of the circuit board of embodiment of this invention

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a circuit board according to an embodiment. In the circuit board 1, a conductor portion 4 having a predetermined pattern is formed on an insulating substrate 2 by a copper foil or the like. The conductor portion 4 is covered with a resist 5 and a part thereof is exposed, and first and second land portions 11 and 21 are formed. The second land portion 21 is provided around a through hole 21 a that penetrates the insulating substrate 2.

  A paste-like first solder 12 such as cream solder is applied on the first land portion 11, and the leg portion 10a of the chip component 10 such as an IC is soldered. A second solder 22 is provided on the second land portion 12 by dipping the insulating substrate 2 in a solder bath, and a leg portion 20a of an insertion component 20 such as a capacitor is inserted into the through hole 21a and soldered.

  2 to 9 show the manufacturing process of the circuit board 1. FIG. 2 shows a side cross-sectional view of a surface reflow soldering process in which the first solder is applied to the first land portion 11 on one surface (front surface) of the insulating substrate 2. The insulating substrate 2 is formed with first and second land portions 11 and 21 in which a part of the conductor portion 4 is exposed, and paste-like first solder 12 such as cream solder is applied to the first land portion 11 on the surface. The At this time, the second land portion 21 on the surface having the through hole 21a is covered with a mask or the like.

  Next, FIG. 3 shows a side sectional view of a surface chip component mounting process for mounting the chip component 10 on the surface of the insulating substrate 2. On the first solder 12 of the first land portion 11 on the surface of the insulating substrate 2, a leg portion 10 a of a chip component 10 such as an IC is installed. Then, the insulating substrate 2 is placed in a constant temperature bath, and the chip component 10 is soldered by the melted first solder 12.

  Next, FIG. 4 shows a side cross-sectional view of a back surface reflow soldering process in which the first solder 12 is applied to the first land portion 11 on the other surface (back surface) of the insulating substrate 2. On the back surface of the insulating substrate 2, a mask 6 as shown in FIG. The insulating substrate 2 is covered by exposing the first and second land portions 11 and 21 to which the first solder 12 is applied by the mask 6. Then, paste-like first solder 12 such as cream solder is applied to the first and second land portions 11 and 21.

  FIG. 6 shows details of part A and part B of FIG. In the mask 6, a plurality of arch-shaped holes 6 a facing the second land portion 21 are annularly arranged. Thereby, the circular shielding part 6b which covers the through-hole 21a of the 2nd land part 21 is formed inside the inner edge of the hole 6a. When the insulating substrate 2 is covered with the mask 6 and the first solder 12 is applied, the arch-shaped first solder 12 is formed on the second land portion 21 as shown in FIG.

  Next, FIG. 8 shows a side cross-sectional view of a back surface chip component mounting process for mounting the chip component 10 on the back surface of the insulating substrate 2. A leg portion 10 a of the chip component 10 is installed on the first solder 12 of the first land portion 11 on the back surface of the insulating substrate 2. Then, the insulating substrate 2 is placed in a constant temperature bath, and the chip component 10 is soldered by the melted first solder 12.

  Next, FIG. 9 shows a side sectional view of a flow soldering process in which the second solder 22 is provided on the second land portion 21 on the back surface of the insulating substrate 2. The insulating substrate 2 covers the chip component 10 on both sides and the second land portion 21 on the surface with a mask (not shown) and is immersed in a solder bath. Thereby, the second solder 22 is provided on the second land portion 21 on the back surface. At this time, since the second solder 22 adheres on the first solder 12 applied to the second land portion 21, the second solder 22 can be easily attached by the flux component contained in the first solder 12.

  Then, in the insertion component mounting step, the leg 20a of the insertion component 20 is inserted into the through hole 21a and the insertion component 20 is soldered, whereby the circuit board 1 shown in FIG. 1 is obtained.

  According to the present embodiment, the paste-like first solder 12 is applied to the second land portion 21 to which the insertion component 20 is attached in the back surface reflow soldering process (reflow soldering process), and the insulating substrate 2 is placed in the solder bath in the flow soldering process. Since the second solder 22 is provided on the first solder 12 of the second land portion 21 by immersion, oxidation of the second land portion 21 can be prevented without requiring an expensive plating process or the like. Therefore, the soldering failure of the insertion component 20 can be reduced and the yield of the circuit board 1 can be improved. In addition, the second solder 22 is easily attached by the flux component contained in the first solder 12, and the soldering time can be shortened to reduce the thermal stress on the electronic component.

  Further, since the through hole 21a is covered with the mask 6 in the back surface reflow soldering process, the through hole 21a can be prevented from being blocked by the first solder 12.

  In the present embodiment, the back surface reflow soldering process is performed after the front surface chip component mounting process, but may be performed before the front surface chip component mounting process. Thus, the first solder 12 is applied to the second land portion 21 on the back surface on which the second solder 22 is provided before the insulating substrate 2 is placed in the thermostatic chamber in the surface chip component mounting process. Therefore, the oxidation of the second land portion 21 can be prevented more reliably. In addition, you may perform a surface reflow soldering process and a surface chip component mounting process after a back surface chip component mounting process.

  The present invention can be used for a circuit board on which a chip component and an insertion component are mounted.

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Insulating board 4 Conductor part 5 Resist 6 Mask 6a Hole part 10 Chip component 11 1st land part 12 1st solder 20 Insertion part 21 2nd land part 21a Through-hole 22 2nd solder

Claims (4)

  Provided are first and second land portions exposing a part of the conductor portion formed on the insulating substrate, soldering the chip component to the first land portion, and soldering the insertion component to the second land portion having a through hole. In a method of manufacturing a circuit board to be attached, a reflow soldering process in which a predetermined position is covered with a mask and paste-like first solder is applied to first and second land portions, and the chip component is soldered to the first land portions. Chip component mounting step, flow soldering step of immersing the insulating substrate in a solder bath to provide second solder on the second land portion, and insertion for soldering the inserted component inserted into the through hole to the second land portion A circuit board manufacturing method comprising: a component mounting step.   The method for manufacturing a circuit board according to claim 1, wherein the through hole is covered with the mask.   The first land portions are provided on both surfaces of the insulating substrate to mount the chip component, the second solder is provided on the second land portion on one surface, and the reflow soldering process on one surface is performed on the other surface. The method for manufacturing a circuit board according to claim 1 or 2, wherein the method is performed before the chip component mounting step.   A first land portion and a second land portion having a through hole are exposed on the insulating substrate, and a paste-like first solder is applied to the first land portion to solder a chip component. In the circuit board in which the second solder is provided in the second land portion by being immersed in the solder bath and the insertion component is soldered, the second solder is provided after the first solder is applied to the second land portion. A circuit board.

Images