JP2007142255A - Method of manufacturing circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a circuit board by which a small circuit board is obtained. <P>SOLUTION: The method of manufacturing the circuit board removes a dam 9 after forming an underfill 7, so that the dam 9 does not exist after manufacturing the circuit board. Thus, on the surface of an insulation board 1 where the dam 9 is positioned conventionally, a land 2b, a cover 8 etc. can be arranged, so that the surface of an insulation board 1 where the dam 9 is positioned conventionally is utilized effectively, and the small circuit board is obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a circuit board suitable for use in various electric devices, electronic circuit units, and the like.

  FIG. 8 is a plan view of an insulating substrate for explaining a conventional circuit board manufacturing method, and FIG. 9 is a diagram for explaining a conventional circuit board manufacturing method. It is principal part sectional drawing.

  Next, a configuration when a circuit board manufactured by a conventional manufacturing method is applied to an electronic circuit unit will be described with reference to FIGS. 8 and 9. A part of a wiring pattern is formed on an insulating substrate 51. A land portion 52a for mounting the semiconductor component 54, a land portion 52b for mounting a chip component (not shown), and a dam 53 provided so as to surround the mounting region S3 of the semiconductor component 54.

  Although not shown here, the chip component is attached to the land portion 52b by soldering, and as shown in FIG. 9, the semiconductor component 54 is disposed in the attachment region S3 and soldered to the land portion 52a by soldering 55. It is attached.

  An underfill 56 is provided within the range of the attachment region S3 so as to include the space between the insulating substrate 51 and the semiconductor component 54. The underfill 56 strengthens the attachment of the semiconductor component 54 and also provides an underfill. 56 is prevented from flowing out by the dam 53 to form a conventional electronic circuit unit (see, for example, Patent Document 1).

  Next, a conventional circuit board manufacturing method will be described with reference to FIGS. 8 and 9. First, as shown in FIG. 8, an insulating substrate 51 provided with lands 52a and 52b and a dam 53 is prepared. In addition, as shown in FIG. 9, a semiconductor component 54 is attached to the land portion 52a by solder 55, and a chip component is attached to the land portion 52b by solder.

Next, an underfill 56 is injected between the insulating substrate 51 and the semiconductor component 54, and the attachment of the semiconductor component 54 is strengthened by the underfill 56, and the underfill 56 flows out by the dam 53. This prevents the conventional circuit board from being manufactured (see, for example, Patent Document 1).
JP 2004-179576 A

  However, in the conventional method of manufacturing a circuit board, the dam 53 exists on the insulating substrate 51 after the manufacturing, and the insulating substrate 51 becomes larger by the space of the dam 53, and the chip component is soldered. Therefore, it is necessary to provide the land portion 52b away from the dam 53, and there is a problem that the insulating substrate 51 becomes larger and the circuit board becomes larger.

  The present invention has been made in view of the actual situation of the prior art, and an object thereof is to provide a method of manufacturing a circuit board from which a small circuit board can be obtained.

  In order to achieve the above object, the present invention provides a mounting step for attaching a semiconductor component to a land portion provided on the insulating substrate, and a dam forming step for forming a dam on the insulating substrate so as to surround the outer periphery of the semiconductor component. And an underfill forming step of providing an underfill between the insulating substrate and the semiconductor component within a range surrounded by the dam, and a dam removing step of removing the dam after the underfill forming step. It is said.

  In the present invention configured as described above, since the dam does not exist after the circuit board is manufactured, the land portion, the cover, or the like can be arranged on the insulating substrate surface on which the dam is located, and the insulating substrate surface on which the dam is positioned can be effectively used. A small circuit board can be obtained.

  Moreover, the present invention is characterized in that, in the above invention, the dam removing step is performed after the underfill is solidified. According to the present invention configured as described above, underfill does not flow out in the dam removing step, and the underfill can be reliably formed.

  Further, the present invention is characterized in that, in the above-described invention, the chip component is attached to the land portion of the insulating substrate by soldering, and the dam is formed over the solder in the dam forming step.

  In the present invention configured as described above, the land portion can be pierced to the surface of the insulating substrate where the dam is located, so that the circuit board can be reduced in size and the dam does not exist on the solder. When the solder is further soldered to the mother board using the terminals, the heat of the reflow furnace expands the moisture and flux residue contained in the dam agent and the insulating board, and pushes out the solder attaching the chip component. There are no defects.

  Moreover, the present invention is characterized in that, in the above invention, the insulating substrate has a region for attaching a cover, and the dam is formed over the region in the dam forming step. In the present invention configured as described above, the cover can be attached to the cover region where the dam is located, and the circuit board can be miniaturized.

  The present invention is characterized in that, in the above-mentioned invention, the dam is formed of a silicon rubber-based resin and the underfill is formed of an epoxy resin. According to the present invention configured as described above, the semiconductor component can be firmly attached by the underfill, and the outflow of the underfill can be surely prevented by the dam, and the dam can be easily removed.

  The present invention is characterized in that, in the above-mentioned invention, the dam is removed by cleaning in the dam removing step. In the present invention configured as described above, the dam can be easily removed by washing the fluorocarbon organic solvent, and a product with good productivity can be obtained.

  In the present invention, since the dam does not exist after the circuit board is manufactured, the land portion, the cover, etc. can be arranged on the insulating substrate surface where the dam is located, and the insulating substrate surface where the dam is located can be used effectively, and the small size A circuit board can be obtained.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a main part in which a circuit board manufactured by the manufacturing method of the present invention is applied to an electronic circuit unit, and FIG. It is a top view which shows the state in which the manufactured circuit board was applied to the electronic circuit unit, and the cover was removed.

  3 is a front view showing a first step of the circuit board manufacturing method of the present invention, FIG. 4 is a front view showing a second step of the circuit board manufacturing method of the present invention, and FIG. 5 is a circuit board of the present invention. FIG. 6 is a front view showing a third step of the circuit board manufacturing method of the present invention, and FIG. 7 is a plan view showing the third step of the circuit board manufacturing method of the present invention. FIG.

  Next, the configuration when the circuit board manufactured by the manufacturing method of the present invention is applied to an electronic circuit unit will be described with reference to FIGS. 1 and 2. The insulating substrate 1 includes a wiring pattern 2 and the wiring pattern. 2, a land portion 2 a for attaching the semiconductor component 3 provided on the upper surface of the insulating substrate 1, a land portion 2 b for attaching the chip component 4, and a lower surface of the insulating substrate 1. A terminal 2c is provided.

  The semiconductor component 3 made of a bare chip or the like is disposed in the mounting region S1 of the semiconductor component 3 of the insulating substrate 1 and attached by being soldered 5 to the land portion 2a, and the chip component 4 made of a chip capacitor, a chip resistor or the like. The solder 6 is attached to the land portion 2b, and a desired electric circuit is formed on the insulating substrate 1 which is a circuit board.

  The underfill 7 is formed of an epoxy resin and is provided on the insulating substrate 1 positioned around the semiconductor component 3 including the space between the insulating substrate 1 and the semiconductor component 3. The underfill 7 firmly attaches the semiconductor component 3. I have to.

The box-shaped cover 8 made of a metal plate has a cover 8a and a plurality of legs 8b extending downward from the cover 8a. The cover 8 covers the semiconductor component 3 and the chip component 4 with the cover 8a. Covering, the leg portion 8b is inserted into the hole 1a of the insulating substrate 1, and the lower end portion of the covering portion 8a is positioned in the mounting region S2 of the cover 8 of the insulating substrate 1, and is attached to the insulating substrate 1 by appropriate means, The electronic circuit unit of the present invention is formed.
The electronic circuit unit of the present invention having such a configuration is not shown here, but the terminal 2c provided on the insulating substrate 1 is placed on the cream solder provided on the land portion of the mother substrate, and then reflowed. It is transported to the furnace and soldered to the mother board.

  Next, a method of manufacturing a circuit board according to the present invention will be described with reference to FIGS. 3 to 7. First, as shown in FIG. 3 as a first step, the semiconductor component 3 is attached to the land portion 2a with solder 5 attached thereto. At the same time, an attachment process is performed in which the chip component 4 is attached to the land portion 2b by soldering.

  Next, as shown in FIG. 4 and FIG. 5 as a second step, the insulating substrate 1 located in the vicinity of the outer periphery of the semiconductor component 3 is made of a silicon rubber resin so as to surround the outer periphery of the semiconductor component 3. A dam formation process for forming the dam 9 is performed.

  At this time, the dam 9 is formed over the solder 6 to which the chip component 4 is attached and the attachment region S2 of the cover 8.

  Next, as shown in FIGS. 6 and 7 as a third step, an underfill 7 made of an epoxy resin is formed on the insulating substrate 1 including the space between the insulating substrate 1 and the semiconductor component 3 in the region surrounded by the dam 9. After performing the underfill forming step for forming the underfill 7, a solidifying step for solidifying the underfill 7 by heating or the like is performed.

  The underfill 7 strengthens the mounting of the semiconductor component 3 and the underfill 7 is prevented from flowing out by the dam 9.

  Next, when a dam removing process for removing the dam 9 made of silicon rubber resin is performed by cleaning with a fluorocarbon organic solvent, as shown in FIG. 2, the solder 6 to which the chip component 4 is attached and the cover 8 are attached. The dam 9 on the insulating substrate 1 including the region S2 is removed, and the manufacture of the circuit board of the present invention is completed.

  When the electronic circuit unit of the present invention is manufactured, if the cover 8 is disposed and mounted in the mounting region S2 including the position where the dam 9 is present, the manufacturing of the electronic circuit unit of the present invention is completed.

  Further, as a method for removing the dam 9, the dam 9 may be removed by tweezers or a cutter knife.

It is principal part sectional drawing by which the circuit board manufactured by the manufacturing method of this invention was applied to the electronic circuit unit. It is a top view which shows the state which the circuit board manufactured by the manufacturing method of this invention was applied to the electronic circuit unit, and the cover was removed. It is a front view which shows the 1st process of the manufacturing method of the circuit board of this invention. It is a front view which shows the 2nd process of the manufacturing method of the circuit board of this invention. It is a top view which shows the 2nd process of the manufacturing method of the circuit board of this invention. It is a front view which shows the 3rd process of the manufacturing method of the circuit board of this invention. It is a top view which shows the 3rd process of the manufacturing method of the circuit board of this invention. It is a top view of the insulated substrate for demonstrating the manufacturing method of the conventional circuit board. It is principal part sectional drawing for demonstrating the manufacturing method of the conventional circuit board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation board | substrate 1a Hole 2 Wiring pattern 2a, 2b Land part 2c Terminal 3 Semiconductor component 4 Chip component 5, 6 Solder 7 Underfill 8 Cover 8a Cover part 8b Leg part 9 Dam S1 Semiconductor component attachment area S2 Cover attachment area

Claims (6)

A mounting step of attaching a semiconductor component to a land portion provided on the insulating substrate, a dam forming step of forming a dam on the insulating substrate so as to surround an outer periphery of the semiconductor component, and a range surrounded by the dam An underfill forming step of providing an underfill between the insulating substrate and the semiconductor component, and a dam removing step of removing the dam after the underfill forming step . 2. The circuit board manufacturing method according to claim 1, wherein the dam removing step is performed after the underfill is solidified. 3. The chip part is attached to the land portion of the insulating substrate by soldering, and the dam is formed over the solder in the dam forming step. The manufacturing method of the circuit board of description. The insulating substrate has a region for attaching a cover, and the dam is formed across the region in the dam formation step. The manufacturing method of the circuit board as described in a term. 5. The method of manufacturing a circuit board according to claim 1, wherein the dam is formed of a silicon rubber-based resin, and the underfill is formed of an epoxy resin. 6. 6. The method of manufacturing a circuit board according to claim 5, wherein, in the dam removing step, the dam is removed by cleaning.

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