JPH0621604A - Circuit board device having chip electronic components mounted thereon - Google Patents

Abstract

PURPOSE:To improve productivity by preventing the production of solder bridge (short-circuiting), unsoldered portions and spider balls and thus making subsequent steps less troublesome. CONSTITUTION:In mounting a chip electronic component 2a on a circuit board 1, the total of the thickness of a resist 3a in the first resist processing and that of a resist 3b in the second resist processing is set to about 100mum. The electronic component 2a is placed in contact with the resists 3a and 3b, with a clearance of 100mum above the surface of the circuit board 1. This clearance reduces the amount of solder paste to be pressed under pressure and spreading of the solder by the reflow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount circuit board device for a chip electronic component which is used for a mother board of electronic equipment and prevents the generation of solder bridges (short circuits), unsoldered parts and solder balls.

[0002]

2. Description of the Related Art Conventionally, in this type of chip electronic component surface mount circuit board device, a resist film is printed as a surface treatment. This resist film prevents the generation of solder bridges (short circuits), unsoldered parts and solder balls when connecting chip electronic components between lands by cream solder printing and reflow.

[0003]

However, in the above-mentioned conventional chip electronic component surface mounting circuit board device, a relatively thin resist film is formed by one-time resist printing as the surface treatment during surface mounting. Therefore, the cream solder printed when the chip electronic component is connected to the land is crushed, and a solder bridge (short circuit), an unsoldered portion, and a solder ball are likely to be generated due to spread during reflow. Therefore, it is necessary to manually select and correct in the next process, and there is a problem that the work takes time.

The present invention solves the problems in the prior art as described above, and provides a resist printing portion of about 100 μm in which the chip electronic parts are floated and arranged,
An object of the present invention is to provide an excellent surface mounting circuit board device for a chip electronic component that prevents generation of solder bridges (short circuits), unsoldered parts and solder balls, saves time and effort in the next step, and improves productivity.

[0005]

In order to achieve the above object, a chip electronic component surface mount circuit board device of the present invention comprises:
To have a chip electronic component and a circuit board provided with a plurality of lands for connecting the chip electronic component, and the chip electronic component abuts between the lands for arranging the chip electronic component, and is arranged so as to float from the surface of the circuit board. At least 100 μm
This is a configuration in which a resist printing portion having a thickness is provided.

[0006]

With such a configuration, the chip electronic component surface-mounting circuit board device of the present invention provides a chip electronic component circuit by providing a resist printed portion having a thickness of at least 100 μm between lands by, for example, two times of resist printing. Since it is made to float from the board surface, when connecting the chip electronic component to the land, the printed cream solder is crushed,
Also, solder bridge (short circuit) due to spread during reflow,
The generation of unsoldered parts and solder balls is prevented, and the labor of the next process is reduced, thus improving the productivity.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a surface mounting circuit board device for a chip electronic component of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the external structure of the embodiment. In FIG. 1, reference numeral 1 is a circuit board, 2a and 2b are surface-mounted chip electronic components.

FIG. 2 shows a side structure in which the chip electronic component 2 is surface-mounted on the circuit board 1. In FIG. 2, 1 is a circuit board, 2a is a surface-mounted chip electronic component, 3a,
3b is a two-layer resist film arranged by two times of resist printing. Numerals 4a and 4b are lands arranged on the circuit board 1 and to which both electrodes of the chip electronic component 2 are soldered. Denoted at 5a and 5b are soldering portions where the cream solder is melted and solidified and both electrodes of the chip electronic component 2 are connected to the lands 4a and 4b.

Next, the function of the configuration of this embodiment will be described. In FIG. 2, when the chip electronic component 2 is mounted on the circuit board 1, first, the resist film 3a is formed by resist printing except the lands 4a and 4b.

In FIG. 3, the thickness of the resist film 3a formed by the first resist printing is, for example, 50 μm.
Then, lands 4a and 4b on which the chip electronic component 2 is arranged
Then, a resist film 3b is formed by second resist printing. That is, the thickness of the two layers is about 100 μm.

After forming the resist films 3a and 3b, a conventional cream solder printing process on the lands 4a and 4b is processed, and thereafter, a chip electronic component 2 placement process and a reflow process are performed, followed by a chip electronic component surface. Complete the mounted circuit board.

In this case, the chip electronic component 2 is placed in contact with the resist films 3a and 3b. That is, the chip electronic component 2 is arranged so as to float above the surface of the circuit board 1 by a height of 100 μm.

With this height of 100 μm, the amount of the cream solder printed when the chip electronic component 2 is connected to the lands 4a and 4b is crushed less, and the spread during reflow, for example, the spread due to the capillary phenomenon is reduced. Solder bridges (short circuits), unsoldered parts and solder balls are less likely to occur.

[0015]

As is apparent from the above description, the chip electronic component surface mounting circuit board device of the present invention has, for example, a resist printed portion having a thickness of at least 100 μm provided between the lands by two times of resist printing, Since the chip electronic components are floated from the surface of the circuit board, the printed cream solder is crushed when connecting the chip electronic components to the land, and the solder bridge (short circuit) due to the spread during reflow, unsoldered This has the effect of preventing the generation of parts and solder balls, reducing the labor of the next process, and improving the productivity.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external configuration of an embodiment of a chip electronic component surface-mounting circuit board device of the present invention.

FIG. 2 is a cross-sectional view showing a side structure in which a chip electronic component is surface-mounted on the circuit board shown in FIG.

FIG. 3 is a sectional view for explaining a resist film in an example.

[Explanation of symbols]

 1 Circuit Board 2 Chip Electronic Components 3a, 3b Resist Films 4a, 4b Lands 5a, 5b Soldering Section

Claims (1)

[Claims] 1. A chip electronic component, and a circuit board provided with a plurality of lands for connecting the chip electronic component, wherein the chip electronic component abuts between the lands where the chip electronic component is arranged, A surface mount circuit board device for a chip electronic component, which is provided with a resist printed portion having a thickness of at least 100 μm so as to be floated from the surface of the board.