JPH0427182Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a chip component mounting device, and particularly provides a chip component mounting device suitable for mounting chip components with adhesive.

BACKGROUND OF THE INVENTION In recent years, electrical circuits on printed circuit boards have become denser. Among these, parts are made into chips, and when they are mounted using automatic machines, adhesives are used to secure the chips to the solder dip side. However, if there is a hole such as a through hole under the chip component, the adhesive for fixing the chip may get into the hole and may not perform the function of securing the chip sufficiently. As a preventive measure, before mounting chip components on a printed circuit board,
Fill the holes that exist under the chip parts with adhesive, etc., or print in the manufacturing process to cover the holes under the chip parts with the same ink as the letters (white, black, yellow, etc.) used when printing on the printed circuit board. was doing. FIG. 2 is a diagram showing a cross section obtained by the former method, and FIG. 3 is a diagram showing a cross section obtained by the latter method. That is, in FIGS. 2 and 3, 6 is a printed circuit board, 4 is a soldering land for mounting chip components, and 5 is a printed circuit board.
3 is a solder resist layer, and 3 is a silk printing layer formed on the solder resist layer 5 for various indications. In FIG. 2, both the solder resist layer 5 and the silk printing layer 3 have through-holes. Prior to mounting the chip component 1, the hole-filling bond 8 is filled into the hole 7, and an adhesive layer 2 is applied thereon to mount the chip component 1. Further, in FIG. 3, the chip component 1 is mounted by applying the adhesive 2 onto the silk printing layer 3 formed above the through hole 7.

Problems to be Solved by the Invention However, the above-mentioned method has the following problems. The former method of directly filling holes with bond, etc. does not allow for uniform filling, and in some cases, depending on the amount of bond, as shown in Figure 2, the hole may be filled with an automatic machine after it has protruded from the surface of the printed circuit board. When mounting the chip, the chip parts may be tilted and insufficient adhesion may occur. In addition, in the latter method of printing printed circuit boards using the same ink as letters, etc., from above the holes, the ink may not enter the holes sufficiently.
In addition, since the film is always heat-dried after ink is printed in the printed circuit board manufacturing process, it may break as shown in 9 in Figure 3.
It may swell and the hole cannot be sealed sufficiently.

In view of the above-mentioned problems, the present invention is capable of uniformly filling holes with good adhesion to the printed circuit board, and is capable of producing high-density printed circuit boards where holes exist under chip components. purpose.

Means for Solving the Problems In order to solve the above-mentioned problems, the chip component mounting device of the present invention connects a through hole previously formed in a printed circuit board to a first solder resist layer formed on the dip surface of the printed circuit board. The second solder resist layer on the opposite side to the dip surface is formed except for the periphery of the through hole, and the chip component to be mounted is positioned on the through hole. The structure is such that it is bonded to the first solder resist layer using an adhesive.

Effect According to the above configuration, by closing the through hole located under the chip component with the first solder resist, the adhesive applied by an automatic machine etc. used when mounting the chip component is removed. It is possible to prevent the adhesive from entering the through hole, and by preventing this, the uniformity of the adhesive is ensured, and the problem of unstable fixing of chip parts due to a decrease in adhesive force due to insufficient amount of adhesive does not occur. In addition, when a jig for pressing the lower surface of the chip component is inserted into the through hole from the second solder resist layer side and the chip component is removed, the adhesive that has entered the through hole and hardens may cause the jig to press against the bottom surface of the chip component. This eliminates the problem of not being able to press the bottom surface of the chip component. Furthermore, by preventing the second solder resist layer from closing the surface of the through hole opposite to the solder deep dip surface, a space where the second solder resist layer side is opened is formed in the through hole. When removing the chip component, the jig can be easily inserted into the through hole through the opening. Furthermore, since the first resist layer ensures uniformity of the adhesive, it is possible to place chip parts on a high-density designed printed circuit board where there are holes under the chip parts. It is extremely easy to implement.

Embodiment A printed circuit board according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a cross-sectional view of the printed circuit board of the present invention, and the same components as those of the printed circuit boards of FIGS. 2 and 3 are given the same reference numerals. The feature of this embodiment is that the solder resist layer 5 is formed only on the solder dip surface side so as to cover the via hole 7 located under the chip component 1 mounted on the solder dip surface side of the printed circuit board. The solder resist layer 5 on the surface opposite to the dip surface is formed avoiding the via hole 7.

That is, the liquid resist enters the via hole and is in a uniform state between the chips as well as other parts. Also, on top of the liquid resist 5, silk ink 3 similar to that used for character display on printed circuit boards is printed, and on top of that is an adhesive 2 applied by an automatic machine, and the chip parts are bonded. 1 is fixed. By doing this, air will not accumulate in the via holes during printed circuit board manufacturing, and the resist and silk will not swell when the silk dries, allowing perfect hole filling.

Effects of the Invention As described above, the chip component mounting device of the present invention closes the through hole located under the chip component with the first solder resist, thereby allowing the automatic machine used when mounting the chip component to It is possible to prevent the adhesive applied by the above method from entering the through hole, and by preventing this, the uniformity of the adhesive is ensured, and the fixation of the chip parts is prevented due to a decrease in adhesive force due to insufficient amount of adhesive. In addition, when a jig that presses the bottom surface of a chip component is inserted into a through hole from the second solder resist layer side and the chip component is removed, the problem that the chip component gets into the through hole and hardens. This eliminates the problem that the jig cannot press the lower surface of the chip component due to the adhesive. Furthermore, by preventing the surface side of the through hole opposite to the solder dip surface from being closed by the second solder resist layer, a space where the second solder resist layer side is opened is formed in the through hole. So, when removing the chip parts,
The jig can be easily inserted into the through hole through the opening. Furthermore, since the first resist layer ensures uniformity of the adhesive, chip parts can be attached to printed circuit boards with high-density designs in which holes exist below the chip parts. It is extremely easy to implement.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of the printed circuit board of the present invention, and FIGS. 2 and 3 are sectional views of main parts of a conventional printed circuit board, respectively. 1... Chip parts, 2... Adhesive, 3... Silk printing layer, 4... Land for chip parts, 5... Solder resist layer, 6... Printed circuit board, 7... Via hole, 8... Hole filling Bond, 9...Cut due to air leakage from silk.

Claims (1)

[Scope of utility model registration request] A through hole previously formed in the printed circuit board is closed with a first solder resist layer formed on the dip surface thereof, and a second solder resist layer on the opposite side to the dip surface is closed with the through hole formed in advance on the printed circuit board. The chip components to be mounted are
A mounting device for a chip component, characterized in that the chip component is bonded to the first solder resist layer with an adhesive so as to be located above the through hole.