JPH02122594A - Circuit board device - Google Patents

Abstract

PURPOSE:To check a flow of solder and to realize high-density mounting and miniaturization by providing a groove shallower than the thickness of electrode lands for common use by laser light while dividing the electrode land for common use through this groove so as to correspond to a plurality of electronic parts. CONSTITUTION:Ag-Pd paste is printed on an alumina circuit board to form a wiring conductor 2 and electrode lands 3, 4, 5 while forming a coated insulator 10 to be shown by a diagonal line followed by forming a laser-cut groove 11 in the center of a common electrode land 4 to be divided into 4a and 4b. The groove 11 is formed so as to reach from one side edge to the other side edge of the common electrode land 4 while the depth of the groove 11 is made shallower than the film thickness of the common electrode land 4. Next, cream solder is applied to the electrode lands 3, 5 and to the parts 4a, 4b of the electrode land 4 and thereon electronic parts 6 and 7 consisting of a laminated capacitor are arranged for performing a reflow to connect with solder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit board device such as a hybrid integrated circuit device in which a plurality of electronic components are mounted adjacently on a circuit board.

[Prior Art] As shown in FIGS. 4 and 5, a conventional hybrid integrated circuit device has a wiring conductor 2 provided on an insulating circuit board 1 made of ceramic or the like, and electrode lands 3, 4, 5. , by fixing electronic components 6 and 7 with solder 8. Note that the two electronic components 6.7 are mounted on a common electrode land 4 in order to increase the mounting density. In FIG. 4, the common electrode land 4 is divided into first and second parts 4a and 4b, and although they look like separate electrode lands, the first part is separated under the insulator 9 provided to prevent solder flow. and the second portions 4a, 4b are interconnected. The isolation insulator 9 shown with diagonal lines is a portion printed at the same time as the covering insulator 10 such as glass.

If the common electrode land 4 is not separated into the first and second parts by the insulator 9, the solder 8 of one electronic component 6
The solder 8 of the other electronic component 7 will be connected, making it difficult to attach the solder 8 to the electronic component 6.7 in the shape of the foot of Fuji, and when a temperature cycle test etc. is performed, the electronic component 6.7 There is a risk that stress will be applied to the product and defects such as cracks will occur.

Instead of providing the separating insulator 9 of FIGS. 4 and 5, a method is also known in which only a portion of the first and second portions 4a, 4b is connected and the remaining portion is separated by a slit.

[Problems to be Solved by the Invention] By the way, there is a demand for further miniaturization of circuit board devices. When the insulator 9 is mass-produced by screen printing as shown in FIGS. 4 and 5, the width of the insulator 9 is set to 0.
411! It was difficult to make it smaller than about 1.

In other words, even if the width of the screen is 0°21, 0.1
A sag of about 1 Wl occurred, and the width ended up being about 0.41.

In addition, the first and second portions 4a, 4b are formed by slits.
Even in the method of separating the slits, a slit width of about 0.11!1111 is required. In addition, the first and second parts 4
Since a and 4b were partially connected, it was impossible to completely separate the solder.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a circuit board device capable of increasing density.

[Means for Solving the Problems] To achieve the above object, the present invention provides a circuit board device having an electrode land shared by a plurality of electronic components in order to mount the plurality of electronic components adjacent to each other. In the circuit board device, a groove shallower than the thickness of the shared electrode land is provided by a laser beam, and the shared electrode land is divided so as to correspond to the plurality of electronic components by this groove. It is something.

[Function] The groove of the present invention is formed to be shallower than the thickness of the electrode land. Therefore, the width of the groove is smaller than when cutting the entire groove, and can be, for example, 50 μm to 100 μm. Furthermore, since the laser beam is applied, an oxide film of the material of the electrode land is formed on the surface due to heat. The flow of solder can be prevented by the action of the oxidizer and the action of the oxide film.

[Embodiment] Next, a circuit board device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

When manufacturing this circuit board device, AQ-Pd paste is printed on an alumina circuit board, dried, and
The wiring conductor 2 and the electrode mold 3.4.5 are formed by firing.

Next, a ruthenium oxide (Ru 02 )-based paste is printed, dried, and fired to form a resistor (not shown), and a glass paste is printed, dried, and fired to form a resistor (see FIG. 1). The covered insulator 10 is not shown with diagonal lines.

Next, using a YAG laser, the power was 1.5 W, the speed was 100 nn/sec, and the pulse frequency was 10 Hz.
Under these conditions, the laser cut groove 11 is connected to the common electrode land 4.
It is formed at the center of and divided into first and second parts 4a and 4b. The arm 11 is formed from one edge of the common electrode land 4 to the other edge as shown in FIG. 1(B). In this example, the film thickness of the common electrode land 4 is 12 μm, and ? The depth of 1111 is approximately 10 μm. Therefore, as shown enlarged in FIG. 3, the first portion 4a and the second portion 4b
and are interconnected under the river 11. When a laser beam is projected onto the electrode land 4, it is oxidized by heat,
? ll! As shown in FIG.
Oxidation of the material M! 11a is formed, and the eraser 11 and the oxide film 11a share a function of preventing solder flow.

Next, cream solder is applied to the electrode land 3.5 and the first and second portions 4a and 4b of the electrode land 4 to a thickness of 0.2 nn, and an electronic component 6.
7 is placed and reflowed at 230° C. to achieve connection by solder 8 as shown in FIG.

In addition, the dimensions of the independent electrode land 3.5 are llllx21
1M, and the dimensions of the common electrode land 4 are 211+1X2
It is 101. The common electrode land 4 is divided by 7!411, but the width of the spring 11 is extremely narrow, about 50 to 100 μm, so the first and second portions 4a, 4b have almost the same dimensions as the independent electrode land 3.5. As shown in FIG. 2, the cap-like cap-shaped caps 6a, 6b, 7a, and 7b on both end faces and the outer periphery of the electronic component 6.7 are connected by Fuji's foot-shaped solder 8, which has almost the same shape as each other. Connected stably.

[Effects of the Invention] As is clear from the above, according to the present invention, common electrode lands can be divided by extremely narrow grooves and the flow of solder can be prevented. Therefore, high-density packaging and miniaturization are possible.

[Brief explanation of the drawing]

Figure 1 is a plan view showing a part of the circuit board before the eraser is provided and after the groove is provided, and Figure 2 is the electronic component in the part corresponding to the line ■-■ in Figure 1 (B). A sectional view showing the state after installation, Figure 3 is Figure 1 (B)
FIG. 4 is a plan view showing a part of a conventional circuit board, and FIG. 5 is a sectional view of the circuit board shown in FIG. 4 after electronic components are mounted thereon. 1... Circuit board, 2... Wiring conductor, 3, 4.5...
・Electrode land, 6.7...Electronic component, 8...Solder,
10...Covered insulator, 11...Clear.

Claims (1)

[Claims] In a circuit board device having an electrode land shared by the plurality of electronic parts in order to mount a plurality of electronic parts adjacent to each other, a groove shallower than the thickness of the shared electrode land is formed. A circuit board device, characterized in that the shared electrode land is divided by the groove formed by a laser beam so as to correspond to the plurality of electronic components.