JPH04171902A - Manufacture of rectangular type chip resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a rectangular chip resistor to be installed in an electronic component circuit device for a high-density wiring circuit mainly used for small video movies and the like. .

Conventional technology In recent years, there has been an increasing demand for electronic devices to be lighter, thinner, and smaller (in order to increase the wiring density of circuit boards, very small square chip resistors are increasingly being used in electronic components). It's here.

The structure of a conventional rectangular chip resistor is shown in FIG. 3. The conventional rectangular chip resistor has a 96 alumina substrate 11 with a thickness of approximately 0.3 to 0.5 l, and an upper surface electrode layer 12 made of a silver-based thick film electrode.
It consists of a pair of electrode parts consisting of an end face electrode layer 13, a resistance layer 14 made of a ruthenium-based thick film resistor, and a glass layer 15 covering this resistance layer 14.

In order to improve solderability, a Ni plating layer I7 and a 5n-Pb plating layer 18 are applied to the exposed electrode surface by electrolytic plating.

In addition, as a method for forming the upper surface electrode layer 12, the resistance layer 14, and the glass layer 15, screen printing, which has excellent pattern accuracy and film thickness accuracy, is usually used, and as a method for modifying the resistance value of the resistance layer 14, laser trimming is usually used. ing.

Problems to be Solved by the Invention However, in the conventional film forming method using screen printing,
When the thickness of the 96 alumina substrate is reduced to about 0.21 or less,
The printing pressure during screen printing will destroy the substrate, and similarly, if the thickness of the substrate is 0.11 or less,
Since it is difficult to laser-cut only the resistive layer during laser trimming, the 96 alumina substrate must also be cut at the same time, resulting in destruction of the substrate.

Due to these issues, there are limits to reducing the thickness of microchip resistors using conventional manufacturing methods! III
! It had

The present invention solves these problems all at once, and aims to reduce the thickness of a rectangular chip resistor and improve the mounting density of a circuit board.

Means for Solving the Problems In order to achieve the above object, the method for manufacturing a rectangular chip resistor of the present invention includes a step of printing and drying an electrode paste on a ceramic green sheet, which becomes an insulating substrate with a thickness of 100 μm or less after firing. printing and drying a resistor paste so as to partially overlap the dried electrode paste; printing and drying a glass paste so as to completely cover the dried resistor paste; A process of simultaneously firing the top electrode paste, dried resistance paste, and dried glass paste to simultaneously form the ceramic substrate, electrode, resistance, and protective glass, and pulse aging to adjust the resistance value of the resistance between the electrodes. and a step of applying Ni, 5n-Pb plating to the exposed portion of the electrode by electrolytic plating. Further, the present invention has a thickness of 10
A process of forming copper electrodes on a flexible printed circuit board with a thickness of 0 μm or less by etching, a process of printing and curing a polymer-based resistor so as to partially overlap the electrode, and a process of coating a resin so as to completely cover the resistor. The process consists of a printing and curing process, and a process of performing pulse aging to adjust the resistance value of the resistance between the upper surface electrodes.

Function: According to the method of manufacturing a square chip resistor of the present invention, a flexible unfired ceramic green sheet or a flexible printed circuit board is used as the base material in order to withstand the printing pressure during screen printing. Furthermore, the resistance value can be adjusted by pulse trimming (applying a short pulse high voltage between the electrodes of the finished product to gradually break down the insulation of the glass component of the resistor layer), which causes less damage to the base material. By using the modification method), it becomes possible to use a thin base material with a thickness of 1100 a or less, and it becomes possible to realize an ultra-thin rectangular chip resistor.

Example (Example 1) Next, an example of the present invention will be described using FIG. 1. FIG. 1 is a sectional view showing an embodiment of the present invention.

First, A1.03 powder and lead borosilicate glass were heated at 6°C.
An acrylic organic binder was further added to this mixture, and the mixture was kneaded for 24 hours to form a slurry.

Further, this is formed into a sheet with a width of 20C1 and a thickness of 1L10L1 using a doctor blade, and after drying, grooves for dividing after firing in the subsequent process are formed with a mold to a depth of 50μm to produce a dried ceramic green sheet. . This ceramic green sheet has a thickness of t after firing.
It becomes ooam.

Next, a thick film silver paste was printed on the dried ceramic green sheet using a screen printer, and the temperature was increased to 150°C.
Dry for 10 minutes to form a dried thick film top electrode. Further, a thick film resistor paste was printed using a screen printer so as to overlap a part of the dried thick film top electrode.
Dry at 0°C for 10 minutes to form a dried resistor.

Next, print a thick film glass paste using a screen printer to completely cover the dried thick film top electrode,
Dry at 150°C for 10 minutes to form a dried glass.

Then, 90 pieces of this printed ceramic green sheet
By firing according to the firing profile at 0°C for 2 hours, the alumina substrate 1, top electrode 2, resistor 3, and protective glass 4 are formed.
are formed by sintering them at the same time.

At this time, the thickness of the rectangular chip resistor was approximately 95 μm.The alumina substrate was then divided according to the dividing grooves formed before firing.

Next, in order to modify the resistance value of the resistor 3 between the upper surface electrodes 2, trimming is performed by pulse aging.

Finally, a N1.5n-Pb plating layer was formed on the exposed electrode surface by electrolytic plating, and a square chip resistor according to Example 1 of the present invention was fabricated.

By this method, the square chip resistor is approximately 11 mm thick in the thickness direction.
Achieved 0 μm.

(Example 2) Next, another example of the present invention will be described using FIG. 2.

First, a flexible printed circuit board 5 with a thickness of 80 μm is prepared, and an upper surface electrode 6 is formed by etching.

Next, a polymer-based resistor was formed by screen printing so as to overlap a part of the upper surface electrode 6, and
The resistor 7 is formed by curing under the conditions of 10 minutes.

Further, a polymer-based protective resin is formed by screen printing so as to completely cover the resistor 7, and is cured at 180° C. for 30 minutes to form the resin 8.

Finally, in order to modify the resistance value of the resistor 7 between the upper surface electrodes 6, trimming was performed by pulse aging, and the rectangular chip resistor of this example was prototyped.

In this example, the thickness of the rectangular chip resistor was approximately 110 μm.

Example 1 above. According to No. 2, it is possible to realize a chip resistor that is approximately 1/3 as thick as a conventional square chip resistor.

In Examples 1 and 2, a rectangular chip resistor having a thickness of about 110 am was prototyped, but it may naturally be thinner than this.

Effects of the Invention As is clear from the above explanation, according to the method for manufacturing a rectangular chip resistor of the present invention, a substrate having a thickness of 100 μm or less (
(including ceramic green sheets) with a thickness of 100 μm or less after firing, it is possible to manufacture thin prismatic chip components with a thickness of approximately 110 II m or less, which is superior to conventional prismatic chip resistors. In comparison, a reduction of about 173 or less in the thickness direction can be achieved.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a rectangular chip resistor according to an embodiment of the present invention, Fig. 2 is a cross-sectional view showing a rectangular chip resistor according to another embodiment of the present invention, and Fig. 3 is a conventional rectangular chip resistor. It is a sectional view showing a container. 1...Alumina substrate, 2.6...Top electrode, 3゜7...Resistor, 4...Protective glass, 5... Flexible printed circuit board. Name of agent: Patent attorney Akira Okaji and 2 others/---
Aluminum substrate 2-2m

Claims (2)

[Claims] (1) A step of printing and drying an electrode paste on a ceramic green sheet that will become an insulating substrate with a thickness of 100 μm or less after firing, a step of printing and drying a resistance paste so as to partially overlap the dried electrode paste, and a step of drying the resistor paste. The ceramic green sheet, the dried top electrode paste, the dried resistance paste, and the dried glass paste are simultaneously fired, and the ceramic substrate, electrode, resistor, and A step of simultaneously forming a protective glass, a step of performing pulse aging to adjust the resistance value of the resistance between the electrodes, and a step of applying Ni, Sn-Pb plating to the exposed portions of the electrodes by electrolytic plating are sequentially performed. A method of manufacturing a rectangular chip resistor characterized by passing through the resistor. (2) A step of forming a copper electrode by etching on a flexible printed circuit board with a thickness of 100 μm or less, a step of printing and curing a polymer-based resistor so as to partially overlap the electrode, and a step of completely removing the resistor. A method for manufacturing a rectangular chip resistor, characterized by sequentially passing through a step of printing and curing a resin so as to cover it, and a step of performing pulse aging to adjust the resistance value of the resistance between the upper electrodes.