JPS61102702A - Chip-shaped electronic component - 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 chip-shaped electronic components such as chip resistors and chip capacitors mounted on printed Q-boards, etc., and relates to the structure of their upper poles. .

(Prior art) Conventionally, when forming electrodes of chip resistors, for example, a paste made of silver and palladium or a paste of silver and glass was applied to the electrode formation portion of the end face of each chip piece. There is a method in which a metal cap is fitted onto the end face of a cylindrical chip.Since electroplating cannot be applied to a ceramic chip piece, electroless plating is applied to it. There was a method of forming electrodes by applying solder plating.

[Problem that the invention seeks to solve]

In the above-mentioned method, the method of coating Benist using silver has the following problems. Since silver tends to form an alloy with molten solder, a so-called sagging phenomenon occurs, reducing the adhesive strength of the terminal. Silver and palladium are octavalent and therefore expensive. Since high temperature firing of 800° C. or higher is required for firing, the material of the resistive film is limited, and nocobon film resistors, metal film resistors, etc. cannot be used. Next is the metal character/
Since the chip pieces are small, this method is technically difficult and time-consuming in terms of fitting accuracy, which limits the production speed by υ1, and also reduces yield. Next is no electricity, VF? The method using only plating has a problem in that the adhesive strength between the ceramic and the plating film is 1 (1) and less practical than the above-mentioned two methods.

In order to solve the above-mentioned problems, the present invention aims to solve the above-mentioned problems by using an expensive 1! It uses inexpensive materials without using upalladium, and at the same time solves the problem of solder creases caused by silver.
Does it fit in each piece or base 1- on each piece? Tli
The aim is to improve productivity by eliminating the hassle of doing so.

(Means for solving the problems) The present invention provides a part of the metal glaze of a chip-shaped helical base, which is liquid-distilled with a resistive film made of metal glaze,
The electrode forming portion consisting of the ceramic surface of the end surface of the base is provided with an etched surface by hydrofluoric acid treatment, a nickel P-plating layer,
Sequentially form a copper electroplating layer and a nickel electroplating layer,
Hydrofluoric acid treatment dissolves the glass on the metal glaze surface as well as the glass generated by firing the ceramic surface, making it an etched surface and increasing the bonding of nickel through electroless plating, followed by copper electroplating and nickel electroplating. By forming the layers sequentially, the lack of thickness and strength of the nickel electroless plating layer is compensated for, and the electrodeposition of the nickel electroplating layer 4 and the next '-1' field plating is more uniform than the IA heavy air plating layer. In addition, by processing a large amount at once using electroless plating and electroplating, it is possible to improve productivity by eliminating the trouble of processing microscopic chip-shaped substrates one by one.

[Effect]

In the present invention, an etched surface is formed by hydrofluoric acid treatment on the electrode forming part of a chip-shaped helical base coated with a low-resistance coating 19 made of a metal glaze, and the vitreous quality of the ceramic surface deposited by firing is obtained by forming an etched surface by hydrofluoric acid treatment. Next, a nickel electroless plating layer is formed to bond nickel to the ceramic as well as a metal glaze, and then copper electroplating β is performed to achieve the thickness and strength that the nickel electroless plating layer lacks compared to the nickel electroplating layer. , and the copper electroplating layer makes the electrical η of the nickel and solder uniform.

Actual Example 1 An example of 114 formations of a cylindrical chip-shaped electronic component will be explained with reference to manufacturing process diagrams shown in FIGS. 1 to 7.

(1) A resistive film 2 made of a metal glaze made of glass mixed with silver and palladium is formed on the surface of the cylindrical chip-shaped ceramic substrate 1 except for both end faces. (FIG. 1 shows a longitudinal side view. The same applies hereafter.) (2) A resistive protective film 3 made of heat-resistant epoxy paint is formed on the surface of the resistive film 2, leaving both ends intact.

(FIG. 2) (3) Cover the surface of the protective film 3 with a synthetic resin masking film 4. (Figure 3) (4) Masking is done when the whole is processed with FFit! 1
The metal glaze surfaces exposed at both ends of the substrate 14 and the glassy surfaces of the ceramic surfaces at both ends of the substrate 1 are melted and removed, and the surface of the electrode forming portion 50 consisting of the metal glaze surface and the ceramic surface that is not covered with the masking film 4 becomes an etched surface. 6 and the subsequent process, I! ! ! The bonding force with nickel is strengthened by electrolytic plating. (FIG. 4) (5) An activated surface 7 is formed by palladium chloride treatment on the electrode forming portion 5, which has become the etched surface 6, so that the electroless plating metal is easily adhered. (9] Figure 5) (6) Maintenance installation I! i! Its masking on 3! 4
Remove with solvent etc. (Fig. 6) (7) The entire body is immersed in a nickel electroless plating solution to perform electroless plating, and the nickel electroless plating is activated and the nickel electroless metal plate 1 to 3 thick is applied to the 4-forming portion 5. Form layer 8.

8) Next, electroplating of copper is performed by dipping in a copper electroplating bath, and the electroless nickel plating layer 8 is coated with a thickness of 0.
A copper electroplating layer 9 of 27 m to 0.47 g is formed.

(9) Next, it is immersed in a nickel electroplating bath to perform nickel electroplating to form a nickel-Ti gas layer 10 having a thickness of 2 to 5 m on the bottom 9 of the copper electroplating layer 1. If the thickness of the nickel electroplated layer 10 is this single step, the phenomenon of so-called solder hollow can be prevented.

(10) Next, apply solder electroplating in a solder plating bath, and apply P25 on the nickel electroplated layer 10.
An electric mesh V layer 11 of gtn~10 depths is formed.

(Fig. 7) As described in 1 below, a cylindrical L-shaped electronic component △ or 1°1 is mounted with electric current 15a on both ends.

The copper electroplating layer 94 is formed on the nickel electroless plating layer 8 to form a nickel layer of 10. To overcome the lack of 7sado strength 1α, form one layer of copper electric metal 9 and one layer of Nisoul electric metal 10 to increase the V and strength to jl-I.
') Sa l! Ru.

Furthermore, nickel, pyroelectric VI? Directly form 18,27, 1L, 1fiio on 1st layer 8 of nickel electricity and 1st layer of 10th layer of nickel electricity? 1 becomes non-uniform, and if you omit the copper electric metal layer 9, the solder electric metal I! In order to form a small hook by electrodepositing YI11, there is a thin copper electroplated layer 9 in the middle.

The structure of the (-112) rectangular L-shaped element will be explained with reference to the process diagrams shown in FIGS. 8 to 17.

(1) Metal glaze resistor skins 2 made of the same material as in Example 1 are arranged at appropriate intervals on the surface of a flat ceramic 'Jl&1a' which is an assembly of a large number of square chip-like heramic substrates 1. Form the entire length of each early body in the longitudinal direction. (The plan view is shown in FIG. 8) (2) On the surface of each resistive film 2, an llt anti-resistance film 3 made of heat-resistant epoxy paint is formed, leaving both ends in one direction along its length. (The plan view is shown in FIG. 9) (3) Synthesis of the surface of the protective film 3 and the back surface of the base 10 1j.1 fat masking 1! Nami Riruru on J4, 4a. Large masking 1J
4a leaves a small portion of both ends in the length direction in each group 14i1 fQ. (The plan view from the back is shown in Figure 10 and Figure 1.
Figure 0 shows the Al17i surface in Figure 11) (4)
The ceramic substrate 1a is vertically divided in the IJ direction in FIG. 10 to obtain a large number of strips 1b. (According to plan view 4, Figure 12) (5) The strip 1b is treated with hydrofluoric acid in the same manner as in Example 1, washed with water and dried in the same manner, and masked 1lQ4, 4a.
An etched surface 6 is formed on the ceramic surface on the more exposed surface of the metal glaze to form an electrode forming portion 5. (1
(6) The 7tNI formed portion 5, which became the etched surface 6 of the strip 1b, was treated with palladium chloride in the same manner as in implementation V141 to form the activated bamboo surface 7. Form. <A cross-sectional view in the middle direction of the m-long piece is shown in FIG. 14 1) (7) Masking films 4 and 4a are dissolved and removed using a solvent.

(The plan view is shown in Fig. 15) (+1) 'iIJ V Piece 1b, each base 1FrJp
, 1.11 min. (The plan view is 16th
As shown in the figure) (9) Square chip-shaped ceramic substrate 1 divided by υ1
As in Example 1, nickel electroless plating 4, copper electroplating, nickel "mountain plating 1-", and solder electroplating V are sequentially applied to the viscous i+ forming part 5 to form a nickel electroless plating layer. 8. Forming a copper electroplating layer 9, a nickel electroplating layer 10, and a solder electroplating layer 11. (An enlarged vertical side view is shown in FIG. 17.) As described in 1 below, the electrodes 5a@(1q) square chip-shaped finished parts Δ' are provided at both ends.

(Effect of R-light) According to the present invention, a resistive film made of metal glaze formed on a chip-shaped helical base is corrugated with a resistive protective film, leaving both ends of the resistive film, and the resistive film is not covered with the resistive protective film. An etched surface is formed by hydrofluoric acid treatment on the electrode 1~ formation area, which consists of the metal glaze surface of the film and the ceramic surfaces on both end faces of the substrate, and a nickel electroless plating layer and a copper electroless plating layer are sequentially applied to the St+ formation area where this etched surface is formed. Since the electroplating layer and the nickel electroplating layer were sequentially formed, ceramic 1.
The ceramic surface of the edge of the substrate is treated with hydrofluoric acid to form a smooth resistive film made of glass (formed on the body). The combination U can be easily written as 8. In addition, by applying electroless plating to the ceramic surface with a low electrical resistance film, metal nickel was bonded, so Seiden 1'1 was ``1.1'' and the next electroplating was possible. can.

Further, although the nickel electroless plating layer is easy to peel off and the bullet holes on the surface are low, the thickness and strength of the plating layer can be maintained by the following copper electroplating F'j and one layer of nickel electroplating. Furthermore, copper metallurgical metal 1: n / J of the layer, one layer of solder electric metal t ? S can be distributed uniformly.

, L /5, rs +v +if”l Toshite High 1i1
1+ <i grv solder'/ I solder without unevenness + A $1 is 1lIll, and since no silver is used, there is no risk of the four solders' current homes being sold.

(Experimental example) Using the fJ method of practical example 1, 1r7 and 1. : As a comparative example, compare the 1811 strength of the electrode with 11 layers of 18 hantamet on top of 4 layers of 1811
I'm going to do an experiment.

Test 111: 171.0m1n in diameter, 2mm in length, electrolytic plating layer of 1 nickel to the power of nickel on both ends, this nickel? ! ! Electrolytic Electrolyte - 1 Place the upper electrode on the right side, and set the neck diameter of 0.5 m in the axial direction of the electrode. A chip resistor whose lead wires are connected with solder.

Try. 1. i+ 2: Same shape as test Fll, with nickel electroless plating layer (2m), copper electroplating layer (0.3m), nickel electroplating layer (3-), solder electroplating layer (7m) on both ends in this order. Test R A chip resistor with the formed electrodes connected to lead wires in the same way as in 1.

Experimental method: We gripped the lead wire and applied a tensile force in the axial direction, and measured the length of the mold until it peeled off.

As a result of the experiment, as shown in Fig. 18, sample 1 was damaged by lightning under I Kg (7 parts were peeled off, but the present invention was not tested).
FC below Kg also caused the electrode to peel off. At over 8g, the lead wire broke and measurement became impossible, but the strength increased to r1J +A+
I found out that it goes up.

[Brief explanation of the drawing]

1 to 7 are manufacturing process diagrams for a cylindrical chip-shaped electronic component showing one embodiment of the present invention, and FIGS. 8 to 17 are angular chip-shaped electronic components showing other embodiments. Manufacturing process diagram for electronic parts, 118 figures +. 1 is a chart showing the tensile strength of a product according to the present invention and a comparative example. 1. Substrate, 2. Resistive film, 3. Preservative film, 5. Electrode (hole forming part), 6. Etched surface, 8. Nickel (1 (
(Electronic VRmet layer, 9. Copper electroplating layer, 10. Nickel electroplating layer. October 26, 1981.

Claims (1)

[Claims] (1) Form a metal glaze resistance film on a chip-shaped ceramic substrate, leave both ends of this resistance film and form a resistance protection film in the center, and cover the ceramic surfaces of both ends of the substrate and the resistance film not covered with the protection film. An etched surface was formed by hydrofluoric acid treatment on the electrode forming part consisting of the metal glaze surface, and a nickel electroless plating layer, a copper electroplating layer, and a nickel electroplating layer were sequentially formed on the electrode forming part where this etched surface was formed. A chip-shaped electronic component characterized by: