JP2529359B2 - Green Sheet Pressing Method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial field In recent years, with regard to chip parts that contribute to weight reduction, thickness reduction, and size reduction of electronic devices, dimensional accuracy and terminal strength are improved, and further weight reduction and size reduction are achieved. As the demand for thinner products increases from the market, all thickness conditions (ceramics for electronic parts) are required for ceramic substrates that are used as base materials for chip parts and have split grooves installed on the same straight line on both front and back surfaces. The thickness of the substrate is generally 0.3 mm to 2.0 mm), while it is required to eliminate variations in the depth and shape of the dividing groove in the sheet and to secure excellent dividing property.

The present invention relates to a method for pressing an alumina substrate green sheet used for manufacturing such a ceramic substrate.

2. Description of the Related Art Conventionally, a method of pressing a dividing groove to be applied to a green sheet for producing a ceramic substrate of this type has been such that a front surface dividing groove forming die is moved, while a rear surface dividing groove forming die is fixed. The tooth angle was set to the same condition, and the green sheet dividing groove was formed by simultaneous pressing. FIG. 4 shows a die of a press working method according to a conventional technique. Five teeth of the front surface dividing groove forming die 11 and the back surface dividing groove forming die 12 are prepared at uniform intervals, and tooth angles f and h are set. 45 °, tooth angle height g, i
It is a sectional view of a metal mold set to a condition of 0.12 mm. FIG. 5 is a sectional view of a ceramic substrate 13 having a plate thickness of 0.47 mm produced by the mold of FIG. FIG. 3 shows the measurement points showing the shape of the dividing groove of the ceramic substrate.
Is the depth of the dividing V groove 9 (hereinafter referred to as V groove depth),
b is the width of the dividing V groove 9 (hereinafter abbreviated as V groove width), c
Indicates the total length of the V groove depth and the depth of the crack 10 (hereinafter, abbreviated as total length). And, Table 1 shows that the ceramic substrate 13 of FIG.
It is the result of measuring the V-groove depth, V-groove width, and total length by pulling out the sheet. When the green sheet is pressed by the die shown in FIG. 4, the ceramic substrate 13 as shown in FIG. 5 is obtained, and as shown in Table 1, the front surface dividing groove and the back surface dividing groove penetrate, and the total length is The variation becomes very large, and the variation and penetration of the dividing grooves are different each time the material lot of the green sheet is changed, so that stable quality cannot be secured.

Problems to be Solved by the Invention In such a conventional configuration, if the green sheet is pressed to install the dividing grooves on the ceramic substrate on the same straight line on both front and back surfaces, the dividing grooves may penetrate or the total length may be reduced. However, there is a problem in that the quality of the dividing sheet is different and the penetration is different each time the material lot of the green sheet is changed, and stable quality cannot be secured.

An object of the present invention is to solve such a problem and to make it possible to perform installation in accordance with the set depth and shape of the dividing groove under any plate thickness condition.

Means for Solving the Problem In order to solve this problem, the present invention is to move a front surface dividing groove forming die, fix a back surface dividing groove forming die, and set the former tooth angle to A ° and the latter tooth angle. Is B °, A ° +
The tooth angle condition is set so that 5 ° ≦ B °, the front surface dividing groove and the back surface dividing groove are simultaneously pressed, and the depth and the depth of the dividing groove can be adjusted by adjusting the tooth angle and the tooth height of the dividing groove forming die. This is a press working method in which dividing grooves are formed on the front and back surfaces on the same straight line by determining the shape.

Operation With this configuration, a large number of division grooves are set on the same straight line on both the front and back surfaces of the ceramic substrate, and the V groove depth, the V groove width, the total length, etc. are set with extremely small variations while complying with all plate thickness conditions. It will be installed according to the specifications, and stable quality will be obtained even if the material lot of the green sheet is changed. Further, by performing simultaneous pressing on both the front and back sides, the pitch deviation between the front surface dividing groove and the back surface dividing groove can be suppressed to a very small level. Furthermore, by performing simultaneous press working on both the front and back sides, the number of man-hours is small and the mass productivity is high.

EXAMPLES Next, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a view showing a press molding apparatus, in which five teeth of a movable front surface dividing groove forming die 1 and a fixed back surface dividing groove forming die 2 are prepared at uniform intervals, and a surface dividing groove forming die is prepared. The conditions are set such that the tooth angle a of 1 is 45 °, the tooth height b is 0.12 mm, the tooth angle c of the back surface split groove forming die 2 is 50 °, and the tooth height d is 0.12 mm. With this device, split grooves are pressed on both sides of the green sheet at the same time. FIG. 2 is a sectional view of a ceramic substrate 3 having a plate thickness e of 0.47 mm produced by the apparatus of FIG. Table 2 shows the ceramic substrate shown in FIG.
The results are obtained by randomly sampling 10 sheets and measuring V groove depth, V groove width, and total length.

Tooth angle condition of split groove forming dies 1 and 2 for front and back sides is A ° + 5
When a trial production of a ceramic substrate was performed on 500 sheets by the device shown in FIG. 1 in which the setting of ° ≦ B ° and the depth and shape of the dividing groove were confirmed and measured, the results are shown in FIG. 2 and Table 2. It is possible to obtain the depth and shape of the dividing groove having a very stable variation of σ of 10 μm or less.

Next, in order to improve the dimensional accuracy of the chip component due to the excellent division property of the ceramic substrate and the roundness of the edge portion of the small substrate divided into the small substrates, in order to improve the terminal strength, the mold conditions described above are actually applied. In consideration of the specifications of the prototyped ceramic substrate, the mold conditions, and the measurement results of the dividing grooves will be described. Total surface division groove length is 200 μm, V groove depth is 60
μm, V depth 40 μm, total back dividing groove length 70 μm, V groove depth 50 μm, V groove width 70 μm dividing groove vertical length 625 mm, horizontal length 520 mm, plate thickness 0.47 mm ceramic Vertically on the board
31 pieces, 2 mm only at both ends, and others at 1.95 mm intervals were installed on the front and back sides on the same straight line. ，
Tooth height is 0.18mm The tooth angle of the backside split molding die is set to 60 ° and the tooth height is set to 0.08mm. Both die presses with 31 teeth installed at the same interval are used to press both the front and back sides of the green sheet at the same time. Was carried out and a 500-seat prototype was made. Table 3 shows the results obtained by randomly measuring the V-groove width, V-groove depth, and total length of 10 sheets of the divided groove from the prototype. Table 3
As shown in the figure, when 10 sheets are randomly sampled from the prototype and the results of all rows of divided grooves are measured, σ = 10 μm or less, variation is very small, and the depth and shape of the divided grooves are also specified. Therefore, it is possible to obtain a ceramic substrate of stable quality.

EFFECTS OF THE INVENTION As described above, according to the present invention, the V groove depth, V groove width, and total length of a large number of dividing grooves on the same straight line on both the front and back surfaces of the ceramic substrate are extremely varied according to the specified specifications. Can be held small. Further, when the material lot of the green sheet is changed, the characteristics such as the strength of the green sheet are slightly different, but the difference in the division groove due to the difference in the material lot is eliminated, and stable quality can be secured. Furthermore, the dividing groove described above can be easily installed in correspondence with all plate thickness conditions of the ceramic substrate, and according to the conventional technique, when the V groove depth, the V groove width, and the total length are changed. It was necessary to change all conditions such as strict selection of materials, readjustment of split groove forming die conditions, resetting of press working pressure, etc., but adjustment of tooth angle and tooth height of split groove forming die It is possible to obtain an effect that it is possible to easily cope with the situation.

 Further, the effects of the present invention are listed below.

Simultaneous press working of the above-mentioned dividing grooves on the alumina green sheet reduces the number of steps and facilitates the work, which facilitates mass production.

Due to the effect described in 1), it becomes possible to mass-produce chip parts based on a ceramic substrate in which the dividing grooves are installed on the same straight line on both the front and back surfaces, and to market chip parts with excellent product characteristics, dimensional accuracy, and terminal strength. Can be supplied.

By simultaneously pressing the front surface division groove and the back surface division groove on the green sheet, the pitch deviation between the front surface division groove and the back surface division groove can be made very small, so the dimensional accuracy of the small substrate after division is very excellent. You can make things.

[Brief description of drawings]

FIG. 1 is a sectional view of an apparatus having a front surface dividing groove forming die and a back surface dividing groove forming die for carrying out the pressing method of the present invention, and FIG. 2 is a ceramic produced by the die of FIG. FIG. 3 is a sectional view of the substrate, FIG. 3 is an explanatory view showing measurement points indicating the depth and shape of the dividing groove of the ceramic substrate, and FIG. 4 is a conventional technique in which dividing grooves are formed on the same straight line on both front and back surfaces of the green sheet. FIG. 5 is a cross-sectional view of a ceramic substrate manufactured by the mold shown in FIG. 1 …… Surface dividing groove forming die, 2 …… Back surface dividing groove forming die.

Claims (1)

(57) [Claims] 1. A movable front surface dividing groove forming die and a fixed rear surface dividing groove for arranging dividing grooves on the same straight line on both front and back surfaces in order to divide an electronic component ceramic substrate into a large number of small substrates. A groove forming die is provided, the tooth angle of the front surface dividing groove forming die is A °, and the tooth angle of the back surface dividing groove forming die is B °.
In this case, the tooth angle condition is set so that A ° + 5 ° ≦ B °, and the front sheet dividing groove and the rear surface dividing groove are simultaneously pressed on the green sheet by these dies. Press processing method.