JP2705230B2 - Manufacturing method of multilayer ceramic capacitor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer ceramic capacitor used for an electronic device circuit.

Conventional technology Conventionally, in order to evaluate the strength of the internal and external electrodes of a multilayer ceramic capacitor, a certain number of samples were extracted from one unit manufactured under the same conditions, and the external electrode of each multilayer ceramic capacitor was pulled. The fracture strength was examined and one unit was evaluated.

When at least one of them had a strength equal to or lower than the reference strength, one unit was regarded as defective.

Problems to be Solved by the Invention However, in the above-mentioned method, even if a defect is contained in one unit, if it is not contained in the extracted unit, there is a risk that the whole will be a good product. However, pulling all the articles as described above cannot be performed because the whole articles are destroyed.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and improves the testability by performing all the tests.

Means for Solving the Problems In order to achieve this object, the present invention measures the capacitance at two or more frequencies for all of the multilayer ceramic capacitors and compares the respective values.

Thus, the connection strength between the internal electrode and the external electrode is evaluated based on the electric resistance, and the multilayer ceramic capacitor having a weak connection strength is removed.

Operation According to the present invention, it is possible to easily select all of the multilayer ceramic capacitors to be measured without breaking the multilayer ceramic capacitors to be measured by the above-described inspection method. Therefore, the manufacturing loss can be minimized and the reliability can be improved.

Example Hereinafter, an example of the present invention will be described. In the multilayer ceramic capacitor, 1000 samples were sampled from one unit that was defective in the method of measuring the strength by pulling the external electrode portion, which is the conventional method. This product is of type A for temperature compensation.

This sample product was applied with each frequency of 100 KHz and 4 MHz, and the capacity was measured. And 100K capacity at 4MHz
Table 1 shows values classified by the value of R, where R is the value divided by the capacity in Hz. As is clear from this, the product with poor tensile strength has a large drop in capacity as the frequency increases,
That is, it is understood that the value of R becomes small. On the other hand, those used for comparison had no capacity reduction as shown in Table 1. Therefore, in the step of measuring the capacitance of the multilayer ceramic capacitor, the capacitance is measured at two or more frequencies, and by comparing the ratios, those having a weak connection strength between the internal and external electrodes are removed, and the connection strength is high. Things can be taken out.

Effect of the Invention As described above, according to the method of the present invention, by measuring and comparing the capacitance at two or more frequencies, a multilayer ceramic capacitor having a weak connection strength is removed, and a capacitor having a strong connection strength is taken out. be able to.

This eliminates the need for a conventional test for evaluating the connection strength between the internal electrode and the external electrode, such as a tensile strength test by wiping, and enables automatic selection when measuring the total capacity. Further, since it is possible to select all the products, it is possible to prevent defective products from being mixed into non-defective products, and the effect is extremely large.

Claims (1)

(57) [Claims] 1. A laminated ceramic capacitor comprising a plurality of ceramic dielectric layers and a plurality of conductor layers alternately laminated, and an outer surface provided with external electrodes electrically connected to the conductor layers. A multilayer having a process of applying different frequencies and comparing the capacitance at each frequency to evaluate the connection strength between the internal and external electrodes of the multilayer ceramic capacitor, and separating and removing the multilayer ceramic capacitor with a weak connection. Manufacturing method of ceramic capacitor.