JP2740696B2 - Aging method for tantalum capacitors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal aging method for a tantalum capacitor, and can be applied to a method for producing an electronic component which self-ignites due to current aging or the like.

[0002]

2. Description of the Related Art Aging (hereinafter, aging means a process for inspecting an initial failure or an initial failure of a product at an accelerated time, such as heating, voltage application, current application, etc.). The aging process is conventionally performed, for example, by a method shown in FIG.

Referring to FIG. 7, a tantalum capacitor 2
One of the lead portion 22 _-2 1 is linked to the tie bar 23, respectively, the capacitor 2 by the tie bar 23
1 are arranged in a line. While the other lead portion 22 _-1 of each capacitor are separated from each other. And, between each tantalum capacitor 21, a fire preventing partition 24 is provided, and each capacitor 21 is partitioned by the fire preventing partition 24.

When the aging process is performed, for example, the rated voltage of each capacitor is set to 2
Double DC voltage 25 is applied and each capacitor is heated at a temperature of about 120 ° C. In this process, a non-defective capacitor causes no change, but an excessive current flows through a defective capacitor that is short-circuited inside or short-circuited during the aging process. The short-circuit current causes the defective capacitor to generate heat and ignite. However, since the fire preventing barrier 24 is provided between the capacitors, the ignition of the defective capacitor does not affect other capacitors.

[0005]

As described above, the conventional aging treatment method requires a partition to prevent burning. For this reason, there is a problem that the equipment becomes complicated, and furthermore, the cost for processing the partition walls is increased. Further, even though the partition walls can prevent similar burning, once the defective capacitor burns, there is a problem that the soot and the like adhere to the spread portion of the fire, and the soot and the like must be cleaned.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a method of performing an aging process without burning a defective tantalum capacitor.

[0007]

In order to achieve the above object, a tantalum capacitor is ignited by providing a solder bridge portion on an electrode lead and fusing the solder bridge portion when an excessive current flows through a defective capacitor. Has been prevented. That is, in an aging process performed on a large number of tantalum capacitors connected by a tie bar, a cutting step of providing at least one cut point between the tie bar and the electrode lead of the capacitor, and a solder dip forming a solder bridge portion at the cut point Process, sidebar cutting process to cut the sidebar connecting both electrode parts of the capacitor, aging process to apply high voltage to each capacitor under heating, and tie bar and electrode of each capacitor across the solder bridge part And a continuity test step for conducting a continuity test between the leads.

[0008]

In the cutting step, the electrical connection between one of the electrodes of the capacitor and the tie bar is cut. In the solder dip step, the cut portions are electrically connected by solder bridges. In the sidebar cutting step, since the sidebar electrically connecting the two electrodes of the capacitor is cut, both electrodes of the capacitor are opposed only via the dielectric of the tantalum capacitor. In the aging step, since a high voltage is applied between the electrodes of each capacitor, an excessive current flows through the defective capacitor that is short-circuited in the dielectric portion or short-circuited in the aging step. Although the defective capacitor generates heat due to the excessive current, a solder bridge is formed on the electrode lead in the solder dipping step, so that the solder portion is blown before the capacitor is ignited. In the continuity test step, a continuity test is performed across the solder bridge portion, and it is determined by the continuity test whether the solder portion is blown (that is, the capacitor is a defective product).

[0009]

1 to 6 are process diagrams showing one embodiment of the present invention. That is, FIG. 1 shows a state before the aging processing according to the present invention, and FIGS. 2, 3, and 4 show a cutting step, a solder dipping step, and a sidebar cutting step, respectively. 5 shows a state after the aging step, and FIG. 6 shows a continuity test step.

Hereinafter, the state of FIG. 1 will be described. The tantalum capacitor 1 has lead portions 2 ₋₁ ,
2 _-2 are provided, and the lead portions 2 _-1 and 2 _-2 are connected to tie bars 3 _-1 and 3 _-2 , respectively. Side bars 4 are provided on the left and right sides of each capacitor 1.
The tie bars 3 _-1, the 3 _-2, are connected a number of tantalum capacitors 1, tie bars 3 _-1, 3 _-2 lead 2 _-1, 2 _-2 magnitude of the groove _5-2 between, 5 _-1 is provided (see FIG. 1).

From the above state, the aging process according to the present invention is started. First, in the cutting step (see Fig. 2), the upper side of the lead portion 2 _-1 of the tantalum capacitor 1, to provide a new cutting groove 6. In solder dip process (FIG. 3), the cutting groove 6 provided in the cutting step (FIG. 2), providing a solder bridge the groove 5 _-1 already provided divers 3 _-1. Then, in the side bar cutting step (FIG. 4), a part 7 of the side bar 4 on both sides of the tantalum capacitor is cut and dropped. As a result of the above processing, between the upper and lower tie bars 3 _-1 and 3 _-2 , the solder bridged grooves 5 _-1 and 6 and the leads 2 _-1 and 2 are connected.
_-2 and the dielectric of the tantalum capacitor 1 are electrically connected.

Subsequently, while heating at about 120 ° C., a voltage E about twice the rated voltage of the capacitor is applied between the upper and lower tie bars 3 _-1 and 3 _-2 . In this case, since a part 7 of the sidebar in the sidebar cutting step (FIG. 4) is disconnected, never above voltage E is short-circuited by the side bar portion 4, the voltage E solder bridge section 5 _{- It} is applied to the dielectric of each capacitor via ₁ and 6. By the way, a series of capacitors 1 may include a defective product in which the dielectric is short-circuited or short-circuited due to aging processing. In such a defective capacitor, the solder bridge portions 5 _-1 and 6 are not provided. Excessive short-circuit current flows through this.
For this reason, the solder bridge portions 5 _-1 and 6 generate heat. However, when a predetermined current or more flows, the solder bridge portions are melted by the heat. Therefore, in a defective capacitor, the lead portion 8 connected by the solder bridge is lost due to its weight. After all, in this aging process, if the capacitor is defective,
Since the lead 8 of the capacitor is lost due to its own weight (there is also a forced drop method such as blowing off), the capacitor does not ignite (see FIG. 5).

[0013] After this (see Fig. 6), moves to continuity test step, conducting judgment is between the upper lead portion 2 _-1 and the upper tie bars 3 _-1 of each capacitor. The result of this continuity determination, between the test terminals 3 _-1, if 2 _-1 conductive state, to understand and is normal (1 _-2 in this example) its capacitor, conversely,
Test between terminals 3 _-1, if 2 _-1 cutoff state, and the capacitor (1 in this example _-1, 1 _-3) can be seen is abnormal. Therefore, the defective capacitors may be sorted as good by cutting the electrode lead 2 _-2 lower, eventually, only non-defective capacitor is rotated in subsequent steps. Although the continuity test has been described, the present invention is not limited to this. For example, a method of optically detecting the lack of the lead 8 in FIG. 5 can be adopted.

[0014]

As described above, the aging method according to the present invention does not cause fire from a defective capacitor. Therefore, a barrier for preventing fire from burning like the conventional method is not required, and the aging equipment can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state before the start of an aging process according to the present invention.

FIG. 2 is a schematic diagram illustrating a cutting step.

FIG. 3 is a schematic diagram illustrating a solder dip process.

FIG. 4 is a schematic diagram illustrating a sidebar cutting step.

FIG. 5 is a schematic view showing a state after an aging step.

FIG. 6 is a schematic diagram illustrating a continuity test step.

FIG. 7 is a schematic diagram showing a conventional aging process.

[Explanation of symbols]

1 Tantalum capacitors 2 _-1, 2 _-2 electrode lead 3 _-1, 3 _-2 tie bars 4 sidebar _5-1, power cutting missing portion E aged six solder bridge portion 7 sidebar

Claims (1)

(57) [Claims] In an aging process applied to a plurality of tantalum capacitors connected by a tie bar, a cutting step of providing at least one cut point between the tie bar and the electrode lead of the capacitor, and forming a solder bridge portion at the cut point Solder dip process, side bar cutting process that cuts the side bar connecting both electrode parts of the capacitor, aging process of applying high voltage to each capacitor under heating, and tie bar A continuity test step of conducting a continuity test between electrode leads of the capacitor.