JPH07118428B2 - Reactor for semiconductor circuit - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a semiconductor circuit reactor for suppressing current spikes and current ringing.

[Technical background of the invention and its problems]

Conventionally, in a semiconductor circuit such as a switching power supply that controls a large current in a high frequency range, a peak value higher than a standard value based on a transient phenomenon at the time of turning the current on and off due to the characteristics of the semiconductor itself and other circuit factors. There is a problem that current, that is, current spikes and pulse current fluctuations, that is, current ringing easily occurs. These phenomena hinder the normalization of circuit operation and may eventually destroy the semiconductor. Further, such a rapid change in current has been a major cause of device noise.

In recent years, in response to a request for strengthening international measures against such noise disturbances, measures for preventing noise generated by devices using semiconductors without decreasing efficiency η (output / input) are being strengthened, and prevention of noise is important. It's becoming a problem.

In order to suppress such current spikes and current ringing, a semiconductor circuit reactor is arranged in a semiconductor circuit, but the core of a conventional semiconductor circuit reactor is formed of ferrite or permalloy, etc., It was impossible to carry out sufficient suppression.

That is, when a ferrite core is used, the suppression ratio is small because the squareness ratio (Br / B ₁ ) and the saturation magnetic flux density are small, and it is necessary to enlarge the shape of the core to make it effective. When using, the coercive force (Hc) was large, and there was the problem that it could not be applied to higher frequencies.

[Object of the Invention]

The present invention has been made to solve such a problem, and provides a reactor for a semiconductor circuit capable of preventing current spikes and current ringing that cause noise without substantially lowering the efficiency η. With the goal.

[Outline of Invention]

That is, the semiconductor circuit reactor of the present invention is a reactor for a semiconductor circuit, which is formed by combining a core formed of an amorphous magnetic alloy and a conductor, and is inserted in series with a semiconductor. A reactor for a semiconductor circuit, which is a thin plate having a surface roughness of −) / t ≦ 0.30 (where t is the maximum plate thickness, is the average plate thickness).

Here, t is obtained as an actual measurement value for the thin plate,
Is the weight, width, length and density of the above thin plate, respectively W, d, l, ρ
Is a calculated value calculated from the formula of W / d · l · ρ.

When the value of (t-) / t exceeds 0.30, the surface irregularity of the ribbon becomes remarkable (the surface becomes rough), and the iron loss in the high frequency region becomes significantly large, which makes it unsuitable for use.
Further, if the surface roughness is large, the packing factor of the core becomes small, and as a result, the total magnetic flux becomes small, which is not preferable.

When the maximum thickness (t) of the above thin plate is less than 5 μm, a large amount of interlayer insulator is required when winding the obtained magnetic core, so that the space factor thereof is remarkably reduced and practical use occurs. It becomes untargetable. Further, when t exceeds 40 μm, iron loss in the high frequency region remarkably increases and the effect of suppressing current spikes and the like decreases. Therefore, in the magnetic core of the present invention, it is preferable to set the maximum thickness of the ribbon in the range of 5 μm ≦ t ≦ 50 μm.

Generally, MaNbYc is used as the amorphous magnetic alloy used in the present invention.
An alloy represented by In this case, M is at least one element selected from Fe and Co, N is at least one element selected from transition metals other than Fe and Co, and Y is Si, B,
At least one element selected from P, C, Ge, Al,
The composition is preferably 0.60 ≦ a ≦ 0.90, 0 ≦ b ≦ 0.15, 0.10 ≦ C ≦ 0.35.

In the present invention, a toroidal core is formed by winding an amorphous magnetic alloy into a ribbon shape by a single roll method, or a toroidal core is formed by stacking punched pieces in a ring shape, and the core is formed on this core. A semiconductor circuit reactor is obtained by providing a plurality of windings. By inserting this semiconductor circuit reactor in series with the semiconductor, current spikes and ringing of the semiconductor circuit can be suppressed.

Example of Invention

 Next, examples of the present invention will be described.

Example 1 (Co _0.87 Fe _0.05 Ni _0.04 Mn _0.02 Nb _0.02 ) ₇₃ Si ₁₃ B ₁₄ was formed into a ribbon-shaped thin plate having a plate thickness of 25 μm and various surface roughness, and an inner diameter of 6 mm. Was wound about 20 times to form a toroidal core, which was then wound to form a reactor for semiconductor circuits.

By inserting these semiconductor circuit reactors in series with the diode, the efficiency η at 100kHz can be used as a switching power supply.
When the (output / input) was determined, the results shown in FIG. 1 were obtained. From this, it can be seen that the efficiency is good when the surface roughness is 0.30 or less.

Moreover, the current spikes and the current ringing were largely suppressed and the surface roughness of 0.30 or less was hardly seen.

Example 2 (Co _0.90 Fe _0.06 Cr _0.04 ) _{74 An} amorphous magnetic alloy represented by Si ₁₄ B ₁₂ was formed in a ribbon shape having a surface roughness of 0.20 to 0.23 and a plate thickness of 18 μm, 25 μm and 45 μm by a single roll method. The thin plate of Fig. 2 was inter-layer insulated with magnesium oxide powder, wound 20 times with an inner diameter of 6 mm to form a toroidal core, and winding was applied to each toroidal core to form a semiconductor circuit reactor.

By inserting these semiconductor circuit reactors in series with the diode, the efficiency η at 100kHz can be used as a switching power supply.
When (output / input) was obtained, the results shown in the table were obtained.

[Advantages of the Invention] The reactor for a semiconductor circuit of the present invention has efficiency (output / input).
It is possible to prevent current spikes and current ringing with almost no decrease in voltage.

[Brief description of drawings]

 FIG. 1 is a graph showing efficiency η with respect to surface roughness.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Juno Hirose 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Tokyo Shibaura Electric Co., Ltd. Yokohama Metal Factory (56) Reference JP-A-58-44702 (JP, A) Kaisho 58-44704 (JP, A)

Claims (2)

[Claims] 1. A reactor for a semiconductor circuit, which is formed by combining a core made of an amorphous magnetic alloy and a conductor and is inserted in series with a semiconductor, wherein the amorphous magnetic alloy is (t −) / t ≦ 0.30. A reactor for a semiconductor circuit, which is a thin plate having a surface roughness of (where, t is the maximum plate thickness and is the average plate thickness). 2. The amorphous magnetic alloy is a thin plate having a plate thickness of 5 μm or more and 40 μm or less.
A semiconductor circuit reactor according to the paragraph.