A Kind Of Power Inductance Using Injection Molding Packaging.

▼This is a summary of the Chinese invention patent CN106158245B, titled "A kind of power inductance using injection molding packaging."

I. Abstract and Technical Field

This invention relates to the technical field of power inductances and provides a structure and manufacturing method for a power inductance using injection molding packaging.

The primary goal of the invention is to overcome the limitations of existing power inductances, such as those made with metal powder press molding or I-shaped magnetic glue, which often require trading off a low DC resistance (DCR) for better DC stacked saturation characteristics. The patented design aims to achieve an excellent balance, resulting in a higher saturation current and smaller DCR.

II. Technical Solution and Structure

The power inductance structure is defined by its components and critical dimensional constraints:

1. Structure

The inductance primarily consists of:

A Coil Winding.

A Soft Magnetic Ferrite Center Pillar which is plugged inside the coil winding.

A Magnetic Aerogel (magnetic glue) that encapsulates both the coil winding and the center pillar via injection molding.

2. Materials

Soft Magnetic Ferrite Center Pillar: The material is specified to include Manganese-zinc (MnZn) ferrite and Nickel-zinc (NiZn) ferrite.

Magnetic Aerogel: This material is a mixture of:

Resin (e.g., epoxy resin, silicone resin, phenolic resin).

Magnetic Metallic Powder (e.g., α-Fe, iron-silicon alloy, iron-molybdenum-nickel alloy (Molybdenum alloy), or an amorphous metal alloy like Sendust).

3. Critical Dimensional Constraints (Main Claims)

For the power inductance to achieve the desired performance, the cube-shaped component must meet specific proportional relationships between its overall dimensions and the center pillar's dimensions.

Overall Dimensions: Length (2L), Width (2W), Height (H).

Center Pillar Dimensions: Cross-sectional width (2r_c), Height (h_c).

The required constraints are:

Length to Width Ratio: L≥W

Pillar Width Constraint: 2r_c>0.4×2W (The width of the center pillar is proportionally large relative to the overall width).

Pillar Height Constraints:

h_c>H/2

h_c≥H−2r_c/3

By adhering to these dimensional restrictions, the invention ensures that the magnetic flux is optimally managed, preventing premature saturation of the soft magnetic ferrite center pillar, which is a common issue in prior art.

III. Main Claims

The key aspects of the invention are summarized in its main claims:

Claim 1: A power inductance using injection molding packaging, comprising a coil winding, a soft magnetic ferrite center pillar plugged inside, and a magnetic aerogel encapsulating them via injection molding. The power inductance is in a cube shape and satisfies the dimensional formulas: L≥W, 2r_c>0.4×2W, h_c>H/2, and h_c≥H−2r_c/3. The magnetic aerogel is a mixture of resin and magnetic metallic powder.

Claim 2: The soft magnetic ferrite center pillar is set to the central symmetry position of the power inductance.

Claim 3: The cross-sectional shape of the center pillar can be a circle, square, rectangle, or raceway shape.

Claim 4: The material for the soft magnetic ferrite center pillar includes MnZn and Nickel-zinc ferrite.

Claim 5: The resin material includes epoxy resin, silicone resin, and phenolic resin, and the magnetic metallic powder includes α−Fe and various alloys.