JPH0543445Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to improvements in surface-mounted coil components used for hybrid ICs for communication equipment and control equipment.

2. Description of the Related Art In general, when a transformer is exemplified as a surface-mounted coil component, external terminals 3, 3, . , the ends of the coil 4 wound around the winding shaft of the bobbin 1 are connected to external terminals 3, 3...
It is constructed by binding the core 5 on the axis of the bobbin 1 and assembling the core 5 to the bobbin 1.

If the transformer is left bare without being covered with any material, it will have poor solder resistance and solvent resistance when wave soldering or reflow soldering is performed during the circuit assembly process, and it will also have poor solder resistance and solvent resistance after mounting. It also lacks reliability due to moisture resistance, etc.

For this reason, it has been proposed to mold the entire external terminal except for the shaft end, which is soldered and fixed to the printed circuit board, using heat-resistant insulating plastic material (Utility Model Publication No. 54-7320). .

However, when molding this surface-mounted coil component with plastic material, stress due to hardening of the plastic material and expansion due to temperature changes,
A situation arises in which the magnetic properties change due to the stress associated with contraction.

If it is a low impedance coil component with an open magnetic path, some deterioration in characteristics can be tolerated, but
In the case of coil parts that form a closed magnetic circuit, molding using plastic materials cannot be applied at all, since the cores may be separated or destroyed by the above-mentioned stress, resulting in a significant deterioration of the magnetic properties. Can not.

Therefore, components other than the coil components that form a low-impedance open magnetic path are still mounted bare, and other components are automatically attached and then soldered manually. However, this is not preferable because it not only takes a lot of time to mount, but also lacks moisture resistance and other reliability after mounting as described above.

Problems to be solved by the present invention The present invention is a surface-mounted coil that maintains solder resistance, solvent resistance, moisture resistance, etc. without impairing magnetic properties, is highly reliable, and is easy to assemble. The purpose is to provide parts.

Means for Solving the Problems In the surface-mounted coil component according to the present invention, the coil is wound around the winding shaft of the bobbin, and the end of the coil is placed on the axis of the lead-out terminal attached to the terminal block of the bobbin. In order to prevent the core from being tied to the bobbin, and to airtightly seal the coil assembly formed by assembling the core to the bobbin inside the outer case, a base plate made of a heat-resistant insulating plastic material and a heat conductive material are used. The cap-shaped cover part is made of a metal material with good heat dissipation and good heat dissipation, and the inner shaft end is exposed on the plate surface, and the outer shaft end is bent laterally from the bottom of the plate. an outer case having an external terminal for surface mounting embedded in the base plate of the outer case, and the lead-out terminal of the coil assembly is superimposed and fixed onto the inner shaft end of the external terminal embedded in the base plate of the outer case. Then, the coil assembly is attached and fixed on the plate surface of the base plate, and is housed in the space of the cover section fixedly attached on the plate surface of the base plate, and hermetically sealed with an outer case. It is composed of:

Function In this surface mount type coil component, in addition to the lead-out terminal of the coil assembly which is configured in advance in the form of one component, the outer case is also provided with an external terminal for surface mounting, and the lead-out terminal of the coil assembly is provided with an external terminal for surface mounting. The coil assembly is mounted and fixed on the plate surface of the base plate by overlapping and fixing it to the external terminal of the exterior case, so the assembly does not require the effort of tying the end of the coil to the external terminal. It doesn't hang. In addition, since the cover part that seals this coil assembly is fixedly mounted on the plate surface of the base plate to form an exterior case, the entire body including the exterior case can be easily assembled as one complete component. I can do it.

Since the coil assembly is housed within the space of the outer case, it does not come into direct contact with solder solution or solvent even when wave soldering or reflow soldering is applied during automatic mounting, and it is free from molten solder. Heat can also be blocked from propagating to the coil assembly, thereby preventing thermal damage from occurring. In addition, this coil assembly is hermetically sealed in an outer case, which prevents it from being exposed to moisture even after mounting, and the outer case has a cover made of metal material, which provides a shielding effect and is extremely reliable. It can be configured as a surface-mounted coil component with high performance.

Embodiments The following description will be made with reference to FIGS. 1 to 3.

The surface-mounted coil component shown in Figure 1 has a fourth
Coil assembly 10 having a similar structure as shown in the figures
It is constructed by having the following as a single component. This coil assembly 10 is a bobbin 100.
A terminal block 100 integrally molded with a winding shaft portion 100a of
Attach lead-out terminals 101, 101... to b, and
The coil 1 is wound around the winding shaft portion 100a of the bobbin 100 on the axis of the lead-out terminals 101, 101...
02 and the core 103 is assembled to the bobbin 100. Also,
This surface-mounted coil component has external terminals 11, 1
The coil assembly 1 is installed in the space of the outer case 12 whose bottom is the base plate 12a in which the coil assembly 1 is embedded and mounted.
It is assembled by placing 0 in the storage position.

The exterior case 12 is formed using a base plate 12a made of a heat-resistant and insulating plastic material as a terminal base. When forming the base plate 12a, each of the inner and outer shaft ends 11a, 11a..., 11b, 11b...
External terminals 11, 11... are exposed on the board surface.
It is designed to be integrally embedded and installed. The external terminal 11 is connected to the lead-out terminal 10 of the coil assembly 10 as described later on the shaft inner end side 11a, 11a...
Base plate 1 so that it can be fixed by overlapping with 1,101...
2a on the inner surface of the plate, and also the shaft outer end side 11
b, 11b, . . . are embedded and mounted by bending them laterally from the outer surface of the plate to form flat terminals for surface mounting. This base plate 12
The exterior case 12 including a has a substantially rectangular frame edge 12b fixed upright on the plate surface of the base plate 12a,
It is formed from a cap-shaped cover part 12c that accommodates the coil assembly 10 in the space. Frame edge 12b and cover portion 12c of the exterior case 12
Both are made of a metal material such as aluminum, which has good thermal conductivity and excellent heat dissipation.

In order to assemble the coil assembly 10 to the exterior case 12, the inner shaft ends 11a, 11a of the external terminals 11, 11, . . . exposed on the plate surface of the base plate 12a.
... and the lead-out terminals 101, 10 of the coil assembly 10
1. Polymerize and fix by soldering. To fix the solder, apply cream solder to the external terminal 1.
1, 11... are attached to the inner shaft ends 11a, 11a... of the coil assembly 10, and the lead-out terminals 101, 101 of the coil assembly 10.
... to the inner shaft end 11a of the external terminals 11, 11...
11a..., the coil assembly 10 is placed on the base plate 12, and then reflow soldering is applied. After this, as shown in FIG. 3, the cover part 12c of the outer case 12 is
The coil assembly 10 is placed on the flange portion of the outer case 1 so that the coil assembly 10 is airtightly joined to the outer case 1.
The outer case 12 is assembled so as to be accommodated in the space of 2. When joining the cover part 12, pressure welding, welding, caulking, adhesion, etc. can be applied between the metal frame edge part 12b and the flange part of the cover part 12c. It is preferable to set the external terminals 11, 11, . . . at a high enough position so as not to interfere with the soldering process when mounting the external terminals 12a on the printed circuit board, since this makes it difficult for the external terminals 11, 11, . . .

The surface-mounted coil component configured in this way is placed on the board surface of the printed circuit board P, and is connected to the conductive pattern of the printed circuit board P and the base plate 1 of the exterior case 12.
External terminals 11, 11... projecting laterally from 2a.
It can be automatically mounted by soldering the outer shaft ends 11b, 11b, . . . . During automatic mounting, wave soldering or reflow soldering can be applied to solder the parts together with other parts. Even if the heat from the molten solder acts on the exterior case 12 side during this soldering,
Since the heat can be transmitted from the base plate 12a made of a heat-resistant plastic material to the frame edge 12b and cover part 12c made of metal material and dissipated, the coil assembly 10 housed in the space of the outer case 12 can be dissipated. can be prevented from spreading. Similarly, it is also possible to prevent solvents, moisture, etc. from acting on the coil assembly 10. In addition, the cover portion 1 of the outer case 12 that accommodates the coil assembly 10 is
Since 2c is made of metal, it can also exhibit a shielding effect.

Note that in the embodiment described above, the core 103 is EI,
Although the description has been made based on the case where a coil component forming a closed magnetic path is constructed by assembling EE type etc., the present invention may also be applied to constructing a coil component having an open magnetic circuit. Further, the coil assembly 10 can be constructed by assembling a toroidal type.

Effects of the invention As described above, according to the surface mount type coil component according to the present invention, the coil assembly can be easily assembled and fixed inside the outer case, and can be configured as a surface mount type, as well as a closed magnetic circuit. It is extremely reliable as it can be applied to automatic mounting by imparting solder resistance without impairing the magnetic properties of the coil component, and it can also impart moisture resistance as well as solvent resistance, and can also exhibit a shielding effect. It can be configured as a coil component.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a surface-mounted coil component according to the present invention, Fig. 2 is a perspective view showing a base plate constituting the outer case of the coil part, and Fig. 3 is a perspective view showing the external appearance of the coil part. FIG. 4 is an explanatory diagram showing a surface mount component according to a general example. 10...Coil assembly, 100...Bobbin, 1
00a... Winding shaft portion, 100b... Terminal block, 10
1,101...Leading terminal, 102...Coil, 1
03... Core, 11, 11... External terminal, 11
a, 11a……Inner shaft end of external terminal, 11b,
11b...Outer shaft end of external terminal, 12...Exterior case, 12a...Base plate, 12b...Frame edge, 12c...Cover part.

Claims (1)

[Claims for Utility Model Registration] (1) A coil is wound around the winding shaft of a bobbin, the end of the coil is tied onto the axis of a lead-out terminal attached to the terminal block of the bobbin, and the core is A surface-mounted coil component that hermetically seals the coil assembly assembled to the bobbin inside the outer case, has a base plate made of heat-resistant and insulating plastic material and has good thermal conductivity. A cap-shaped cover part made of a metal material with excellent heat dissipation properties, and a base plate with the inner shaft end side exposed on the plate surface and the outer shaft end side bent sideways from the bottom surface of the plate. an outer case having an external terminal for surface mounting embedded in the base plate of the outer case; The coil assembly is mounted and fixed on the plate surface of the base plate, and is housed in a space of a cover portion fixedly attached on the plate surface of the base plate, and is hermetically sealed with an exterior case. Surface-mounted coil components. (2) The above-mentioned cover part is a utility model in which the flange parts are fixedly attached to the frame edge part which is made of the same metal material as the cover part and which is fixed upright on the plate surface of the base plate. A surface-mounted coil component according to claim 1.