JP2627812B2 - Electronic component manufacturing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electronic component in which a thin lead wire is connected to a terminal member derived from an enclosure for housing a circuit board.

FIG. 6 shows a hybrid IC used for an automobile igniter or an actuator control circuit. The hybrid IC includes an enclosure (1), a terminal member (2) having a central portion partially embedded in the enclosure (1), and a heat radiation fixed to a bottom surface of the enclosure (1). A plate (4), a circuit board (3) fixed to the heat radiating plate (4) in the envelope (1), and electrodes and terminal members (2) not shown formed on the circuit board (3)
A thin lead wire (5) connecting between the inner end (2a) of
A protective resin (6) which covers the inner end (2a) of the circuit board (3) and the terminal member (2) and is filled inside the outer enclosure (1).
And a cover (7) fixed to the upper surface of the enclosure (1).

To form the envelope (1) of this hybrid IC,
Mold molding is performed using a molding die having an upper mold and a lower mold. That is, when the upper mold and the lower mold are closed, a molding mold in which a molding cavity corresponding to the outer enclosure (1) is formed is prepared. Next, one end and the other end of the terminal member (2) are clamped by an upper die and a lower die, and the terminal member (2) is placed in a molding cavity while the center portion of the terminal member (2) is placed in the molding cavity. (2) is mounted in a mold. Subsequently, the fluidized sealing resin is put into the molding cavity and solidified to form an outer enclosure (1) covering the center of the terminal member (2). Next, a heat sink (4) on which the circuit board (3) is placed is attached to the outer enclosure (1),
A lead wire (5) is connected between the electrode on the circuit board (3) and the terminal portion (2). After that, the protective resin (6) is filled in the outer enclosure (1) so as to cover the inner ends of the circuit board (3) and the terminal member (2), and the cover (7) is attached to complete the hybrid IC. I do.

Problems to be Solved by the Invention According to the above-described manufacturing method, when the outer casing (1) is clamped between the upper mold and the lower mold, dirt and scratches are formed on the surface of one and the other ends of the terminal member (2). Even if the lead wire (5) is connected to the terminal member (2) which is easily attached and is dirty or damaged, there is a possibility that sufficient connection strength may not be obtained. The connection strength when the thin lead wire (5) is soldered to the terminal member (2) does not pose a significant problem. However, in the wire bonding method with excellent productivity, dirt or scratches are formed on the surface of the terminal member (2). The problem that a sufficient connection strength cannot be obtained in the state where the connection is made becomes remarkable.
Heretofore, attempts have been made to remove stains on the terminal member holding surface of the mold by resin injection or the like for each resin molding. However, it is difficult to sufficiently remove dirt by air, and it is also impossible to repair a flaw formed on the terminal member (2). Therefore, it has been difficult to completely prevent poor connection of the fine lead wires (5).

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing an electronic component which can prevent dirt and damage of an electrode connection region of a terminal member and can connect fine lead wires satisfactorily.

Means for Solving the Problems The method for manufacturing an electronic component according to the present invention is characterized in that the method comprises:
A terminal member (14) buried in the outer enclosure (27) and having an end derived from each of the inner wall (27c) and the outer wall (27d) of the outer enclosure (27); An electronic device comprising: a circuit board (28) disposed in a circuit board (27); and a thin lead wire (31) for electrically connecting an electrode of an electronic element and a terminal member (14) provided on the circuit board (28). In the component manufacturing method, the surface (14) on which the concave portion (16) serving as the electrode connection region (17) is formed.
d) and a molding cavity (26) corresponding to the shape of the envelope (27) when the first mold (19) and the second mold (20) are closed. A step of preparing a forming die (18) to be formed; and an inner back surface (14a) and an inner back surface (14a) provided on the back surface (14e) of the terminal member (14) opposite to the electrode connection region (17). The coating back surface (14b) and the coating surface (14c) of the surface (14d) of the terminal member (14) opposite to the coating back surface (14b) are exposed to the molding cavity (26),
The recess (16) does not come into contact with the mold (18) and the molding cavity (2
6) The terminal member (14) is not exposed to the first mold (1).
A step of attaching the terminal member (14) to the mold (18) by sandwiching the terminal member (9) with the second mold (20); a step of injecting the fluidized resin into the mold cavity (26); The resin in (26) cures and covers the inner back surface (14a), the coated back surface (14b) and the coated surface (14c) of the terminal member (14) and the concave portion (16).
After the outer envelope (27) not covering the terminal member is formed, a step of removing the terminal member (14) from the molding die (18), and a step of removing the terminal member (1).
Insert the lead wire (31) into the recess (16) of 4) and the terminal member (14).
And pressing in the thickness direction to connect.

When the outer body (27) is molded together with the terminal member (14), the recess (16) does not directly contact the molding die (18) and is not exposed to the molding cavity (26). The electrode connection region (17) is not stained or damaged, and the fine lead wires (31) can be reliably connected to the electrode connection region (17) in a later step.

Also, the electronic member (14) on the opposite side of the electrode connection region (17)
The inner back surface (14a) of the back surface (14e) is exposed to the molding cavity (26), and a projection (27b) of the outer enclosure (27) is formed on the back surface of the electrode connection region (17). When connecting the fine lead wire (31) to the electrode connection region (17), a sufficient pressing force by the capillary is applied to the terminal member (14) supported by the protruding portion (27b) of the envelope (27). In addition to (31), the lead wire (31) can be connected to the electrode connection region (17) with sufficient connection strength.

Embodiment An embodiment of a method for manufacturing an electronic component according to the present invention applied to a method for manufacturing a hybrid IC for an automobile igniter will be described below with reference to FIGS.

In manufacturing this hybrid IC, first, as shown in FIG. 2, a terminal member assembly (11) in which a plurality of terminal members (14) are integrally connected is prepared. Terminal member assembly (1
1) five terminal members (14) in the form of five plates each having a narrow portion (13) formed at one end and a wide portion (12) formed at the other end; A connection member (15) for connecting the members (14) to each other. The concave portion (16) serving as the electrode connection region (17) is provided on the surface (14d) between the wide portion (12) and the narrow portion (13) of the three terminal members (14) arranged inside. Can be Further, a concave portion (16) used as a wiring terminal is formed on the surface of the connecting member (15).
The terminal member assembly (11) is formed by press molding from an aluminum plate material, and the respective recesses (16) are formed over the entire width of the terminal member (14) and the connecting member (15) by a known coining process during the press molding. ) Are simultaneously formed at a depth of about 0.3 mm. The terminal member (14) has a surface (14d) shown on the bottom side of the terminal member (14) in FIG. 1 and on the top side in FIG.
And a back surface (14e) shown on the top side of the terminal member (14) in FIG. 1 and the bottom side in FIG. Electrode connection area (17)
At the inner end of the terminal member (14) located on the back side of the outer enclosure (27)
The back surface (14e) in contact with is referred to as the inner back surface (14a). The outer surface of the terminal member (14) is continuous with the inner back surface (14a), and the back surface (14e) in contact with the envelope (27) is covered with the back surface (1).
4b). On the same side as the electrode connection area (17),
The surface (14d) of the terminal member (14) that comes into contact with 7) is called a coated surface (14c).

Next, as shown in FIG. 3, the upper die (1
9) and a molding die (1) including a second die (20).
8) Prepare. The upper mold (19) and the lower mold (20) have an enclosure (2
A recess (2) forming a molding cavity (26) corresponding to the shape of (7)
1, 22), and a groove (25) for mounting the gate (23) and the runner (24) and the terminal member assembly (11) connected to the concave portion (22) is formed in the lower mold (20). The terminal member (14) and the connecting member (1
The width of the groove (25) is formed so as to match the width of the terminal member (14) and the width of the connecting member (15) such that the side surface of (5) is in close contact with the side surface of the groove (25). The concave portions (21, 22) shown separately in the left and right directions in FIGS. 1 and 3 are each formed in an annular shape in plan view.

Subsequently, the terminal member assembly (1
The terminal member assembly is performed with the surface (14d) of (1) abutting against the bottom of the groove (25) and the electrode connection region (17) formed on the bottom of the recess (16) facing the bottom of the groove (25). Body (11)
Into the groove (25) of the lower mold (20). Connecting member (15)
Thereby, the terminal member assembly (11) in which the five terminal members (14) are integrally connected can be easily mounted on the molding die (18).

Next, as shown in FIG. 1, the upper mold (19) and the lower mold (20)
When the upper mold (19) and the lower mold (20) are clamped, one end of the terminal member (14) where the narrow portion (13) is formed and the connecting member (15) and the terminal member (14) Of the terminal member (14) fitted in the groove (25) of the lower mold (20), except for the recess (16). Adhere to the bottom. Also, the inner back surface (14a) and the back surface (14b) of the terminal member (14) are recessed (2) of the upper die (19).
Exposed to 1), the coating surface (14c) is recessed (2
Exposure to 2). Electrode connection area (17) of terminal member (14)
Is not exposed to the molding cavity (26).

Subsequently, the molten resin is pressed into the molding cavity (26) through the runner (24) and the gate (23) formed in the lower mold (20). The molten resin injected from the gate (23) is formed in the entire annular molding cavity (26) from the molding cavity (26) on the right side to the molding cavity (26) on the left side of the molding die (18) in FIG. Fill.
At this time, the surface (14d) and the side surface of the terminal member (14) fitted into the groove (25) of the lower mold (20) are in close contact with the bottom surface and the side surface of the groove (25). Recess of the (16)
No molten resin flows into

After the resin injected into the molding cavity (26) is cured, the upper mold (19) and the lower mold (20) are released, and the terminal member assembly (11)
5 is removed from the molding die (18). The narrow part (13) of the terminal member (14) is led out from the inner wall (27c) of the annular outer body (27) shown in FIGS. 4 and 5, and is drawn from the outer wall (27d) of the outer body (27). A wide part (12) is derived. Thick part (27) of outer enclosure (27)
a) covers the coating back surface (14b) and the coating surface (14c) on both sides of the terminal member (14). Projection (27) of outer enclosure (27)
b) covers the inside back surface (14a) of the terminal member (14),
The back surface of the recess (16) contacts the back surface (14e). The concave portion (16) formed in the terminal member (14) and the connecting member (15)
It protrudes slightly from the protruding portion (27b) of the outer enclosure (27). The terminal member assembly (11) molded in the outer enclosure (27) is cut along the broken line in FIG. 4 to electrically separate the terminal members (14) from each other. The concave portion (16) of the terminal member (14) forms an electrode connection region (17) in order to perform wire bonding of the fine lead wire (31) well. The connecting member (1
The concave portion (16) formed on the right side of (5) does not become a connection portion of the lead wire after cutting, and the protruding portion (27b) of the envelope (27)
Are not formed below the recess (16).

Next, as shown in FIG. 5, the radiator plate (29) on which the circuit board (28) is placed is fixed to the outer casing (27) with an adhesive (not shown). The circuit board (28) includes an electric circuit including a thick-film conductor (not shown), a thick-film resistor, and a semiconductor element (30). The semiconductor element (30) includes a power element such as a power transistor chip, a thick film resistor and a thick film conductor formed on a circuit board. Subsequently, a not-shown electrode of the semiconductor element (30) on the circuit board (28) and an electrode connection region (17) of the terminal member (14) are connected to the electrode connection region (17) by a well-known wire bonding using a lead wire (31) made of aluminum (A1). Connect by law. In addition, ultrasonic vibration which vibrates in parallel with the main surface of the terminal member (14) is applied to the capillary, and the capillary is pressed against one end of the fine lead wire (31) in the thickness direction of the terminal member (14). Is crushed in the radial direction to connect one end of the fine lead wire (31) to the electrode connection region (17). Dirt and damage to the electrode connection region (17) formed on the bottom surface of the concave portion (16) during resin molding can be prevented, and the outer casing (2) provided below the electrode connection region (17) can be prevented.
7) Lead wire (3) securely supported by the protrusion (27b)
1) Fully transmit the vibration and pressing force of the cab
The thin lead wires (31) can be securely connected to all the electrode connection regions (17).

After connecting the fine lead wires (31), a silicone resin (32) is injected into the enclosure (27), and the circuit board (28) and the terminal member (1
4) Cover the concave portion (16) and the fine lead wire (31) formed in the connecting member (15), and attach the cover (33) to the envelope (27) to complete the hybrid IC.

In the method for manufacturing a hybrid IC described above, the concave portion (16) is formed by press molding which can securely connect the fine lead wire (31) to the terminal member (14) and the connecting member (15) and form the terminal member assembly (11). Since it can be formed at the same time and the productivity does not decrease, it is advantageous as compared with the method of connecting the fine lead wires (31) via a separate metal member of the electrode connection region (17).

Modifications Embodiments of the present invention can be modified. For example, the envelope (27) may be formed by injection molding, such as transfer molding, in addition to injection molding. Outer enclosure (27)
Is not limited to the embodiment. For example, the terminal member (14) may be led out from the bottom surface of the outer wall portion having a U-shaped cross section.

The cutting terminal member (14) is previously formed to be short at the broken line portion in FIG. 4, and the thick portion extending slightly from the recess (16) is sandwiched between the upper mold (19) and the lower mold (20). Resin molding. Further, a portion excluding the electrode connection region (17) on the bottom surface of the concave portion (16) may be sandwiched. In this case, it is not necessary to cut the terminal member after the resin molding. However, the point that the terminal member (14) can be securely fixed at the time of the resin molding and the terminal member assembly (11) integrated with the connecting member (15) are better. From the viewpoint of easy handling, it is preferable to form the terminal member (14) longer as in the embodiment and cut it later.

Effect of the Invention As described above, in the method for manufacturing an electronic component according to the present invention, it is possible to prevent dirt and damage to the electrode connection region of the terminal member, reliably connect the lead wire to the terminal member, and obtain a highly reliable quality electronic device. Parts can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a molding die used in a method of manufacturing an electronic component according to the present invention, FIG. 2 is a plan view of a terminal member assembly used in the manufacturing method, and FIG. FIG. 4 is a plan view of an enclosure in which a terminal member assembly is insert-molded, FIG. 5 is a cross-sectional view of a hybrid IC used in an automobile igniter manufactured according to the present invention, and FIG. The figure shows a cross-sectional view of a hybrid IC used in a conventional automobile igniter. (11) ... terminal member assembly, (12) ... wide part, (13)
... Narrow part, (14) ... Terminal member, (14a) ... Inside back surface, (14b) ... Covered back surface, (14c) ... Covered surface, (14
d) Front surface, (14e) Back surface, (16) recess, (1
7) Electrode connection area, (18) Mold, (19)
1st type (upper type), (20) ... 2nd type (lower type), (2
6) molding cavity, (27) outer enclosure, (27c) inner wall, (27d) outer wall, (28) circuit board, (31)
… Lead wire,

Claims (1)

(57) [Claims] An external enclosure (27) and a terminal embedded in the external enclosure (27) and having an end extending from each of an inner wall (27c) and an outer wall (27d) of the external enclosure (27). The member (14), the circuit board (28) disposed in the enclosure (27), and the circuit board (2
8) A method of manufacturing an electronic component including a lead wire (31) for electrically connecting an electrode of an electronic element and a terminal member (14) provided in an electronic device, wherein a concave portion (16) serving as an electrode connection region (17) is provided. ) Is formed on the terminal member (14) provided with the surface (14d), and the shape of the envelope (27) when the first mold (19) and the second mold (20) are closed. A step of preparing a molding die (18) for forming a molding cavity (26); and an inner back surface (14a) provided on the back surface (14e) of the terminal member (14) opposite to the electrode connection region (17). ), Inside back (14
a) the coating back surface (14b) and the coating surface (14d) of the surface (14d) of the terminal member (14) opposite to the coating back surface (14b);
c) is exposed to the molding cavity (26), and the concave portion (1) is exposed.
The terminal member (14) is connected to the first mold (19) with the second mold (6) while the terminal member (6) is not in contact with the molding die (18) and is not exposed to the molding cavity (26).
Attaching the terminal member (14) to the molding die (18) by holding the terminal member (14) to the molding die (18); injecting the fluidized resin into the molding cavity (26); The resin is cured and the inner back surface (14a), the back surface (14b) and the front surface (14) of the terminal member (14) are cured.
Enclosure (27) covering c) and not covering recess (16)
After the is formed, a step of removing the terminal member (14) from the mold (18), and pressing the thin lead wire (31) into the concave portion (16) of the terminal member (14) in the thickness direction of the terminal member (14). Connecting the electronic components to each other.