JP3183552B2 - Manufacturing method of multilayer lead frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer lead frame.

[0002]

2. Description of the Related Art FIG. 6 shows a configuration of a multilayer lead frame having a three-layer structure of a lead frame 2, a power plane 3, and a ground plane 4. The multi-layered lead frame is integrally formed by pressing and crimping a tape 5 having electrical insulation such as polyimide between layers of the lead frame 2, the power plane 3, and the ground plane 4. Conventionally, when manufacturing such a multilayer lead frame, a strip-shaped lead frame strip and a plane holder are overlapped and crimped. A lead frame on which predetermined leads are formed is formed on the lead frame strip, and a plane holder having a rectangular frame shape or a rectangular plate shape is formed on a plane holder serving as a power supply plane and a ground plane in accordance with the lead frame. I have.

Since the plane portions serving as the power supply plane and the ground plane are hung on a support frame of a plane holder formed in a strip shape, the plane holders for the power plane and the ground plane are provided on the lead frame strip. After overlapping and joining, the support frame portion is separated and removed except for the plane portion joined to the lead frame strip. Thus, a multilayer lead frame in which the power plane and the ground plane are joined to the lead frame is obtained.

[0004]

In the case where a multilayer lead frame is formed by laminating a strip-shaped lead frame strip and a plane holder as described above and crimping the same, conventionally, a conventional lead frame strip is used. An electrically insulating tape is temporarily pressure-bonded to the lead frame, a power plane is bonded to the tape, and a ground plane is bonded to the power plane. Therefore, in this conventional method, a pressing force is applied to the lead frame twice when the power plane is joined to the lead frame and when the ground plane is joined to the power plane, and the inner lead of the lead frame is deformed. This could cause them to stick or push the leads.

Further, in the conventional method, the lead frame is thermally expanded and deformed due to the heating at the time of pressing the power supply plane or the like, and the tape is not sufficiently pressed at the portion between the leads of the lead frame. There is a problem that air is not completely pushed out from the interlayer during the pressure bonding and air entrainment occurs. Further, in the conventional method, the strip-shaped plane holder is overlapped on the lead frame strip and pressed, and then the support frame portion is separated and removed, but the width of the support frame is considerably widened to facilitate this separation work. . For this reason, the support frame occupies a considerably large area compared to the area of the power plane or the ground plane actually used by being joined to the lead frame, and there is a problem that the material of the plane holder is wasted. Was.
Therefore, the present invention has been made to solve the above problems, and the object thereof is to be able to produce a good product by performing accurate crimping without causing deformation of the lead and the like. An object of the present invention is to provide a method for manufacturing a multilayer lead frame that can eliminate waste.

[0006]

The present invention has the following arrangement to achieve the above object. That is, in the method of manufacturing a multilayer lead frame, in which a plane holder for a power plane, a ground plane, or the like is separately attached to a lead frame with an electrical insulating layer interposed between layers, The tape which becomes the electrical insulating layer is temporarily pressure-bonded to one surface of the body, and another plane holder is joined to the plane holder with the tape interposed therebetween. A tape to be an electrically insulating layer is temporarily pressure-bonded, and the plane holder and the lead frame strip are combined with the tape interposed therebetween, and then pressurized and heated so that the lead frame strip and the plane holder are interposed. And the other plain holding member is completely press-bonded. Further, when joining the another plane holder to the plane holder with the tape interposed therebetween, the other plane holder is made into individual planes and joined.

[0007]

According to the present invention, a plane holder and a lead frame are provided.
When laminating strips, press flare and heat
Pressure and heat applied only once to the
It is possible to suitably prevent the deformation of the frame. One
In other words, in the present invention, the plane holder is relatively resistant to deformation.
Lead frame that is vulnerable to deformation
The pressurizing and heating steps applied to the
The inner lead of the frame-shaped strip is pressurized during lamination,
Deformation can be prevented by heating. In addition, it is possible to save material by joining the planes in pieces.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The embodiment shows a method for manufacturing a multilayer lead frame including three layers of a lead frame, a power plane, and a ground plane. In this embodiment, a ground plane is bonded to one surface of a power plane serving as an intermediate layer, and then a lead frame is bonded to the other surface of the power plane to manufacture a multilayer lead frame. FIG. 1 shows a step of temporarily bonding a tape 16 having electrical insulation properties to a plane holder 10 for a power plane. The plane holder 10 for the power plane is formed in a strip shape in which the power plane 12 finally joined to the lead frame is suspended by the support frames 14 on both side edges. The power plane 12 is formed in a rectangular frame shape, and the tape 16 is formed in a frame shape corresponding to the rectangular frame shape. The tape 16 is formed of a polyimide film in the embodiment, and the attachment of the tape 16 to the power supply plane 12 is performed by temporary crimping.

FIG. 2 shows a step of joining the ground plane 18 to the temporarily crimped tape 16. The ground plane 18 is formed in a rectangular plate shape corresponding to the outer shape of the power plane 12 of the plane holder 10 and is joined so as to cover the inside of the frame of the power plane 12. A tape 16 is interposed between the ground plane 18 and the power plane 12 to provide electrical insulation. In the illustrated example, the ground planes 18 are formed in individual pieces and are aligned with and joined to the individual power planes 12 of the plane holder 10, but similarly to the plane holder for the power plane shown in FIG. The strip-shaped plane holder may be aligned with the power supply plane 12 and joined.

After bonding the ground plane 18, the plane holder 10 is turned over and a tape 16 a for bonding the individual lead frames 2 of the lead frame strip 20 on the opposite side of the power plane 12 of the plane holder 10 is applied. Temporarily crimp. The tape 16a is formed in a frame shape in accordance with the bonding position of the inner lead of the lead frame 2, and the power supply plane 1 is formed.
Temporarily pressure-bonded to the upper surface of 2. A ground plane 18 is joined to the lower surface of the power plane 12. After the tape 16a is temporarily pressure-bonded, the lead frame strip 20 is bonded thereon as shown in FIG. The bonding of the lead frame strip 20 is performed by a final press bonding operation, and the lead frame strip 20, the plane holder 10 and the ground plane 18 already bonded are entirely pressurized, heated to a predetermined temperature, and subjected to the final press bonding. .

In a state where the lead frame strip 20 and the plane holder 10 and the ground plane 18 are integrally joined, the support frame 14 of the strip-shaped plane holder 10 is formed.
Since the portion remains, the support frame 14 is separated and removed from this state to finally produce a product. FIG. 5 shows how the support frame 14 is separated and removed from the plane holder 10. In order to remove the support frame 14, a V-notch is provided in advance at the boundary between the power plane 12 and the support frame 14 when the plane holder 10 is formed, and the support frame 14 is bent up and down at the V-notch portion. The support frame 14 is separated leaving the power plane 12. A section bar 15 is provided between the adjacent power supply planes 12, but since the tapes 16 and 16 a are not attached to the section bar 15, the section bar 15 is separated and removed together with the separation of the support frame 14. Thus, a multilayer lead frame in which the power plane and the ground plane are joined to the lead frame strip 20 is obtained.

In the manufacturing method according to the present embodiment, the temporary holding of the tape 16, the bonding of the ground plane 18, and the temporary pressing of the tape 16 a are performed on the plane holder 10 for the power supply plane, so that the lead frame strip 20 is attached to the lead frame strip 20. On the other hand, since the joining is performed by applying a pressing force only in the final final pressure bonding step, the joining operation to the lead frame strip 20 only needs to be performed once, and the inner lead is deformed by pressing the lead frame strip 20. , Or a push flaw can be prevented. In addition, since the lead frame strip 20 is heated only in the final pressing step,
Problems such as deformation of the inner lead due to thermal expansion can also be prevented. In addition, in this embodiment, since the tapes 16 and 16a are temporarily pressure-bonded to the power supply plane first, the bondability between the power supply plane and the ground plane and the tape is improved, and it is possible to eliminate air from being caught between layers. It becomes possible. Further, in the above embodiment, the ground plane 18 is joined to the power plane 12 in an individual state, so that it is possible to save material as compared with the case where the ground plane 18 is supported by the frame and joined. Become.

In the above embodiment, the ground plane 18 is bonded to the plane holder 10 of the power plane serving as the intermediate layer. , And further, a method of joining a lead frame strip. As described above, various steps can be selected under the condition that the final press bonding of the lead frame strip is the final step.

The same applies to the case of a multi-layered lead frame having four or more layers. The required planes such as a power plane and a ground plane are bonded in advance by a temporary crimping method, and finally, the lead frame strip is bonded. It is possible to manufacture a good product without deformation of the lead.

[0015]

According to the present invention, a plane holder and a lead holder are provided.
When laminating lame strips, lead
The pressure and heat applied to the frame strip only once,
The deformation of the card frame strip can be suitably prevented.
You. In other words, in the present invention, the plane protection that is relatively resistant to deformation
Leads that are vulnerable to deformation by joining the holding bodies in advance
Only one pressurization and heating process to apply to the frame strip
When the inner leads of the lead frame
Can be prevented from being deformed by pressurizing and heating
You. In addition, it is possible to save material by joining the planes in pieces.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state in which a tape is temporarily pressure-bonded to a power plane.

FIG. 2 is an explanatory diagram showing a state where a ground plane is joined to a power plane.

FIG. 3 is an explanatory diagram showing a state in which a tape is temporarily pressure-bonded to a ground plane.

FIG. 4 is an explanatory diagram showing a state in which a lead frame is fully pressure-bonded to a power supply plane.

FIG. 5 is an explanatory diagram showing a state in which a support frame is removed from a power plane frame.

FIG. 6 is a cross-sectional view showing a three-layer multilayer lead frame.

[Explanation of symbols]

 2 Lead frame 3 Power plane 4 Ground plane 5 Tape 10 Plane holder 12 Power plane 14 Support frame 16, 16a Tape 18 Ground plane 20 Lead frame strip

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-25163 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 23/50

Claims (2)

(57) [Claims] 1. A method of manufacturing a multilayer lead frame, comprising joining a plane holder for a power plane, a ground plane, or the like separately to a strip of a lead frame with an electrically insulating layer interposed between layers. After temporarily bonding the tape to be the electrical insulating layer to one surface of the above, and bonding the other plane holder to the plane holder with the tape interposed, the electric power is applied to the other surface of the plane holder. Temporarily press-bonding a tape to be an insulating layer, and combining the plane holder and the lead frame strip with the tape interposed therebetween, pressurizing and heating the lead frame strip and the plane holder. A method for manufacturing a multi-layer lead frame, comprising: fully press-bonding the another plane holder. Wherein when joining with the other planes holder in the plane holding member is interposed the tape, according to claim 1, characterized in that joining by the said other plane holding body plane pieces A method for manufacturing the multilayer lead frame according to the above.