JP2827750B2 - Apparatus and method for manufacturing lead frame material with heat sink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame material for forming a lead frame, and more particularly to an apparatus and a method for manufacturing a lead frame material with a heat sink.

[0002]

2. Description of the Related Art As the output and integration of semiconductors increase, the amount of heat generated from the semiconductors increases. Therefore, it is necessary to dissipate the heat to the outside in order to prevent the performance of the semiconductors from being deteriorated by the heat. Therefore, it has been considered to embed a heat sink having an excellent heat dissipation property in a semiconductor package.

[0003] One example of this is an irregularly shaped strip, which is used as a lead frame material for transistors.

FIG. 2 is an external perspective view of a conventional modified cross section of this type.

As shown in FIG. 1, the irregularly shaped strip 1 is not a flat plate-shaped member, but a plate-shaped member formed so that the center in the width direction has a larger gap than both ends. A semiconductor chip is mounted on the thick plate portion 2 at the central portion, and leads are formed on the thin plate portions 3 at both ends and embedded in a package.

[0006] As a method of manufacturing such a deformed cross-section strip,
There is a method in which a metal plate is rolled using one of the rolling rolls, which has a groove along the circumferential direction on both sides in the axial direction of the outer peripheral surface of the roll. This is a rolled part that becomes the lead part on both ends along the longitudinal direction of the metal plate,
The central portion is a non-rolled portion serving as a heat sink. Since the material deformation of the rolled portion is generated not in the longitudinal direction but in the width direction of the metal plate to form the thin plate portion 3 serving as the lead portion, it can be efficiently processed into a deformed cross section.

[0007]

However, the above-mentioned conventional irregular cross section is a lead frame material having a portion having a different plate thickness only in the plate width direction, using the thick plate as a heat sink and using the thin plate as an external connector. And a lead portion for connection. Therefore, the portion serving as a lead in this irregular cross section is limited to one or both sides of the heat sink portion. For this reason, although it can be used as a lead frame material for a transistor having a small number of terminals, it cannot be used as a lead frame material for an IC having a large number of signal terminals if only one or both sides of the heat sink portion have insufficient pins. .

As a lead frame material for a multi-pin IC having a large number of signal terminals, it is necessary to secure lead portions in four directions of a heat sink portion. That is, a lead frame having thin plate portions serving as lead portions on four sides of the thick plate portion serving as a heat sink is required.

On the other hand, in the above-mentioned conventional method for producing a deformed cross-section strip by rolling using a grooved roll, a thin plate portion continuous in the longitudinal direction can be formed on both sides of the strip material, but as a heat sink portion. A functioning thick plate cannot be formed intermittently in the longitudinal direction of the strip.

[0010] As a method of manufacturing a lead frame material having lead portions in four directions, a deformed cross-section having a thin plate portion continuously formed on both sides of the strip in the longitudinal direction by a conventional method, and then the thick plate portion is formed. It is conceivable that the lead portions are formed on both sides in the longitudinal direction by cutting by cutting. However, the yield is deteriorated, and cutting flaws remain on the surface of the lead frame.

Therefore, an object of the present invention is to solve the above-mentioned problems and to manufacture a lead frame material with a heat sink having excellent surface quality, having thin plate portions serving as leads in four directions of a thick plate portion serving as a heat sink portion. An object of the present invention is to provide an apparatus and a method for manufacturing a lead frame material with a heat sink.

[0012]

In order to achieve the above object, a first aspect of the present invention has a rolling roll composed of two opposing rolls, and rolls a plate-shaped member using the rolling roll to form a lead portion. And a heat sink part having a thickness greater than that of the lead part. A device for manufacturing a lead frame material with a heat sink, wherein one or a plurality of the rolls are provided along the circumferential direction on the outer peripheral surface of one of the rolling rolls. A concave portion for heat sink that forms the heat sink portion by rolling; and a notch portion that is provided adjacent to the concave portion for heat sink by the same number as the concave portion for heat sink and that is cut out in the axial direction of the roll and does not roll the plate-shaped member. And the heat sink concave portion and the cutout portion are integrally connected to each other and formed as a pair, and the heat sink is formed by the cutout portion. Materials of the heat sink is characterized in that to allow the extending in the rolling direction during rolling molding the click portion.

Further, the second invention provides a method for rolling a plate-like member using the rolling roll having the concave portion for heat sink and the notch on the outer peripheral surface of one of the rolls. After sequentially forming the front lead portion, the heat sink portion and the lateral lead portions on both sides of the heat sink portion with the rolling roll, once stop sending out the plate-like member, send out the rear lead portion again after the cutout portion rotates, and the rear lead portion. It is characterized by being molded.

[0014]

When the lead portion and the heat sink portion are roll-formed by the outer peripheral surface of the rolling roll and the heat sink concave portion, if the volume of the material in the heat sink concave portion is large, excess material flows into the notch portion. Thereby, a lead frame material with a heat sink having excellent surface quality is manufactured.

By stopping the plate-like member fed according to the rolling process while the notch portion rotates after the heat sink portion is formed, a portion that is not rolled by the notch portion is rolled, and the heat sink portion and the four sides of the heat sink portion are rolled. And a lead portion located at

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

According to the present invention, by rolling the plate-like member with the rolling roll, a portion where the rolling reduction of the plate-like member is small occurs in the concave portion for the heat sink formed in the rolling roll,
The position of the plate-shaped member corresponding to the concave portion is a thick plate portion, that is, a heat sink portion. On the other hand, a thin plate portion is formed around the thick plate portion by an outer peripheral surface other than the heat sink concave portion of the roll, and the thin plate portion becomes a lead portion.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a main part showing a rolling roll of the present embodiment. FIG. 3 is an external perspective view of an ideal lead frame material with a heat sink manufactured by the manufacturing apparatus of the present embodiment, and FIG. 4 is a schematic configuration diagram showing an apparatus for manufacturing a lead frame material with a heat sink according to the present embodiment.

As shown in FIG. 3, the apparatus and method for manufacturing a lead frame material with a heat sink according to the present embodiment include a thick plate portion 7 serving as a heat sink portion and lead portions provided on four sides of the thick plate portion 7. And a lead frame material 9 including a thin plate portion 8 to be formed.

As shown in FIG. 1, the manufacturing apparatus for a lead frame material with a heat sink includes a rolling roll 10 for rolling and forming a lead frame material 9 having a thick plate portion 7 and a thin plate portion 8. The rolling roll 10 includes an upper roll portion 10A and a lower roll portion 10B provided to face the upper roll portion 10A. The lower roll portion 10B is configured as a normal roll having a flat outer peripheral surface. The upper roll portion 10A is provided with two heat sink recesses 11, 11 on the outer peripheral surface thereof along the circumferential direction. Each of the heat sink recesses 11 is provided at a line symmetrical position about the axial center of the upper roll portion 10 </ b> A, and is formed in a quadrangular shape according to the shape of the heat sink portion 7.

Further, on the outer periphery of the upper roll portion 10A,
Two notches 12 are provided adjacent to the heat sink recesses 11, respectively. The cutout portion 12 is provided on the rear side in the rotation direction of the upper roll portion 10A with respect to the heat sink concave portion 11. Each of the notches 12 is provided so as to be cut out over the entire length of the upper roll portion 10A in the axial direction, and has a configuration integrally continuous with the depression of the concave portion 11 for the heat sink. Side shape of the notch 12 is formed in a small diameter concentric with respect to the upper roll unit 10A, the groove depth is in the t _4. The groove depth t ₄ is formed to be deeper than the thickness t ₃ of the plate member 13 before processing, and the notch 12
Then, the plate-shaped member 13 is not rolled. Note that the thickness of the thick plate portion 7 is t ₁ , and the thickness of the thin plate portion 8 is t ₂ .

[0023] In the rolling roller 10 of the structure, the upper roll unit 10A is rotated in the L ₁ direction, the corresponding the lower roll unit 10B which rotates the L ₂ direction, which is the opposite direction. Thus, the plate-like member 13 is moved in the L ₃ direction.

The rolling roll 10 having the above configuration is incorporated in a manufacturing apparatus shown in FIG. In the figure, 15 is a plate-like member 13
Is a take-up roll that takes up the rolled lead frame material 9. Between the delivery roll 15 and the take-up roll 16, the rolling roll 10, the guide roll 17, the accumulator 18, and the deflor 19 are provided in this order from the delivery roll 15.

A take-up tension is applied to the take-up roll 16, and the take-up roll 16 receives the take-up tension by the deflor 19. A back tension is applied to the delivery roll 15. This back tension is set to the following magnitude. Notch 12 during rolling by rolling roll 10
Is not rolled when facing the plate member 13, only the lower roll portion 10B contacts and rotates with the plate member 13, so that the plate member is opposed to the frictional force of the lower roll portion 10B. 13 is applied with enough back tension to stop the motor.

Next, a method of manufacturing a lead frame material with a heat sink using the manufacturing apparatus having the above-described configuration will be described.

First, the plate member 13 is bridged between the delivery roll 15 and the take-up roll 16. The winding tension is applied to the winding roll 16, and the back tension is applied to the feeding roll 15.

Next, the rolls 10, 15, 16, and 19 are rotated, and the plate-like member 13 sent out from the feed roll 15 is rolled by the rolling roll 10 and sent to the take-up roll 16 side. In this case, the thickness t ₂ is first a front lead portion at the portion without the recess of the upper roll unit 10A side the thin plate portion 8A
(See FIG. 3). Then, the thick plate portion 7 of the thickness t ₁ of the heat sink portion is formed in the heat sink recess 11, forms a horizontal side lead section and comprising a thickness t ₂ thin plate 8B on both sides of the heat sink recess 11. At this time, if the volume of the material of the plate-shaped member 13 is larger than the volume of the concave portion 11 for the heat sink, the material flows out of the concave portion 11 for the heat sink to the outside. Go. That is, a surplus of the material in the concave portion 11 for the heat sink is allowed in the cutout portion 12.

When the rolling in the heat sink recess 11 is completed, the notch 12 becomes a contact portion with the plate-like member 13.
In this portion, since the groove depth t ₄ of the concave portion 11 is formed deeper than the thickness t ₃ of the plate member 13, rolling is not performed. Further, since deeper than the thickness t ₃ is the groove depth t _4, becomes only the lower roll unit 10B in contact with the plate-like member 13 in this state, the plate by the back tension exerted on the delivery roll 15-like member 13 Stops moving. At this time,
Winding tension of the winding roll 16 side is suppressed by the accumulator 18 and Defuroru 19, the plate-like member 13 L ₃
Do not move in the direction of. During this time, the upper roll portion 10A and the lower roll portion 10B are rotated in the directions of L ₁ and L ₂ , and the plate-like member 13 is again moved to the upper and lower roll portions at the time when the notch 12 has passed in the upper roll portion 10A. Part 10
The plate member 13 is moved by rolling at A and 10B. This forms a thickness t ₂ of the thin plate portion 8C serving as a rear lead portion by rolling a portion that has not been rolled by the notch 12.

Thereafter, by repeating the same means as above, a lead frame material 9 having a thick plate portion 7 as a heat sink portion and a thin plate portion 8 as a lead portion is formed. In addition, it is possible to manufacture the lead frame material 9 having excellent surface quality without distortion of the plate thickness portion 7 and the thin plate portion 8.

Note that the thickness t ₁ of the thick plate portion 7 is
Is set to be equal to or less than the thickness t ₃ . Upper roll part 10A and lower roll part 10B of rolling roll 10
Is the thickness t ₂ of the thin plate portion 8.

In the above embodiment, the upper roll 10
Although the shape of the notch portion A of A is formed in a cylindrical shape concentric with the upper roll portion 10A, it may be formed in another shape.

[0033]

In summary, according to the present invention, it is possible to process a lead frame material having a thin plate portion serving as a lead portion in four directions around a thick plate portion serving as a heat sink, and a heat sink for a cover IC having a number of pins. The lead frame material with the attached can be obtained.

In addition, at the time of forming the thick plate portion, excess material located in the thick plate portion is allowed to escape to the notch portion, and the extension of the thick plate portion in the longitudinal direction is not restricted. It is possible to reliably prevent the accuracy from deteriorating and improve the surface quality.

Further, productivity can be improved by the method of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing a rolling roll according to the present invention.

FIG. 2 is an external perspective view of a conventional irregularly shaped cross section.

FIG. 3 is an external perspective view of an ideal heat sink lead frame material.

FIG. 4 is a schematic configuration diagram showing an apparatus for manufacturing a lead frame material with a heat sink according to the present invention.

[Explanation of symbols]

 Reference Signs List 7 thick plate portion 8 thin plate portion 9 lead frame material 10 rolling roll 10A upper roll portion 10B lower roll portion 11 concave portion for heat sink 12 cutout portion 13 plate member

Continuation of the front page (56) References JP-A-5-115938 (JP, A) JP-A-5-123807 (JP, A) JP-A-5-138281 (JP, A) JP-A-6-63676 (JP) JP-A-5-275588 (JP, A) JP-A-5-13641 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B21H 8/00 H01L 23/50

Claims (2)

(57) [Claims] 1. A lead having a heat sink having a rolling roll comprising two opposing rolls, and rolling a plate-like member using the rolling roll to form a lead portion and a heat sink portion having a thickness larger than the lead portion. In the apparatus for manufacturing a frame material, one or a plurality of concave portions for heat sink formed along the circumferential direction on the outer peripheral surface of any one of the rolling rolls to form the heat sink portion by rolling, and the same number of concave portions for heat sink. Provided only adjacent to the concave portion for the heat sink, notch formed in the axial direction of the roll and not rolling the plate-shaped member,
The concave portion for the heat sink and the cutout portion are formed by being integrally connected to each other in pairs, and the cutout portion allows the material of the heat sink portion to extend in the rolling direction during rolling forming of the heat sink portion. For manufacturing a lead frame material with a heat sink. 2. The method according to claim 1, wherein when the plate-shaped member is rolled using the roll having the concave portion for the heat sink and the notch on the outer peripheral surface of one of the rolls, the plate-shaped member to be fed is forward-leaded by the roll. After sequentially forming the side portion, the heat sink portion and the lateral lead portions on both sides of the heat sink portion, once the sending out of the plate-like member is stopped, the notch portion is rotated and then sent out again to form the rear side lead portion. Of manufacturing a lead frame material with a heat sink.