JP2000031370A - Lead frame and manufacture thereof and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead frame with high accuracy. SOLUTION: This lead frame manufacturing device, wherein a slope part 16 is formed on a stage support bar 15 connected to the stage part 14 of a lead frame 10 and levels are formed between the lead formed surface on which lead parts 12 are formed and the surface of the stage part 14, has first interposing means and second interposing means for interposing a part adjacent to the slope part 16 to be formed on the stage support bar 15 and the other part on the side opposite to the slope part 16 respectively and driving means for moving both the interposing means relatively in the direction perpendicular to the lead formed surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame, a method of manufacturing the same, and a manufacturing apparatus, and more particularly, to forming a slanted piece by bending a part of a stage support bar.
The present invention relates to a lead frame in which a stage portion has a required height lower than a lead forming surface, a method of manufacturing the same, and a manufacturing apparatus.

[0002]

2. Description of the Related Art A stage of a lead frame on which a semiconductor chip is mounted is one step lower than a lead forming surface on which a lead such as an inner lead is formed.
The electrodes are formed such that the electrode formation surface of the mounted semiconductor chip and the wire bonding plane of the lead are substantially the same. Thereby, the bonding wire can be shortened and bonding can be performed with high reliability. In order to obtain the above-mentioned lead frame, conventionally, a part of the stage support bar is bent by pressing to form an inclined piece portion, so that the stage portion has a required height lower than the lead forming surface (depressed portion). processing). FIG. 10 shows a mold for the depressing process. 50 is a punch (upper type) and 52 is a die (lower type). The lead frame 10 (FIG. 1)
1) is placed, and the punch 50 is moved downward, so that a part of the stage support bar 15 (two places, four places in the case of a QFP type lead frame) is brought into contact with the slopes 52 a and 52 b Slope 50a, 5
0b, crushed, bent, and inclined pieces 16, 16
Is formed, so that the stage portion 14 is lower than the lead formation surface (FIG. 12).

[0003]

However, the above-mentioned conventional depressing method has the following problems. That is, as shown in FIG. 10, even when the punch 50 and the die 52 are slightly offset from each other,
The distance between the slope 50a and the slope 52a, the slope 50b and the slope 5
There is a large difference in the distance from the second electrode 2b. Therefore, when pressed, there is a difference between the extension of one inclined piece 16 and the extension of the other inclined piece 16, and as a result, the stage 1
4 has a problem that it is difficult to obtain a required flatness due to warpage.
In addition, the depressing is performed such that a plurality of lead frames are simultaneously performed by a plurality of dies. At this time, even when the mounting height of the die 52 and the punch 50 of each mold is slightly shifted, a difference occurs in the pressing force by the press in each mold, and a difference occurs in the extension of the inclined piece portion 16. Therefore, there is also a problem that the stage section 14 is warped.

[0004] It is only necessary to manufacture a highly accurate mold, but if the accuracy of the mold is improved, the manufacturing cost is increased. In particular, it is difficult to measure the dimensions of the inclined surface of the mold with high accuracy, and there is a limit in increasing the processing accuracy. Even if a high-precision mold is manufactured, it is not always easy to mount the mold accurately, and accurate processing cannot be performed even with a slight displacement as described above.

Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a lead frame in which a required step is accurately formed between a lead surface and a stage surface, and a mold of a die itself. An object of the present invention is to provide a method and an apparatus for manufacturing a lead frame, which can provide a lead frame with high accuracy without requiring much improvement in accuracy.

[0006]

To achieve the above object, the present invention has the following arrangement. That is, in the lead frame according to the present invention, the inclined piece is formed on the stage support bar connected to the stage of the lead frame, and a step is formed between the lead forming surface on which the lead is formed and the surface of the stage. In the lead frame provided, the inclined piece portion is formed by extending a stage support bar by a tensile process.

In the method for manufacturing a lead frame according to the present invention, an inclined piece is formed on a stage support bar connected to the stage of the lead frame, and the lead forming surface on which the lead is formed and the surface of the stage. In the method for manufacturing a lead frame in which a step is formed, the one portion adjacent to the inclined piece portion to be formed on the stage support bar and the opposite side of the one portion with the inclined piece portion interposed therebetween. The other part is clamped by the first clamping means and the second clamping means, respectively, and these two clamping means are moved relatively in a direction perpendicular to the lead forming surface, and the stage between the two clamping means is moved. The present invention is characterized in that the inclined bar portion is formed by stretching a support bar by a pulling process. By controlling the relative movement stroke of the first holding means and the second holding means, it is possible to form the inclined piece uniformly extended by the pulling process, so that the lead forming surface and the required step without warping can be formed. A lead frame having a stage portion can be manufactured. In this case, if the both holding means are moved relatively plural times in the direction perpendicular to the lead forming surface to form the inclined piece, the inclined piece can be easily formed without breakage. It is.

In the lead frame manufacturing apparatus according to the present invention, an inclined piece is formed on a stage support bar connected to the stage of the lead frame, and the lead forming surface on which the lead is formed and the surface of the stage are formed. And a part adjacent to the inclined piece part to be formed on the stage support bar, and an opposite side of the one part with the inclined piece part interposed therebetween. It is characterized by comprising a first holding means and a second holding means for holding the other part, respectively, and a driving means for relatively moving the two holding means in a direction perpendicular to the lead forming surface. . First clamping means and second clamping means
By controlling the relative movement stroke of the clamping means, it is possible to form an inclined piece uniformly extended by a pulling process, and therefore a lead frame having no warp and a stage having a lead forming surface and a required step is provided. Can be manufactured. In this case, when forming the inclined piece portion,
It is preferable to provide control means for controlling the driving means so as to move the both holding means relatively plural times in a direction perpendicular to the lead forming surface.

Further, in the lead frame manufacturing apparatus according to the present invention, an inclined piece is formed on the stage support bar connected to the stage of the lead frame, and the lead forming surface on which the lead is formed and the surface of the stage. And a lower die fixed to a lower die set, a lower punch provided through the lower die so as to be vertically movable, and a lower punch. A first driving means for vertically moving the upper die set, an upper die set provided above the lower die set so as to face the lower die set and capable of moving up and down, and 2 and the upper die set is mounted on the upper die set facing the lower die by a spring, and when the upper die set is moved downward, the upper die set is moved between the lower die and the upper die set. With the stay A holding member for holding one portion adjacent to the inclined piece portion to be formed on the support bar; and an upper die set facing the lower die punch and being fixed to be able to penetrate the holding member, When the upper die set is still moved down after one of the portions is clamped, the other portion adjacent to the inclined piece portion to be formed on the stage support bar is interposed between the lower die punch and the lower die punch. An upper die to be clamped, wherein the holding member and the lower die hold the one part, and the lower die and the upper punch hold the other part, The first driving means and the second driving means are driven synchronously to move the lower punch and the upper punch in a direction perpendicular to the lead forming surface, and the one part and the other part are moved. Stage support bar between And causing elongation due tensile processed, it is characterized by forming the inclined projection.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view showing an example of the lead frame 10. 12 is an inner lead, 13 is an outer lead, 14 is a stage,
Reference numeral 18 denotes a frame portion in which guide holes for alignment are formed. The stage section 14 is connected to and supported by a frame section 18 by two stage support bars 15. An inclined piece 16 is formed in the middle of the stage support bar 15, so that the stage 14 is set to have a required height lower than the lead formation surface. Note that the lead frame 10 may be of a QFP type (not shown) or another type. In the case of the QFP type, the stage section is connected to and supported by the frame section by four stage support bars. The shape of the lead frame 10 is not particularly limited. The lead frame 10 of the present embodiment is characterized in that the inclined piece 16 is formed not by crushing but by extending a part of the stage support bar 15 by stretching.

FIGS. 2 to 8 show an example of a method and an apparatus for manufacturing the lead frame 10. FIG. In FIG.
Is a lower die (hereinafter simply referred to as a die), and 21 is a pressing member, which constitutes a first holding means 22. A concave portion 23 is formed on the upper surface of the die 20, and a through hole 24 having a smaller diameter than the concave portion 23 is opened on the inner bottom surface of the concave portion 23. A lower punch (hereinafter simply referred to as knockout) 25 is disposed in the through hole 24 so as to be vertically movable. A through hole 27 having the same diameter as the concave portion 23 is provided in the center of the pressing member 21. An upper punch (hereinafter simply referred to as a punch) 28 is disposed in the through hole 27 so as to be vertically movable. A protrusion 29 having the same shape as the knockout 25 is provided on the lower end surface of the punch 28. Knockout 25 and punch 28
These form the second holding means 30.

The die 20 is appropriately fixed to a member. Then, the pressing member 21, the knockout 25, the punch 28
Can be driven in the vertical direction by a suitable driving means (not shown) such as a servomotor. The lead frame 10 includes an upper die including a pressing member 21 and a punch 28,
It is inserted between the die 20 and the lower mold composed of the knockout 25 (FIG. 2). Then, first, the pressing member 21 is moved down to clamp the lead frame 10 with the die 20 (FIG. 3). In the first holding means 22, one part 13a adjacent to the inclined piece 16 to be formed on the stage support bar 15 (a part outside the inclined piece 16 in the example shown in the drawing, may include an inner lead or the like). )).

Next, the knockout 25 is moved up, and the punch 28 is moved down, so that
The other part 1 adjacent to the inclined piece part 16 to be formed
3b (in the illustrated example, a portion inside the inclined piece 16; the stage may be included) (FIG. 4). Thus, the lead frame 10 is clamped from above and below.
Is bound. Next, as shown in FIG. 5, the punch 28 and the knockout 25 (second holding means) are slightly lowered while holding the one part 13a and the other part 13b by the holding means 22 and 30 (lead). Move in the direction perpendicular to the forming surface). Thus, it is understood that the stage support bar 15 between the parts held by the holding means 22 and 30 is stretched by the tensile processing.

Next, as shown in FIG. 6, the punch 28 and the knockout 25 are slightly raised while holding the above portions. Then, as shown in FIG. 7, the punch 28 and the knockout 25 are again moved down to a predetermined position below the position shown in FIG. As a result, the stage support bar 15 between the two holding portions is further stretched by a pulling process. As described above, the punch 28 and the knockout 25 are driven up and down a plurality of times while holding the above-mentioned portions, and the stage support bar 15 between both the holding portions is gradually extended, and the required inclined piece 16
(FIG. 8). When the second holding means 30 is moved up and down a plurality of times, the initial stroke is small.
If the stroke is gradually increased, the load on the stretched portion is reduced, which is preferable.

As understood from FIGS. 5 to 7, during the above-mentioned machining operation, the portion of the stage support bar that becomes the inclined piece 16 is formed by the corner of the recess 23 and the projection 29.
Located in the space A (FIG. 5) formed by the corners of
It does not come into contact with the mold, and the crushing action from the mold does not work.

FIG. 8 is a view showing a state in which the upper die is opened.
The required lead frame 10 is obtained by opening the mold as described above and taking it out of the mold. As described above,
By raising and lowering the second holding means 30 a required number of times while holding the other portion 13b, the stage support bar 15 between the two holding portions can be extended without difficulty (without breaking or the like). In addition, the portion of the stage support bar 15 is bent while being extended a plurality of times, so that the portion is not plastically deformed and springback does not occur. Therefore, the stage portion 14 is lowered to a required position with respect to the lead forming surface. be able to.

In the above description, the second holding means 30 is moved up and down after the required portion is held. Alternatively, the first holding means 22 may be moved up and down, or the first and second holding means 22 and 3 may be moved.
Needless to say, both of 0 may be relatively moved up and down (in a direction perpendicular to the lead forming surface). In the case of a soft material such as copper, or a stage support bar 1
Depending on the width and shape of 5, and the amount of depression, it is possible to form the required inclined piece portion by one operation of the holding means instead of a plurality of times. In addition, the corner of the knockout 25, the corner of the protrusion 29, the corner of the recess of the die 20, and the corner of the pressing member 21 are chamfered or formed into a round shape. It is effective to prevent breakage by preventing stress concentration.

FIG. 9 shows an example in which the above manufacturing apparatus is further embodied. Reference numeral 32 denotes an upper die set, and the pressing member 21 having a through hole 27 formed on the lower surface thereof is used for the spring 3.
3 (attached to the spring 33). An upper punch 28 is fixed to the center of the lower surface of the upper die set 32. The punch 28 has a through hole 27
It is formed to have a smaller diameter than that, and can enter the through hole 27. Reference numeral 35 denotes a lower die set, which is fixed on a base 36.
The lower die 20 on which is formed is fixed. A knockout (lower punch) 25 is vertically movably disposed in the through hole of the lower die set 35 and the through hole 24 of the die 20.

The through-hole 24 has the same diameter as the through-hole 27, and the punch 28 and the knockout 25 have the same diameter. That is, the knockout 25 is formed in the through hole 2.
The diameter is smaller than 4. The upper die set 32 is driven vertically by a second servomotor (second driving means) 40. Knockout 25 is a first servomotor (first
Is driven in the vertical direction by the driving means 42). The drive of both servomotors 40 and 42 is controlled by control means (not shown).

The lead frame 10 is supplied to a space between the die 20 and the pressing member 21. The upper die set 32 is moved downward by the servomotor 40. As a result, the pressing member 21 also moves downward, and the lead frame 10 is sandwiched between the pressing member 21 and the die 20. The spring 33 is compressed, and the pressing force of the spring 33 acts.
When the spring 33 is compressed, the punch 28 further moves downward, and clamps the lead frame 10 with the knockout 25. The holding position of the lead frame 10 between the pressing member 21 and the die 20 and the holding position of the lead frame 10 by the punch 28 and the knockout 25 are the positions described in FIG. 4 (one part 13a and the other part 13a).
Same as b).

Next, the servo motor 40 and the servo motor 42 are driven synchronously while holding the predetermined position between the punch 28 and the knockout 25, and as described with reference to FIGS. Is moved up and down a required number of times in the vertical direction, and the inclined piece 16 is formed. During this time, the lead frame 10 is held between the holding member 21 and the die 20. After the above processing, the upper die set 32 moves up to the standby position, takes out the lead frame 10, and ends the processing.

In this embodiment, the accuracy of the height of the stage section 14 from the lead formation surface is determined by the accuracy of the stroke between the punch 28 and the knockout 25. This stroke control can be accurately performed by controlling the servo motors 40 and 42 by the control means, so that the processing for lowering the stage section 14 to a required position can be performed with extremely high precision. Further, since the inclined piece portion 16 is formed in a state in which the inclined portion portion 16 is not crushed as in the related art but is stretched uniformly by pulling while holding both ends, it is possible to prevent the stage portion 14 from warping. Even when a plurality of lead frames are processed at the same time, the stroke control of each servomotor only needs to be performed accurately, so that simultaneous and accurate lead frame processing can be easily performed. The precision of the mold itself is not so required.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to these embodiments, and it is possible to make various modifications without departing from the spirit of the invention. Of course.

[0024]

According to the present invention, the portions on both sides (one portion and the other portion adjacent to the inclined piece) sandwiching the inclined piece to be formed on the stage support bar are respectively the first.
And the second support means, and the two support means are relatively moved in a direction perpendicular to the lead forming surface, so that the stage support bar between the two support means is stretched by pulling. Since the inclined piece is formed,
By controlling the relative movement stroke of the first holding means and the second holding means, it is possible to form the inclined piece uniformly extended by the pulling process, so that the lead forming surface and the required step without warping can be formed. A lead frame having a stage portion having the same can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a lead frame.

FIG. 2 is an explanatory diagram of a state where a lead frame is set in a mold.

FIG. 3 is an explanatory view showing a state where a lead frame is held by first holding means.

FIG. 4 is an explanatory view showing a state where a lead frame is held by a second holding means.

FIG. 5 is an explanatory view showing a state where a second holding means is moved downward.

FIG. 6 is an explanatory view showing a state in which a second holding means is moved upward.

FIG. 7 is an explanatory view showing a state where the second holding means is further moved down from the position shown in FIG. 5;

FIG. 8 is an explanatory view of a state where a mold is opened.

FIG. 9 is an explanatory view showing a further specific example of the manufacturing apparatus.

FIG. 10 is an explanatory view showing an example of a conventional manufacturing mold.

FIG. 11 is an explanatory sectional view of a lead frame before depressing.

FIG. 12 is an explanatory sectional view of the lead frame after depressing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lead frame 12 Inner lead 14 Stage part 15 Stage support bar 16 Inclined piece part 18 Frame part 20 Lower die (die) 21 Pressing member 22 First clamping means 25 Lower punch (knockout) 28 Upper punch (punch) Reference Signs List 30 Second clamping means 32 Upper die set 33 Spring 35 Lower die set 40 Second servo motor (drive means) 42 First servo motor (drive means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Soichi Yamaguchi 711, Toshida, Kurita-sha, Ono, Nagano City, Nagano Prefecture (72) Inventor Tetsuo Minemura 711, Toshida, Kurita-Sha, Nagano, Nagano Prefecture Shinko F term (reference) 5F067 AA11 AB02 BD02 DA11 DF17

Claims (6)

[Claims] In a lead frame, an inclined piece is formed on a stage support bar connected to a stage of a lead frame, and a step is formed between a lead forming surface on which the lead is formed and a surface of the stage. The lead frame, wherein the inclined piece portion is formed by extending a stage support bar by a tensile process. 2. A lead frame manufacturing method, wherein an inclined piece is formed on a stage support bar connected to a stage of a lead frame, and a step is formed between a lead forming surface on which the lead is formed and a surface of the stage. In the method, a first portion adjacent to an inclined piece portion to be formed on the stage support bar and another portion opposite to the one portion with the inclined piece portion interposed therebetween are first held. Means and the second holding means, and these two holding means are relatively moved in a direction orthogonal to the lead forming surface.
A method for manufacturing a lead frame, wherein the inclined piece is formed by stretching a stage support bar between both holding means by pulling. 3. The method of manufacturing a lead frame according to claim 2, wherein said holding means is moved a plurality of times in a direction perpendicular to the lead forming surface to form said inclined piece. 4. A lead frame manufacturing method, wherein an inclined piece is formed on a stage support bar connected to a stage of a lead frame, and a step is formed between a lead forming surface on which the lead is formed and a surface of the stage. In the apparatus, a first portion which sandwiches one portion adjacent to an inclined piece portion to be formed on the stage support bar and another portion which is opposite to the one portion with the inclined piece portion interposed therebetween is firstly held. An apparatus for manufacturing a lead frame, comprising: a clamping means, a second clamping means, and a driving means for relatively moving the both clamping means in a direction perpendicular to the lead forming surface. 5. A control means for controlling said driving means so as to move said both holding means a plurality of times in a direction perpendicular to the lead forming surface when forming said inclined piece portion. An apparatus for manufacturing a lead frame according to claim 4. 6. A lead frame manufacturing method, wherein an inclined piece is formed on a stage support bar connected to a stage of a lead frame, and a step is formed between a lead forming surface on which the lead is formed and a surface of the stage. In the apparatus, a lower die fixed to a lower die set, a lower punch provided through the lower die so as to be vertically movable, and first driving means for vertically moving the lower punch. An upper die set provided above the lower die set so as to be vertically movable in opposition to the lower die set; second driving means for vertically moving the upper die set; The lower die is opposed to the lower die and is attached to the set by a spring. When the upper die set moves downward, the stage support bar is formed between the lower die and the lower die. Next to the inclined piece A holding member for holding one portion in contact with the lower die punch, the upper die set being fixed to the lower die punch so as to be able to penetrate the holding member; An upper die for clamping the other part adjacent to the inclined piece to be formed on the stage support bar between the lower die and the lower die when the die set is moved downward; The first drive unit and the second drive unit are held in a state where the one part is held between the member and the lower die, and the other part is held between the lower punch and the upper punch.
And the lower punch and the upper punch are moved in a direction orthogonal to the lead forming surface, and pulled by a stage support bar between the one part and the other part. An apparatus for manufacturing a lead frame, wherein the inclined piece portion is formed by causing elongation by processing.