JPS6076155A - Lead frame and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve productivity and dimensional accuracy by connecting lead pins, in which wide sections are formed by cutting wire rods in predetermined length and adjusting shapes while pushing and molding one ends of the wire rods, to a beltlike support section at regular intervals. CONSTITUTION:A wire rod coil 10 is cut, one end is pushed and shaped, a cup section 16 is formed, and a first lead pin 11 is shaped. A second lead pin 12 with a wide head section 17 is formed simultaneously by the same processing. The lead pins are aligned by using a holder 18 for alignment with groove section at regular intervals. A beltlike body 13 to which holes 15 for feed-pitches is cut, and the cut bodies 13 are welded to the aligned lead pins 11, 12, thus forming lead frame structures 19. The structures 19 are stacked and pretreatment such as washing, the strike plating of copper, copper plating and nickel plating are executed in succession, and lastly silver plating and post-treatment such as washing are executed to the head sections and the cup sections. Lastly, the wholes are dried, and tie bars 14 are fixed at the intermediate positions of the lead pins by adhesive tapes.

Description

[Detailed Description of the Invention] [Field of application on VF, beams] The present invention relates to a lead frame and a method for manufacturing the same,
In particular, the present invention relates to lead frames used for mounting semiconductor devices and methods of manufacturing the same.

[Prior art] In recent years, semiconductor devices such as light-emitting diodes (1, El) have made significant progress in the electronics era, and have been applied to a wide range of fields, and various techniques have been developed to reduce manufacturing costs. Efforts have been made.

For example, a light emitting diode is manufactured by subjecting a compound semiconductor such as gallium arsenide (GaAs) to a predetermined process as shown in FIG. The chip thus formed is adhered to the chip mounting portion 5 formed at the tip of the lead bin of the lead frame 4 as shown in FIG. 2, and electrical connection is made between the first electrode and the lead pin. At the same time, an electrical connection is made between the second electrode and the tip of the other lead pin by wire bonding, etc., and a cap 6 made of a transparent resin or the like is covered to cover and protect the element part. To,
By cutting and removing the strip corresponding to the frame of the lead frame, a light emitting diode as a product as shown in FIG. 3 is completed.

The lead frame used here has conventionally been formed into a desired shape by punching a plate-shaped body such as a Kovar plate.

However, the large number of waste parts due to punching is a major impediment to reducing manufacturing costs, and various pattern designs have been attempted in order to reduce the rate of material waste.

In addition, since the lead pins serve as a path for current to pass through, their width must be set with strict precision.Furthermore, the mounting of the chip on the chip mounting section and the wire bonding are often performed by an automatic control device. However, lead frame processing required a fairly high degree of dimensional accuracy.

Furthermore, there is a strong demand for lead pins to have considerable bending strength and mechanical stability, and for this purpose it is desirable to use a thick plate-like material. Due to problems with processing accuracy, there is a limit to the thickness of the plate-shaped body that can be used. [Objective of the Invention] The present invention has been made in view of the above circumstances, and aims to provide a lead frame with low manufacturing cost. The porpose is to do.

Another purpose is to improve the processing accuracy of lead frames.

Still another object is to provide a lead frame with excellent mechanical strength as a lead pin.

[Structure of the invention]

In order to achieve the above object, the present invention provides a lead frame including a plurality of lead pins and a band-shaped supporting part that supports one end of the lead pins so that the lead pins are arranged at predetermined intervals. It is characterized in that it is made of wire.

That is, instead of the forming method by punching from a plate-shaped body, the wire rod is cut to a desired length, formed, and then connected at the intervals of the band-shaped support parts KPfr. The aim is to eliminate any waste of materials in the case of.

〔Example〕

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

This is used as a lead frame for 14 light emitting diodes, and as shown in Figure 4, the diameter φ = o, s
mm 1 Consists of a first lead pin 11 and a second lead pin made of a mild steel wire with a length of 35' mm, each having a length of 6 mm.
30 pairs of leads arranged in parallel at a pitch of 111111, and a strip 13 made of bar steel of 11ν'A10+mn, length 180mm, and thickness 0.3 mm for connecting and holding one end of these lead pins. , a width of 5 mm and a length of 180 mm, which is glued to the middle part of the lead pin parallel to the strip.
It is made up of a plastic tie bar 14 (1).This band-shaped body is provided with feed pitch holes 15 at regular intervals.The free end of the lead pin of wJl is also is a wide cup portion 16 formed into a cup shape by pressure molding, and the second
The free end of the lead pin is a wide head portion 17 formed by compression molding.

Next, the final step of manufacturing this lead frame is carried out in the fifth step.
This will be explained with reference to the flowchart shown in the figure.

First, a wire coil 10 made of a mild steel wire with a diameter φ = 0.5 wa is cut, and one end is press-molded to form a cup portion 16, thereby forming a first lead pin 11 as shown in FIG. 6(al). form. (First lead bin forming step 101) At the same time, a wire coil made of a mild steel wire with a diameter φ = 0.5 mm is cut, bent, and press-formed at one end to form a wide head portion 17. By forming the second lead pin 1 as shown in FIG. 6(a2),
(Second +J-dopin forming step 102) Next, as shown in FIG. [Using the alignment holder 18 having four parts, the first lead pin and the second lead pin are aligned. (Alignment step 103) Furthermore, as shown in FIG. 6(C), the width 11j is
rnra, a strip 13 formed by punching a 0.3-node thick bar with holes 15 for the feed pitch is cut into a length of 180 mm, which is then aligned with the above-mentioned -1 and W, It is attached to the lead pins 11 and 12 of No. 2 by welding. (Adhesion step 104) Subsequently, the lead frame structures 19 thus formed are stacked with paper interposed between them, as shown in FIG. 6(J). (Pirin process 105) The lead frame structure 1 is stacked in this way.
9 is subjected to pretreatment (pretreatment step 106) as shown in FIG. Strike plating (strike plating process 107L, then copper plating (copper plating process 108), followed by nickel plating and nickel plating process 1)
09), and finally, a silver plating step (110) is performed on the head and cup portions, and post-processing such as cleaning (processing step 5111) as shown in FIG. 6(g) is performed.

Finally, after drying, the plastic tie bars 14 are attached with adhesive tape as shown in FIG. 6(h).
Fix the lead pin in the middle position.

(Tie bar attachment step 112) The lead frame completed in this way is shown in Figure 6 (
After completing the packaging step 113 shown in i), the product is shipped as shown in FIG. 6(J) (shipping step 114).

Further, in accordance with the flowchart 1, each step of manufacturing the lead frame for a light emitting diode of the J embodiment of the present invention will be described in detail with reference to the drawings, as well as various devices used in each step.

A mold device is used. This mold device includes a first station 201 for cutting and bending the supplied wire material, and a first station 201 for cutting and bending the supplied wire material, and a Nf
, a second station 202 for compression molding one of the free ends of the lead pin 1 to form a flat wide head; and a second station 202 for molding the head into a cup shape to form a cup. 3 station 203; and a 4th station 204 for turning the molded first lead pin by 90 degrees and delivering it to the assembly device in an aligned state.
From the first station to the fourth station,
It has a first transfer mechanism 205 for transferring the first lead pin in the direction of arrow A.

In this process, all operations are performed in the mold using the mold apparatus, and the mold apparatus shown in FIG.
0 At the first station 201, 8-1-1 to 8-1
Cutting to ■ and bending are performed in sequence as shown in J-6. It is then transferred to the second station by a transfer of ml<8 til.

At the second station 202, 8-2-1 to 8-2
As shown in 1-6, the free end of the first glued pin is press-molded to form a flat head portion. After this, the first
is transferred to the third station according to the transfer mode δ.

At the third station 203, 5-3-1 to 8-3
As shown in -6, the head t1- is molded into a cup shape to form a cup portion 1''. Thereafter, it is transferred to the station of ratio 4 by the ml transfer mechanism.

At the fourth station 204, 824-1 to 8-4
As shown in Fig. 6, the first lead pin is turned 90° and delivered to the position on the strip to be bonded.

Next, a second lead pin forming step 102 is carried out in parallel with the first lead pin forming step, and the mold device for the second lead pin used here is schematically shown in FIG. (a fifth station 301 for cutting the wire and forming the head; and a sixth station 301 for discharging the second lead bin formed at the fifth station in an aligned state to the assembly device. station 302 and a second transfer machine 3 for transferring this second lead pin from the fifth station to the sixth station.
03.

A second lead bin is molded in the same manner using this mold device, and is supplied to the assembly device in alignment. (Alignment 1 Step 103) In this alignment step, a feeding device as shown in FIG. 10 is used for feeding. This device has two arms 401
．． 402, and a gripper 403 provided at the tip of this arm allows the first glue dot bin and the second lead bin dispensed from the mold device for the first lead bin and the mold device for the second lead bin. The lead bins are then gripped, rotated by 180 degrees, and fed into the groove of the holder 18.

As shown in enlarged schematic diagrams in FIGS. 11(a) and 11(b), this holder has four portions 501 for the WJl lead bin and a groove portion 502 for the second lead bin, which are mutually disposed. and holds each lead bin in an aligned state.
I can do that. Note that FIG. 11(b) is similar to FIG. 11(a).
FIG.

This holder is disposed in a driving air cylinder 601 of the assembly device, as shown in FIG.

In this assembly device, the empty holder 18 is connected to the pitch feed claw 6.
The first for pressing the boulder until it meshes with 02 by 1 degree.
The first lead bin and the second lead bin are sequentially transferred onto the holder 18, which is transferred pitch by pitch by the bushier 603 and the pitch feed claw 602, and the lead pin supply section 604 is used to feed the first lead bin and the second lead bin from the feeding device to each other. ,
A strip supply section 605 for supplying a strip, a welding section 606 for attaching a lead bin to the strip, a holder with an L-equipped pin from the lead pin supply section to the strip supply section, and First dog 607 for transporting to the welding section
, a bailer 608 for receiving the lead frame structure after the welding process from the holder and stacking it on top of each other, a second pusher 609 for transferring the holder that has left the welding section to the pipe 2608, and a lead frame structure to the bailer. A cleaning zone 610 for supplying structures and removing dirt stuck to empty holders, a second dog 611 for transporting the holders from the bailer to the cleaning zone, and a third dog 610 for transporting the holders from the cleaning zone to the cleaning zone. Butsusha 6
A third dog 612 moves the holder up to the thirteenth position, and the empty holder returns to its original position when pressed by a third bushing 613.

In the lead pin supply section 604, each time the lead bin is molded, it is held by the gripper 403 of the supply device d and supplied to the groove 501 of the holder. Each time the pitch feeding claw 6 (12) advances the holder one pitch at a time as shown in FIGS. 13(,) and 13(b), bJ is an AA cross-sectional view.

In the strip supply section, a strip supply device as shown in FIG. 14 is provided. This device includes an uncoiler 700 formed by winding a strip, a Vinci repeller 701,
A drive roll 702 for conveying the strip, a pinch roll 703, and a cutter 70 for cutting the strip.
4, a guide 705, and a guide cover 706.

The cutter 704 is shown in FIGS. 15(a) and 15(a).
b) As shown in K (), the band-shaped material fed in the direction shown by arrow B is cut into a predetermined length by a fixed blade 707 and a presser foot 708. FIG. 15(b) is a sectional view taken along line A-A in FIG. 15(b).

The guide 705 is shown in FIG. 16(a) and FIG. 16(b).
It is as shown in FIG. 16(c), and includes a kite cover 706, a guide rail 71o for a band-shaped object, a side guide 711 for a boulder, and a side guide 712 for a band-shaped object.

After the strip stops, the pinch roll opens and is pulled onto the welding machine by the strip side kite 712, automatically confirming that it is in the predetermined position. , after being recognized,
It is cut into short pieces (here 180 mm). Thereafter, the strip side guide 712 and the guide cover 706 are retracted upward.

A projection welder 713 and a pin holder 714 are provided in the welding section. The bottle holder 714 is shown in FIGS. 17(&1 (top view), FIG. 17(b) (side view), FIG.
), as shown in Figure 17(e), and as shown in Figure 17(e).
d) and Fig. 17 te) are part D in fi417 (e)? This is shown in detail.

In this bath contact section, when the holder with a fully loaded bottle or the holder side guide 711 is approached, the lower electrode (not shown) of the welding machine rises and the strip comes into contact with the bottom of the bottle. Germany 1-ru. Further, a bottle holder 714 holds down the bottle on the front side of the welding machine. At this time, the bottle receives a slight force in the direction of the head, and is equipped with an adjustment device (t) that can align the heads. In this way, the upper electrode of the welding machine descends, and the welding machine Sandwich it with the lead bin,
Current flows and welding is completed.

Further, the first bushing is as shown in FIG. This first pusher has the ability to push only one holder, and the thrust is adjusted so that it cannot push 411 holders.
A pressure reducing valve is installed at 4 f.

In addition, the first, second, and third dogs (the main part is t
As shown in the top view), a drum 801, a wire rope 802, a sheep 803, a stopper 804, a guide 805
etc. are also configured.

The holder with the lead frame on which the welding of the strip and the lead pins has been completed is fast-forwarded to the 011 plane of the second pusher, and then the second pusher moves the lead frame to the position shown in Fig. 20 (,).
Then, it is transported to the position of the bailer as shown in FIG. 20(b).

This bailer has a 2ffi suction head 901. 902
They are constructed in such a way that the lead frame structure and the paper are adsorbed and stacked on top of each other (1.I).

The bailer's piling schedule is as shown in FIG.

Here, the reason why paper is sandwiched between the lead frame bodies is to prevent the tip ends of the pins from becoming entangled.

After the stuck dirt and the like are removed from the empty holder in the cleaning zone, it is transported by the third busher to the etJ surface of the first busher and waits for the next process.

In addition, the plating process can be carried out in a convenient manner by using equipment at the mouth, but since the lead frame structure has a delicate structure, the plating process requires feeding in the thickness direction. The intention of living is 1- should be.

The lead frame formed in this way has almost no wasted material, so the manufacturing cost is extremely low compared to a punched platform. In order to be
It has extremely good dimensional accuracy and has a circular cross section compared to plate-shaped lead pins, so it has greater mechanical strength such as bending strength.Furthermore, the lead frame formed by this method can be easily cut and pressed. rJy, since a mold is used in the mold-setting process, =J method h'Ia is good, and the quality of production is also good.

In the examples, lead frames for light emitting diodes have been described, but the scope is not necessarily limited to this, and can be applied to all lead frames, from single-in-line type ICs to dual-in-line type ICs. Applicable.

In addition, if a large chip curve is used, the wide part at the tip of the lead bin may be formed into a flat shape, and a plate-shaped body for mounting the chip may be adhered to this wide part.

In addition, in the examples, the beams and bins were glued to the strip and the integrated plating was performed;
After this material is used to form and assemble the bottle,
It's also interesting to think about the silver plating on the head part. However, in this case, a double plating process is required and there are problems such as contamination of the contact electrode due to contacting the plated product 7d, so the method shown in the example is preferable.

〔Effect of the invention〕

As explained above, according to the lead frame of the present invention, by constructing the lead bin with a wire rod,
It is low cost and has a good dimension ML, which in turn makes it possible to significantly improve the reliability of the product.

Further, according to the method for manufacturing a lead frame of the present invention, the wire rod is cut into a predetermined length, adjusted to the shape of 14 mm, and
There is a lead bin forming process in which one end is press molded to form a wide part, and this lead bin is made with a 1yr shop's 11th (
t)-shaped support t-b, the production workability is good and the size 111
It becomes possible to obtain a lead frame with good suction.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a light emitting diode chip, FIG. 2 is a diagram showing an example of a conventional lead frame, FIG. 3 is a diagram showing a light emitting diode after mounting, and FIG. 4 is a diagram showing an example of a conventional lead frame. 5 is a flowchart showing the manufacturing process of the lead frame according to the embodiment of the present invention, and FIG. 6 is a diagram showing the lead frame.
a8) is a diagram showing the first lead bin forming process, and FIG.
Figures a and 2) do not show the second lead bin forming process, Figure 6 (b) shows the scenery process - 1, Figure 6 (c) shows the contacting process, and Figure 6 ( d) is a diagram showing the piling process, FIG.
Figure (g) shows the post-processing process, Figure 6 (h) shows the tie bar fitting process, Figure 6 (i) shows the packaging process, and Figure 6 (i) shows the packaging process.
Figure (j) shows the state at the time of shipment, Figure 7 shows the molding device for the first lead bin, and Figure 8 shows the flow of the molding process for the first lead bin. , FIG. 9 is a diagram showing the mold device for the second lead pin, FIG. 10 is a diagram showing the supply device, and FIGS. 11(a) and 11(b) are enlarged schematic diagrams of the holder. Figure 12 is a diagram showing the assembly device, Figure 13 (a) and Figure 13 (b) 1 are
Figure 14 shows the pitch feeding claw, figure m14 shows the strip supply device, figure 15 (a) and figure 15 (b) show the cutter, figure vJ16 (a), figure 16 (b) and 1st
Figure 6 (c) is a diagram showing the guide, Figure 9g17m17, 1st
Figures 7(b), 17(c), and 17(d) show the pin holder; , Fig. 19(b), Fig. 19(c)
19(d) is a diagram showing the first, second, and third dogs, FIGS. The figure which shows the piling schedule. l... PN junction, 2... first electrode, 3... second
electrode, 4... lead frame, 5... chip mounting part, 11... first lead bin 1.12... lead bin of m2, 13... strip-shaped body, 14... tie bar,
DESCRIPTION OF SYMBOLS 15... Hole, 16... Cup part, 17... Head part, 18... Holder, 19... Lead frame structure, 101... First lead bin forming step, 102...
- Second lead bin forming step, 103... alignment step,
104... Adhesion work 4 times, 105°. Piling step, 106...RiI treatment step, 107
...Strike plating process, 108...Copper plating process, 109...Nickel plating process, 110...Silver plating process, 11.1...Post-treatment process, 112.・・・
・Tie bar installation process, 113... Packaging process, 114・
...Shipping process, 201...First station, 20
2... second station, 203... third station, 204... fourth station, 205...
...First transfer machine (one, 3010/fJ5 station, 302...a16 station, 303...
・, 2nd transfer Isokare, 401.402... Arm, 4
03...Gripper, 501...Groove, 601...
Air cylinder, 602... Pitch feed claw, 603...
- First hooker, 604. ...S5-dopin supply section, 605...Strip body supply section, 606
... Welding section, 607 ... First dock, 6
08...Baila, 609...Second Busha, 61
0... Cleaning zone, 611... Second dock, 612... Third dog, 613... Third buttonhole, 700... Uncoiler, 701... Vinci repeller, 702... ut+ motion o, -/l/, 7
03... Pinch roll, 704... Cutter, 705
...Guide, 706...Guide cover, 707...
・Fixed blade, 708... Presser foot, 710... Kite rail for band-shaped object, 711... Side guide for holder, 71
2...Side guide for band-shaped body, 713...Glojection mount, 714...Bin holder, 801...
Drum, 802... Wire rope, 803... Sheep, 804... Stopper, 805... Guide, 90
1, 902... Suction head. Figure 2 Figure 4 Figure 5 Figure 6 (Q+) Figure 6 (02) Figure 6 (b) Figure 6 (C) Figure 6 (d) Figure 6 (e) Figure 6 (1 ) Figure 6 (9) Figure 6 (h) Figure 6 (i) Figure 6 (j) Figure 15 (Q) Figure 15 (b) Δ Figure 16 (α) Figure 16 (C) Figure 117 (d) Figure 17 (e) Figure 20 (Q) Sennoshi'E? f13 i: I Milo 4 (Method) Ill February 1959,, 1st 11-\- Director General of the Patent Office 1, Display of the Case 1988 fFr l'iT Condyle No. 18373 (3 No. 2,
Title of the invention - Manufacture of lead frame 1 , Z 51! Za 2-11-2 Ginza Daisaku Building 6th floor Phone 03-545-3508
(Representative) 11F, January 1981 (Ship date: 1982 T1FJ311LI) 6. Side showing a simple explanation of the drawings issued by Mei II on the surface certifying the right of representation subject to amendment ``T'+ 4 -:'-L-” 7. Contents of the amendment (1) The document certifying the authority of representation shall be amended and reversed as shown in the attached sheet. (2) Mei I 11 yen page 21 91'T-
Figure 7 ((1)) is changed to Figure 17 (d), d3.J:
and Figure 17(e) 1”.

Claims (4)

[Claims] (1) In a lead frame consisting of a plurality of lead pins and a band-shaped supporting portion that supports one end of the lead pins in order to arrange the lead pins at predetermined intervals, the front six lead pins are made of wire. A lead frame characterized by: (2) The lead pin has a wide portion formed by compression molding at its free end.
#Required range (lead frame described in item 17). (3) A lead bin forming step in which the wire is cut to a predetermined length, adjusted to its shape, and one end of the wire is compressed to form a wide part; A method for manufacturing a lead frame, comprising: a connecting step for connecting to a lead frame. (4) The method for manufacturing a lead frame according to claim (3), characterized in that a mold is used in all molding steps in the lead pin forming step.