JPH0740601B2 - Lead terminal cutting device for electronic parts and rustproof structure for lead terminals - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lead terminal cutting device for electronic parts, and more particularly, a lead on which a semiconductor chip such as an IC chip or an LSI chip used in communication equipment is mounted. The present invention relates to a lead terminal cutting device for an electronic component for obtaining an electronic component having a lead terminal by cutting a comb-shaped lead of a frame, and an improvement in a rust preventive structure of the lead terminal.

(Prior Art) In order to improve production efficiency, an electronic component used in a conventional communication device or the like is generally manufactured as follows.

That is, the DIP (D
The component 101 of the IC of the ual in line package type is a connecting piece 103 arranged in parallel at a predetermined interval, and a plurality of comb-shaped leads 10 extending inward from the appropriate places inside each connecting piece 103.
Of the lead frame 107, the IC chip 109 conveyed by the belt 108 that faces the lead frame 107 is arranged at a predetermined position of the lead frame 107 that is conveyed in the longitudinal direction. Lead 105 and IC chip 109
After electrically connecting to the internal circuit (not shown) of the IC chip by frame bonding or the like, the entire periphery of the IC chip 109 is molded with epoxy resin 111 or the like, and then the comb-shaped leads 105, 105 of the lead frame 107. After obtaining the individual IC component 101 having the lead terminals 105A, 105A ... Having a predetermined length by cutting the IC component at an appropriate length (for example, at the position indicated by the alternate long and short dash line in the figure), the IC component 101 The lead terminal 105
A, 105A ... Are molded into a predetermined shape.

By cutting the comb-shaped leads 105, 105, ... Of the lead frame 107, the lead terminals 105A, 105A of the IC component 101 are cut.
To obtain ..., For example, a lead terminal cutting device 201 as shown in FIG. 6 is used. The cutting device 201 shown in FIG.
Cutting of IC component 101 from lead frame 107 and lead terminals
105A, 105A, etc. are formed at the same time, and the lead terminals 105A, 105A ... Are clamped from above and below to form the lead terminals 105A, 105A. A pair of upper and lower molds 203, 205, which are opposed to each other at a distance, and a lower mold 205, which is closely arranged on the side faces of the upper and lower molds 203, 205 and descends from above.
Lead frame 107 in pressure contact with the corner 205a of the
A cutting blade (lower end surface) 207a for shearing the comb-shaped leads 105A, 105A ... Is provided with a cutter 207 having a flat shape. After shearing, the upper die 203 is lifted to move the IC having lead terminals 105A, 105A ...
The part 101 can be removed.

On the other hand, the cutting device 209 shown in FIG. 7 is closely arranged on the side surfaces of the upper and lower molds 203 and 205, and ascends from below, so that the comb-shaped leads 105 of the lead frame 107 are formed between the corners 203a of the upper mold 203. A cutting blade (upper end surface) 211a is provided with a cutter 211 having a flat shape for shearing 105 ...

QSP (Quad Flat Package) in addition to the DIP ICs mentioned above
Also in the case of IC type IC parts, such comb-shaped leads 105, 105.
The lead terminals 107A, 105A, ... Are obtained by using the lead frame 107 having the ... And cutting by the cutters 207, 211 after the mounting of the IC component 101 is completed.

The individual IC components 101 thus manufactured are mounted on the board by soldering the lower surface of the crank-shaped lead terminals 105A, 105A ... To a pattern on a printed board (not shown), Lead frame described above
The leads 105, 105 ... Of 107 are made of a copper alloy or an iron alloy, and their outer surfaces are provided with anticorrosion coatings 111, 111.

However, such a conventional lead terminal cutting device 20
For 1 and 209, cutting blades 207a and 211a of cutters 207 and 211
Since the cutting edge of has a flat shape, the lead terminal 105
The end faces of A, 105A ... Are sharply cut (along the direction perpendicular to the axis of the lead terminal), and as shown in FIG. 8, the rust preventive coatings 111, 111. Without extending to the end surface 11
Copper material of 3 is exposed over a large area. Lead terminal 105
If the copper material is exposed over a large area on the end surface 113 of A, 105A, ..., Rust will occur on the copper material end surface 113 until the IC component 101 is mounted on the printed circuit board, and soldering will occur. In many cases, the adhesion force becomes weak and it becomes difficult to mount on a printed circuit board.

By the way, in the device 209 for cutting by raising the cutter 211, as shown in FIG.
A, 105A ... End face 113, 113 ...
11 and 111 remain, but the end surface 113 of the lead terminal 105
Since most of the solder is exposed, it rusts and the adhesive force of the solder decreases as in the lead terminal shown in FIG.

Therefore, in any of the devices shown in FIGS. 8 and 9, the copper material is exposed in most of the area of the cut end surface.
There is no change in the situation where the adhesive strength of the solder decreases due to the rust on the exposed surface, and in order to prevent the situation where the lead terminals are easily separated from the wiring pattern on the printed circuit board, rust prevention treatment should be performed immediately after cutting. Although desirable, it is desired to improve this point because the process is complicated and the cost is increased due to an increase in the number of processes.

(Object of the invention) In order to achieve the above-mentioned object, the present invention has a problem that a solder connection failure occurs during mounting on a printed circuit board due to rust occurring on the cut end surface after cutting a lead terminal extending from an electronic component. An object of the present invention is to provide a lead terminal cutting device for an electronic component and a lead terminal rust preventive structure capable of simultaneously performing rust preventive treatment for preventing the occurrence of the above.

(Outline of the Invention) In order to achieve the above object, the present invention has the following configurations.

That is, the cutting device of the present invention is a device for cutting a comb-shaped lead terminal connected to an internal circuit of a semiconductor chip included in an electronic component at the same time as molding, and in a direction orthogonal to the axis of the linear lead terminal. In a lead terminal cutting device for an electronic component, which is provided with a cutter for cutting the lead terminal by moving up and down, the lead terminal is provided with an anticorrosive coating on the outer surface of the conductor portion, and the cutter is after cutting. In the electronic component, a cross-sectional shape of the tip portion of the lead terminal has a shape of a cutting edge that is inclined with respect to the up-and-down direction of the cutter, and the rust preventive applied to the outer surface of the lead terminal during cutting by the cutting edge. It is characterized in that it has an angle of a cutting edge that covers the surface of the inclined cut surface at the tip of the lead terminal by stretching the coating film by pressure. Device for cutting lead terminals of electronic parts.

Further, the cutting device of the present invention includes an upper die and a lower die which are arranged so as to face each other in a vertical positional relationship and at least one of which moves up and down to press-mold the lead terminal between the other die and the upper and lower die. Non-integrated cutter that cuts the lead terminal in an inclined plane between the integrated cutter integrated with any one of the molds and the other cutter that independently moves up and down along the other mold. And each of the cutters has a cutting edge shape such that a cross-sectional shape of a tip portion of a lead terminal of an electronic component after cutting is inclined with respect to an ascending / descending direction of the cutter, and during cutting by the cutting edge, It is characterized in that the rust preventive coating applied to the outer surface of the lead terminal is stretched by pressure to have an angle of the cutting edge which covers the surface of the inclined cut surface of the tip of the lead terminal.

Further, the cutting device of the present invention includes an upper die and a lower die which are arranged so as to face each other in a vertical positional relationship and at least one of which moves up and down to press-mold the lead terminal between the other die and the upper die. The die and the lower die are independently moved up and down to cut the lead terminals in an inclined surface shape by the cooperation of the respective cutting edges of the two dies, and the cutters are the lead terminals of the electronic component after cutting. Has a shape of a cutting edge whose cross-sectional shape at the tip of the blade is inclined with respect to the ascending / descending direction of the cutter, and press-stretches and extends the rust preventive coating applied to the outer surface of the lead terminal during cutting by the cutting edge. It is characterized in that it has an angle of a cutting edge that covers the surface of the inclined cut surface of the tip of the lead terminal.

Further, the rust preventive structure of the lead terminal of the present invention is a comb-shaped lead terminal connected to an internal circuit of a semiconductor chip included in an electronic component, the conductor part having an rust preventive coating on the outer surface thereof. It is characterized in that an inclined cut surface of the tip portion of the lead terminal is covered with a rust preventive film.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings.

FIG. 1 shows a lead terminal cutting device 1 for an electronic component according to an embodiment of the present invention. The cutting device 1 extends from a lead frame 3 shown in the conventional example and is connected to an IC component (semiconductor component) 5. The lead 15 having the tip shape as shown in FIG. 2 is manufactured by cutting and forming the lead 15 at the same time. The lead 15 (hereinafter referred to as the lead terminal 7) is manufactured. A pair of upper and lower molds 9 and 11 arranged to face each other at a predetermined interval in order to form a crank shape by sandwiching the upper and lower molds, and an upper cutter (integrated cutter) integrally configured at the lower edge of the upper mold 9. ) 13 and the side portions of the lower mold 11 are closely arranged and rise from below to shear the lead terminals 7 that are in pressure contact with the upper cutter 13, so that the cutting surface (upper end surface) 17a is flat. Shaped lower cutter (non-integral cutter ) And a 17, and the upper cutter 13, the cross-sectional shape at the tip of the lead terminals 7, 7, ... of the IC component 5 after cutting the upper cutter 13
The blade shape is inclined with respect to the ascending / descending direction (about 40 degrees in this embodiment), and the inclined portion 21 is formed at the tip of the conductor portion 7a of the lead terminals 7, 7 ... The rustproof coating 19, 19 ... on the outer surface of 7a is sloped.
21 is stretched by pressure to form a rust preventive film 19a.

With this structure, after mounting the IC chip (not shown) at a predetermined position on the lead frame 3, the upper die 9 is lowered and the lower cutter 17 is raised, so that the lead terminals 7
The upper cutter of the upper mold 9 while sandwiching the upper mold 9 between the upper mold 9 and the lower mold 9.
The lead terminal 7 is cut at a proper position between the lower cutter 13 and the lower cutter 17, and the upper cutter 13 presses the upper rustproof coatings 19, 19 ... And the conductor portion 7a at the cut portion of the lead terminal 7.

Therefore, the sloping portion 21 is formed at the tip of the lead terminal 7, and the rust preventive coating 19 is pushed downward along the sloping portion 21. As a result, the rust preventive coating is provided at the tip of the lead terminal 7. 19a is formed. Cutting and rustproof coating on this tip 1
The formation of 9a occurs almost simultaneously. Since an anticorrosive film is formed on the tip of the lead terminal 7, when the IC component 5 is soldered to a printed circuit board, there is no rust on the side surface of the lead terminal including the cut surface, This serves to solidify the solder into a fillet shape, which increases the connection strength.

Next, FIG. 3 is a structural explanatory view of a cutting device according to a second embodiment of the present invention, in which the upper cutter 13 shown in the above-described embodiment is a side portion of the upper mold 9 as an independent lifting type (non-integrated type). The lower cutter 17 has a blade shape which is inclined so as to face the blade shape of the upper cutter 13 and is arranged close to the upper cutter 13. In this case, it goes without saying that the tip shape of the lead terminals 7, 7 ... Is double-edged as shown in FIG. In this case, the cutting edges of the upper and lower cutters 13 and 17 both contribute to rolling the rust preventive film 19 to cover the cut end face 21 when cutting the lead terminals, and as a result, it is possible to obtain the rust preventive structure as shown in the figure. Becomes

In the present invention, electronic parts are not limited to ICs, LSIs, etc., but are concepts including various modules, connectors, etc. on which electronic parts are mounted. Also, the lead terminal 7,
It is needless to say that 7 ... Can perform similar cutting processing even for flat leads, connector pins, DIP terminals, SIP terminals, and the like, which are not shown.

(Effects of the Invention) As described above, the present invention extends the rust preventive coating in which the blade shape of the cutter for cutting the lead terminal of the electronic component is applied to the outer surface of the lead terminal to extend the surface of the tip slope of the lead terminal. Since the inclination angle is set so as to cover, the end surface of the lead terminal of the electronic component can be rust-proofed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a lead terminal cutting device for electronic parts according to the present invention, FIG. 2 is an enlarged cross-sectional end view of a lead terminal cut by the cutting device of FIG. 1, and FIG. Is a sectional view showing another embodiment, FIG. 4 is an enlarged sectional view of the tip of the lead terminal cut by the cutting device shown in FIG. 3, and FIG. 5 is a plan view showing a conventional method for manufacturing an electronic component. 6 is a sectional view of a conventional lead terminal cutting device, FIG. 7 is a sectional view of another conventional lead terminal cutting device, and FIG. 8 is an enlarged tip of a lead terminal cut by the cutting device of FIG. FIG. 9 is a sectional view showing an enlarged tip sectional view of the lead terminal cut by the apparatus of FIG. 3 ... Lead frame, 5 ... IC parts (electronic parts),
7, 7 ... Lead terminal, 15 ... Lead, 17 ... Cutter,
19, 19 ... Rust-proof coating, 21,21 ... Lead terminal end face, 23 ...
… IC chips (semiconductor chips)

Claims (4)

[Claims] 1. A device for cutting a comb-shaped lead terminal connected to an internal circuit of a semiconductor chip included in an electronic component at the same time as molding, and raising and lowering in a direction orthogonal to the axis of the linear lead terminal. In a lead terminal cutting device for an electronic component provided with a cutter for cutting the lead terminal, the lead terminal is provided with a rust preventive coating on the outer surface of the conductor portion, and the cutter is the electronic component after cutting. The tip portion of the lead terminal has a shape of a cutting edge that is inclined with respect to the ascending and descending direction of the cutter, and the rust-preventive coating applied to the outer surface of the lead terminal is stretched by pressure during the cutting by the cutting edge. A lead terminal cutting device for an electronic component, which has an angle of a cutting edge so as to cover the surface of the inclined cutting surface of the tip of the lead terminal. 2. An upper die and a lower die having a configuration in which the cutting device is arranged so as to face each other in a vertical positional relationship and at least one of which is moved up and down to press-mold the lead terminal between the die and the other die.
A non-universal cutter that cuts the lead terminal in an inclined plane between an integrated cutter integrated with one of the upper and lower dies and independently moves up and down along the other die. The cutter comprises a body-shaped cutter, and each of the cutters has a cutting edge shape such that a cross-sectional shape of a tip portion of a lead terminal of an electronic component after cutting is inclined with respect to an ascending / descending direction of the cutter, and during cutting by the cutting edge. The rust preventive coating applied to the outer surface of the lead terminal is stretched by pressure to have a blade edge angle so as to cover the surface of the inclined cut surface at the tip of the lead terminal. A lead terminal cutting device for the electronic component described. 3. An upper mold and a lower mold, wherein the cutting device is arranged to face each other in a vertical positional relationship and at least one of which is moved up and down to press-mold the lead terminal between the other mold.
The upper die and the lower die are independently elevated and lowered, and the blade terminals of both dies cooperate with each other to cut the lead terminals in an inclined plane shape. The cross-sectional shape of the tip of the lead terminal has a shape of a cutting edge that is inclined with respect to the ascending / descending direction of the cutter, and the rustproof coating applied to the outer surface of the lead terminal is stretched by pressure during the cutting by the cutting edge. The lead terminal cutting device for an electronic component according to claim 1, wherein an angle of a cutting edge is provided so as to cover the surface of the inclined cutting surface of the tip of the lead terminal. 4. A comb-shaped lead terminal connected to an internal circuit of a semiconductor chip included in an electronic component, wherein an outer surface of a conductor portion is provided with an anticorrosion coating, wherein the tip portion of the lead terminal is inclined. A rustproof structure for lead terminals of electronic parts, characterized in that the cut surface is covered with a rustproof film.