JPH0453000Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention relates to lead frames for diodes, transistors, ICs, etc., and more specifically, the invention relates to lead frames for diodes, transistors, ICs, etc. The present invention relates to a lead frame for an electronic component having lead-out leads.

[Conventional technology and its problems]

A typical conventional lead frame has a plurality of body parts each consisting of a part for fixing a semiconductor chip or the like and a part for connecting internal leads, and a lead part led out from each body part in one or both directions. and a connecting portion that connects the main body portion and/or the lead portion to each other.

Incidentally, the width of the main body portion of the lead frame in the arrangement direction is generally larger than the width of the leads. For this reason, in a lead frame in which a plurality of body parts are simply arranged in one row, the lead part cannot effectively utilize the metal plate for forming the lead frame, and the lead frame obtained from the unit area of the metal plate cannot be used effectively. The number will inevitably decrease. One way to solve this type of problem is to arrange the main body parts in two rows, as disclosed in US Pat. No. 4,012,765.
It is also disclosed that the leads are arranged in a staggered manner. However, this document only discloses a lead frame for an electronic component in which leads are led out in one direction from a main body portion, but does not disclose a lead frame for an electronic component in which leads are led out in both directions.

Further, Japanese Utility Model Publication No. 46-25765 discloses that the leads of a lead frame of an integrated circuit are arranged alternately. However, in this method, it is necessary to set the distance between the fixed portions to be greater than the length of the leads, and if the number of lead wires is small, area saving cannot be achieved.

Therefore, an object of the present invention is to provide a lead frame that can save area, has high mechanical stability, and can save resin during resin molding.

[Means for Solving the Problems] The present invention for achieving the above object will be described with reference to the reference numerals in FIGS. 1 and 4 showing the embodiments. and a plurality of first main body portions including pad portions 5a or 25a, 26a for connecting internal leads and arranged in parallel with each other on a first imaginary straight line, each of which includes an electronic element fixing portion 4b or 24b and an internal lead It includes a connection pad portion 5b or 25b, 26b, and has an interval greater than or equal to the width of the first body portion in the direction orthogonal to the first imaginary straight line with respect to the first imaginary straight line. between a plurality of third imaginary straight lines that are juxtaposed with each other on second imaginary straight lines that extend in parallel, and that are perpendicular to the first imaginary straight lines passing through the centers of the plurality of first body portions; a plurality of second main body portions respectively arranged on a plurality of fourth imaginary straight lines extending parallel to the third imaginary straight line; a first lead 2a or 23a led out from the first main body part and arranged to extend between the second main body parts;
A second lead 3a or 21a, 22a is led out from the first main body portion on the opposite side to the lead 2a or 23a and is arranged to extend in the same direction as the third imaginary straight line; A third lead 2b or 21 led out from the second main body portion in the same direction as the virtual straight line of No. 4 extends.
b, 22b and the third lead 2b or 21
b, a fourth lead led out from the second body portion on the opposite side to 22b, disposed to pass between the first body portions, and extending in the same direction as the fourth imaginary straight line; 3b or 23b, and the first line extending parallel to the first virtual straight line.
lead 2a or 23a and the fourth lead 3b.
or the first strip 7 interconnecting 23b
and the second lead 3a or 21a, 22a and the fourth lead extending parallel to the first strip 7.
a second strip 6 interconnecting the leads 3b or 23b; 21b and 22b.
Note that the first and second virtual straight lines are indicated by arrow 1 in FIG.
3 and 14, the third and fourth imaginary straight lines are lines extending vertically in line with the leads 3a and 3b in FIG. The strips 7, 6, and 8 are portions called tie bars in the embodiment.

[Function] The electronic element fixing portion 4a or 24a of the present invention is a portion for fixing a diode chip, a transistor chip, or the like. First, second and third subsections 7,
By providing 6 and 8, a lead frame having a lattice-like structure can be obtained.

[Embodiment 1] Next, a resin molded silicon diode and its lead frame according to an embodiment of the present invention will be explained with reference to FIGS. 1 to 3. The lead frame 1 has a pair of leads 2a, 3a for the diodes in the first row and a pair of leads 2b, 3b for the diodes in the second row. The leads 2a, 2b extending in the first direction (downward) are continuous with the large-area element (chip) fixing parts 4a, 4b, and the leads 3a, 3b extending in the second direction (upward) is a portion continuous to pad portions 5a and 5b. Tie bars 6, 7, and 8 are provided to connect the leads 2a, 2b, 3a, and 3b. Reference numerals 9 and 10 denote lead end connecting portions, which are provided at the ends of the leads 3a and 2b. Reference numeral 11 denotes a longitudinal connecting strip that is finally removed. If a long lead is required, the lead may be extended to this extent.
Reference numeral 12 denotes a guide hole used for fixing and moving the lead frame 1.

The lead frame 1 is formed by pressing a plate-shaped Ni-coated Cu plate. This lead frame 1 includes element fixing parts 4a and 4b, pad parts 5a and 5b, and leads 2a and 2a connected to these parts.
2b, 3a, and 3b (the part where the package is applied), and the leads 2a, 2.
It can be roughly divided into a lead portion (a portion to which no package is applied), which is a combination of tie bars 6, 7, 8, connecting portions 9, 10, and band portion 11.
The main body portion consists of a first row consisting of an element fixing part 4a and a pad part 5a aligned in the direction of arrow 13, and an element fixing part 4b and a pad part 5b aligned in the direction of arrow 14. They are arranged separately from the second column. The first and second columns are parallel to each other and extend along a straight line.

The features of this lead frame 1 are:
The leads 2a to be connected to the element fixing parts 4a of the first row extend to between the main body parts of the second row, and the leads 3b to be connected to the pad parts 5b of the second row. It extends between the body portions of the first row.

When manufacturing a resin molded silicon diode using a lead frame, as shown in FIG. This connects the upper surface of the chip 15 and the pad portions 5a, 5b. After that, chip 1
The portion 5 is covered with a protective resin (not shown) made of silicone resin.

Next, as shown in FIG.
form b. In this application, molded bodies 17a, 17b
The area where the lead frame is formed is called the main body portion of the lead frame. 18 and 19 conceptually show the flow of resin during transfer molding. In transfer molding, the lead frame 1 is held between an upper mold and a lower mold, and the molded bodies 17a and 17b are formed into empty spaces called cavities. Furthermore, a main resin passage called a runner is formed by the upper and lower molds, and a branch passage called a gate is formed, and the gate is connected to the cavity. Flow 18 assumes resin flowing to the runner, and flow 19 assumes resin flowing to the gate. Note that the resin remaining in the flows 18 and 19 and solidified together with the molded bodies 17a and 17b will be discarded as unnecessary resin.

FIG. 3 shows a resin-molded silicon diode 20 (solid line) separated from the lead frame 1 by press working. Note that the portion to be cut and removed is indicated by a broken line. The completed diode 20 has a molded body 17 which is the main body part.
It has leads 2a, 2b extending from a, 17b in a first direction (downward) and leads 3a, 3b extending in a second direction (upward).

As is clear from the above explanation, lead 2a,
3b is the main body portion, that is, the molded bodies 17a, 17b.
By extending so as to be sandwiched between them, the length in the lead direction (the distance between the connecting parts 9 and 10) is shorter than that of a conventional single-row lead frame as well as a conventional double-row lead frame. has also decreased significantly. Even in the arrangement direction (horizontal direction) of the main body part,
No increase in length due to part of the leads 2a, 3b being interposed between the main body parts is observed.
In other words, even in the past, the main body part was designed to connect the lead part on one side and the lead part on the other side to integrate the lead frame, and also to act as a stopper for the resin that would slightly flow out into the gap between the upper and lower molds. This is because a band-shaped portion is provided in between, which is ultimately cut and removed. Even if this band-shaped portion is not provided, the length of the main body portion in the arrangement direction will be slightly increased due to the presence of the narrow leads. Therefore, the area of the lead frame 1 is saved, and the number of products that can be produced per unit area is larger than that of a conventional single-row lead frame as well as a conventional two-row lead frame.

In addition, since only one mold runner is needed for the first and second rows of the main body, compared to when using a conventional single row lead frame, the runner portion (flow 18) ), the amount of resin remaining can be reduced and the amount of resin can be saved. Compared to the conventional two-row type lead frame, it is the same in that it saves resin by sharing the runner, but since the distance between the first and second rows is narrower, the gate part ( The amount of resin remaining in the flow 19) is reduced, and the amount of resin can also be saved.

[Embodiment 2] Next, an example in which the present invention shown in FIGS. 4 and 5 is applied to a resin molded silicon transistor will be described. However, since this is substantially the same as the diode except that the number of leads is increased, detailed explanation will be omitted. Note that in FIGS. 4 and 5, parts common to those in FIGS. 1 to 3 are given the same reference numerals. In the case of this transistor, element fixing parts 24a, 24b and pad parts 25a, 25
b are arranged along a first column indicated by an arrow 13 and a second column indicated by an arrow 14, and two pad portions 25a, 26a, 25 per one transistor 29.
b, 26b are provided, and from these leads 21
a, 22a, 21b, and 22b are derived, respectively. Leads 23a and 23b are also led out from the element fixing parts 24a and 24b in each row, and the lead 23a is connected to the element fixing part 24a in the first row.
extends between the element fixing portions 24b of the second row,
Leads 23b to be connected to the element fixing parts 24b in the second row extend between the element fixing parts 24a in the first row. Each element fixing part 24a, 24b
A transistor chip 27 is fixed to the pad portions 25a, 26a, 25b, 26b.
An internal lead 28 connects the two. Molding is carried out in the same manner as in Example 1, molded bodies 17a and 17b are provided as shown in FIG. 5, and the transistor 29 is separated by removing the portion indicated by the broken line.

[Embodiment 3] FIG. 6 shows an example in which the present invention is applied to an integrated circuit (IC). In this example as well, the number of lead wires is
Since it is substantially the same as Embodiments 1 and 2 except that the number of diodes and transistors is greater than that of diodes and transistors, detailed explanation will be omitted. Further, in FIG. 6, parts common to those in FIGS. 1 to 3 are given the same reference numerals. The resin molded integrated circuits 39 in FIG. 6 are arranged in a first column and a second column, and the integrated circuits 39 in the first column have six leads 31a extending in a first direction, 32a, 33
a, 34a, 35a, 36a, and two leads 37a, 38a extending in the second direction. The second column of integrated circuits 39 includes two
Book leads 37b, 38b and six leads 31b, 32b, 33b, 34 extending in the second direction
b, 35b, and 36b. The two leads 37a, 38a of the first row of integrated circuits 39 extend between the molded bodies 17b of the second row of integrated circuits 39, and the two leads 37 of the second row of integrated circuits 39 extend between the molded bodies 17b of the second row of integrated circuits 39.
b, 38b extend between the molded bodies 17a of the first row.

What should be noted here is that the leads located between the main body parts are 37a, 38a or 37b, 38b.
There are two (plural) of these. Connecting part 9,
Leads 31a to 36a or 3 led out to the 10 side
The larger the occupied width L of the leads 1b to 36b is than the occupied width l of the leads 37a, 38a or 37b, 38b located between the main body parts, the more space can be saved.

[Modified example]

The present invention is not limited to the embodiments described above, but can be modified. For example, it is applicable not only to semiconductor devices but also to various electronic components such as resistors, capacitors, and fuses. Although it is particularly effective for resin molded parts made by transfer molding, it can also be applied to resin molded parts made by casting or potting, or ceramic sealed parts. Although an example is shown in which the main body portion has two rows, it is also applicable to a case where the main body portion has three or more rows.

[Effect of idea]

The present invention has the following effects.

(b) Since the mutual distance between the first and second main body parts can be made shorter than the length of the leads, the number of electronic components per unit area of the lead frame increases, making it possible to downsize the lead frame and use materials. You can save money.

(b) Since the lead frame has at least the first, second, and third stripes, the lead frame becomes a grid-like structure, and mechanical stability is improved.

(c) By providing a resin pumping path between the first and second main body portions arranged at an interval smaller than the length of the lead, this path can be shortened. Therefore, the amount of resin wasted in the pressure feeding route can be reduced.

[Brief explanation of drawings]

1 is a plan view showing a lead frame of a diode according to Example 1 of the present invention, FIG. 2 is a plan view showing the state after molding when the lead frame shown in FIG. 1 is used, and FIG. FIG. 4 is a plan view showing the lead frame of the transistor of Example 2 with unnecessary parts removed. FIG. 5 is a plan view showing the lead frame of the transistor of Example 2 with unnecessary parts removed after molding. , FIG. 6 is a plan view showing the lead frame of the integrated circuit according to the third embodiment after molding. 1...Lead frame, 2a-3b...Leads, 4a, 4b...Element fixing portion, 5a, 5b...
Pad portion, 17a, 17b... molded body.

Claims (1)

[Claims for Utility Model Registration] A plurality of first pads, each of which includes an electronic element fixing portion 4a or 24a and an internal lead connection pad portion 5a or 25a, 26a, and which are juxtaposed with each other on a first imaginary straight line. each of which includes an electronic element fixing part 4b or 24b and an internal lead connection pad part 5b or 25b, 26b, and a direction perpendicular to the first imaginary straight line of the first main body part. The first body portions are arranged in parallel to each other on second imaginary straight lines extending parallel to the first imaginary straight line with an interval greater than the width, and passing through the centers of the plurality of first body portions, respectively. A plurality of second body portions each arranged on a plurality of fourth imaginary straight lines extending parallel to the third imaginary straight line between a plurality of third imaginary straight lines that are perpendicular to the imaginary straight line. and a first lead 2a or 23a that is led out from the first body part in the same direction as the third virtual straight line and is arranged to extend between the second body parts. and a second lead 3a or 21a that is led out from the first main body portion on the opposite side of the first lead 2a or 23a and is arranged so as to extend in the same direction as the third virtual straight line. , 22a
and a third lead 2b or 21b, 22b led out from the second main body portion in the same direction as the direction in which the fourth imaginary straight line extends; and on the opposite side from the third lead 2b or 21b, 22b. a fourth lead 3b or 23b led out from the second main body part, arranged to pass between the first main body parts, and extending in the same direction as the fourth imaginary straight line; a first strip 7 extending parallel to one imaginary straight line and interconnecting the first lead 2a or 23a and the fourth lead 3b or 23b; and the first strip 7. a second strip 6 extending in parallel to the second lead 3a or 21a, 22a and the fourth lead 3b or 23b; The first lead 2a or 23a and the third lead 2 extend parallel to each other.
21b, 22b.