JPH0488664A - Lead frame provided with insulating base material - Google Patents

Abstract

PURPOSE:To enable a lead frame of simple structure excellent in general-purpose properties to be offered by a method wherein an integral structure composed of an insulating base material, a land, an electronic component mount, a pad, and a pattern forming space is provided to both the sides of the inner end of leads. CONSTITUTION:In a lead frame 10 provided with a large number of leads 11 linked together with connecting parts 13, an insulating base material 14 provided to both the sides of the inner end of the leads 11 in one piece, lands 15 electrically connected to the inner ends of the leads 11 through the intermediary of through-holes 17, and an electronic component mount 19 are provided. A pattern forming space 18 is provided onto the base material 14 between a large number of pads 16 provided surrounding the mount 19 and the lands 15. Both the sides of the inner ends of the leads 11 are sandwiched between the base materials 14, and a space is provided to enable the lands 15 to be optionally connected to the pads 16 on the base material 14, whereby a lead frame of simple structure excellent in general-purpose properties can be offered.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a lead frame for configuring a board for mounting electronic components, and particularly relates to a lead frame having an insulating base material for integrating each lead. It is something.

(Prior art) In a lead frame, a large number of leads are formed by punching or etching a metal plate, each electrically connected to the connection terminal of the mounted electronic component, and are connected to each other at the connection part. Although the lead frame is formed in advance, the number of leads is determined depending on the electronic component mounting device to be formed using this lead frame. In recent years, the number of leads in electronic component mounting devices has become extremely large, such as 256 or 304.

On the other hand, even if we consider the electronic components to be mounted, it is necessary to adopt various connection forms to the electronic component mounting board depending on the usage and development of functions. When producing high-mix, low-volume products, it is necessary to change the connection method for each lead in various ways.

For this reason, conventional lead frames have been designed and manufactured independently for use in necessary electronic component mounting devices, while achieving higher densities to accommodate the increasing density of electronic components.

As with the conventional lead frames mentioned above, it goes without saying that designing and manufacturing products in different formats each time is extremely inefficient, especially when the number of products is small. This leads to an increase in the cost of the product. Therefore, the inventors of the present invention have repeatedly considered how to configure a lead frame that can be used for all products, and as a result, the inventors have conducted various studies on how to configure a lead frame that can be used for all products. The present invention was completed based on the new finding that good results can be obtained by selectively connecting the pads to the pads in a post-process.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned circumstances, and the problem to be solved is the lack of versatility in conventional lead frames.

The purpose of the present invention is to sandwich both sides of the inner end of each lead between insulating base materials, and to create a space above the insulating base so that each land and pad can be freely connected. By providing this, it is possible to provide a highly versatile lead frame with a simple configuration.

(Means for Solving the Problems) In order to solve the above problems, the means taken by the present invention are as follows:
[A lead frame (lO) having a large number of leads (11) connected to each other by a connecting part (13),
An insulating base material (14) integrated on both sides of the inner end of each lead (11), and a through hole (17) formed in the insulating base material (14) and connecting the inner end of each lead (11). A land (15) electrically connected to the insulating base material (14)
) An electronic component mounting portion (19) formed approximately in the center of one side of the
, a large number of pads (16) formed around this electronic component mounting portion (19), and a pattern provided on an insulating base material (14) located between these pads (16) and each land (15). A lead frame (10) J characterized in that it has a forming space (18).

That is, the lead frame (10) according to the present invention has an insulating base material (
14), and this insulating base material (14)
The land (15) formed in the insulating base material (14) and each lead (11) are electrically connected through the through hole (17) formed in the insulating base material (14).
) A pattern forming space (18) for a connection pattern (20) is actively formed between the pad (16) and the land (15) on the top.

(Operation of the invention) The lead frame (1
0), since the insulating base material (14) is integrated on both sides of the inner end of each lead (11), each lead (
11) is completely protected from being easily bent, in conjunction with the protection provided by the respective connecting portions (13) connected thereto. Therefore, with respect to the lead frame (10) according to the present invention having this insulating base material (14), each connection pattern (20) required on the insulating base material (14) is
), each lead (11)
This means that you can do it without paying too much attention to it.

In addition, in this lead frame (10), as shown in FIGS. 1 and 2, each land (15) is formed near the periphery of the insulating base material (14), and each pad (
16) is formed around the electronic component mounting portion (19), the electronic component (30) mounted on the electronic component mounting portion (19)
) and each pad (16) with bonding wire (3 steps)
This makes it easier to connect each lead (
11) and the land (15) through the through hole (17). In other words, as electronic components (30) become denser, the number of pads (16) and leads (11) increases accordingly, as described above. On the other hand, by electrically connecting the lands (15) formed on the insulating base material (14) through the through holes (17), it is possible to maintain a sufficient distance between each lead (11), and each lead (11) It is possible to prevent the occurrence of defective impedance due to the proximity of the elements (11) to each other. Of course, since it is possible to have a wide interval between the leads (11), the processing is easy.

What is particularly important is that in this lead frame (10), a sufficiently wide pattern forming space (18 ) is actively formed, by using this pattern forming space (18), each connection pattern (20) for selectively connecting each land (15) and pad (16) can be freely formed. This means that it can be formed into For example, as shown in FIG. 2, each connection pattern (20) is connected to a land (15
) and pads (16) are selectively connected, the electronic component (30) mounted on the electronic component mounting portion (19) and each pad ( 16) by the bonding wire (31), each land (15) is individually connected to each lead (11) by the through hole (17), so the electronic component mounting part (19) and each lead (
11) are selectively electrically connected.

In this way, the lands (15) and pads (16) on the insulating base material (14) can be selectively connected by the connection pattern (20), and each lead (11) and its corresponding land ( By forming the pads (15) and pads (16) multiple times, this lead frame (
lO) can have sufficient versatility. In other words, as mentioned above, the total number of leads (11) when completed as an electronic component mounting device has increased considerably, but the number of pre-formed leads (11) is the largest number currently manufactured. If the number of leads (11) is smaller than the number of leads (11), when manufacturing an electronic component mounting device with fewer leads (11), it is sufficient to avoid using the excess leads (11).

In other words, the leads (11) of the lead frame (10), which conventionally resulted in increased costs, are pre-processed to the maximum number of leads (11) currently manufactured, and the inner end of each lead (11) is Insulating base material (
14), the processing of the lead (11) can be made common to various models, and therefore it can be manufactured in large quantities and costs can be reduced. Furthermore, since the insulating base material (14) is formed in advance on both sides of the inner end of the lead (11), the cost of forming the insulating base material (14) can be similarly reduced.
Furthermore, since the formation of the insulating base material (14) of this lead frame (1O) determines the insulation interval between the leads (11) and the connection pattern (20) on the insulating base material (14),
It is also possible to obtain stable insulation spacing and stable electrical characteristics.

Therefore, the lead frame (10) according to the present invention is extremely versatile in configuring an electronic component mounting device in which the number of leads has increased in recent years, and is suitable for mounting electronic components. Even if the device is produced in a wide variety of small quantities, it can be manufactured with stable characteristics without increasing its cost.

(Example) Next, the lead frame (10) according to the present invention will be described in detail according to the example shown in the drawings. FIG. 1 shows a plan view of this lead frame (10). Although FIG. 1 only shows one lead frame (10) for forming one electronic component mounting device, in reality, the lead frame (10) shown in FIG.
A connection pattern (20) is formed and electronic components (30) are mounted on this at the same time, and after completion, individual electronic components are mounted as shown in Figure 3. It is considered to be a device.

As shown in FIG. 1, this lead frame (lO) has a large number of leads (11) connected to each other by each connection part (13), and each of these leads (
Insulating base materials (14) as shown in FIGS. 1 and 3 are integrally formed on both sides of the inner end portion of 11). As each insulating base material (14), a general insulating material may be used, and in this example, a glass epoxy plate was used. Further, in this embodiment, a lead frame (10) is shown having a ground (12) located in the same plane as each lead (11), and this ground (12) is connected to a predetermined lead (11).
It is connected to.

As shown in FIG. 1, this insulating base material (14) is provided with a large number of lands (15) by metal foil etching or metal plating after or before being integrated into each lead (11). A pad (16) and an electronic component mounting portion (19) located approximately in the center are formed. In addition,
In this embodiment, a ground pattern (19a) is formed between each pad (16) and the electronic component mounting part (19), and this ground pattern (19a) and the above-mentioned ground (12) are through-holes. It is electrically connected through a hole. These lands (15), pads (16)
And the electronic component mounting part (19) is formed as an electrically independent part on the insulating base material (14), and each pad (16) and a land (15), each land (15) and a ground. As shown in FIG. 2, the pattern (19a) refers to electrical connection patterns (20) and ground connection patterns (21) that will be described later. It connects to each other.

In addition, especially in each land (15), as shown in FIG.
A pair of through-holes (17) formed in the insulating base material (14) are used to electrically connect the inner ends of the insulating base material (11). Therefore, by connecting the land (15) and the pad (16) with the connection pattern (20), the pad (16) and the lead (11) become electrically integrated.

Each land (15) is formed along the outer periphery of the insulating base material (14), and each pad (16) is formed around the electronic component mounting part (19) located at the center. Therefore, these pads (16) and lands (15
) is formed with a pattern forming space (18) as shown in FIG. 20), each land (15) and pad (16) are selectively connected to each other.

The connection pattern (20) and the ground connection pattern (21) may be formed by various methods, but mainly by etching a metal foil pasted or formed on the insulating base material (14), or Selected pad (16) and land (15) or land (15)
There are two methods of forming the insulating base material (14) by applying plating to connect the ground pattern (19a) and the ground pattern (19a). Connection pattern (20) as above
An electronic component (
30), and as shown in Figure 3, this electronic component (
30) and the necessary pads (16) using bonding wires (31), each terminal of the electronic component (30) can be selectively led out through each lead (11). .

FIG. 4 shows a part of a lead frame (lO) according to another embodiment of the present invention.
0), a large number of openings (12a) are formed in the portion of the ground (12) sandwiched between two insulating base materials (14) located on the outer periphery of the electronic component mounting portion (19). A through hole (17a) is formed in an appropriate one of the openings (12a) of the opening (12a). This through hole (17a) is connected to the ground (12
) is not electrically connected, but is connected to a pattern (not shown) of the insulating base material (14) on the back side. And these through holes (17a
) is located between each pad (16) and the electronic component mounting portion (19), and is connected to the selected pad (16) by the connection pattern (20a).

(Effect of the invention) As detailed above, in the present invention, the “connection portion (13
) A lead frame (lO) having a number of leads (11) connected to each other by
) an insulating base material (14) integrated on both sides of the inner end of the
Each Lee F (11) is formed on this insulating base material (14).
a land (15) that is electrically connected to the inner end of the through hole (17); an electronic component mounting portion (19) formed approximately in the center of one of the insulating base materials (14); A large number of pads (1
6) and a pattern forming space (18) provided on the insulating base material (14) located between these pads (16) and each land (15). , both sides of the inner end of each lead are sandwiched between insulating base materials, and a space is provided on the insulating base material so that each land and pad can be freely connected, thereby increasing versatility. This makes it possible to provide an excellent lead frame with a simple structure.

[Brief explanation of drawings]

Fig. 1 is a plan view of a lead frame according to the present invention, Fig. 2 is a plan view of the lead frame with a connection pattern formed thereon, and Fig. 3 is a plan view of the lead frame shown in Fig. 2 with electronic components mounted thereon. FIG. 4 is a partial plan view showing another embodiment of the lead frame according to the present invention. Explanation of symbols 1G...Lead frame, 11...Lead, 12.
... Ground, 13... Connection portion, 14... Insulating base material, 15... Land, 16... Pad, 17... Through hole, 18... Pattern forming space, 19...
Electronic component mounting section, 20... Connection pattern, 21...
Ground connection pattern, 30...Electronic components. Figure 2 above

Claims (1)

[Scope of Claims] A lead frame having a large number of leads connected to each other by connecting portions, comprising: an insulating base material integrated on both sides of the inner end of each lead; and a lead frame formed on the insulating base material. a land that is electrically connected to the inner end of each lead by a through hole; an electronic component mounting portion formed approximately at the center of one of the insulating base materials; and a land formed around the electronic component mounting portion. A lead frame comprising a large number of pads and a pattern forming space provided on the insulating base material located between these pads and each of the lands.