JPS6084851A - Lead frame - Google Patents

Abstract

PURPOSE:To enable to attain the variety in models each in small quantity production of semiconductor devices securely and inexpensively by using a lead frame partly provided with a photo shielding part which can be removed easily by utilization of an air gap, in the case of automation of the producing process by means of an optical reader. CONSTITUTION:A discrimination code whereby the information about the shape of the lead frame is made understandable in appearance by coding, e.g., the photo shielding parts 7 of lead for are provided between a frame 1 and a lead 6 and between a lead 6 and a lead 6. A deficit part 8 is formed by removal of the photo shielding part at the required position corresponding to the discrimination code by the method such as cutout, and the discrimination of the kinds of products in the production process is performed. In other words, the optical reader is placed at a required position of the process, and the presence of the photo shielding parts is read by means of a light emitting element and a light receiving element; the kinds of products are discriminated from the discrimination code indicated by the presence of the shielding parts, and then made to cope with many-model production so as to automatically change over the producing process according to the kinds of product.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a technology for efficiently producing a wide variety of products, and in particular to a technology that is effective when applied to the small-volume, high-mix production of semiconductor devices produced using lead frames. It is.

[Background Art] With the diversification of demand for semiconductor devices, it is thought that the cases of producing and supplying a wide variety of products in small quantities will increase.

In this case, it becomes necessary to produce many different types of products in small quantities on the same production line, and it becomes necessary to specify the process for each type in a short period of time immediately before starting the production process.

Conventionally, mass production of one type of product was common, and the number of 10-foot lofts was large, so it was possible to cope with this by specifying the necessary materials, processes, etc. for each loft in advance.

For example, for semiconductor devices produced using lead frames, (11) a method in which a hole or notch is formed in a part of the frame section to specify the designation, (2) an identification code is attached to the frame section. How to engrave with numbers etc.
Alternatively, (3) a method of marking the frame portion with ink or the like may be considered.

However, according to the studies of the present inventors, there are the following problems. In the method according to (1) above, discrimination is easy with an optical reading device, but it is necessary to provide a hole corresponding to the required discrimination code, or to close a pre-provided hole. Therefore, there is a problem in that it is difficult to form holes, etc. corresponding to the discrimination codes using this method immediately before the production process.

In addition, when using method (2) above, pattern recognition technology must be used to detect the engraved identification code, and the equipment required for this is extremely expensive, so the necessary number of It is economically problematic to install one.

In addition, when methods (1) and (2) above are adopted, the frame parts used for transport guides and positioning in the production process are directly processed, so the frame parts are likely to be damaged or distorted. it is conceivable that. From this point of view, it is better to avoid it as much as possible.

Furthermore, method (3) requires an additional step of drying the ink, and the marked identification code is likely to disappear, which poses a problem in practice.

[Object of the Invention] An object of the present invention is to provide a technique that is applicable and effective for high-mix, low-volume production of semiconductor devices produced using lead frames.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

In other words, when adopting a production system that automates the production process using an optical reading device, it is possible to use a lead frame with a light shielding part that can be easily removed by using a void in a part of the lead frame. , it is possible to reliably and inexpensively achieve high-mix, low-volume production of semiconductor devices.

[Example 1] FIG. 1 is a partial plan view of a lead frame for a DIP type semiconductor device according to Example 1 of the present invention. An actual frame is formed by connecting a plurality of frames in the left and right direction, with the frame shown in FIG. 1 as one unit.

The lead frame shown in Example 1 has a skeleton made up of a frame 1, a tab suspension lead 2 directly connected to the frame 1, a dam 3, and a partition frame 4 formed between an adjacent unit. At the tip of the hanging lead 2, a tab 5 is fixed to the center of the unit shape, and a tie bar (
It has a structure including a lead 6 extending from the partition frame 4 to the vicinity of the tab 5 and supported by a dam 3 at approximately the center thereof.

The feature of the present invention in this embodiment is that information regarding the shape of the lead frame (or the product used) is encoded between the frame 1 and the leads 6 and between the leads 6, so that the information can be expressed in the external shape. A distinguishing code, specifically a lead-shaped light shielding section 7, is provided here.

By removing the light shielding portion 7 at a predetermined position corresponding to the discrimination code by cutting or other methods to form a defective portion 8, the type of product can be discriminated in the production process.

That is, by installing an optical reading device at a required position in the process, the presence or absence of a light shielding part is read using a light emitting element and a light receiving element (light emitting diode and phototransistor), and the presence or absence of the shielding part is displayed. This system is intended to support multi-product production by identifying the type of product from the identification code and automatically switching the production process depending on the type.

Automation of production process switching using the lead frame allows the removal of the light shielding part, which is the printing of the identification code, to be performed quickly and easily using a method such as a press just before entering the production process, so It is effective when applied to a system that uses a frame to produce a wide variety of products in small quantities on the same production line.

In addition, the identification code can be read reliably by placing the light-emitting element and the light-receiving element in the position corresponding to the light-shielding part, and using a binary signal that indicates whether the light is shielded or transmitted. Since it can be carried out with a simple optical reading device that uses a light emitting element and a light receiving element, it can be carried out at a much lower cost than when pattern recognition technology is employed.

Furthermore, since a commonly used lead frame has a structure in which a plurality of units shown in FIG. 1 are connected, a large amount of information can be printed by providing a light shielding portion between the leads of each unit. Therefore, even for products with complicated processes, automation of production can be achieved with the same effects as described above.

[Example 2] FIG. 2 is a plan view showing one unit of a lead frame that is the same as the lead frame shown in Example 1, but provided with a protrusion-shaped light shielding part 9.

By forming the light shielding portion in the shape of a protrusion, when producing a semiconductor device using the lead frame, in addition to the same effect as described in Example 1, the light shielding portion may be formed immediately before entering the production process. Since removal can be achieved by cutting only one side with a press or the like, it can be done even more easily.

[Embodiment 3] FIG. 3 is a plan view showing one unit of a lead frame for a flat package type semiconductor device to which the present invention is applied. An actual lead frame has a shape in which a plurality of units shown in FIG. 3 are connected in the left and right direction.

The lead frame shown in Example 3 has substantially the same structure as the lead frame shown in Example 1, but the leads 2 are formed in four directions, so that the dam 10 supporting the leads is longitudinally It consists of a structure in which two more stripes are formed in the direction.

Gaps 11 are formed at the four corners of this lead frame, and the lead-shaped light shielding portions 7 are formed using the gaps 11.
By removing the shielding portion and forming the defective portion 8, it is possible to print an identification code and obtain the same effect as shown in Example 1 in the production of a flanto path cage type semiconductor device. can.

[Effects] (1) By using a lead frame with a light shielding part for identification that is easy to remove, the light shielding part can be removed and the identification code can be printed just before entering the production process.
It is possible to efficiently produce a wide variety of semiconductor devices in small quantities on the same production line.

(2) Since the identification code described in (1) above can be read by an optical reader using a photoelectric element, high-mix low-volume production can be carried out extremely economically and reliably. .

(3) The light shielding portion shown in (1) above is installed in the shape of a lead between the frame and the leads or between the leads.
By doing so, the void can be used effectively, so the present invention can be applied to commonly used lead frames without making any fundamental changes.

(4) The same effect as in (3) above can be obtained by providing the light shielding portion shown in (1) above in the gap formed at the corner of the φ square shape formed by the frame and the partition frame.

(5) By making the curved light shielding part described in (3) or (4) into a protruding shape, the light shielding part can be removed by cutting only one side, which reduces the need to change the production process. It can be done quickly.

+01. As shown in t1) to (5) above, by not performing any processing on the frame, no scratches or distortions will occur in the frame portion, so it is possible to prevent a decrease in the reliability of the production process. .

(7) 1 Regarding semiconductor devices manufactured using the lead frame according to the present invention, the identification code displayed on the lead frame can be used quickly even during the production process.
Since product types and lots can be reliably classified by 411, mixed products can be quickly classified and product naming can be performed.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, place a light shield between the leads or in a corner.
Needless to say, the gap is not limited to the case where the gap is placed in the space 1, and may be provided in any position as long as the gap can be effectively utilized.

In addition, the light shielding part is not limited to the shape shown in the example, but if it is a lead shape, it may have a shape with a large area in the middle, or if it is a protrusion shape, it may have a shape with a large area in the middle. It is particularly effective if the shape has a large area to completely block light.

Furthermore, with respect to the lead frame for the flanged bass cage type semiconductor device, although only a lead-shaped light shielding portion has been described, it goes without saying that the lead frame may also have a protrusion shape.

[Field of Application] In the following explanation, the invention made by the present inventor is mainly applied to lead frames, which is the background field of application, but the invention is not limited to this, and for example, the invention is applied to lead frames. It is an effective technology that can be applied to devices, home appliances, etc., if there is a process for assembling various products on the same frame or frame.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a part of a lead frame which is an embodiment of the present invention; FIG. 2 is a plan view showing a part of a lead frame which is another embodiment of the invention; The figure is a partial plan view showing a state in which an embodiment of the present invention is applied to another type of lead frame. 1... Frame, 2... Tab hanging lead, 3...
Dam, 4... Tie bar, 5... Tab, 6... Lead, 7... Light shielding part, 8... Missing part, 9... Light shielding part, lO... Dam, 11 ...Void area.

Claims (1)

[Claims] 1. A lead frame characterized in that a part thereof is provided with a light shielding portion for discrimination. 2. The lead frame according to claim 1, wherein the light shielding portion is in the shape of a lead. 3. The lead frame according to claim 1, wherein the light shielding portion has a protrusion shape. 4. The lead frame according to claim 1, 2 or 3, wherein the light shielding portion is formed between the frame and the leads or between the leads. 5. The lead frame according to claim 1, 2 or 3, wherein the light shielding portion is formed at a corner of the lead frame.