JPH01171234A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve positional accuracy of a semiconductor chip, by close contacting external leads directly with side faces of the semiconductor chip in electrically insulated relation, and electrically connecting the external leads with electrodes on the semiconductor chip. CONSTITUTION:Each external lead 34 whose outer periphery is coated with an insulative material 24 is close contacted directly with a pair of opposing side faces 22, 23 of a semiconductor chip 31 consisting of an active area 20 and a peripheral area 21. While such close contact between the external leads and the semiconductor chip is kept by a special-purpose jig, bonding pads 25 on the chip 31 are wire bonded with the top faces of the leads 34 by means of wires 33. The device as a whole is sealed with resin 35 by the transfer molding process or the like. Since the leads 34 are close contacted with the side faces of the chip 31 in electrically insulated relation and they are connected with each other by wire bonding, there is no clearance between the chip 31 and the leads 34 and the size of the packaging structure is close to the outer diameter of the chip 31. Further, since the leads 34 are contacted directly with the chip side faces, it is possible to ensure satisfactory positional accuracy of the chip 31 in the package.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Application of Santo The present invention relates to semiconductor devices, and particularly to a mounting structure (pancaging) for semiconductor chips.

BACKGROUND ART Conventional packaging technology generally involves fixing a semiconductor (IC) chip l on a chip mount part 2 of a lead frame and bonding wires 3 as shown in FIG.
The pads on the chip 1 are electrically connected to the external leads 4 of the lead frame, and then the whole is sealed with resin 5 by transfer molding.

In addition, as another pancaging technique, as shown in FIG. However, a structure is known in which a transparent window 9 is further fixed to the upper surface via an insulator 8.

However, in all of the above-described pancages, a sufficient clearance 10 is required around the chip 1 in order to mount the chip 1, which inevitably increases the size of the puff cage itself. Moreover, if the mounting position accuracy of the chip l is insufficient,
For example, CCD (Charge Coupled Dev
tce), etc. ~ chip 1 relative to the package outline
This becomes a serious problem for devices that require strict positional accuracy. For example, in the case of a small COD for endoscopes (stomach and rectal cameras), even if there is a slight positional shift, the tip 1
Because of the small size of the wire 3, characteristic changes (for example, changes in the effective area or efficiency of the light-receiving surface) due to the misalignment occur significantly.As a result of the above-mentioned misalignment, the wire 3 may be connected to another lead due to resin pressure during molding, etc. It may come into contact with the metal and cause a short circuit or leak.

OBJECTS OF THE INVENTION An object of the present invention is to provide a semiconductor device in which the size of the package is reduced and the positional accuracy of the semiconductor chip is improved.

26 Structure of the Invention That is, the present invention provides a semiconductor device in which an external lead is directly closely attached to a side surface of a semiconductor chip in an electrically insulated state, and the external lead and the electrode of the semiconductor chip are electrically connected. It is related to the device.

E, Example The present invention will be explained in detail below.

In the example of FIGS. 1 to 3, the active area 20
The outer peripheral surface is made of an insulating material 24 with respect to a pair of opposing side surfaces 22 and 23 of the semiconductor chip 3I consisting of a peripheral area 21 and a peripheral area 21.
The coated external leads 34 are directly brought into close contact with each other. This adhesion condition is then checked using a special jig (
The bonding pad 25 of the chip 31 and the upper surface of the leads 34 are wire-bonded with the wire 33 while holding the chip 31 with the resin 35 (not shown). (Indicated by phantom lines in the figure.)

In the above, the lead 34 is attached to the surface of the metal bottle 26.
It is coated with a thin film 24 of an inorganic insulator such as iOz or Al2203 or an organic insulator such as polyimide. Further, wire bonding using the wire 33 and transfer molding itself are performed by conventional methods.

In this way, without using a conventional lead frame,
Since the leads 34 are closely attached to the side surfaces of the chip 31 in an electrically insulating state and are connected by wire bonding, there is no clearance between the chip 31 and the leads 34 as described above, which makes the fabrication process easier. The resulting puff caging structure has a size close to the outer diameter of the tip 31.

In addition, in order to bring the leads 34 into direct contact with the side surface of the chip,
The positional accuracy of the chip 31 in the package becomes sufficient. Moreover, since positional deviation does not occur, wire bonding can always be performed reliably, and short-circuit defects and the like can be prevented.

FIG. 4 shows a package according to another example.

In this example, the chip 31 is fixed on a substrate 36, and the external leads 34 are taken out downwardly by passing through the substrate 36, and the external leads 34 are brought into close contact with the chip 3I and bonded with wires 33.

A transparent glass window 29 is provided on the upper surface of the substrate 36 via an insulator 28 provided around the periphery thereof.

In this package, light can enter from the window 29 side and be received by the chip 31.

Therefore, as the chip 31, it is possible to use the small CCD 20 mentioned above for a stomach or rectal endoscope, which is used as the light receiving surface of the small CCD. In such a case, for the above-mentioned reasons, miniaturization of the package size and improvement of chip position accuracy are extremely advantageous for small-sized CODs.

FIG. 5 shows an example in which a small CCD is used in an endoscope.

Here, 37 in the figure is a printed circuit board or connector, and 38
3 schematically shows a focusing lens, 3 a flexible tube, 40 an optical fiber for a light source, and 41 a cylindrical socket.

Next, still another embodiment will be described with reference to FIGS. 6 and 7.

In this example, the external leads 34 are attached to the substrates 36a and 36b in each row, and these side substrates are butted and combined, and the chip 31 is sandwiched between them.

Therefore, compared to the example shown in FIG.
It becomes easier to perform fixing, wire bonding, etc. Moreover, since it is a structure that is fixed on the board as in Fig. 4,
The mechanical strength of the puff cage is increased.

In the example shown in FIGS. 8 to 10, the external lead 34 is sandwiched between two layers of insulating tape 42 and 43, and is wrapped around the circumferential surface of the chip 31 with adhesive or adhesive 44. Therefore, since the leads 34 are located between the insulating tapes 42 and 43 and are insulated from the chip 31, the insulating thin film 24 as described above is not necessary, and the metal pins 26 can be used directly. Each lead 34 can be arranged in advance in accordance with the lead pitch of the final product. In this case, if an adhesive or adhesive is applied to the bonding surfaces of the tapes 42 and 43, attachment of the leads will be facilitated. and,
Tapes 42 and 43 are wrapped around the chip 31 as shown, and bonding is performed using the wire 33 while temporarily fixed with a tape holding jig (not shown), followed by resin sealing.

In this example, the lead 34 is placed between the tapes 42 and 43 in advance.
Since the lead can be clamped, it is easy to determine the position of the lead, and since it can be attached around the chi knob 31 by wrapping tape, the installation work is easy.

In the example shown in FIG. 8, an insulating frame of the same size (that is, the same size as the chip external shape) is used instead of the tapes 42 and 43, and the leads 34 are inserted and embedded in this frame, and then heated. After the frame is expanded and expanded somewhat outwardly, the chip 3.1 is inserted inside, after which the frame can be contracted back to its original shape by cooling. That is, by expanding the frame and then contracting it, the leads 34 relative to the chip 31 are
can be achieved through a continuous thermal process, improving work efficiency. After that, wire bonding and resin sealing can be performed in the same manner as described above.

In the example of FIG. 11, the side surfaces 22 and 23 of the semiconductor chip 31 are
On the other hand, an external lead 34 is closely attached via an insulating material (for example, adhesive) 44, and a bump electrode 45 provided on the side of the lead 34 is thermocompression bonded onto the pad 25 for electrical connection. . The entire structure may be sealed with resin in the same manner as described above.

Although the present invention has been described in detail above, the above-mentioned examples can be further modified based on the technical idea of the present invention.

For example, various insulation means for external leads to the chip can be used in addition to the above-mentioned coating film, adhesive, tape, etc., and such insulation means may be provided on the chip side. The insulating film coated on the leads may be present only on the chip side. Further, the connection between the chip and the leads is not limited to the above-mentioned method, and can be made in various ways. The examples shown in FIGS. 4 and 7 described above may also be modified to a resin-sealed structure bar 7 cage as shown in FIG. 3. In the example shown in FIG. 7, the number and size of the boards to which the leads are attached may be changed; for example, three or more boards may be combined. The bumps 45 shown in FIG. 11 may be formed on the chip side. Note that the devices to which the present invention can be applied are not limited to the above-mentioned CCD,
It can be extended to other ICs in general.

Effects of the Invention As described above, in the present invention, the external leads are directly adhered to the side surfaces of the semiconductor chip in an electrically insulated state, and the electrical connection between the two is made. There is no clearance between them, and the fabricated pancaging structure has a size close to the outer diameter of the chip.

Furthermore, since the leads are brought into direct contact with the side surfaces of the chip, the positioning accuracy of the chip in the pancage is sufficient.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the package, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a sectional view taken along line um in FIG. 2, and FIG. 4 is a sectional view of a package according to another example. Fig. 5 is a schematic sectional view of the main parts of an example used for an endoscope, Fig. 6 is a perspective view showing a lead and a board for fixing the lead separated from the left and right sides according to another example, and Fig. 7 is the same as that of Fig. 6. 8 is a perspective view of a package according to another example; FIG. 9 is a front view of a portion of the lead attached to the tape; FIG. 1O is a plan view of FIG. 9; FIG. 11 is a sectional view of a package according to still another example. FIGS. 12 and 13 are cross-sectional views of conventional packages. In addition, in the reference numerals shown in the drawings, 20--------------------------Active area 21
------------Peripheral area 22.23--11-----Side surface 24--Insulating thin film 25-- Pad 26----- Metal pin 28.44--
----Insulating material 29--Transparent window 31--Semiconductor chip 33--
---------Wire 34-----External lead 35--
---------Resin 36.36a, 36b-----One substrate 42.
43-----1----Tape 44----------
-.- Adhesive or pressure-sensitive adhesive 45 -.-- Bump electrode. Agent Patent Attorney Hiroshi AisakaFigure 1Figure 2Figure 3Figure 4Figure 9Figure 10Figure 11

Claims (1)

[Claims] 1. A semiconductor device in which an external lead is directly attached to a side surface of a semiconductor chip in an electrically insulated state, and the external lead and an electrode of the semiconductor chip are electrically connected.