JP2663703B2 - Resin-sealed solid-state imaging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-encapsulated solid-state imaging device, and more particularly to treatment of a lead frame surface.

[Conventional technology]

The conventional resin-encapsulated solid-state imaging device is shown in FIG.
As shown in FIG. 2B, the solid-state image sensor chip 2 is fixed to the island 1C of the lead frame, and the electrodes 2a on the solid-state image sensor chip and the internal leads 1b are electrically connected to each other by the thin metal wires 3, and then are transparent. Transfer molding was performed with the resin (4). As the lead frame 1 at that time, there is a lead frame 1 obtained by patterning a 42 or 45 alloy plate by etching or pressing, and applying a Au or Ag plating to a bonding portion of the thin metal wire 3.

[Problems to be solved by the invention]

In the above-mentioned conventional resin-encapsulated solid-state imaging device, as shown in FIG. 3, the incident light 8a is reflected on the surface of the internal lead 1b, and the reflected light 8b is re-reflected on the surface of the transparent encapsulating resin 4, and The light reached the photodiode formed on the image sensor chip, and generation of a false signal such as ghost or flare was recognized.

[Means for solving the problem]

The present invention relates to a resin-encapsulated solid in which a solid-state image sensor chip is fixed to an island portion of a lead frame, an internal lead is connected to an electrode on the solid-state image sensor chip by a thin metal wire, and is sealed with a transparent resin. In the imaging device, except for the metal wire bonding portion on the internal lead, the incident light region on at least the upper surface of the lead frame portion embedded in the sealing resin, than the lead frame material and the metal wire bonding portion on the internal lead, A low-reflection portion having a small reflectance with respect to visible light is provided, and the low-reflection portion is a chromium plating film or a chromium oxide film, a chromium film, and a chromium oxide film.
It is either a layer film or a gold-plated portion of the lead frame is blackened by heat treatment.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 (a) is a plan view of one embodiment of the present invention (however, an upper half of the transparent sealing resin is removed), and FIG. 1 (b) is Y in FIG. 1 (a). FIG. 4 is a sectional view taken along line -Y.

The solid-state imaging device chip 2 is fixed on the island portion 1C of the lead frame, the internal leads 1b and the electrodes of the solid-state imaging device chip 2 are electrically connected by the thin metal wires 3, and then the transparent sealing resin is formed by transfer molding or the like. 3 is a solid-state imaging device on which is formed.

In the resin-encapsulated solid-state imaging device of this embodiment, the internal leads
Except for the thin metal wire joint on 1b, the low-reflection portion 5 is formed in the incident light region on the upper surface of the lead frame portion embedded in the sealing resin, thereby reducing the reflectance with respect to visible light and reducing ghost or flare. To prevent

The low-reflection portion 5 is obtained by, for example, applying Au plating or the like to the internal lead 1b, and then heating the lead frame 1 in an oxidizing atmosphere to blacken it. Further, in the present embodiment, the low reflection portion is provided only in the incident light region, but may be provided in all regions of the internal lead.

As a second example of the low reflection portion, a chromium plating film may be used. In that case, the reflectance can be set to some extent freely by controlling the plating film thickness. As a third example, a three-layer film of a chromium oxide film 50 nm, a chromium film 100 nm, and a chromium oxide film 50 nm can be given, and the reflectance at a wavelength of 540 nm can be reduced to 35% or less.

A fourth example is a coating film of black ink. Since a commercially available marking ink for a semiconductor device can be used as the black ink, there is an advantage that the printing can be performed at low cost. In addition, when ink is used, it can be dried at a low temperature, so that the metal thin wire joint of the lead frame can be plated with Ag.

〔The invention's effect〕

As described above, the present invention provides a low-reflection portion having a small reflectance to visible light in at least an incident area on an upper surface of a lead frame portion embedded in a sealing resin, excluding a thin metal wire portion on an internal lead. Thereby, a false signal such as a ghost or a clear signal can be prevented, and the performance of the resin-sealed solid-state imaging device can be improved.

[Brief description of the drawings]

FIG. 1A is a plan view of a first embodiment of the present invention, and FIG.
FIG. 2B is a cross-sectional view taken along line YY in FIG. 1A, FIG. 2A is a plan view of a conventional resin-encapsulated solid-state imaging device, and FIG. FIG. 3A is a cross-sectional view taken along the line YY in FIG. 3A, and FIG. DESCRIPTION OF SYMBOLS 1 ... Lead frame, 1a ... External lead part, 1b ... Internal lead part, 1c ... Island part, 2 ... Solid-state image sensor, 2a ... Electrode, 3 ... Fine metal wire, 4 ... Transparent sealing Resin, 5: low reflection portion, 6: plating film, 7: 42 alloy surface, 8a to c: light.

Claims (3)

(57) [Claims] 1. A resin-sealed type in which a solid-state image sensor chip is fixed to an island portion of a lead frame, and internal leads and electrodes on the solid-state image sensor chip are connected by thin metal wires and sealed with a transparent resin. In the solid-state imaging device, excluding the fine metal wire joints on the internal leads, at least in the incident light area on the upper surface of the lead frame portion embedded in the sealing resin, the lead frame material and the fine metal wire on the internal leads are more strongly bonded. A resin-encapsulated solid-state imaging device, wherein a low-reflection portion having a small reflectance with respect to visible light is provided, and the low-reflection portion is blackened by heat-treating a gold-plated portion of the lead frame. 2. A resin-sealed type in which a solid-state image sensor chip is fixed to an island portion of a lead frame, and internal leads and electrodes on the solid-state image sensor chip are connected by thin metal wires and sealed with a transparent resin. In the solid-state imaging device, excluding the fine metal wire joints on the internal leads, at least in the incident light area on the upper surface of the lead frame portion embedded in the sealing resin, the lead frame material and the fine metal wire on the internal leads are more strongly bonded. A resin-encapsulated solid-state imaging device, wherein a low-reflection portion having a small reflectance with respect to visible light is provided, and the low-reflection portion is a chrome-plated film. 3. A resin-sealed type in which a solid-state image sensor chip is fixed to an island portion of a lead frame, and internal leads and electrodes on the solid-state image sensor chip are connected by thin metal wires and sealed with a transparent resin. In the solid-state imaging device, except for the thin metal wire joints on the internal leads, at least in the incident light area on the upper surface of the lead frame part embedded in the sealing resin, the lead frame material and the metal thin wires on the internal leads are more tightly joined. A resin-encapsulated solid-state imaging device, comprising: a low-reflection section having a small reflectance with respect to visible light; and the low-reflection section is a three-layer film of a chromium oxide film, a chromium film, and a chromium oxide film.