JP2002134763A - Container for semiconductor light receiving element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a gap being generated between a resin frame and a ceramic substrate, and a part of dust remaining in that gap during a cleaning process adhering to a semiconductor light-receiving element, thus causing an erroneous operation, and to prevent an adhesive from projecting to the mounting surface of the semiconductor light-receiving element at the bonding of the resin frame and the ceramic substrate. SOLUTION: A groove 5 is made at a lower part of a resin frame 2 in the upper surface of a ceramic substrate 1 over a substantially entire circumference thereof, such that the inner side face of the resin frame 2 is located above the opening thereof, where arithmetic mean roughness Ra of the inner surface of the groove 5 is 0.05-0.4 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for housing a semiconductor light receiving element having a hollow portion for mounting and receiving a semiconductor light receiving element such as a long CCD for a line sensor used for a facsimile or an image scanner.

[0002]

2. Description of the Related Art Conventionally, a line sensor used for a facsimile or an image scanner of OA equipment includes a semiconductor light receiving element such as a long line sensor CCD (Charge Coupled Device). It is configured by being mounted on a container (hereinafter, referred to as a semiconductor container). In such a semiconductor container, a ceramic package having a semiconductor light receiving element mounting portion in a groove formed on an upper surface of a ceramic substrate has been used. Then, a semiconductor light receiving element is die-bonded to the mounting portion, and electrical wiring is performed by a bonding wire or the like.
It was used as a line sensor by sealing a transparent window made of glass or plastic at the opening of the groove.

Further, in order to meet various specifications and demands for cost reduction, potting with a light-transmitting sealing resin is performed instead of sealing a transparent window, or a plastic package using a resin substrate instead of a ceramic substrate. Was used.

Recently, a semiconductor container has been proposed in which a resin frame body holding a plurality of lead frames and a ceramic substrate are bonded with an adhesive, so that the mounting surface has high dimensional accuracy and excellent heat dissipation. (Japanese Unexamined Patent Application Publication No.
No. 05).

Further, as another conventional example, a groove is provided along the inside of the seal portion of the container main body to prevent the sealing material for bonding the container main body and the cap from flowing into the central portion of the container main body. A semiconductor device having a configuration has been proposed (see Japanese Patent Application Laid-Open No. 3-266453).

[0006]

However, in the semiconductor container disclosed in Japanese Patent Application Laid-Open No. 12-138305 as shown in FIG. 6, when the ceramic substrate 11 and the resin frame 12 are joined with the thermosetting adhesive 14, Agent 14 shrinks upon curing,
In some cases, a gap C is generated between the ceramic substrate 11 and the resin frame 12, and the dust is likely to be caught in the gap C, making it difficult to remove the dust even in the cleaning process.
As a result, a part of the dust may be scattered after the package is sealed, and the dust may adhere to the surface of the semiconductor light receiving element, causing the semiconductor light receiving element to malfunction.

In order to reduce material costs, the adhesive 1
When the width of 4 is reduced, the gap C between the ceramic substrate 11 and the resin frame 12 becomes larger than in the case of FIG. 6, whereby the dust is more likely to be trapped. Could not be removed. As a result, dust may further adhere to the surface of the semiconductor light receiving element, and the semiconductor light receiving element may malfunction. Furthermore, since the width of the adhesive 14 is small, the bonding strength between the ceramic substrate 11 and the resin frame 12 has been reduced.

On the contrary, when the width of the adhesive 14 is increased, FIG.
As shown in (1), the adhesive 14 protrudes from the mounting surface 11a during the bonding, flows into the semiconductor light receiving element side, adheres to the side surface of the semiconductor light receiving element, and may affect the operation characteristics of the semiconductor light receiving element itself. Was.

On the other hand, as described in Japanese Patent Application Laid-Open No. 3-266453, when a groove is provided in the mounting portion inside the seal portion, the mounting surface of the semiconductor light receiving element becomes large, and the package becomes large and heavy. Had.

[0010] Accordingly, the present invention has been completed in view of the above problems, and an object thereof is to form a gap between the resin frame and the ceramic substrate, and the dust remains in the gap in the cleaning step, and the dust is removed. An object of the present invention is to solve the problem that a part of the adhesive adheres to the semiconductor light receiving element to cause a malfunction, and to prevent the adhesive from protruding to the mounting surface of the semiconductor light receiving element at the time of joining the resin frame and the ceramic substrate.

[0011]

A semiconductor container according to the present invention comprises:
A ceramic substrate and a resin frame having substantially the same outer dimensions as the ceramic substrate and holding a plurality of lead frames are joined by an adhesive, and are surrounded by the resin frame on the upper surface of the ceramic substrate. In a semiconductor light-receiving element storage container having a mounting surface for a semiconductor light-receiving element in a region, a groove in which an inner side surface of the resin frame is located on an opening of the lower surface of the resin frame on the upper surface extends over substantially the entire circumference. And the arithmetic average roughness R of the inner surface of the groove
a is 0.05 to 0.4 μm.

According to the present invention, a groove is formed at a predetermined location over substantially the entire periphery of the upper surface of a ceramic substrate, and the arithmetic mean roughness Ra of the inner surface of the groove is 0.05.
When the thickness is about 0.4 μm, dust remaining in the gap between the resin frame and the ceramic substrate can be easily removed in the cleaning step, and the dust does not adhere to the semiconductor light receiving element, and the semiconductor light receiving element can be normally used. Can be activated. Further, the protrusion of the adhesive onto the mounting surface of the semiconductor light receiving element at the time of joining the resin frame and the ceramic substrate can be greatly reduced. Further, since the groove is formed on the upper surface of the ceramic substrate, it is possible to prevent a manufacturing error such as printing and applying an adhesive upside down.

In the present invention, preferably, a notch is formed over substantially the entire circumference from the middle of the lower surface of the resin frame to the inner surface of the resin frame.

According to the above configuration, it is easier to remove dust remaining on the inner surface of the groove in the cleaning step.

In the present invention, preferably, the depth of the groove is 0.05 mm to 0.5 Y (where Y is the thickness of the ceramic substrate).

According to the above configuration, dust can be easily removed in the cleaning step, and the rigidity of the ceramic substrate can be maintained to prevent cracks and the like from occurring in the ceramic substrate when the ceramic substrate and the resin frame are joined. it can.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The semiconductor container of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of a semiconductor container of the present invention, and FIG. 2 is a perspective view thereof.

1 and 2, 1 is a ceramic substrate, 2 is a resin frame having substantially the same outer dimensions as the ceramic substrate 1, 3 is a plurality of lead frames sandwiched between the resin frames 2, 4 is a ceramic frame. It is a thermosetting adhesive for joining the substrate 1 and the resin frame 2. In this semiconductor container, a resin frame 2 integrally formed with a lead frame 3 on a ceramic substrate 1 is joined by an adhesive 4.

The ceramic substrate 1 of the present invention is formed of a plate-like body, and has a mounting surface 1a of the semiconductor light receiving element in a region surrounded by the resin frame 2 on the upper surface thereof.

The material of the ceramic substrate 1 is as follows.
Aluminum oxide (Al ₂ O ₃ ) sintered body, mullite (3
Al ₂ O ₃ .2SiO ₂ ) sintered body, aluminum nitride (AlN) based sintered body, silicon nitride (Si ₃ N ₄ ) based sintered body,
Various ceramic materials such as silicon carbide (SiC) -based sintered bodies and glass ceramics can be used.
What is necessary is just to select suitably according to required characteristics, such as intensity | strength and heat dissipation. Among them, when an aluminum oxide sintered body is used, it has a suitable thermal conductivity and is easily processed by polishing or the like, so that it has a mounting surface 1a with desired dimensional accuracy, strength, reliability, and heat dissipation. A semiconductor container having excellent characteristics and excellent characteristics can be obtained.

As shown in FIGS. 1 and 3, the groove 5 is formed on the upper surface of the ceramic substrate 1 at a position below the resin frame 2 so that the inner side surface 7 of the resin frame 2 is positioned over the opening thereof and is substantially entirely formed. It is formed over the circumference. The size of the groove 5 is determined by the position of A (the position of the inner surface on the outer peripheral side of the groove 5 when the end face of the ceramic substrate 1 is set to 0) and the position of B (the groove when the end face of the ceramic substrate 1 is set to 0). 5 (the position of the inner surface on the side of the mounting surface 1a) and the depth of the groove 5. With respect to the width X of the resin frame 2, the position A is 0.5X to (X-0.1 mm), and the position B is (X
+0.1 mm) to 1.5X. The depth of the groove 5 is 0.05 mm with respect to the thickness Y of the ceramic substrate 1.
~ 0.5Y is preferred.

If the position of A is less than 0.5X, the adhesive strength between the ceramic substrate 1 and the resin frame 2 is reduced, and the resin frame 2
Of the ceramic frame 1 and the resin frame 2 are likely to remain in the gap between the ceramic substrate 1 and the resin frame 2, making it difficult to remove the dust in the cleaning process. When the distance exceeds (X-0.1 mm) (at a position 0.1 mm away from the inner side surface 7 of the resin frame body 2 toward the outer peripheral side), the adhesive 4 easily protrudes toward the mounting surface 1a. The position of B is (X + 0.1 mm) (a position 0.1 mm away from the inner surface 7 of the resin frame 2 toward the semiconductor light receiving element).
If it is less than 1.5 mm, dust tends to remain in the gap between the ceramic substrate 1 and the resin frame 2, so that it is difficult to remove the dust in the cleaning step, and 1.5X (from the inner surface 7 of the resin frame 2 to the semiconductor light receiving element side). When the distance exceeds 0.5X), the mounting surface 1a becomes large as a result, and the semiconductor container is increased in size and weight.

If the depth of the groove 5 is less than 0.05 mm, dust tends to remain in the gap between the ceramic substrate 1 and the resin frame 2, making it difficult to remove dust in the cleaning step. If it exceeds 0.5Y, the rigidity of the ceramic substrate 1 will decrease, and cracks will occur in the grooves 5 when the ceramic substrate 1 and the resin frame 2 are joined. Specifically, the length of X is about 2 to 8 mm, and the thickness of Y is about 0.5 to 3 mm.

The arithmetic mean roughness Ra of the inner surface of the groove 5 is set to 0.05 to 0.
It is about 4 μm. If it is less than 0.05 μm, it is the limit of polishing, and if it exceeds 0.4 μm, it becomes difficult to remove dust in the cleaning step.

Further, when the arithmetic average roughness Ra of the inner surface of the groove 5 is 0.05 to 0.4 μm, generally large amount of dust having a size exceeding 0.4 μm hardly adheres. Even if dust having a size of 0.05 μm or less adheres to the inner surface of the groove 5, such small dust often adheres to the inner surface by an intermolecular force with the inner surface, and as a result, the adhesive force is weak, It can be easily removed in the washing step. Therefore, almost no dust adheres to the groove 5, and the semiconductor light receiving element can be normally operated.

The resin frame 2 is joined to the upper surface of the ceramic substrate 1 with an adhesive 4 to form a space for accommodating the semiconductor light receiving element in a region surrounding the inner mounting surface 1a, and forms a container together with the ceramic substrate 1. .

As the resin material of the resin frame 2, epoxy resins such as bisphenol A type epoxy resin, novolak type epoxy resin, glycidialamine type epoxy resin, polyimide resin, phenol resin, unsaturated polyester resin, silicone resin Or other thermosetting resin, or
Thermoplastic resins such as liquid crystal polymer, polyphenylene sulfide resin, and polysulfone resin are used. Particularly, an epoxy resin is preferable from the viewpoint of good heat resistance and moisture resistance and low cost. Further, these resins may contain a curing agent, a curing accelerator, a filler, a flame retardant, a pigment, a release agent, and the like.

In order to manufacture the resin frame 2, for example, an injection molding method or a transfer molding method is used to put a plurality of lead frames 3 in a mold in which a plurality of lead frames 3 are set at predetermined positions.
20MPa (megapascal) pressure, about 150-200
It may be manufactured by injecting and solidifying a resin material under molding conditions such as a temperature of ° C. and a molding time of about 1 to 10 minutes.

The lead frame 3 is made of an iron (Fe) -nickel (Ni) -cobalt (Co) alloy, an Fe-Ni alloy,
It is made of a metal material such as a copper (Cu) alloy, and is connected to a semiconductor light receiving element housed in a container by an electric connection means such as a bonding wire and is connected to an external electric circuit via solder or the like. , Function as a conductive path between them.

The lead frame 3 is made of, for example, Fe
-An ingot (a lump) of a Ni-Co alloy is formed into a predetermined shape and dimensions by applying a conventionally known metal working method such as a rolling method or a punching method. On the exposed surface, a highly conductive metal plating film such as nickel or gold having excellent corrosion resistance and good wettability with a brazing material or a bonding wire is applied to a thickness of 0.1 to 20 μm. By doing so, the oxidative corrosion of the lead frame 3 can be effectively prevented, and the electrical connection using a bonding wire, solder, or the like can be improved.

The adhesive 4 for joining the resin frame 2 to the upper surface of the ceramic substrate 1 is made of epoxy resin containing acrylic rubber or the like. Specific examples of the adhesive composed of such an epoxy resin include an epoxy resin such as a bisphenol A type epoxy resin, a novolak type epoxy resin, a glycidylamine type epoxy resin, an amine type curing agent, an imidazole type curing agent, and an acid anhydride. Using a resin adhesive to which a curing agent such as a product curing agent has been added, and containing particles of acrylic rubber such as butyl acrylate rubber, cross-linked polymethyl methacrylate rubber, ethyl acrylate rubber, urethane acrylate rubber, etc. Used.

In order to join the ceramic substrate 1 and the resin frame 2 with such an adhesive 4, for example, first, a screen printing method or the like is applied to a portion of the upper surface of the ceramic substrate 1 to be joined to the resin frame 2. The adhesive 4 is printed and applied in a frame shape by a dispenser method or the like. Next, the resin frame 2 is placed, and a heat treatment is performed at a temperature of 120 to 180 ° C. for about 5 minutes to 3 hours while applying a pressure of about 2 to 8 N (Newton) according to the curing characteristics of the adhesive 4. Then, the resin frame 2 is joined to the ceramic substrate 1 by thermally curing the adhesive 4.

The semiconductor light receiving element is mounted on the mounting portion 1a of the semiconductor container of the present invention, and the electrode of the semiconductor light receiving element and the lead frame 3 are electrically connected by a bonding wire or the like. A semiconductor light receiving device such as a line sensor used in a facsimile, an image scanner, or the like is obtained by sealing a transparent window made of plastics or the like, or sealing a semiconductor light receiving element by potting of a light-transmitting sealing resin. .

Thus, according to the present invention, a groove is formed at a predetermined position over substantially the entire circumference on the upper surface of the ceramic substrate, and the arithmetic average roughness Ra of the inner surface of the groove is 0.05 to 0.1.
When the thickness is 4 μm, dust remaining in the gap between the resin frame and the ceramic substrate can be easily removed in the cleaning step, so that dust does not adhere to the semiconductor light receiving element, and the semiconductor light receiving element operates normally. be able to. Further, the protrusion of the adhesive onto the mounting surface of the semiconductor light receiving element at the time of joining the resin frame and the ceramic substrate can be greatly reduced.

Further, since the groove is formed on the upper surface of the ceramic substrate, it is possible to prevent a manufacturing error such as printing and applying an adhesive on the ceramic substrate by using the groove as a mark.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various changes and improvements can be made without departing from the gist of the present invention.
For example, the present invention can be applied to a semiconductor container having a hollow portion for mounting a semiconductor light receiving element such as a CCD for an area sensor used in a digital camera, a video camera, and the like. Further, as shown in FIG. 4, by providing a notch portion 6 extending from the middle of the lower surface of the resin frame 2 to the inner surface 7 of the resin frame 2 over substantially the entire circumference, the notch 6 remained on the inner surface of the groove 5 in the cleaning step. Removal of dust becomes easier. In addition, in the configuration of FIG. 4, the outer side surface 6 a in the notch 6 is substantially flush with the inner side surface 5 a on the outer side of the groove 5, or is on the outer side of the inner side surface 5 a (the inner side surface 5 a). It is preferable that it is recessed. In this case, it is possible to suppress the adhesive 4 from protruding toward the mounting surface 1a.

[0037]

As described above, according to the present invention, a groove is formed at a predetermined position over substantially the entire circumference on the upper surface of a ceramic substrate, and the arithmetic average roughness Ra of the inner surface of the groove is 0.05 to 0.4 μm. Accordingly, dust remaining on the inner surface of the groove can be easily removed in the cleaning step, and dust does not adhere to the semiconductor light receiving element, and the semiconductor light receiving element can be normally operated. Further, it is possible to greatly suppress the adhesive from sticking out to the mounting surface of the semiconductor light receiving element when the resin frame and the ceramic substrate are joined. Further, since the groove is formed on the upper surface of the ceramic substrate, it is possible to prevent a manufacturing error such as printing and applying an adhesive on the ceramic substrate upside down. Further, since the groove is formed such that the inner side surface of the resin frame is located above the opening, the semiconductor container is smaller than when the groove is formed in a region surrounded by the resin frame. It also has an effect.

Further, according to the present invention, preferably, a notch is formed over substantially the entire periphery from the middle of the lower surface of the resin frame to the inner surface of the resin frame, so that the notch remains on the inner surface of the groove in the cleaning step. Removal of dust becomes easier.

Further, according to the present invention, preferably, the depth of the groove is 0.05 mm to 0.5 Y (where Y is the thickness of the ceramic substrate), so that dust can be easily removed in the cleaning step. In addition, it is possible to maintain the rigidity of the ceramic substrate and prevent cracks and the like from occurring in the ceramic substrate when the ceramic substrate and the resin frame are joined.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an embodiment of a semiconductor container of the present invention.

FIG. 2 is a perspective view of the semiconductor container of FIG. 1;

FIG. 3 is an enlarged sectional view of a main part of the semiconductor container of FIG. 1;

FIG. 4 is an enlarged sectional view of a main part showing another embodiment of the semiconductor container of FIG. 1;

FIG. 5 is a sectional view of a conventional semiconductor container.

FIG. 6 is an enlarged sectional view of a main part of a conventional semiconductor container.

FIG. 7 is an enlarged sectional view of a main part of another example of a conventional semiconductor container.

[Explanation of symbols]

 1: ceramic substrate 2: resin frame 3: lead frame 4: adhesive 5: groove 7: inner surface

Claims (3)

[Claims] 1. A resin frame on an upper surface of a ceramic substrate, wherein a ceramic substrate and a resin frame having substantially the same external dimensions as the ceramic substrate and holding a plurality of lead frames are joined by an adhesive. In a semiconductor light receiving element storage container having a mounting surface of a semiconductor light receiving element in a region surrounded by a body, a groove in which an inner side surface of the resin frame is positioned above an opening in a portion of the upper surface below the resin frame. Are formed over substantially the entire circumference, and the arithmetic average roughness Ra of the inner surface of the groove is 0.05 to 0.4 μm. 2. A container for accommodating a semiconductor light-receiving element according to claim 1, wherein a notch is formed over substantially the entire circumference from the middle of the lower surface of the resin frame to the inner surface of the resin frame. . 3. The groove has a depth of 0.05 mm to 0.5 Y.
3. The container according to claim 1, wherein Y is the thickness of the ceramic substrate.