Apparatus for manufacturing semiconductor device

An apparatus for manufacturing a semiconductor device is provided. The semiconductor device includes a chip packaged with a resin mold. The apparatus includes a first mold, a second mold, and a buffer sheet. The first mold has a first cavity for forming the resin mold on a first side of the semiconductor device, and a convex part for forming an exposed area of the chip. The second mold has a second cavity for forming the resin mold on a second side of the semiconductor device. The buffer sheet is disposed between the convex part and the chip for covering the exposed area.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Applications No. 2006-218432 filed on Aug. 10, 2006, and No. 2007-47645 filed on Feb. 27, 2007, the contents of which are incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and a method for manufacturing a semiconductor device.

2. Description of the Related Art

Conventionally, a technique for packaging a semiconductor chip on a die pad of a lead frame by resin molding so as to expose the chip to an outside is developed. For example, U.S. Pat. No. 5,622,873 (corresponding to JP Patent No. 3,630,447) discloses a process for manufacturing a solid type image pick-up device. In the process, an image pick-up chip (a semiconductor chip), which is wire-bonded to leads of the lead frame, is packaged by resin molding by using an upper mold having a stepped projection of a size corresponding to a light-receiving region. Thus, a resin mold has a cavity through which the light-receiving part of the image pick-up chip is exposed to the outside.

The above-described manufacturing process can improve productivity compared with a manufacturing process, in which the image pick-up chip is attached to a cavity in a chip-receiving vessel formed by sintering, before the image pick-up chip is wire-bonded to a chip pad. In addition, U.S. Pat. No. 5,622,873 discloses that when the upper mold has a groove at a bottom of the stepped projection, the stepped projection is separated from the light-receiving region of the image pick-up chip. Therefore, the light-receiving region of the image pick-up chip can be prevented from contamination during a process of the resin molding.

However, in a typical image pick-up device, a distance between the light-receiving region and an adjacent pad for wire bonding is set to be about 0.1 to 1 mm. Therefore, at the bottom of the stepped projection, it is difficult to form the groove at a portion corresponding to the light-receiving region by using a mold with a normal accuracy required for a typical resin molding, while arranging a concave part surrounding the groove (i.e., the most projected portion of the stepped projection20awhich is located at both sides of the groove 20′a in FIG. 7 in U.S. Pat. No. 5,622,873) within an area separated from the pad for wire bonding, i.e., within the above-described distance.

Thus, in the manufacturing process disclosed in U.S. Pat. No. 5,622,873, the upper mold having the stepped projection is required to be formed with a high accuracy. However, a cost of the upper mold is generally increased with accuracy, and a production cost of the image pick-up device is increased with an equipment cost. Further, a life of a microfabricated mold tends to be short compared with a mold for the typical resin molding. As a result, an equipment cost and a production cost may increase.

Additionally, in order to position the most projected portion of the stepped projection20awithin the area smaller than 1 mm, the stepped projection is required to be positioned within an accuracy of 10 μm with respect to the image pick-up chip bonded to the lead frame. Thus, the lead frame is required to be positioned with a high accuracy in a horizontal direction, and a carrying system of the lead frame is required to be changed to meet the high accuracy. Therefore, the equipment cost and the production cost may further increase.

As described above, in the manufacturing process disclosed in U.S. Pat. No. 5,622,873, various problems are caused by increasing the accuracy of the mold. It is difficult to prevent the light-receiving region from contamination, i.e., to improve a reliability of the image pick-up device, without increasing the accuracies of the mold and the carrying system. Thus, a yield rate and a mass productivity may be reduced.

SUMMARY OF THE INVENTION

In view of the foregoing problems, it is an object of the present invention to provide an apparatus and a method for manufacturing a semiconductor device for improving a reliability and a mass productivity of a semiconductor chip packaged by resin molding without increasing accuracies required for a mold and a positioning of a lead frame.

According to an aspect of the invention, an apparatus for manufacturing a semiconductor device is provided. The semiconductor device includes a semiconductor chip, a lead frame and a resin mold. The semiconductor chip is disposed on a die pad of the lead frame. The semiconductor chip together with the lead frame is packaged with the resin mold in such a manner that an exposed area of the semiconductor chip is exposed to an outside of the resin mold. The apparatus includes a first mold, a second mold, and a buffer sheet. The first mold has a first cavity for providing a shape of the resin mold on a first side of the semiconductor device, and a convex part for forming the exposed area of the semiconductor chip. The second mold has a second cavity for providing a shape of the resin mold on a second side of the semiconductor device. The buffer sheet is disposed between the convex part and the semiconductor chip for covering the exposed area of the semiconductor chip in order to prevent a resin material of the resin mold from adhering to the exposed area.

The buffer sheet prevents the convex part from directly contacting and contaminating to the exposed area of the semiconductor chip. Therefore, the reliability and the mass productivity of the semiconductor chip packaged by resin molding are improved without increasing the accuracies required for the mold and the positioning of the lead frame.

According to another aspect of the invention, a method for manufacturing a semiconductor device is provided. The semiconductor device includes a semiconductor chip, a lead frame and a resin mold. The semiconductor chip is disposed on a die pad of the lead frame. The semiconductor chip together with the lead frame is packaged with the resin mold in such a manner that an exposed area of the semiconductor chip is exposed to an outside of the resin mold. The method includes a step of setting a first mold on the semiconductor chip, in which the first mold has a first cavity for providing a shape of the resin mold on a first side of the semiconductor device and a convex part for forming the exposed area of the semiconductor chip, a step of arranging a buffer sheet between the convex part and the semiconductor chip for covering the exposed area of the semiconductor chip, and a step of filling a resin material into the first cavity.

The buffer sheet prevents the convex part from directly contacting and contaminating to the exposed area of the semiconductor chip. Therefore, the reliability and the mass productivity of the semiconductor chip packaged by resin molding are improved without increasing the accuracies required for the mold and the positioning of the lead frame.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An apparatus and a method for manufacturing a semiconductor device according to an embodiment of the invention can be applied to a molding apparatus20which packages a semiconductor chip Sc such as a solid-state image sensor by resin molding.

The solid-state image sensor is a photoelectric conversion element which is formed into an integrated circuit by using a manufacturing technique of a semiconductor element. The solid-state image sensor packaged by resin molding is used as an image sensor Dv, e.g., a CCD image sensor and a CMOS image sensor. Thus, the semiconductor chip Sc is packaged so that a light-receiving part Pt is exposed to an outside for receiving a light from the outside.

As shown inFIG. 1, the molding apparatus20is a semiconductor manufacturing apparatus for packaging the semiconductor chip Sc disposed on a die pad Dp of a lead frame Lf by resin molding, and includes an upper mold21, a pressure device22, a lower mold23, a base24, a buffer sheet28, carrying device28, and a suction device40. The semiconductor chip Sc is die-bonded to the die pad Dp, and leads La of the lead frame Lf are connected to wires Wh which are wire-bonded.

The upper mold21is a mold for forming a shape of a resin mold on a side of the surface of the semiconductor chip Sc, i.e., on a side of the light-receiving part Pt. The upper mold21is moved up/down by the pressure device22and a guiding device (not shown).

Inside the upper mold21, an upper cavity21ais formed into a concave shape so that a resin mold Ma, which is an upper half of a resin mold of an image sensor Dv, for instance inFIGS. 9A-9C, is formed thereby. A convex part21b, which protrudes into a trapezoidal pillar shape, is formed at an approximately center portion of the upper cavity21a.

The convex part21bis used for forming a window part Wd of the image sensor Dv. A shape of a convex surface21b1, which is a top of the trapezoidal pillar shape, becomes a shape of the window part Wd. The window part Wd is an opening part for exposing the semiconductor chip Sc to the outside. A height of the convex part21bis set to be lower than a contact surface21fof the upper mold21by a distance DD.

InFIG. 2A, which shows the inside of the upper mold21, the convex surface21b1of the convex part21bis formed into a rectangular shape in which a long side is defined as M and a short side is defined as N. Therefore, the window part Wd formed with the convex part21bbecomes the rectangular shape, and an area Pa. pressed by the convex part21b(hereafter, a pressed area) becomes the rectangular shape. When the buffer sheet28is pressed by the convex part21btoward the semiconductor chip Sc, a wrinkle may be generated. However, when the convex surface21b1is the rectangular shape, the wrinkle can be escaped in a longitudinal direction of the convex part21b. Therefore, when the convex surface21b1is the rectangular shape, the wrinkle of the buffer sheet28is less generated surrounding the convex part21bcompared with a case where the convex surface21b1is a square shape.

As shown inFIG. 1andFIG. 2A, the upper mold21has a plurality of adsorbing holes21h. The adsorbing holes21hare communicating holes for communicating with the outside and the inside of the upper mold21in a direction of a thick. In the embodiment, the adsorbing holes21hcommunicates with an inner space21sof the upper mold21including the convex part21band an inner passage (i.e., an air passage22a) of the pressure device22.

As shown inFIG. 1, the pressure device22is connected to an outside of the upper mold21, i.e., an opposite side of a side on which the upper cavity21ais formed. The pressure device22includes an oil hydraulic cylinder (not shown) for pressing down and pulling up the upper mold21. In the embodiment, the air passage22ais formed in the pressure device22. The air passage22ais connected with each of the adsorbing holes21hand an air pipe42of the suction device40.

The upper mold21further includes a runner21c, through which a resin material (e.g., an epoxy resin) for forming the shape of the resin mold is injected from the outside, and an air hole (not shown) for discharging air in the upper cavity21ato the outside.

Instead of the upper mold21inFIG. 2A, upper molds21inFIGS. 3A-3Cmay be used, for example. As shown inFIG. 3A, the upper mold21includes stepped parts IIIA and IIIB, and other parts. The stepped part IIIA is disposed around a boundary between the upper cavity21aand the contact surface21f. The stepped part IIIB is disposed around a boundary between the convex part21band the upper cavity21a. The adsorbing holes21hin the stepped parts IIIA and IIIB may be more than in the other parts. When a number of the adsorbing holes21hformed in the stepped parts IIIA and IIIB is increased, an adsorbing force in the stepped parts IIIA and IIIB due to a suction by the suction device40is increased.

As shown inFIG. 3B, projected parts21dfor forming attaching slots Dh for a holder Hd may be formed in a predetermined part in the upper cavity21aof the upper mold21. Herewith, the holder Hd, for instance inFIGS. 10A and 10B, can be attached on an upper surface of an image sensor Dva, and a lens Le held by the holder Hd trough a barrel Br is positioned easily and reliably.

Further, a shape of the convex surface21b1of the convex part21bis not limited to be the rectangular shape as described above. For example, as shown inFIG. 3C, a convex part121bhaving a square-shaped convex surface121b1may be formed in the upper mold21instead of the convex part21b. Herewith, the window part Wd formed in the resin mold Ma becomes a square shape. Therefore, the semiconductor chip is exposed to the outside by focusing the minimum area.

The lower mold23is a mold for forming the resin mold of the image sensor Dv on a backside of the semiconductor chip Sc, i.e., on a side of the die pad Dp. The lower mold23is fixed to the base24, and the base24is fixed to a reference surface of the molding apparatus20.

Inside the lower mold23, a lower cavity23afor forming a resin mold Mb, which is a lower half of the image sensor Dv, for instance shown inFIGS. 9A-9C, is formed. A die mount23b, which is formed into an approximately cone shape, is formed in an approximately center portion of the lower cavity23a.

The die mount23bis used for supporting the die pad Dp from a lower side thereof. The semiconductor chip Sc is disposed on the die pad Dp. Therefore, when the semiconductor chip Sc is pressed by the convex part21bof the upper mold21, the semiconductor chip Sc is not pressed out on a side of the lower cavity23. A height of the die mount23bis set to be even to a contact surface23fof the lower mold23. The lower mold23also includes an air hole (not shown) for discharging air in the lower cavity23ato the outside.

The buffer sheet28is a film sheet formed into a belt shape made of a synthetic resin such as a Teflon-based synthetic resin (Teflon is a registered trademark). A width and a length of the buffer sheet28is set so that when the resin material for forming the resin mold Ma is filled in the convex part21bof the upper mold21, the buffer shape28covers the whole area of the light-receiving part Pt (exposed area Ea) of the semiconductor chip Sc, by lying between the convex part21band the light-receiving part Pt. When the buffer sheet28is made of the Teflon-based synthetic resin, the thickness of the buffer sheet28is set to be approximately 10 to 100 μm. However, the thickness of the buffer sheet28is set based on a material, so that the buffer sheet28is not torn by a pressure of the convex part21b, and easily adsorbs to an inner surface of the upper mold21.

When the lead frame Lf is carried in a longitudinal direction (Xa) of the lead La of the lead frame Lf, i.e., a direction in which the leads La extends, the buffer sheet28is arranged to move in the longitudinal direction (Xa) of the lead La, as shown inFIGS. 4A-4D. The width of the buffer sheet28, i.e., the width in a direction perpendicular to the longitudinal direction (Xa) of the lead La is set to be a value which is not less than a width tw1. As shown inFIG. 4A, when a buffer sheet28awith the width of tw1is used, the buffer sheet28acovers at least the light-receiving part Pt (exposed area Ea) of the semiconductor chip Sc disposed on the die pad Dp. Therefore, the buffer sheet28aprevents the convex part21bof the upper mold21from directly contacting the light-receiving part Pt. Further, the buffer sheet28ais the belt shape, so the buffer sheet28acovers over the width of the light-receiving part Pt in the longitudinal direction (Xa).

When the width of the buffer sheet28can be set to be greater than the width tw1, a buffer sheet28bwith a width of tw2, which covers the whole surface of the semiconductor chip Sc, may be used as shown inFIG. 4B. Herewith, the buffer sheet28bcovers not only the light-receiving part Pt but also the whole semiconductor chip Sc. Because the width of the buffer sheet28bis set to be the width tw2which is greater than the width tw1, even if the buffer sheet28bslides in the direction perpendicular to the longitudinal direction (Xa) of the lead La, the buffer sheet28bis positioned easily.

Further, when the width of the buffer sheet28can be set to be greater than the width tw2, a buffer sheet28cwith a width of tw3, which covers the whole surface of the die pad Dp and the area Pa pressed by the convex part21b, may be used as shown inFIG. 4C. Herewith, the buffer sheet28cprevents the convex part21bfrom directly contacting the semiconductor chip Sc. Because the buffer sheet28chas a dimensional allowance in the direction perpendicular to the longitudinal direction (Xa) of the lead La, the buffer sheet28cis positioned more easily. When the buffer sheet28cis positioned in a carrying device30, a required accuracy in a direction of the width is reduced. Therefore, the setting up of the carrying device30becomes easy.

When the width of the buffer sheet28can be set to be greater than the width tw3, the buffer sheet28dwith a width of tw4, which covers the whole surface of the lead frame Lf, may be used as shown inFIG. 4D. Because the buffer sheet28dhas a dimensional allowance in the direction perpendicular to the longitudinal direction (Xa) of the lead La, the buffer sheet28dis positioned more easily. When the buffer sheet28dis disposed in a carrying device30, an accurate-positioning is rarely required in the direction of the width. Therefore, the setting up of the carrying device30becomes easy.

As shown inFIGS. 5A and 5B, typically, a plurality of lead frames Lf are arranged in a line or a plurality of lines, and form a tape-shaped lead frame collectivity LFC. In this case, the belt-shaped buffer sheet28is carried along a direction of the line in which the lead frames Lf are arranged (hereafter, linearly-arranged direction (Xb)).

When the lead frames Lf are arranged in a line as shown inFIG. 5A, for instance, the buffer sheet28d, which covers the whole lead frame Lf, may be used without positioning in the linearly-arranged direction (Xb) and a direction approximately perpendicular to the linearly-arranged direction (Xb). Therefore, the arrangement of the currying device30becomes easy compared with a case where the positioning in each or both of the directions is required.

When the lead frames Lf are arranged in two lines as shown inFIG. 5B, for instance, the buffer sheet28f, which covers two lines of lead frame Lf, may be used without positioning in the linearly-arranged direction (Xb) and the direction approximately perpendicular to the linearly-arranged direction (Xb). Therefore, the arrangement of the currying device30becomes easy compared with a case where the positioning in each or both of the directions is required.

In the above-described example, the belt-shaped buffer sheet28(28a,28b,28c,28dand28f) is disposed in the longitudinal direction (Xa) of lead La. However, the buffer sheet28may be disposed in the direction (Xc) approximately perpendicular to the longitudinal direction (Xa) of lead La.

For example, the buffer sheet28awith the width of tw1, which covers at least the light-receiving part Pt, is carried in the direction (Xc) approximately perpendicular to the longitudinal direction (Xa) of the lead La. Herewith, the buffer sheet28aprevents the convex part21bof the upper mold21from directly contacting the light-receiving part Pt.

Alternatively, a buffer sheet28ewith a width of tw5, which is greater than the width tw1and approximately same width with a short side of the pressured area Pa by the convex part21b, may be used. The buffer sheet28ecovers not only the light-receiving part Pt but also approximately whole surface of the pressured area Pa without a relation to the length of the long side of the pressured area Pa. Therefore, the buffer sheet28eis used efficiently.

Further, as shown inFIG. 6C, the buffer sheet28b, which covers the whole surface of the semiconductor chip Sc, may be used. Because the width of the buffer sheet28bis set to be the width tw2which is greater than the width tw1, even if the buffer sheet28bslides in the longitudinal direction (Xa) of the lead La, the buffer sheet28bis positioned easily.

Alternatively, as shown inFIG. 6D, the buffer sheet28d, which covers the whole surface of the lead frame Lf in the direction (Xc) approximately perpendicular to the longitudinal direction (Xa) of the lead La, may be used. Because the buffer sheet28dwith the width of tw4has the dimensional allowance in the longitudinal direction (Xa) of the lead La, the buffer sheet28dcovers the light-receiving part Pt without positioning accurately, i.e., with positioning roughly.

When the buffer sheet28is carried in the direction (Xc) approximately perpendicular to the longitudinal direction (Xa) of the lead La, the buffer sheet28is positioned in the direction (Xc) approximately perpendicular to the direction in which the lead frame Lf is carried. Therefore, the lead frame Lf is positioned with respect to the carrying device of the lead frame Lf. In other words, the resin material is required to be filled in the upper cavity21aof the upper mold21and the lower cavity23aof the lower mold23, when the lead frame Lf is positioned below the buffer sheet28.

Next, the carrying device30and the suction device40will be described with reference toFIG. 1. The carrying device30includes a delivering unit31and a rewinding unit33. The carrying device30is used for carrying the buffer sheet28. In the embodiment, the delivering unit31delivers the winding buffer sheet28to the semiconductor chip Sc on the lead frame Lf located between the upper mold21and the lower mold23, and rewinding unit33rewinds a used buffer sheet28uwhich has passed on the semiconductor chip Sc.

The delivering unit31and the rewinding unit33are controlled coincidently with a vertical movement of the upper mold21so that the used buffer sheet28u, which is generated by finishing the resin molding with the upper mold21and the lower mold23, is changed with the buffer sheet28before use. Therefore, the buffer sheet28is delivered automatically.

As described above, the buffer sheet28is required to be positioned with respect to the light-receiving part Pt of the semiconductor chip Sc in the direction of the width of the buffer sheet28. Therefore, the delivering unit31and the rewinding unit33are formed so that the buffer sheet28is positioned by setting up the carrying device30.

The suction device40is a suction pump for sucking gas such as air, and is communication with the air passage22aof the pressure device22through the air pipe42connected with the suction holes (not shown). When the suction device40is operated, the suction device40sucks an object in the inner space21sof the upper mold21through the pressure device22and air passage22a. Therefore, when the buffer sheet28is disposed in the inner surface21s, the buffer sheet28is adsorbed to the inner wall of the upper mold21. The suction device40is formed not only for sucking but also for discharging a pressured air from the suction holes.

The semiconductor chip Sc which is die-bonded to the lead frame Lf is set to the mold equipment20, and is packaged with the resin material by processes, for instance inFIGS. 7A-7Cand8A-8C, for forming the image sensor Dv in FIG.8D. Following the above-described setting up process, in which the lead frame Lf and the buffer sheet28are set in a predetermined position and a predetermined direction as shown inFIGS. 4A-6D, a lead frame setting process is performed.

As shown inFIG. 7A, in the lead frame setting process, the lead frame Lf having the semiconductor chip Sc bonded to the die pad Dp is set on the die mount23of the lower mold23. Then, the buffer sheet28is disposed between the semiconductor chip Sc of the lead frame Lf and the convex part21bof the upper mold21. The width and position of the buffer sheet28is as described above. In this case, the semiconductor chips Sc are disposed on the lead frame collectivity LFC in which the plurality of lead frames Lf are arranged in a line as shown inFIG. 5A. Therefore, the buffer sheet28dwith the width of tw4, which covers the whole surface of the lead frame Lf, is used.

After the lead frame setting process inFIG. 7A, a buffer sheet adsorbing process inFIG. 7Bis performed. In the embodiment, the buffer sheet28ddisposed between the semiconductor chip Sc and the convex part21bof the upper mold21is adsorbed to the inner wall of the upper mold21by operating the suction device40through the adsorbing holes21hof the upper mold21. Therefore, the buffer sheet28dbetween the convex part21band the semiconductor chip Sc is exactly adsorbed to the convex part21band the upper cavity21aof the upper mold21.

After the buffer sheet adsorbing process inFIG. 7B, a pressing process inFIG. 7Cis performed. The lead frame collectivity LFC disposed between the upper mold21and the lower mold23is pressed by the both molds21and23. The both molds21and23form the upper cavity21aand the lower cavity23ain which the resin material is injected. The buffer sheet28dis disposed between the upper mold21and the lower mold23as well as between the convex part21band the light-receiving part Pt of the semiconductor chip Sc.

In the center portion of the both molds21and23, the semiconductor chip Sc on the die pad Dp is pressed by the convex part21bof the upper mold21and the die mount23bof the lower mold. The buffer sheet28disposed between the convex part21band the light-receiving part Pt of the semiconductor chip Sc prevents the convex part21bfrom directly contacting and contaminating to the light-receiving part Pt.

The convex part21bfunctions as a mold holder by pressing. Thus, when the upper cavity21bis filled with the resin material in a resin injecting process, a portion in which the convex part21bis occupied is prevented from filling with the resin material. As a result, the window part Wd is firmed on the light-receiving part Pt of the semiconductor chip Sc.

A pressure by the upper mold21is set so that the resin material filling into the upper cavity21aand the lower cavity23ais prevented from leaking out of the both molds21and23, and that the light-receiving part Pt pressed by the convex part21bis prevented from being damaged by the pressure.

In the resin material injecting process inFIG. 8A, the resin material is injected into the upper cavity21aand the lower cavity23athrough the runner21cof the upper mold21. Because the air in the upper cavity21aand the lower cavity23ais discharged form the air holes (not shown) formed in the upper mold21and the lower mold23, the resin material is injected easily.

After the resin material injecting process inFIG. 8A, a mold stripping process inFIG. 8Bis performed. The semiconductor chip Sc and the lead frame Lf, which are packaged by the harden resin mold, is removed from the upper mold21and the lower mold23.

At this time, the suction device40which has been sucking in the upper cavity21ais stopped or changed to discharge. Thus, an adsorptivity which adsorbs the buffer sheet28dto the inner wall of the upper mold21through the adsorbing holes21his reduced rapidly. Further, a discharging force working to a direction, in which the buffer sheet28dis taken from the inner wall of the upper mold21, is generated by air pressure discharged from the adsorbing holes21h. Therefore, the buffer sheet28dand the resin mold Ma is easily removed from the upper mold21.

The buffer sheet28dremoved with the resin mold Ma from the upper mold21becomes the used buffer sheet28u. Thus, the new buffer sheet28before use, for changing with the used buffer sheet28u, is carried by the carrying device30, and is prepared for the lead frame setting process, in which the semiconductor chip Sc of the next lead frame Lf is packaged by resin molding.

The resin molds Ma and Mb removed from the upper mold21and the lower mold23are connected to the lead frame through a diver as shown inFIG. 8C. Therefore, in a diver cutting process, an unnecessary resin mold portion Mc formed by the runner21cand an unnecessary portion of the lead La are cut and removed. Then, the lead La is formed into a predetermined shape in a forming process.

In this way, the image sensor Dv, which includes a resin mold Ma having the window part Wd for exposing the light-receiving part Pt of the semiconductor chip Sc to the outside, is formed as shown inFIG. 8D. The image sensor Dv inFIG. 8Dis a SOP (Small Outline Package) type, and its external appearance is shown inFIGS. 9A-9C. The above-described processes also may be used for a SOJ (Small Outline J-leaded) typed image sensors Dv and a DIP (Dual In-line Package) typed image sensors Dv, for example.

In the image sensor Dva, the barrel Br for holding the lens Le is attached to the window part Wd of the resin mold Ma through the holder Hd. For forming the image sensor Dva, the projected parts21dfor forming the attaching slots Dh corresponding to each of the posts Po of the holder Hd are formed in the predetermined part in the upper cavity21a of the upper mold21. Herewith, in a process after the forming process, when the holder Hd is attached to the resin mold Ma, a positioning of the Hd, i.e., a positioning of the lens Le held by the barrel Br is easily and reliably performed. The positioning of the lens Le, for example, a positioning in which a Z axis of the lens Le is corresponded with a center Ct of the light-receiving part Pt as shown inFIGS. 10A and 10Bis performed easily and reliably.

In an image sensor Dvb inFIGS. 11A and 11B, the window part Wd of the resin mold Ma is covered with a transparent cover Cv. For forming the image sensor Dvb, in a process after the forming process, the transparent cover Cv is attached to the resin mold Ma with an adhesive and the like. The transparent cover Cv prevents a foreign material such as a dust from entering in the window part Wd from the outside and adhering to the light-receiving part Pt. Therefore, the light-receiving part Pt is prevented from the contamination.

As described above, in the molding apparatus20of the embodiment, when the resin material for forming the resin mold Ma is filled into the upper cavity21aof the upper mold21, the light-receiving part Pt of the semiconductor chip Sc is covered by the buffer sheet28provided between the convex part21band the semiconductor chip Sc.

Because the convex part21bis separated from the light-receiving part Pt, the convex part21bis prevented from contaminating the light-receiving part Pt. Therefore, the reliability of the semiconductor chip and the yield rate of the semiconductor chip Sc is improved. Thus, the reliability and the mass productivity of the semiconductor chip Sc packaged by resin molding are improved without increasing the accuracy of forming the upper mold21and the accuracy of the positioning of the lead frame Lf.

The delivering unit31deliveries the belt-shaped buffer sheet28on the semiconductor chip Sc, and the rewinding unit32rewinds the used buffer sheet28uwhich passed on the semiconductor chip Sc. In this way, the buffer sheet28is carried automatically, and the used buffer sheet28uis easily changed to the buffer sheet28before use. Therefore, the mass productivity is further improved.

Further, when the buffer sheet28is carried along the direction approximately perpendicular to the linearly-arranged direction (Xb) of the lead frames Lf, the buffer sheet28covers each of the light-receiving part Pt of the semiconductor chip Sc disposed on the die pad Dp of a portion of the lead frames Lf which passes between the upper mold21and the lower mold23. Therefore, the buffer sheet28is not required to be positioned in the direction approximately perpendicular to the linearly-arranged direction (Xb) of the lead frames Lf. Therefore, the setting of the buffer sheet28is easy.

When the buffer sheet28dor28fis used, the buffer sheet28dor28fcovers the whole surface of a portion of the lead frames Lf which passes between the upper mold21and the lower mold23. Therefore, the buffer sheet28dor28fis not required to be positioned in both the linearly-arranged direction (Xb) of the lead frames Lf and the direction approximately perpendicular to the linearly-arranged direction (Xb) of the lead frames Lf. Therefore, the setting of the buffer sheet28dor28fis easy compared with a case where the positioning is required.

The convex surface21b1of the convex part21bis formed into the rectangular shape so that the window part Wd becomes the rectangular shape. When the buffer sheet28is pressed by the convex part21bto the semiconductor chip Sc, the wrinkle may be generated in the buffer sheet28. However, when the convex surface21b1is the rectangular shape, the wrinkle can be escaped in the direction of the long side of the rectangular shape, and the wrinkle is reduced compared with a case where the convex surface21b1is a square shape. Therefore, defective molding of the window part Wd (e.g., burr and deformation) caused by the wrinkle is reduced. As a result, the mass productivity is improved.

The upper mold21has the plurality of the adsorbing holes21hwhich are communication with the inner space21sincluding upper cavity21a. The adsorbing holes21hare connected with the suction device40. The buffer sheet28provided between the convex part21band the semiconductor chip Sc is adsorbed to the inner wall of the upper mold21by the suction device40through the adsorbing holes21h, before the resin material is filled into the upper cavity21a. Because the buffer sheet28is stuck along the inner wall, the defective molding of the resin mold Ma which may be caused by the buffer sheet28provided between the resin material and the inner wall is reduced. Therefore, the mass productivity is improved. Further, because the buffer sheet28is stuck to the inner wall due to the adsorbing of the suction device40, the buffer sheet28is easily taken off from the inner wall by stopping the suction by the suction device40. Therefore, the buffer sheet28is easily taken off from the upper mold21compared with when the buffer sheet28is stuck with an adhesive.

When the adsorbing holes21hin the stepped parts IIIA and IIIB are more than in other parts, the adsorptive property is improved in the stepped parts IIIA and IIIB, in which the buffer sheet28is especially difficult to be stuck. Therefore, the buffer sheet28is stuck even in the stepped part IIIB corresponding to a surrounding of the convex part21b, and the defective molding of the window part Wd of the resin mold Ma is reduced. As a result, the mass productivity is improved.

The lower mold23has the die mount23bfor supporting the die pad Dp of the lead flame Lf. Even if the die pad Dp is connected to the lead frame Lf with a flexible member, when the convex part21bpresses the die pad Dp, the die mount23bsupports the die pad Dp from an opposite side. Thus, the die mount23bprevents the semiconductor chip Sc disposed on the die pad Dp from being pushed to a side of the lower cavity23aof the lower mold23. Therefore, the semiconductor chip Sc is packaged by resin molding appropriately, and the yield rate is improved. As a result, the mass productivity is improved.

Next, a modification of the above-described upper mold21of the mold apparatus20will be described with reference toFIGS. 12A and 12B. An upper mold51has a movable mold53corresponding to the convex part21bof the upper mold21. The movable mold53is provided for forming the window part Wd in the resin mold Ma. The movable mold53is movable separately from the upper mold51, and closes to and leaves from the semiconductor chip Sc. Other parts of the upper mold51are similar to those of the upper mold21.

As shown inFIG. 12A, the upper mold51has an upper cavity51afor providing an inner space51s, and a sliding hole51bformed in an approximately center portion of the upper cavity51aso that the movable mold53is slidable therein up and down. The upper mold51further includes a runner51cand the adsorbing holes51h, similar to the upper mold21.

The movable mold53is formed into a trapezoidal pillar shape, and has a convex part53aat a pointed end thereof. The movable mold53is slidable in the sliding hole51bin an axial direction. The movable mold53is pressed by a pressure device55, which is provided apart from the pressure device22for pressing the upper mold51. A pressure sensor56detects a pressure by the movable mold53as shown by an arrow XIIA, and feeds back a data of the pressure to the pressure device55so that the pressure device55controls the pressure to the movable mold53.

The pressure of the movable mold53is controlled separately from the pressure of the upper mold51. As shown inFIG. 12B, the movable mold53can be pressed with a lower pressure (small arrow XIIB) than the pressure (big arrows XIIC) of the upper mold51. Therefore, when the light-receiving part Pt of the semiconductor chip Sc is damageable by pressing, the light-receiving part Pt is prevented from damaging by using the movable mold53as a mold holder. As a result, the mass productivity is improved.

As shown inFIGS. 13 and 14, lead frames LfE include supporters Sb having holes Hr. The parts of the lead frames LfE, which are substantially similar to those of the lead frames Lf inFIGS. 4A-6D, have same reference marks as those of lead frame Lf, and a description of the parts is abbreviated.

The lead frame LfE has the supporter Sb and a frame portion. The supporter Sb is connected to the frame portion of the lead frame at one end, and is connected to the die pad Db at another end. The die pad Db is supported by the frame portion through the supporter Sb. The hole Hr is formed in the supporter Sb to be exposed to the outside from the resin molds Ma and Mb formed by the molding apparatus20.

The supporter Sb is longer and broader than those of the lead frames Lf inFIGS. 4A-4D. The hole Hr is formed on one end side (opposite end side to which the die pad Dp is connected) of the lead frame LfE. The portions, in which the hole Hr is formed, is set to be exposed to the outside from the resin molds Ma and Mb. For example the portion may be located outside of the lead La which is located at the most outside, and the portion is set to have a length and a width in which the hole Hr can be formed.

InFIG. 13, the lead frames LfE are arranged in a line to form a lead frame collectivity LFCE similarly to the lead frame collectivity LFC inFIG. 5A. InFIG. 14, the lead frames LfE are arranged in two lines to form the lead frame collectivity LFCE similarly to the lead frame collectivity LFC inFIG. 5B. However, the lead frame collectivity LFCE inFIG. 14is substantially similar to the lead frame collectivity LFC inFIG. 13except for a number of lines.

The above-described molding apparatus20processes the lead frame LfE under the lead frame setting process (FIG. 7A), the buffer sheet adsorbing process (FIG. 7B), the pressing process (FIG. 7C), the resin material injecting process (FIG. 8A), and the mold stripping process (FIG. 8B). Then, the packaged lead frame LfE is performs the diver cutting process (FIG. 8C) and the forming process. As a result, as shown inFIGS. 15A and 15B, the image sensor DvE, in which one end sides of the supporters Sb are exposed to the outside of the resin molds Ma and Mb, is formed.

The image sensor DvE inFIGS. 15A and 15Bhas the supporters Sb being broader and longer than those of the image sensor Dv inFIGS. 9A-9C. Because the supporter Sb in the image sensor DvE extends to a side of the frame portion, one end of the supporter Sb on the side of the frame portion protrudes to the outside of the resin molds Ma and Mb. In a protruding side of the supporter Sb, the hole Hr is formed to be exposed to the outside.

As shown inFIG. 15C, when the barrel Br for holding the lens Le is attached to the window part Wd of the resin mold Ma with the holder Hd, each of the posts Po of the holder Hd is positioned to each of the holes Hr, so that a Z axis of the lens Le corresponds with the center Ct of the light-receiving part Pt which is shown inFIG. 15A. In other words, when the holder Hd is attached to the image sensor DvE which is packaged with the resin molds Ma and Mb by the molding apparatus20, the holder Hd is easily positioned by using the holes Hr as positioning holes. Therefore, an attaching speed of the holder Hd is improved.

Alternatively, an image sensor DvEa inFIGS. 16A and 16Ehas the supporters Sb which are shorter than those of the image sensor DvE inFIGS. 15A and 15B. However, the resin molds Ma and Mb have incision parts so that the hole Hr in the supporter Sb on the side of the frame portion is exposed to the outside of the resin molds Ma and Mb. The incision may be formed by convex parts (not shown) formed in the upper mold21and the lower mold23.

Herewith, as shown inFIG. 16C, in the image sensor DvEa, the hole Hr in the supporter Sb on the side of the frame portion is exposed to the outside. Therefore, the hole Hr functions as the positioning hole of the post Po of the holder Hd, so that a Z axis of the lens Le corresponds with the center Ct of the light-receiving part Pt which is shown inFIG. 16A. Thus, when the holder Hd is attached to the image sensor DvEa, the holder Hd is positioned easily and reliably. Therefore, the attaching speed of the holder Hd is improved.

Alternatively, an image sensor DvEb inFIG. 17AandFIG. 17Bhas the supporters Sb which are longer than those of the image sensor DvE inFIGS. 15A and 15B. In the image sensor DvEb, the supporter Sb is formed into L-shape, and the hole Hr is formed compactly in the supporter Sb on the side of the frame portion. The supporter Sb may be formed into the L-shape in the forming process of the leads La, similarly to the leads La.

Herewith, as shown inFIG. 17C, in the image sensor DvEb, the hole Hr in the supporter Sb on the side of the frame portion is exposed to the outside. Therefore, the hole Hr functions as the positioning hole of the post Po of the holder Hd, so that a Z axis of the lens Le corresponds with the center Ct of the light-receiving part Pt which is shown inFIG. 17A, similarly to those in the image sensors DvE and DvEa. Thus, when the holder Hd is attached to the image sensor DvEb, the holder Hd is positioned easily and reliably. Therefore, the attaching speed of the holder Hd is improved.