JP6106108B2 - Lead frame shape inspection apparatus and lead frame distance measuring method - Google Patents

Description

  Embodiments described herein relate generally to a lead frame shape inspection device and a distance measurement method between lead frames.

  There is a semiconductor device in which two lead frames are combined. For example, the optical coupling device has a structure in which a lead frame to which a light emitting element is bonded and a lead frame to which a light receiving element is bonded are joined in a state of facing each other.

  If the distance between the light emitting element and the light receiving element facing each other changes, the characteristics of the optical coupling device change.

  If a large number of lead frames are taken, the productivity of the optical coupling device can be increased. However, if the variation in the distance between the light emitting element and the light receiving element in the lead frame is large, the change in the characteristics of the optical coupling device becomes large.

  When all the optical coupling devices separated from the lead frame are individually inspected, it becomes possible to select non-defective products, but the productivity is lowered.

JP-A-8-201038

  Provided are a lead frame shape inspection device and a lead frame distance method capable of inspecting the shapes of lead frames joined so as to face each other.

In the lead frame shape inspection apparatus according to the embodiment, the optical coupling structure portion in which the light emitting element bonded to the first lead frame and the light receiving element bonded to the second lead frame face each other extends in the first direction. Lead frame joints arranged in an array with a second pitch along an outer frame portion extending along a second direction perpendicular to the first direction and having a first pitch along the frame portion Including the body. The lead frame shape inspection apparatus includes a light source unit capable of emitting visible light in a third direction perpendicular to the first direction and the second direction, and a first surface parallel to the first direction and the second direction. The lead frame feeding mechanism includes a lead frame feeding mechanism, and when the lead frame joined body is placed on the first surface, the lead frame feeding mechanism moves the lead frame joined body to the second transport section. A first transfer unit that is movable in each of the direction and the third direction, and a first mirror that folds the visible light emitted from the light source unit in the second direction and irradiates the light coupling structure unit And a second mirror part that bends the visible light transmitted through the optical coupling structure part in the third direction, and is separated from the first mirror part by the second pitch in the second direction. Arranged, second And an image pickup unit provided on a side opposite to the light source unit with respect to the lead frame feeding mechanism, wherein the optical coupling structure unit is configured to be the first mirror unit and the second mirror by the lead frame feeding mechanism. while it is transported to a position sandwiched between the parts, and receiving the visible light transmitted through the light coupling structure, that having a, an imaging unit that captures a transmission image of the light coupling structure.

It is a lineblock diagram of the lead frame shape inspection device concerning a 1st embodiment. 2A is a schematic plan view of the first lead frame constituting the lead frame assembly, FIG. 2B is a schematic plan view of the unit region U, and FIG. 2C is a schematic view along the line AA. FIG. 3A is a schematic plan view of a second lead frame constituting the lead frame assembly, FIG. 3B is a schematic plan view of the unit region U, and FIG. 3C is a schematic view taken along the line BB. FIG. FIG. 4A is a schematic plan view for explaining a distance measurement method between lead frames using the lead frame shape inspection apparatus according to the first embodiment, and FIG. 4B is a schematic cross-sectional view taken along the line CC. It is. FIG. 5A is a schematic front view of the lead frame assembly, and FIG. 5B is a perspective image obtained by the lead frame shape inspection apparatus according to the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a lead frame shape inspection apparatus according to the first embodiment.
In the lead frame shape inspection apparatus, the light emitting element 80 bonded to the first lead frame 12 and the light receiving element 82 bonded to the second lead frame 14 form a pair facing each other, and the horizontal direction in the horizontal plane and the horizontal direction in the horizontal plane The lead frame assembly 10 is two-dimensionally arranged.

  The lead frame shape inspection apparatus includes a light source unit 40, a first mirror unit 30, a second mirror unit 32, an imaging unit 50, a first transport unit 90, and a second transport unit 92.

  The light source unit 40 can emit visible light VL1 and can include, for example, a backlight light emitting device. The backlight light emitting device guides light emitted from light emitting elements such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes), wavelength-converted light, or mixed light thereof by a light guide plate or scatters it by a diffusion plate. Etc. to emit visible light (including white light).

  The first mirror unit 30 bends the visible light VL1 toward the lead frame assembly 10. Further, the second mirror unit 32 bends the visible light VL1 transmitted through the lead frame assembly 10 toward the imaging unit 50. The first mirror unit 30 and the second mirror unit 32 may be a highly reflective film made of a dielectric multilayer film or the like. Further, the shape can be a flat plate shape or a prism shape.

  The imaging unit 50 receives the visible light VL <b> 2 bent by the second mirror unit 32. The imaging unit 50 can be, for example, a CCD camera. If the first mirror part 30 and the second mirror part 32 are formed in a prism shape, the bending angle is set to 90 degrees, and the optical system can be easily reduced in size. If the imaging unit 50 is disposed on the stage 70, for example, it can be driven in the XY plane.

  The first transport unit 90 can move the lead frame assembly 10 in the XZ plane. Between the first mirror part 30 and the second mirror part 32, an optical coupling structure part, which is provided in the lead frame joined body 10 and is composed of a light emitting element / light receiving element pair, is inserted. Further, the first transport unit 90 can pitch-feed the lead frame assembly 10 in the X direction.

  The lead frame shape inspection apparatus can further include an image processing unit 60 that can perform image processing on the transmission image information IM imaged by the imaging unit 50.

  In addition, the lead frame shape inspection apparatus can further include a second transport unit 92 capable of pitch-feeding the imaging unit 50 in the Y direction of the lead frame joined body 10. In this way, the step of pitch-feeding the lead frame assembly 10 in the Y direction can be omitted, and the processing time can be shortened.

  The first transport unit 90 and the second transport unit 92 can have a lead frame feed mechanism including a motor and the like.

2A is a schematic plan view of the first lead frame constituting the lead frame assembly, FIG. 2B is a schematic plan view of the unit region U, and FIG. 2C is a schematic view along the line AA. FIG.
The first lead frame 12 is provided with a die pad portion 12a, a lead portion 12b, an inner frame portion 12c, and an outer frame portion 12d. A light emitting element 80 such as an LED is bonded to the die pad portion 12a.

  One first lead frame 12 includes, for example, unit areas U such as 10 columns in the X (vertical) direction and 10 rows in the Y (horizontal) direction, and the number of units can be set to 100 or the like. Further, as shown in FIG. 2C, the lead portion 12b connected to the die pad portion 12a is bent upward to provide a gap portion with the light receiving element.

3A is a schematic plan view of a second lead frame constituting the lead frame assembly, FIG. 3B is a schematic plan view of the unit region U, and FIG. 3C is a schematic view taken along the line BB. FIG.
The second lead frame 14 is provided with a die pad portion 14a, a lead portion 14b, an inner frame portion 14c, and an outer frame portion 14d. A light receiving element 82 such as a photodiode is bonded to the die pad portion 14a.

  One second lead frame 14 includes, for example, unit regions U such as 10 columns in the X direction and 10 rows in the Y direction, and the number of units can be set to 100 or the like. Further, as shown in FIG. 3C, the die pad portion 14a is bent downward to provide a gap portion between the light emitting element.

  The light emitting element 80 (light emission center Ot) bonded to the die pad portion 12a of the first lead frame 12 and the light receiving element 82 (light reception center Or) bonded to the die pad portion 14a of the second lead frame 14 face each other. Thus, the first lead frame 12 and the second lead frame 14 are overlapped so that the light emission center Ot and the light reception center Or coincide with each other when viewed from above. Therefore, a vertical gap portion 16 is generated between the die pad portion 12 a of the first lead frame 12 and the die pad portion 14 a of the second lead frame 14. In addition, when the through holes 12e and 14e are provided, it becomes easy to store them in a magazine or the like.

FIG. 4A is a schematic plan view for explaining a distance measurement method between lead frames using the lead frame shape inspection apparatus according to the first embodiment, and FIG. 4B is a schematic cross-sectional view taken along the line CC. It is.
The lead frame assembly 10 is configured to form an optical coupling structure including a pair in which a light emitting element 80 bonded to the first lead frame 12 and a light receiving element 82 bonded to the second lead frame 14 face each other. The first lead frame 12 and the second lead frame 14 are formed by metal bonding or the like. For metal joining, YAG laser welding, resistance welding, silver brazing, or the like is used to join the outer frame portions 12d and 14d of the two lead frames.

  In this way, the horizontal plane gap portion 18 can be provided between the inner frame portions 10 c of the lead frame joined body 10. A vertical gap 16 is formed between the upper and lower lead frames so that a pair in which the light emitting element 80 and the light receiving element 82 face each other is formed between the two gaps 18 in the horizontal plane.

  First, the lead frame assembly 10 is pitch (Px) fed in the X direction, and the first mirror unit 30, the second mirror unit 32, and the two horizontal plane gaps 18 of the lead frame assembly 10 in the X direction, Are inserted respectively. Since the chip size of the light emitting element 80 can be reduced to, for example, 300 μm × 300 μm, the spread angle of the visible light VL1 may be small.

  For this reason, the size of the first mirror part 30 and the second mirror part 32 can be reduced to, for example, 2 mm on one side of the prism and 50 mm along the Y direction, and the size of the lead frame assembly 10 can be reduced. .

  When the lead frame joined body 10 is sent in the pitch (Px) in the X direction, the lead frame joined body 10 is first moved up and down (M1) by the first transport unit 90 and then horizontally moved along the X direction ( (M2 = Px), and then return to the original vertical position (M3).

  When the lead frame joined body 10 is pitched (Py) fed in the Y direction, the imaging unit 50 disposed on the stage 70 or the like is moved by the second transport unit 92 without moving the lead frame joined body 10. Can do. The lengths of the first mirror part 30, the second mirror part 32, and the light source part 40 in the Y direction are adjusted to the length of the lead frame joined body 10 in the Y direction, whereby the lead frame joined body 10 is pitched in the Y direction. The process of sending can be omitted, and the processing time can be shortened.

  The visible light VL1 bent by the first mirror part 30 is irradiated toward the lead frame joined body 10, and the visible light VL2 transmitted through the lead frame joined body 10 is folded toward the imaging part 50 by the second mirror part 32. The distance TF between the first lead frame 12 and the second lead frame 14 is measured for the pair from the transmission image information IM 1 imaged by the imaging unit 50. Note that the transmission image from the imaging unit 50 is subjected to image processing by the image processing unit 60, whereby the lead frame distance TF can be measured in a short time, and it can be automatically determined that it is out of specification.

  From the transmission image information IM by the lead frame shape inspection apparatus of the first embodiment, it is possible to inspect the deformation of the wire shape, the shape of the resin layer, the presence or absence of foreign matter, and the like. For this reason, the quality of an optical coupling device can be improved.

FIG. 5A is a schematic front view of the joined lead frame, and FIG. 5B is a transmission image by the lead frame shape inspection apparatus according to the present embodiment.
The distance TF between the lead frames in the lead frame assembly 10 in the schematic front view shown in FIG. 5A can be the outer dimension of the first lead frame 12 and the second lead frame 14, for example. The transmission image shown in FIG. 5B substantially corresponds to the front view shown in FIG. The distance TF between the lead frames of the lead frame assembly 10 can be measured within a measurement error of 5 μm, for example, by image processing.

  In the optical coupling device (including an optical coupling type insulating circuit, a photocoupler, a photorelay, etc.) where the light emitting element 80 and the light receiving element 82 face each other, when the inter-lead frame distance TF is larger than the required range, The distance from the light receiving element 82 is increased. For this reason, the light receiving region is widened (the optical path is lengthened), and the switching time is lengthened. If 100% inspection is not performed, an optical coupling device in which the inter-lead frame distance TF varies and the switching response characteristic is out of specification is included. It is difficult to remove these nonstandard products by sampling inspection. For this reason, it is necessary to add a step of individually inspecting the lead frame assembly 10 after molding it by molding and separating it into individual devices.

  In the lead frame shape inspection apparatus of the present embodiment, it is possible to automatically inspect all the lead frame distances TF of the lead frame assembly 10 before performing the molding process using the mold. For this reason, it can be determined that it is out of specification in the lead frame state, and it is possible to prevent the out of specification product from flowing out.

  The lead frame shape inspection apparatus of this embodiment images the shape of the lead frame assembly. For this reason, it is easy to determine the shape defect by the fluoroscopic image information IM. Further, by having the image processing unit, it is possible to automatically determine the shape defect in a short time. As a result, for example, it becomes easy to improve the quality of the optical semiconductor device including the optical coupling device. Moreover, according to the distance measurement method between lead frames of this embodiment, the distance between lead frames of the optical coupling device can be measured with high accuracy. For this reason, the characteristic distribution of the optical coupling device product can be improved.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 Lead frame assembly, 12 First lead frame, 14 Second lead frame, 12a, 14a Die pad portion, 12b, 14b Lead portion, 12c, 14c Inner frame portion, 12d, 14d Outer frame portion, 16 Vertical gap portion, 18 Horizontal plane gap part, 30 1st mirror part, 32 2nd mirror part, 40 Light source part, 50 Imaging part, 60 Image processing part, 80 Light emitting element, 82 Light receiving element, 90 1st conveyance part, 92 2nd conveyance part , VL1 Visible light (irradiated light), VL2 Visible light (transmitted light), IM transmission image information, TF Distance between lead frames

Claims (8)

The optical coupling structure portion in which the light emitting element bonded to the first lead frame and the light receiving element bonded to the second lead frame face each other has a first pitch along the inner frame portion extending in the first direction. And a lead frame shape inspection apparatus capable of inspecting a lead frame assembly arranged in an array having a second pitch along an outer frame portion extending along a second direction orthogonal to the first direction. Because
A light source unit capable of emitting visible light in a third direction perpendicular to the first direction and the second direction ;
A first transport unit including a lead frame feeding mechanism having a first surface parallel to the first direction and the second direction, wherein the lead frame assembly is placed on the first surface. The lead frame feeding mechanism is capable of moving the lead frame assembly in the second direction and the third direction, respectively,
A first mirror part that folds the visible light emitted from the light source part in the second direction and irradiates the light coupling structure part ;
A second mirror part that bends the visible light transmitted through the optical coupling structure part in the third direction, and is disposed apart from the first mirror part by the second pitch in the second direction; A second mirror part ;
An imaging unit provided on a side opposite to the light source unit with respect to the lead frame feeding mechanism, wherein the optical coupling structure unit is sandwiched between the first mirror unit and the second mirror unit by the lead frame feeding mechanism. An imaging unit that receives the visible light transmitted through the optical coupling structure unit and captures a transmission image of the optical coupling structure unit;
Lead frame shape inspection device. 2. The lead frame shape inspection apparatus according to claim 1, wherein the first transport unit is capable of pitch-feeding the lead frame assembly in the first direction by the first pitch . The lead frame shape inspection apparatus according to claim 1, further comprising a second transport unit capable of moving the imaging unit in the first direction by the first pitch .   The lead frame shape inspection apparatus according to claim 1, further comprising an image processing unit capable of performing image processing on the transmission image.   The lead according to claim 4, wherein the image processing unit measures a distance between the first lead frame and the second lead frame, and determines that the standard is out of specification when the distance is out of a predetermined range. Frame shape inspection device. The optical coupling structure portion in which the light emitting element bonded to the first lead frame and the light receiving element bonded to the second lead frame face each other has a first pitch along the inner frame portion extending in the first direction. And a method for measuring a distance between lead frames of a lead frame assembly arranged in an array having a second pitch along an outer frame portion extending along a second direction orthogonal to the first direction. There,
Placing the lead frame assembly on a first surface parallel to the first direction and the second direction of the surfaces of the lead frame feeding mechanism;
Transporting the optical coupling structure portion using the lead frame feed mechanism to a position sandwiched between a first mirror portion and a second mirror portion that are spaced apart by the second pitch in the second direction;
Visible light emitted in a third direction perpendicular to the first direction and the second direction is bent in the second direction by the first mirror part to irradiate the optical coupling structure part ,
The visible light transmitted through the optical coupling structure is bent in the third direction by the second mirror unit, and a transmission image of the optical coupling structure is captured by the imaging unit , whereby the first lead frame and the first A method for measuring a distance between lead frames, wherein a distance along the third direction between two lead frames is measured at a position of the optical coupling structure portion . The lead frame assembly is moved by the first pitch in the first direction of the first surface while the imaging unit is fixed, and is arranged next to the optical coupling structure along the first direction. The inter-lead frame distance measurement according to claim 6, wherein the distance between the first lead frame and the second lead frame along the third direction is measured with respect to another optical coupling structure formed. Method. Wherein the imaging unit in a first direction by a pitch feeding first pitch, with respect to another optical coupling portion disposed next to the said optical coupling structure along a first direction, the first lead The method for measuring a distance between lead frames according to claim 6, wherein the distance between the frame and the second lead frame along the third direction is measured.

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