DE102010007752A1 - Optoelectronic semiconductor device manufacturing method, involves extending ridges at lower side of lead frame away from semiconductor chips, and removing ridges by forming chamfer at lead frame, where side is turned away from chips - Google Patents

Abstract

In one embodiment of the optoelectronic semiconductor component (1), this comprises a leadframe (2) with at least two connection regions. In the connection regions, at least one optoelectronic semiconductor chip (4) is electrically and mechanically connected to the leadframe (2). The semiconductor device (1) further includes a potting body (5) covering the semiconductor chip (4) and a part of the lead frame (2). The lead frame (2) and the potting body (5) terminate flush on at least one longitudinal side (12) and / or short side (14) and have singling tracks. On a side facing away from the semiconductor chip (4) underside (25) of the lead frame (2) along at least one of the longitudinal sides (12) and / or the short sides (14) extends a chamfer (7). In addition, a method for producing such a semiconductor device (1) is given.

Description

It is given a semiconductor device. In addition, a method for producing a semiconductor device is specified.

An object to be solved is to provide a semiconductor device which can be mounted reliably, as well as a method for producing such a semiconductor device.

According to at least one embodiment of the semiconductor component, which is preferably an optoelectronic semiconductor component, this comprises one or more semiconductor chips, preferably optoelectronic semiconductor chips. The semiconductor chip is preferably designed as a light-emitting diode, as a laser diode or as a photodiode. At least one of the semiconductor chips is preferably set up to emit electromagnetic radiation in the ultraviolet, in the visible or in the near infrared spectral range during operation of the semiconductor component. The semiconductor chip may include a conversion means which converts radiation emitted by an active region of the semiconductor chip into radiation of a different wavelength.

According to at least one embodiment of the semiconductor device, this comprises a lead frame. The lead frame is completely or partially formed with a material that is electrically conductive. Furthermore, the lead frame is preferably mechanically stable. In other words, the lead frame does not deform during the intended assembly and in the intended use of the semiconductor device. The lead frame is provided for electrical contacting of an optoelectronic semiconductor chip.

In accordance with at least one embodiment of the semiconductor component, the leadframe comprises at least two electrical connection regions. The connection areas are preferably those areas in which the optoelectronic semiconductor chip is mechanically and / or electrically connected to the lead frame, for example via soldering or gluing.

In accordance with at least one embodiment of the semiconductor component, the latter has a potting body, which is preferably at least partially radiation-transmissive and which covers the semiconductor chip and a part of the leadframe. Radiation permeable means that at least a portion of a radiation emitted by the semiconductor chip, for example, can pass through the potting body and be emitted by the semiconductor component. The lead frame is preferably not completely covered by the potting body. This means that portions of the lead frame, in a direction perpendicular to main sides of the lead frame, no material of the potting body is arranged downstream. This refers in particular to two opposing main sides of the lead frame. The potting body can be in direct contact with one or both main sides of the lead frame in places.

In accordance with at least one embodiment of the semiconductor component, the lead frame and the potting body are flush with one another along at least one longitudinal side of the semiconductor component. If a plan view of the semiconductor device is rectangular, for example, the longitudinal sides seen in plan view are the opposite, longer sides of this rectangle or the boundary surfaces of the semiconductor device assigned to these sides. Short sides then correspond to the shorter sides of this rectangle or the boundary surfaces assigned to these shorter sides, as seen in plan view. In particular, all parts of one of the boundary surfaces or the longitudinal sides or the short sides lie in a plane, wherein the plane is preferably oriented perpendicular to one of the main sides of the lead frame.

Flushing means, in particular, that the potting body and the leadframe on the longitudinal side, seen in plan view, in the context of manufacturing tolerances conclude congruent or, seen in plan view, form a common edge of the semiconductor device. Flushing can also mean that the potting body and the leadframe protrude equally far into a specific spatial direction. That is, the lead frame and the potting do not project beyond each other in the region of an interface or a contact point on the longitudinal side.

In accordance with at least one embodiment of the semiconductor component, the potting body and the leadframe have singulation tracks on one or both longitudinal sides. Such separation traces are given for example by roughening or groove-like structures, which may in particular stem from sawing.

In accordance with at least one embodiment of the semiconductor component, the leadframe has a chamfer on an underside facing away from the semiconductor chip along one of or along the two longitudinal sides. In particular, a chamfer is a removal of material that extends along the underside with a substantially constant cross-section along preferably the entire longitudinal side. In particular, an edge of the underside opposite an edge of an upper side of the leadframe opposite the underside is set back by the chamfer, as seen in plan view. For example, the Chamfer has a triangular or triangular shape in cross section.

In at least one embodiment of the semiconductor device, this comprises a leadframe with at least two connection regions. In the connection regions, at least one optoelectronic semiconductor chip is electrically and mechanically connected to the lead frame. The semiconductor device further includes an at least partially radiation-transmissive potting body, which covers the semiconductor chip and a part of the lead frame. The lead frame and the potting close at least one longitudinal side and / or on at least one short side, preferably on both long sides and / or on both short sides, flush and have signs of separation on. On a side facing away from the semiconductor chip underside of the lead frame and optionally on a bottom of the potting extends along at least one of the long sides and / or the short sides of a chamfer.

When singulating semiconductor devices out of a utility or leadframe composite, burrs, in particular sawing, can result. These burrs can lead to short circuits occurring during assembly of the component on an external carrier, for example due to broken away parts of the burrs, or that contact surfaces do not lie flat on one another, so that electrical and / or mechanical contact may be impaired. By a small chamfer, English chamfer, or by the production of the chamfer, especially by the separation of the semiconductor components conditional burrs, in particular on the lead frame, removable.

In accordance with at least one embodiment of the semiconductor device, the potting body extends in a direction perpendicular to the bottom of the leadframe and away from the semiconductor chip to the bottom of the leadframe with a tolerance of at most 50% or at most 25% of a thickness of the leadframe. In other words, the potting body then terminates flush or with one of said tolerances substantially flush with the underside of the leadframe. It may be a part of the bottom of the potting covered. It may also be the entire bottom free of the potting.

According to at least one embodiment of the leadframe, this is planar and flat. The lead frame is then formed, for example, not by a curved, but by a planar sheet. Evenly shaped can mean that one or both main sides of the leadframe can be described by a plane part. This does not exclude that openings, recesses or recesses are formed in the top and / or bottom of the lead frame.

In accordance with at least one embodiment of the semiconductor component, the leadframe has at least two, in particular exactly two parts, between which no continuous connection with a material of the leadframe is formed. The lead frame is then divided into two parts, for example. In particular, apart from an electrical connection via the semiconductor device or an electrostatic discharge protection element, the parts of the leadframe are electrically insulated from each other. A mechanical connection between the parts of the leadframe is preferably given via the potting body, in particular exclusively via the potting body. In other words, then the potting body mechanically stabilizes the semiconductor device.

In accordance with at least one embodiment of the semiconductor component, a partial region of the leadframe is exposed on a longitudinal side of the semiconductor component. In view of the longitudinal side of this portion of the lead frame is completely surrounded by the potting. In other words, on the longitudinal side, a closed path of a material of the potting body is formed around this portion of the lead frame. About such partial areas, by which an additional mechanical connection between adjacent lead frames in a lead frame composite can be produced, the lead frame composite is mechanically stabilized.

In addition, a method for producing a semiconductor device, preferably an optoelectronic semiconductor device, specified. For example, by means of the method, a semiconductor device can be produced, as described in conjunction with one or more of the abovementioned embodiments. Features of the method are therefore also disclosed for the semiconductor device and vice versa.

• – Bereitstellen eines insbesondere einstückigen Leiterrahmenverbundes mit einer Vielzahl von Leiterrahmen, wobei jeder der Leiterrahmen wenigstens zwei Anschlussbereiche aufweist,
• – Anbringen von bevorzugt optoelektronischen Halbleiterchips in oder an den Anschlussbereichen der Leiterrahmen,
• – Vergießen der Halbleiterchips mit einem Verguss, wobei sich der Verguss bevorzugt über zwei oder über mehr als zwei der Leiterrahmen erstreckt,
• – Vereinzeln des Leiterrahmenverbundes zu Halbleiterbauteilen insbesondere mittels eines mechanischen Trennprozesses wie einem Sägen, wobei bei dem Vereinzeln Grate an den zu vereinzelnden Leiterrahmen und/oder am Verguss entstehen und wobei sich die Grate an einer den Halbleiterchips abgewandten Unterseite der Leiterrahmen und/oder des Vergusses in eine Richtung weg von den Halbleiterchips erstrecken, und
• – Entfernen der Grate durch Ausbildung einer Fase an dem Leiterrahmen und/oder an dem Verguss sowie Fertigstellen des mindestens einen Halbleiterbauteils. Die Verfahrensschritte werden bevorzugt in der angegebenen Reihenfolge ausgeführt.

In at least one embodiment of the method for producing a particularly optoelectronic semiconductor component, this comprises the following steps:

• Providing a particularly one-piece leadframe composite with a plurality of leadframes, each of the leadframes having at least two terminal regions,
• Attaching preferably optoelectronic semiconductor chips in or at the connection areas of the leadframes,
• Potting the semiconductor chips with a potting, the potting preferably extending over two or over more than two of the lead frames,
• Separating the leadframe composite into semiconductor components, in particular by means of a mechanical separation process such as sawing, wherein burrs are formed on the leadframe to be singled and / or on the potting, and wherein the ridges are located on an underside of the leadframe and / or of the potting compound facing away from the semiconductor chips extend a direction away from the semiconductor chips, and
• - Removing the burrs by forming a chamfer on the lead frame and / or on the casting and finishing the at least one semiconductor device. The process steps are preferably carried out in the order given.

When singulated by sawing, for example, saw teeth of a saw blade, for example, pass through the ladder frame assembly according to the method such that the saw teeth enter at the top of the lead frame and exit at the bottom. The emergence of the saw teeth creates a burr. The emergence of the burr is by a choice of suitable parameters in the singling, ie by selecting suitable saw blades, sawing speeds and materials, although partially controlled. However, the process parameters in such a control of the formation of the burr are comparatively narrow and complex. Removal of the burr eliminates the need to precisely control the formation of burrs by adjusting process parameters.

In also usable separation processes such as cut-off grinding or scratches can also create undesirable burrs. In the case of laser separation processes, in particular slags can be formed on separating edges. In the context of the present application, the term burrs are also to be understood as meaning such slags. Such burrs can also form on the potting, from which they are preferably removable by making the chamfer.

According to at least one embodiment of the method, the singulation takes place exclusively along preferably exactly two of the longitudinal sides of the semiconductor component. The short sides of the semiconductor component are then not affected by the singulation. The short sides are produced, for example, by punching or etching before the assembly of the semiconductor component, in particular before attaching the semiconductor chips and before manufacturing the encapsulation.

According to at least one embodiment of the method, the separation takes place both on the two short sides and on the two longitudinal sides. In each case burrs are formed on the two long sides and on the two short sides. Preferably, the chamfers are then produced on the underside both on the long sides and on the short sides.

Hereinafter, a method described herein and a semiconductor device described herein with reference to the drawings using exemplary embodiments will be explained in more detail. The same reference numerals indicate the same elements in the individual figures. There are no scale relationships shown, but individual elements may be exaggerated to better understand.

Show it:

1 . 3 . 4 . 7 and 8th schematic representations of embodiments of optoelectronic semiconductor devices described herein,

2 1 a schematic representation of a method for producing an optoelectronic semiconductor component described here,

5 a schematic representation of an embodiment of a lead frame composite, and

6 a schematic representation of a light emitting diode.

In 1 is a component 1' shown in the burrs 6 along long sides 12 at a bottom 25 a two-part lead frame 2a . 2 B available. The burrs 6 are exclusively on the long sides 12 , Sawed burrs 6 wise, from the bottom 25 starting in a direction away from an optoelectronic semiconductor chip 4 standing at a top 26 of the ladder frame 2 is electrically and mechanically contacted in connection areas, see the schematic plan view in 1A and the side view from the left in 1B , The connection areas may have a coating.

The semiconductor chip 4 is on the part 2a of the lead frame and over a bonding wire 40 with the part 2 B electrically connected. The semiconductor chip 4 as well as partial areas of the ladder frame 2a . 2 B are from a potting body 5 covered. The bottom 25 is free from the potting body 5 , The potting body 5 is permeable, especially clear, for a part of the semiconductor chip 4 generated electromagnetic radiation. The potting body 5 is designed approximately cuboid.

Seen in plan view, the component 1' a rectangular floor plan, see 1A , Seen in plan view are the long sides 12 above short pages 14 connected with each other. On the long sides 12 close the ladder frames 2a . 2 B and the potting body 5 flush off, leaving the potting body 5 and the ladder frame 2a . 2 B on the long sides 12 seen in plan form a common edge.

A mechanical connection between the two parts 2a . 2 B of the lead frame is through the potting body 5 given. In a direction parallel to the long sides 12 and to the bottom 25 is the potting body 5 , seen in plan view, from external connection points 9 surmounted by sections of parts 2a . 2 B of the lead frame are formed.

The ladder frame 2a . 2 B is based, for example, on or consists of copper or a copper alloy. A thickness of the lead frame 2a . 2 B is for example between 40 microns and 750 microns, in particular between 45 microns and 250 microns inclusive. Lateral dimensions of the component 1' amount along the long sides 12 for example, about 1.6 mm and along the short sides 14 for example, about 0.8 mm. In particular, the component 1' a so-called 0603 Two-terminal Package.

In 2 is a removal of the burrs 6 from the component 1' according to 1 shown. By removing the burrs 6 become embodiments of the semiconductor devices 1 educated. The in conjunction with 1 mentioned features of the component 1' in this respect also apply to the exemplary embodiments of the semiconductor component 1 to.

The burrs 6 be using an example two-piece guide rail 75a . 75b and by a guide over two particular rotating tools 70 removed with axes of rotation A. A direction of movement M of the component 1' or the semiconductor device 1 is parallel to the long sides 12 and to the bottom 25 oriented, see the schematic front view in 2A and the schematic side view from the left in 2 B , When deburring the direction of movement M does not change or essentially not.

The tool 70 , about which, for example, a polishing, grinding or milling is realized, is through an opening in the guide rail 75b guided. The tool 70 is preferably divided into two, compare the schematic sectional view in 2C , perpendicular to the plane of the 2A and perpendicular to the direction of movement M. The axes of rotation A of the two-part tool 70 lie, preferably with a tolerance of at most 5 °, in a plane perpendicular to the direction of movement M.

In 3A is a schematic detail view in a side view of the component 1' before deburring and in 3B of the semiconductor device 1 shown after deburring. When deburring is at an edge of the bottom 25 of the ladder frame 2 where the ridge 6 is a chamfer 7 educated. The chamfer 7 has, for example, a triangular basic shape. An angle α of a boundary surface 72 the chamfer 7 , relative to the bottom 25 is, for example, between 5 ° and 60 ° inclusive, in particular between 15 ° and 50 ° inclusive. Based on a thickness T of the lead frame 2 is a width W of the chamfer 7 on the bottom 25 specifically, between 0.02 times and 0.10 times the thickness T. Preferably, the width W is between 0.04 times and 0.08 times the thickness T.

In 4 is another embodiment of the optoelectronic semiconductor device 1 shown in perspective views. The chamfer is for ease of illustration in 4 not drawn.

The parts 2a . 2c the lead frame are formed integrally and through at an underside of the semiconductor device 1 continuous tracks of a material of the potting 5 separated, see 4A , The semiconductor chip 4 is on the part 2c appropriate. At the part 2 B The ladder frame is a separate part that fits with the parts 2a . 2c mechanically only via the potting body 5 is connected and electrically via the bonding wire 40 ,

The potting body 5 has a level 16 on. Through the stage 16 is a mark for the mounting of the semiconductor device 1 formed, in particular to ensure a properly polarized electrical connection with an external, not shown carrier. On the long sides 12 lies a subarea 8th of the ladder frame 2 B free. This subarea 8th is on the long sides 12 each completely of a material of the potting 5 surround. Seen in side view, the potting 5 , without consideration of the stage 16 , please refer 4A , a rectangular cross-section on. In a direction parallel to the bottom 25 and to the long sides 12 protrude the connection points 9 from the potting body 5 out. In a direction parallel to a main extension direction of the lead frame 2a . 2 B . 2c is except in areas where the connection points 9 the potting body 5 projecting laterally and with the exception of the subarea 8th of the ladder frame 2c , the long side completely by a material of the potting 5 educated. Unlike in 4 it is possible that the potting body 5 not to the bottom 25 enough or parts of the bottom 25 covered. The semiconductor device 1 is surface mountable and thus a so-called SMD component.

In 5 is an embodiment of a lead frame composite in a plan view 20 illustrated, compare the overall view in 5A and the detail view in 5B , The ladder frames become parallel to a y-direction 2a . 2 B . 2c along separation lines S to the semiconductor devices 1 , for example, like in 4 shown, isolated. An additional separation perpendicular to the y-direction is not required, as along the y-direction adjacent lead frames 2a . 2 B . 2c in the ladder frame composite 20 are not connected.

Along the x-direction becomes before singulation to individual semiconductor devices 1 and after attaching the semiconductor chips 4 a casting 50 applied, extending along the x-direction over several adjacent lead frames 2a . 2 B . 2c extends. Preferably, adjacent lead frames are along the y-direction 2a . 2 B . 2c not over the grouting indicated by a dashed line 50 connected. When separating after application and curing of the potting 50 Along the separation line S, both the lead frames become 2a . 2 B . 2c as well as the casting 50 each severed, so that individual components 1' are formed from which by deburring the semiconductor devices 1 result.

The ladder frame composite 20 has, for example, lateral dimensions of between 50 mm × 20 mm and 250 mm × 140 mm, in particular approximately 125 mm × 70 mm. For example, from the ladder frame composite 20 between including 100 leadframes 2a . 2 B . 2c and 10,000 leadframes 2a . 2 B . 2c produced, for example, about 2,300 lead frames 2a . 2 B . 2c and thus also a corresponding number of semiconductor components 1 ,

In 6A is a side view from the left and in 6B a front view of a light emitting diode shown. In the light-emitting diode according to 6 is done by means of sawing, with the burrs 6 at the top 26 of the ladder frame 2 are formed. Such burrs 6 are not by making a continuous chamfer, compare 2 and 3 , disposable. Even with a controllable formation of burrs 6 during singulation is an assembly of the LED according to 6 on a non-subscribed external support at the top 26 , due to the burrs 6 , not or only partially possible, unlike the semiconductor device 1 according to 4 ,

In the 7A and 7B are further embodiments of the optoelectronic semiconductor device 1 shown as bottom views. According to 7A is along the long sides 12 one each of the chamfers 7 both on the lead frame 2 with the several connection points 9 as well as at a bottom 55 of the potting body 5 shaped. The bottom 55 of the potting body 5 occupies a larger proportion of area than the sum of areas of the connection points 9 , seen in bottom view. According to 7B has the semiconductor device 1 a square floor plan, with the connection points 9 of the ladder frame 2 over all four sides of the semiconductor device 1 to distribute. Likewise, on each of the four sides one of the chamfers 7 educated.

In the embodiment of the optoelectronic semiconductor device 1 according to 8th , shown in a sectional view, is the leadframe 2 by a laminate, in particular by a so-called BGA laminate. BGA stands for Ball Grid Array. The connection points 9 are via vias with the semiconductor chip 4 electrically connected. The potting body 5 closes in the lateral direction flush with the lead frame 2 from. The chamfers 7 are along the short sides 14 and optionally along the in 8th Shaped longitudinal sides not shown.

The invention described here is not limited by the description based on the embodiments. Rather, the invention encompasses any novel feature as well as any combination of features, including in particular any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the claims or exemplary embodiments.

Claims (13)

Method for producing an optoelectronic semiconductor component ( 1 ) comprising the steps of: - providing a one-piece lead frame composite ( 20 ) with a plurality of lead frames ( 2 ) each having at least two connection areas, - mounting optoelectronic semiconductor chips ( 4 ) in the connection areas of the lead frames ( 2 ), - casting the optoelectronic semiconductor chips ( 1 ) with a potting ( 50 ), which extends over several of the lead frames ( 2 ), - separating the leadframe composite ( 20 ) to semiconductor devices ( 1 ) by means of a separation process, wherein burrs ( 6 ) to the lead frame ( 2 ) and / or on the potting ( 50 ), whereby the burrs ( 6 ) on one of the semiconductor chips ( 4 ) facing away from the bottom ( 25 ) the lead frame ( 2 ) away from the semiconductor chips ( 4 ), and - removing the burrs ( 6 ) by forming a chamfer ( 7 ) at least on the lead frame ( 2 ). Method according to the preceding claim, wherein the sawing exclusively along two opposite longitudinal sides ( 12 ) of the semiconductor components ( 1 ) or along the long sides ( 12 ) as well as along short pages ( 14 ) he follows. Method according to one of the preceding claims, wherein during sawing both the ladder frame assembly ( 20 ) to lead frames ( 2 ) as well as the casting ( 50 ) to potting bodies ( 5 ) are isolated. Method according to one of the preceding claims, in which the removal of the burrs ( 6 ) by moving the separated semiconductor components ( 1 ) in a direction parallel to the longitudinal side ( 12 ), wherein a direction of movement (M) of the semiconductor components ( 1 ) while removing the burrs ( 6 ) does not change. Method according to one of the preceding claims, in which the removal of the burrs ( 6 ) by guiding the separated semiconductor components ( 1 ) via at least two rotating tools ( 70 ), whereby rotational axes of the tools ( 70 ), with a tolerance of at most 5 °, in a plane perpendicular to the mutually parallel longitudinal sides ( 12 ) lie. Method according to one of the preceding claims, wherein the burrs ( 6 ) are removed by milling, grinding or polishing. Optoelectronic semiconductor component ( 1 ) with a lead frame ( 2 ) with at least two connection regions, - at least one optoelectronic semiconductor chip ( 4 ), which in at least one of the terminal areas electrically and mechanically with the lead frame ( 2 ), - a potting body ( 5 ), the semiconductor chip ( 4 ) and a part of the lead frame ( 2 ), wherein the lead frame ( 2 ) and the potting body ( 5 ) on at least one longitudinal side ( 12 ) and / or on at least one short side ( 14 ) flush and have singulation tracks, and wherein on a the semiconductor chip ( 4 ) facing away from the bottom ( 25 ) of the lead frame ( 2 ) along the longitudinal side ( 12 ) and / or the short side ( 14 ) a chamfer ( 7 ) runs. Optoelectronic semiconductor component ( 1 ) according to the preceding claim, in which the chamfer ( 7 ) has a triangular basic shape in cross-section and an angle (α) of the chamfer ( 7 ), relative to the underside ( 25 ), between 5 ° and 60 ° inclusive. Optoelectronic semiconductor component ( 1 ) according to claim 7 or 8, wherein a width (W) of the chamfer ( 7 between 0.02 times and 0.10 times a thickness (T) of the lead frame ( 2 ) lies. Optoelectronic semiconductor component ( 1 ) according to one of claims 7 to 9, wherein the lead frame ( 2 ) Comprises copper or consists of copper or a copper alloy or in which the lead frame ( 2 ) is a laminate, and wherein the thickness (T) of the lead frame ( 2 ) between 40 μm and 750 μm inclusive. Optoelectronic semiconductor component ( 1 ) according to one of claims 7 to 10, wherein the potting body ( 5 ), in a direction perpendicular to the bottom ( 25 ) and away from the semiconductor chip ( 4 ), with a tolerance of at most 25% of a thickness (T) of the lead frame ( 2 ) in places to the bottom ( 25 ), the lead frame ( 2 ) is just shaped. Optoelectronic semiconductor component ( 1 ) according to one of claims 7 to 11, wherein the lead frame ( 2 ) the potting body ( 5 ) in the direction parallel to the longitudinal side ( 12 ) on two opposite short sides ( 14 ) and this the casting body ( 5 ) protruding parts of the lead frame ( 2 ) at least two external connection points ( 9 ), and in which, in addition to the 7 ), on the long side ( 12 ) another subarea ( 8th ) of the lead frame ( 2 ) is exposed and on the long side ( 12 ) completely from the potting body ( 5 ) is outlined. Optoelectronic semiconductor component ( 1 ) according to one of claims 7 to 12, wherein at least two separate parts of the lead frame ( 2 ) over the potting body ( 5 ) are mechanically interconnected.

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