阅读说明：本技术 用于制造半导体设备的方法和半导体设备 (Method for manufacturing semiconductor device and semiconductor device ) 是由 M·舒尔茨 S·克洛肯卡佩尔 A·K·T·科纳坎奇 于 2020-09-09 设计创作，主要内容包括：一种用于制造半导体设备的方法,该方法包括：提供载体,该载体构造用于在第一侧上承载至少一个半导体芯片；将聚合物分配到与第一侧相对置的第二侧上以产生密封环,其中,如此分配聚合物,使得所产生的密封环沿着其周长具有垂直于第二侧的不同高度。(A method for manufacturing a semiconductor device, the method comprising: providing a carrier configured to carry at least one semiconductor chip on a first side; the polymer is dispensed onto a second side opposite the first side to create a sealing ring, wherein the polymer is dispensed such that the created sealing ring has different heights along its perimeter perpendicular to the second side.)

1. A method (800) for manufacturing a semiconductor device, the method comprising:

providing (801) a carrier configured for carrying at least one semiconductor chip on a first side,

dispensing (802) a polymer onto a second side opposite the first side to create a sealing ring,

wherein the polymer is dispensed such that the resulting sealing ring has different heights along its perimeter perpendicular to the second side.

2. The method (800) of claim 1, wherein the dispensing (802) is performed by means of a dispensing nozzle, wherein the different heights are produced by: changing a distance of the dispensing nozzle from the second side and/or changing an output rate of the polymer.

3. The method (800) of claim 1 or 2, wherein the polymer is dispensed such that the sealing ring has a substantially rectangular perimeter,

wherein the sealing ring has at least partially a greater height along a long side of the substantially rectangular perimeter than along a short side.

4. The method (800) according to any one of the preceding claims, wherein creating the sealing ring further comprises curing the polymer by means of heat or radiation.

5. The method (800) of any of the above claims, wherein the polymer is dispensed curvilinearly.

6. The method (800) of any of the above claims, wherein the sealing ring is produced on a flat, recess-free portion of the second side.

7. The method (800) of any of claims 1-6, wherein the carrier has a recess for receiving the sealing ring, wherein the recess has a varying depth along a perimeter of the sealing ring.

8. A semiconductor device (100, 400, 500), the semiconductor device comprising:

a carrier (110, 900) configured for carrying at least one semiconductor chip on a first side (111),

a first sealing ring (120) made of a polymer and located on a second side (112) opposite the first side (111),

wherein the first seal ring (120) has different heights along its perimeter perpendicular to the second side (112).

9. The semiconductor device (100, 400, 500) of claim 8, wherein the carrier (110, 900) comprises a portion of a lead frame or comprises a ceramic substrate with an applied wiring structure.

10. The semiconductor device (100, 400, 500) of claim 8 or 9, further comprising:

a cooling rib (510) disposed within a perimeter of the first seal ring (120) on the second side (112).

11. The semiconductor device (100, 400, 500) of any of claims 8 to 10, wherein the first seal ring (120) has a substantially rectangular perimeter,

wherein the first seal ring (120) has at least partially a greater height along a long side (121) of the substantially rectangular perimeter than along a short side (122).

12. The semiconductor device (100, 400, 500) of any of claims 8 to 11, wherein the carrier (110, 900) has a bump at least on the second side.

13. The semiconductor device (100, 400, 500) of any of claims 8 to 12, further comprising:

a second seal ring (410) disposed about the first seal ring (120).

14. The semiconductor device (100, 400, 500) of any of claims 8 to 13, wherein the carrier (900) has a recess (910) for accommodating the seal ring (120), wherein the recess (910) has a varying depth along a circumference of the seal ring (120).

15. The semiconductor device (100, 400, 500) of claim 14, wherein the recess (910) has a longer side (911), a shorter side (914), and a corner (912), wherein a depth of the recess (910) is smaller in the middle of the longer side (911) than in the corner (912).

16. The semiconductor device (100, 400, 500) of claim 14 or 15, wherein a bottom (913) of the recess (910) forms a circular arc segment (920).

Technical Field

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

Background

Semiconductor devices, particularly power modules, can generate significant heat during operation. In order to avoid damage to the semiconductor device itself and/or to ensure efficient operation of the semiconductor device, it may be necessary to conduct heat away from the semiconductor device. Direct liquid cooling, in which the carrier of the semiconductor device is in direct contact with a cooling fluid, is a particularly effective possibility for removing heat. Here, it is necessary to ensure the liquid-cooled hermeticity, which may increase the technical complexity and manufacturing cost of the semiconductor device. Improved methods for manufacturing semiconductor devices and improved semiconductor devices may help solve this and other problems.

The object on which the invention is based is achieved by the features of the independent claims. Advantageous embodiments and embodiments of the invention are specified in the dependent claims.

Disclosure of Invention

Specific examples relate to a method for manufacturing a semiconductor device, the method including: providing a carrier configured to carry at least one semiconductor chip on a first side; the polymer is dispensed onto a second side opposite the first side to create a sealing ring, wherein the polymer is dispensed such that the created sealing ring has different heights along its perimeter perpendicular to the second side.

A specific example relates to a semiconductor device including: a carrier configured to carry at least one semiconductor chip on a first side; a first seal ring comprised of a polymer and located on a second side opposite the first side, wherein the first seal ring has different heights along its perimeter perpendicular to the second side.

Drawings

The drawings illustrate examples and together with the description serve to explain the principles of the invention. The elements of the drawings are not necessarily to scale relative to each other. The same reference numerals may denote corresponding, similar or identical parts to each other.

Fig. 1 includes fig. 1A to 1C and shows a semiconductor device with a sealing ring and a cooling fluid channel which is sealed at the semiconductor device by means of the sealing ring;

FIG. 2 shows a height profile of a sealing ring along its perimeter;

fig. 3 shows a method for producing a semiconductor device, according to which a sealing ring is applied to a carrier by dispensing;

fig. 4 shows a further semiconductor device which comprises two sealing rings in order to achieve a redundant or improved tightness;

fig. 5 shows another semiconductor device comprising cooling ribs arranged on a carrier within a sealing ring;

FIG. 6 shows a top view of a section of the sealing ring with a meander;

FIG. 7 shows a cross-section of a sealing ring consisting of a plurality of partial rings;

FIG. 8 shows a flow chart of a method for manufacturing a semiconductor device;

fig. 9A and 9B show a carrier with a variable height profile along the perimeter of the sealing ring.

Detailed Description

Although an example determined feature or determined aspect may have been disclosed with respect to only one of several implementations, such feature or aspect may be combined with one or more other features or aspects of the other implementations in addition to or as may be desired and advantageous for any given or determined application, unless specifically stated or otherwise technically limited. To the extent that the terms "includes," including, "" has, "" with, "or other variants thereof are used in either the detailed description or the claims, these terms are intended to be inclusive in a manner similar to the term" comprising.

Semiconductor devices are described below, which may include one or more semiconductor chips. The semiconductor chips may be of different types and may be manufactured by different techniques. The semiconductor chip can be designed, for example, as a power semiconductor chip, for example as a power MOSFET (metal oxide semiconductor field effect transistor), an IGBT (bipolar transistor with insulated gate), a JFET (junction field effect transistor), a power bipolar transistor or a power diode.

Fig. 1A shows a top view of a semiconductor device 100 comprising a carrier 110 and a first seal ring 120, and fig. 1B shows a cross-sectional view along line a-a' of fig. 1A.

The semiconductor device 100 may be, for example, a power semiconductor module, which is designed to operate at high voltages and/or high currents. The semiconductor device 100 may include one or more semiconductor chips that may implement any circuit (e.g., a rectifier circuit, an inverter circuit, a half-bridge circuit, etc.).

The carrier 110 may be configured for carrying one or more semiconductor chips (drawn in dashed lines in fig. 1B) on a first side 111. The carrier 110 is typically constructed of a thermally conductive material. The carrier 110 may typically comprise or consist of a metal (such as Al, Cu or Fe) or a metal alloy. The carrier 110 may have a layer structure which is composed of one or more electrically conductive layers and one or more electrically insulating layers (for example ceramic layers). The carrier 110 may have, for example, a substrate and/or a base plate. The substrate may be, for example, a substrate of the DCB (direct copper bonding), DAB (direct aluminum bonding), AMB (active metal brazing) type or part of a lead frame. The substrate may additionally be mounted to the base plate, for example by soldering, sintering, gluing, etc., wherein the base plate may extend beyond the substrate in the circumferential direction.

The first seal ring 120 is arranged on a second side 112 opposite the first side 111. The first side 111 may be configured for electrically connecting one or more semiconductor chips to each other or to connection terminals (e.g., external connection terminals) of the semiconductor device 100. The first side 111 may be configured to be at least partially covered with a cover (e.g. a (hard) plastic frame or package).

As shown in fig. 1A, the first seal ring 120 may, for example, have a substantially rectangular perimeter with a long side 121 and a short side 122. However, the seal ring 120 may have any other suitable profile (e.g., square, circular, irregular, etc.).

As shown in the cross-section of fig. 1B, the second side 112 of the carrier 110 may be flat such that the first seal ring 120 is not disposed in a recess, but rather is disposed on a substantially flat surface of the carrier 110.

The second side 112 of the carrier 110 may be configured such that a cooler structure is disposed thereon. Such a cooler structure may be used to conduct away heat generated by the semiconductor chips arranged on the first side 111. For example, cooling fluid channels may be disposed on the second side 112. The cooling fluid may be, for example, water, glycol, or the like.

Fig. 1C shows an example of a cooling fluid channel 130 disposed on the second side 112. The cooling fluid channel 130 may, for example, comprise or consist of a metal, metal alloy and/or plastic. The cooling fluid channel 130 may be secured to the second side 112 by a securing means such as a screw, clamp, or adhesive.

When the packing ring 120 is disposed on the second side 112, the packing ring may be configured to seal the cooling structure (cooling fluid passage 130). The packing ring 120 can be configured in particular to be sealed at a cooling fluid pressure of 5bar or more.

According to an example, the carrier 110 may, for example, have a bulge such that the carrier 110 bulges in the middle towards the cooling fluid channel 130. Such a ridge may help to improve the contact pressure between the carrier 110 and the cooling fluid channel 130 in the area of the carrier 110 remote from the fixing means (e.g. screws). This may improve the sealability of the first packing ring 120.

FIG. 2 shows a schematic height profile 200 of the first seal ring 120 along line B-B' in FIG. 1A. The first seal ring 120 has different heights z along its perimeter that are perpendicular to the second side 112.

According to one example, as shown in FIG. 2, the height of the first packing ring 120 may vary stepwise along its perimeter. However, the height may also be gradually changed. In a stepped height profile, the sides or corners do not necessarily have to be sharp as shown in the schematic illustration of fig. 2, but may also be rounded or continuous.

In the example of fig. 2, it is shown that the height of the first seal ring 120 is greater in the middle part of the long side 121 than in the outer region of the long side 121. However, it is also possible for the height of the first sealing ring 120 to be greater in the outer region, for example on the long side 121, than in the middle region. Obviously, even if the first seal ring 120 is not rectangular in circumference (having a long side 121 and a short side 122) as in the example of fig. 1, the first seal ring may have different heights along its circumference.

For example, the cooler structure (e.g., cooling fluid channel 130) may be secured to the second side 112 of the carrier 110 by screws, and the first seal ring 120 may have a small height in an area proximate the screws and a large height in an area distal from the screws.

Generally, the first packing ring 120 may have a greater height in the following regions of its perimeter: in this region, the contact pressure between the carrier 110 and the cooling fluid channel 130 is lower than in other regions. As mentioned above, this may be the case, for example, in regions which are arranged relatively far from the fixing means (e.g. screws). By the greater height of the first packing ring 120 in these regions, it is possible to compensate for the lower contact pressure and thus ensure that the first packing ring 120 effectively seals the cooling fluid channel 130.

According to one example, the first sealing ring 120 may have a first height z of about 0.6mm in a first region (which may be arranged, for example, close to a fixing device, for example a screw, or which has a relatively high contact pressure)₁. The first sealing ring 120 may have, for example, a second height z of about 0.8mm in a second region (which is further away from the fixing device than the first region, or which has a lower contact pressure)₂. The first sealing ring 120 may, for example, have a third height of about 1.0mm in a third region (which is further away from the fixture than the second region, or which has a further lower contact pressure).

According to another example, the first height z₁May be a third height z₃About 60% of the second height z₂May be about 80% of the third height.

According to an example, having a height z₁And has a height z₂To (1) aThe two regions may be about 20% or less of the length of the long sides 121 of the first seal ring 120, respectively. Having a height z₃May be about 30% or more of the length of the long side 121.

Fig. 3 illustrates a dispense process 300 for creating a seal ring. The first seal ring 120 may be fabricated, for example, using the dispensing process 300.

According to the dispensing process 300, the paste 320 is dispensed onto the second side 112 of the carrier 110 by means of the dispensing nozzle 310. The paste 320 includes a polymer for forming the first seal ring 120. The polymer may include, for example, silicone, acrylic, or the like. The paste may also include a flux.

According to an example, the dispensing nozzle 310 and the carrier 110 may be moved relative to each other in the x-direction and the y-direction in order to create the first sealing ring 120. According to an example, the dispensing nozzle 310 and the carrier 110 can also be moved relative to each other in the z-direction in order to create the first sealing ring 120.

The different heights of the first packing ring 120 may be produced, for example, by: the distance between the dispensing nozzle 310 and the second side 112 is changed (e.g., increased in areas with greater height). Additionally or alternatively, creating regions with greater heights may include: the output rate of the paste 320 is increased in these regions.

The dispensing process 300 may be performed, for example, prior to separating the carrier 110 (e.g., during the time that the carrier 110 is still part of the leadframe strip). The dispensing process 300 may be performed before or after one or more semiconductor chips are arranged on the first side 111 of the carrier 110.

After the paste 320 is dispensed, a curing process may be used to cure the polymer or the flux may be evaporated. Curing can be effected, for example, by means of heat or UV radiation.

The application of the first sealing ring 120 to the carrier 110 by a dispensing process has been described with reference to fig. 3. However, according to another example, the first seal ring 120 may also be an O-ring having different heights along its perimeter, which is applied to the carrier 110 by an assembly process (the english "pick-and-place process"). During such assembly it must be ensured that the O-rings are correctly oriented on the carrier 110 such that the areas with different heights are arranged at the correct positions on the carrier 110, respectively.

Fig. 4 shows another semiconductor device 400, which may be similar or identical to semiconductor device 100, except for the differences described below.

The semiconductor device 400 includes a carrier 110, a first seal ring 120, and a second seal ring 410. The second packing ring 410 may be disposed, for example, to completely surround the first packing ring 120. As described with reference to FIG. 2, the first packing ring 120 may have different heights along its perimeter. Likewise, the second seal ring 410 may have different heights along its perimeter. The two sealing rings 120, 410 may, for example, each have the same height or different heights in the same region (for example, a region having the same contact pressure).

Generally, the heights of the first and second packing rings 120, 410 may be designed relative to each other such that the cooling fluid passage 130 is effectively sealed.

However, according to one example, the two seal rings 120, 410 of the semiconductor device 400 may also have different heights along their respective perimeters. Rather, the use of two sealing rings may be sufficient to effectively seal the cooling fluid passage 130.

The second seal ring 410 may likewise be a dispensed seal ring or O-ring, as described above with respect to the first seal ring 120.

Fig. 5 illustrates another semiconductor device 500, which may be similar or identical to semiconductor devices 100 and 400.

The semiconductor device 500 includes a carrier 110, a first seal ring 120, and a cooling rib 510 disposed within a perimeter of the first seal ring 120 on the second side 112 of the carrier 110.

The cooling ribs 510 may be designed to improve thermal contact between the carrier 110 and the cooling fluid in the cooling fluid channel 130. The cooling ribs may comprise, for example, pins ("pin-fins" in the english language) or may also comprise, for example, a curved metal strip or any other suitable structure mounted on the second side 112.

Fig. 6 shows a top view of a section of a sealing ring 600. The seal ring 600 may be similar or identical to the first seal ring 120.

The sealing ring 600 has a curved course along its circumference (indicated by a dashed line in fig. 6). Such a meandering profile can be generated, for example, in the following manner: the dispensing nozzle 310 is moved back in the xy-plane. The loop shape may, for example, help to improve the sealing of the seal ring 600. The packing ring 600 may have different heights of the first packing ring 120.

Fig. 7 shows a cross-section of another seal ring 700, which may be similar or identical to seal ring 100.

The sealing ring 700 may consist of a plurality of (e.g. three) partial rings 710, which may be arranged alongside one another or above one another. The sealing ring 70 can be produced, for example, in the following manner: the dispensing nozzle 310 is moved along the circumference of the sealing ring 700 a plurality of times and the partial rings 710 are dispensed separately.

Fig. 8 shows a flow chart of a method 800 for manufacturing a semiconductor device. The method 800 may be used, for example, to fabricate the semiconductor devices 100, 400, and 500.

Method 800 includes providing a carrier configured to carry at least one semiconductor chip on a first side in 801, the method further comprising dispensing a polymer onto a second side opposite the first side to create a seal ring in 802, wherein the polymer is dispensed such that the created seal ring has different heights perpendicular to the second side along its perimeter.

It has been shown with reference to the semiconductor device 100, 400, 500 that by using a sealing ring having a height profile that varies along the circumference of the sealing ring, the sealing of the cooling channel may be improved (e.g. due to an increase in contact pressure at those points where the sealing ring has a greater vertical thickness). However, the improved sealing effect can also be achieved by: the carrier 110 with the packing ring 120 disposed thereon has a varying height profile along the perimeter of the packing ring 120. In this case, the packing ring 120 may also be used without the thickness variation.

Fig. 9A and 9B illustrate an example of a carrier 900 having such a varying height profile along the perimeter of the seal ring. Fig. 9A shows a perspective view of carrier 900 and fig. 9B shows a cross-sectional view along line a-a in fig. 9A.

The carrier 900 may have a recess 910 configured to receive a sealing ring. As shown in fig. 9B, the recess 910 has a varying depth t along the long side 911. This depth t may be greater, for example, at a (rounded) corner 912 of the recess 910 than at the middle of the long side 911. By the variable depth t of the recess 910, the sealing ring may have different heights perpendicular to the second side of the carrier (in other words, the sealing ring may protrude differently high above the carrier 900 along its circumference due to the variable depth t of the recess 910).

According to one example, the maximum depth tmax at the corner 912 may be about 3mm and the minimum depth tmin at the middle of the longer side 911 may be about 2.7mm or 2.8mm or 2.9 mm. the proportional relationship of tmax to tmin may depend on the length of the longer side 911 and/or on the contact pressure of the seal ring to be achieved on the cooling fluid passage 130 (see fig. 1C).

According to an example, the bottom 913 of the recess 910 may form a circular arc segment 920 (shown in fig. 9B with a dashed and dotted line). The circular arc segment 920 may be a portion of a circle having a radius R, where R may be, for example, about 230cm, about 290cm, about 385cm, or about 580 cm. As mentioned above, the size of the radius R may depend on the length of the longer side 911 and/or the contact pressure to be achieved. In other embodiments, the bottom of the recess may form an elliptical segment or another suitable shape with varying depth.

The recess 910 may have a shorter side 914 that need not have a varying depth. However, it is also possible: the shorter side 914 also has a varying depth such as that set forth with respect to the longer side 911.

According to one example, the carrier 900 does not have the recess 910. Alternatively, the carrier 900 is configured to accommodate the sealing ring on a flat surface having a varying height profile (e.g., as explained with reference to the longer side 911 of the recess 910).

Further, in semiconductor devices such as semiconductor devices 100, 400, and 500, not only seal rings 120 having varying height profiles but also carriers 900 having varying depths t along the concave portion 910 may be used. The carrier 900 can be used not only with the assigned sealing ring, but also with an O-ring that has been provided by the assembly process.

Examples of the invention

The semiconductor device and the method for manufacturing a semiconductor device are further elucidated below on the basis of specific examples.

Example 1 is a method for manufacturing a semiconductor device, the method including: providing a carrier configured to carry at least one semiconductor chip on a first side; the polymer is dispensed onto a second side opposite the first side to create a sealing ring, wherein the polymer is dispensed such that the created sealing ring has different heights along its perimeter perpendicular to the second side.

Example 2 is the method of example 1, wherein dispensing is performed with a dispensing nozzle, wherein the different heights are produced by: changing the distance of the dispensing nozzle from the second side and/or changing the output rate of the polymer.

Example 3 is the method of example 1 or 2, wherein the polymer is dispensed such that the seal ring has a substantially rectangular perimeter, wherein the seal ring has at least partially a greater height along a long side of the substantially rectangular perimeter than along a short side.

Example 4 is the method of any of the above examples, wherein the creating of the seal ring further comprises curing the polymer with heat or UV radiation.

Example 5 is the method of any of the above examples, wherein the polymer is dispensed curvilinearly.

Example 6 is the method of any of the above examples, wherein the sealing ring is produced on a flat, recess-free portion of the second side.

Example 7 is the method of any of examples 1-6, wherein the carrier has a recess to receive the sealing ring, wherein the recess has a varying depth along a perimeter of the sealing ring.

Example 8 is a semiconductor device, including: a carrier configured to carry at least one semiconductor chip on a first side; a first seal ring comprised of a polymer and located on a second side opposite the first side, wherein the first seal ring has different heights along its perimeter perpendicular to the second side.

Example 9 is the semiconductor device of example 8, wherein the carrier comprises a portion of a lead frame or a ceramic carrier with an applied wiring structure.

Example 10 is the semiconductor device of example 8 or 9, further comprising: a cooling rib disposed within a perimeter of the first seal ring on the second side.

Example 11 is the semiconductor device of any one of examples 8 to 10, wherein the first seal ring has a substantially rectangular perimeter, wherein the first seal ring has at least partially a greater height along a long side of the substantially rectangular perimeter than along a short side.

Example 12 is the semiconductor device of any one of examples 8 to 11, wherein the carrier has a bump on at least the second side.

Example 13 is the semiconductor device of any one of examples 8 to 12, further comprising: a second seal ring disposed about the first seal ring.

Example 14 is the semiconductor device of any one of examples 8 to 13, wherein the carrier has a recess to receive the seal ring, wherein the recess has a varying depth along a perimeter of the seal ring.

Example 15 is the semiconductor device of example 14, wherein the recess has a longer side, a shorter side, and a corner, wherein a depth of the recess is smaller in a middle of the longer side than in the corner.

Example 16 is the semiconductor device of example 14 or 15, wherein a bottom of the recess forms a circular arc segment.

Example 17 is an apparatus having means for performing a method according to any of examples 1-7.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. It is therefore intended that this invention be limited only by the claims and the equivalents thereof.