Semiconductor device and method for manufacturing semiconductor device
By forming a recess and a slope on the periphery of the base plate of the semiconductor device, the wetting and expansion direction of the adhesive when the encapsulation resin is hardened is controlled, and the problem of adhesive spillage or adhesion is solved, the manufacturing quality is improved and the processing cost is reduced.
Patent Information
- Application Number
- CN202111060852.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2020-09-17
- Filing Date
- 2021-09-10
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2041-09-10
AI Technical Summary
During the manufacturing process of semiconductor devices, the viscosity of the adhesive decreases when the encapsulation resin is hardened, resulting in the adhesive being unable to effectively define its wetting and expansion direction, which may cause the adhesive to overflow or adhere to undesirable positions.
The bonding structure between the base plate and the housing is designed, and by forming a recess on the peripheral edge of the base plate and an inclined surface from the recess toward the outer or inner circumference side, ensuring that the adhesive is wet in a specific direction when the viscosity drops. Wet expansion and a slope is formed by stamping or cutting to control its expansion.
The wetting and expansion direction of the adhesive is effectively defined, preventing the adhesive from overflowing or adhering to an intended outer position, while reducing processing costs and ensuring the quality of the semiconductor device.
Smart Images
Figure CN114203644B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. Background Art
[0002] In the manufacturing process of a semiconductor device, an adhesive is used to bond a base plate and a housing. There is a semiconductor device having a structure in which the applied adhesive does not drip when bonding the base plate and the housing.
[0003] For example, Patent Document 1 discloses a structure in which the bonding surface between the cover and the insulating base is an inclined surface, and a recessed portion for accommodating excess adhesive is provided on the inner side surface of the recessed portion of the insulating base so that the adhesive applied excessively does not drip. In addition, Patent Document 1 cites solder, brazing material, glass, and organic resin adhesive as examples of the adhesive.
[0004] Patent Document 1: Japanese Patent Application Publication No. 2013-26506
[0005] However, in the technology described in Patent Document 1, since the application position of the adhesive is not specified, the adhesive is applied to the entire bonding surface between the cover and the insulating base. Therefore, when the adhesive temperature rises during the curing of the encapsulating resin and the viscosity of the adhesive decreases, the adhesive wets and spreads toward the upper and lower sides along the inclined surface. As a result, there is a problem that the direction of the adhesive wetting and spreading cannot be limited. Summary of the invention
[0006] Therefore, an object of the present invention is to provide a technology capable of limiting the wetting and spreading direction of an adhesive used for bonding a base plate and a housing.
[0007] The semiconductor device involved in the present invention comprises: a base plate; and a shell, which is joined to the peripheral portion of the base plate via an adhesive, and a recessed portion, i.e., a coating position for coating the adhesive, and a slope descending from the recessed portion toward the outer peripheral side or the inner peripheral side, is formed on the peripheral portion of the base plate.
[0008] Effects of the Invention
[0009] According to the present invention, when the adhesive temperature rises and the viscosity of the adhesive decreases during the curing of the sealing resin, the adhesive wets and spreads from the recess along the slope, so that the direction of the adhesive wetting and spreading can be limited. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is a cross-sectional view of the semiconductor device according to the first embodiment.
[0011] Figure 2This is an enlarged cross-sectional view of a bonding portion between a base plate and a case included in the semiconductor device according to the first embodiment.
[0012] Figure 3 This is a cross-sectional view of a semiconductor device according to a modification of the first embodiment.
[0013] Figure 4 This is a cross-sectional view of a semiconductor device according to the second embodiment.
[0014] Figure 5 This is a cross-sectional view of a semiconductor device according to a modified example of the second embodiment. DETAILED DESCRIPTION
[0015] <Implementation method 1>
[0016] Next, Embodiment 1 will be described with reference to the drawings. Figure 1 This is a cross-sectional view of the semiconductor device according to the first embodiment. Figure 2 This is an enlarged cross-sectional view of a joining portion between a base plate 2 and a case 1 included in the semiconductor device according to the first embodiment.
[0017] like Figure 1 As shown, there are a base plate 2, a case 1, a metal pattern 3, and a semiconductor element 4. The base plate 2 is rectangular in a plan view and is made of an insulating resin.
[0018] The metal pattern 3 is formed in the center portion of the base plate 2. That is, the metal pattern 3 is not formed in the peripheral portion of the base plate 2. The metal pattern 3 is made of, for example, aluminum, silver, or copper.
[0019] A semiconductor element 4 is fixed to the upper surface of the metal pattern 3 by soldering. Figure 1 In the figure, one semiconductor element 4 is shown, but the number is not limited to one, and two or more may be sufficient.
[0020] The semiconductor element 4 is, for example, an IGBT (Insulated Gate Bipolar Transistor) chip or a free wheel diode chip.
[0021] The housing 1 is rectangular frame-shaped when viewed from above, and is made of resin, for example. A recess 1a is formed all around the lower end of the housing 1. The recess 1a is formed into a shape that can be fitted with the peripheral edge of the base plate 2. In addition, the interior of the housing 1 is filled with a sealing resin (not shown).
[0022] Next, use Figure 1 and Figure 2 , the connection between the base plate 2 and the housing 1 is described. Figure 1 and Figure 2As shown, the housing 1 is bonded to the peripheral edge of the base plate 2 via an adhesive 5. The peripheral edge of the base plate 2 is formed with a recessed portion 2a, an inclined surface 2b, and a groove 2c.
[0023] The recessed portion 2a is a shape that is recessed downward. The recessed portion 2a is formed on the upper surface of the base plate 2, specifically, on the inner peripheral side of the peripheral portion of the base plate 2, all around the circumference. The recessed portion 2a is the application position of the adhesive 5. The inclined surface 2b is formed all around the circumference in a manner that descends from the recessed portion 2a toward the outer peripheral side. The adhesive 5 overflowing from the recessed portion 2a wets and spreads downward along the inclined surface 2b. The groove 2c is a shape that is recessed downward, and is formed all around the circumference at the lower end of the inclined surface 2b. The adhesive 5 wets and spreads downward along the inclined surface 2b is accommodated in the groove 2c.
[0024] Here, in order to make the adhesive 5 easy to wet and spread along the inclined surface 2b, the inclination angle α of the inclined surface 2b is preferably greater than or equal to 45° and less than or equal to 60°. In addition, the adhesive 5 is, for example, a thermosetting epoxy resin adhesive. It is preferred that when the temperature of the adhesive 5 is 25°C, the viscosity of the adhesive 5 is greater than or equal to 25 Pa·s, and when the temperature of the adhesive 5 is greater than or equal to 50°C, the viscosity of the adhesive 5 is less than or equal to 10 Pa·s.
[0025] In the manufacturing process of the semiconductor device, after the semiconductor element 4 is fixed on the upper surface of the metal pattern 3, the temperature of the adhesive 5 is set to 25°C, and the adhesive 5 is applied to the concave portion 2a of the base plate 2, and the housing 1 is bonded to the peripheral portion of the base plate 2 via the adhesive 5. At this time, the adhesive 5 applied to the concave portion 2a becomes difficult to wet and spread. Next, after the encapsulation resin is filled into the housing 1, when the encapsulation resin is cured, if the adhesive 5 is heated to 50°C or more, the viscosity of the adhesive 5 decreases and becomes easy to wet and spread. As a result, the adhesive 5 can be wet and spread from the concave portion 2a along the inclined surface 2b to the lower side.
[0026] At this time, it is preferable that the recessed portion 2 a and the inclined surface 2 b of the base plate 2 are formed by press working or cutting working.
[0027] Next, use Figure 3 , a variation of implementation mode 1 is described. Figure 3 This is a cross-sectional view of a semiconductor device according to a modification of the first embodiment.
[0028] like Figure 3As shown in FIG. 1 , the peripheral portion of the base plate 2 protrudes upward compared to the central portion of the base plate 2. A recess 2a, a slope 2d, and a groove 2e are formed at the peripheral portion of the base plate 2. The recess 2a is formed all around the outer peripheral side of the peripheral portion of the base plate 2. The outer peripheral side of the recess 2a, i.e., the end of the base plate 2, protrudes upward compared to the recess 2a, and the adhesive 5 applied to the recess 2a does not wet and spread from the recess 2a to the outer peripheral side beyond the end of the base plate 2.
[0029] The inclined surface 2d is formed over the entire circumference in a manner that descends from the concave portion 2a toward the inner circumference. The adhesive 5 overflowing from the concave portion 2a wets and spreads toward the lower side along the inclined surface 2d. The groove 2e is a shape that is concave downward and is formed over the entire circumference at the lower end of the inclined surface 2d. The adhesive 5 that wets and spreads toward the lower side along the inclined surface 2d is accommodated in the groove 2e. In addition, in order to make it easy for the adhesive 5 to wet and spread along the inclined surface 2d, it is preferred that the inclination angle α of the inclined surface 2d is greater than or equal to 45° and less than or equal to 60°.
[0030] As described above, the semiconductor device involved in embodiment 1 and the variation of embodiment 1 has a base plate 2 and a shell 1 joined to the peripheral portion of the base plate 2 via an adhesive 5, and a recess 2a, i.e., an application position for applying the adhesive 5, and inclined surfaces 2b, 2d descending from the recess 2a toward the outer peripheral side or the inner peripheral side are formed on the peripheral portion of the base plate 2.
[0031] Therefore, when the adhesive 5 is heated up and the viscosity of the adhesive 5 is reduced during the curing of the encapsulating resin, the adhesive 5 wets and spreads along the inclined surfaces 2b and 2d from the recess 2a, thereby limiting the wet and spread direction of the adhesive 5. In addition, the application position of the adhesive 5 can be specified by forming the recess 2a.
[0032] In addition, the recessed portion 2a is provided on the upper surface of the base plate 2, and the inclined surface 2b is formed so as to descend from the recessed portion 2a toward the outer peripheral side. Therefore, when the adhesive 5 is heated up and the viscosity of the adhesive 5 is reduced during the curing of the encapsulating resin, the wetting and spreading direction of the adhesive 5 can be limited to the direction from the recessed portion 2a toward the outer peripheral side.
[0033] In addition, the peripheral edge of the base plate 2 is convex upward compared to the central portion of the base plate 2, and the inclined surface 2d is formed so as to descend from the concave portion 2a toward the inner circumference. Therefore, when the adhesive 5 is heated up during the curing of the encapsulating resin and the viscosity of the adhesive 5 is reduced, the wetting and spreading direction of the adhesive 5 can be limited to from the concave portion 2a toward the inner circumference. As a result, the adhesive 5 can be prevented from overflowing to the outside of the product.
[0034] Furthermore, since the inclination angle α of the inclined surfaces 2b and 2d is greater than or equal to 45° and less than or equal to 60°, when the temperature of the adhesive 5 rises and the viscosity of the adhesive 5 decreases, the adhesive 5 easily wets and spreads along the inclined surfaces 2b and 2d from the recess 2a.
[0035] In addition, when the temperature of the adhesive 5 is 25°C, the viscosity of the adhesive 5 is greater than or equal to 25 Pa·s, and when the temperature of the adhesive 5 is greater than or equal to 50°C, the viscosity of the adhesive 5 is less than or equal to 10 Pa·s. The method for manufacturing a semiconductor device comprises: step (a) of setting the temperature of the adhesive 5 to 25°C, applying the adhesive 5 to the recess 2a of the base plate 2, and bonding the housing 1 to the peripheral portion of the base plate 2 via the adhesive 5; and step (b) of causing the adhesive 5 heated to greater than or equal to 50°C to wet and spread from the recess 2a along the inclined surfaces 2b and 2d toward the lower side when the encapsulation resin filled in the housing 1 is cured.
[0036] Therefore, when the adhesive 5 is applied, the adhesive 5 is less likely to wet and spread, so it is possible to suppress the adhesive 5 from adhering to unexpected positions and overflowing. On the other hand, after the base plate 2 and the housing 1 are joined, the adhesive 5 is more likely to wet and spread along the inclined surfaces 2b and 2d.
[0037] Furthermore, since the recessed portion 2 a and the inclined surfaces 2 b and 2 d are formed by press working or cutting working, it is possible to reduce the processing cost of the base plate 2 by adopting a common processing method of the base plate 2 .
[0038] <Implementation method 2>
[0039] Next, a semiconductor device according to Embodiment 2 will be described. Figure 4 It is a cross-sectional view of a semiconductor device according to Embodiment 2. In Embodiment 2, the same components as those described in Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.
[0040] like Figure 4 As shown, in Embodiment 2, the peripheral edge of the base plate 2 protrudes upward compared to the central portion of the base plate 2. The peripheral edge of the base plate 2 is formed with a recessed portion 2a, a slope 6, and grooves 2c and 2e.
[0041] The inclined surface 6 includes an inclined surface 2b as a first inclined surface formed so as to descend from the recessed portion 2a toward the outer peripheral side, and an inclined surface 2d as a second inclined surface formed so as to descend from the recessed portion 2a toward the inner peripheral side.
[0042] The recessed portion 2a is formed throughout the entire circumference at the center of the peripheral portion of the base plate 2. The inclined surface 2b is formed throughout the entire circumference in a manner descending from the recessed portion 2a toward the outer peripheral side. The groove 2c is formed throughout the entire circumference at the lower end portion of the inclined surface 2b. The adhesive 5 that wets and spreads toward the lower side along the inclined surface 2b is accommodated in the groove 2c. The inclined surface 2d is formed throughout the entire circumference in a manner descending from the recessed portion 2a toward the inner peripheral side. The groove 2e is formed throughout the entire circumference at the lower end portion of the inclined surface 2d. The adhesive 5 that wets and spreads toward the lower side along the inclined surface 2d is accommodated in the groove 2e. In addition, it is preferred that the inclination angle α of the inclined surfaces 2b and 2d is greater than or equal to 45° and less than or equal to 60°.
[0043] Next, use Figure 5 , a variation of implementation mode 2 is described. Figure 5 This is a cross-sectional view of a semiconductor device according to a modified example of the second embodiment.
[0044] like Figure 5 As shown, a projection 1b received by the recess 2a is provided at a portion of the housing 1 opposite to the recess 2a. The projection 1b is provided over the entire circumference of the housing 1. When the base plate 2 and the housing 1 are joined, the projection 1b crushes the adhesive 5 applied to the recess 2a, thereby promoting the wetting and spreading of the adhesive 5.
[0045] As described above, in the semiconductor device according to the second embodiment and the variation of the second embodiment, the peripheral portion of the base plate 2 protrudes upward compared to the central portion of the base plate 2. The inclined surface 6 includes the inclined surface 2b as the first inclined surface formed in a manner descending from the recessed portion 2a toward the outer peripheral side and the inclined surface 2d as the second inclined surface formed in a manner descending from the recessed portion 2a toward the inner peripheral side.
[0046] Therefore, the wetting and spreading directions of the adhesive 5 can be set to two directions instead of one direction, so the wetting and spreading time can be shortened.
[0047] In addition, a projection 1b received by the recess 2a is provided at a portion of the housing 1 opposite to the recess 2a. Therefore, when the base plate 2 and the housing 1 are joined, the projection 1b crushes the adhesive 5 applied to the recess 2a to facilitate wetting and spreading, thereby further shortening the wetting and spreading time.
[0048] In addition, the various embodiments can be freely combined, or the various embodiments can be appropriately modified or omitted.
[0049] Description of the label
[0050] 1 housing, 1b protrusion, 2 base plate, 2a recess, 2b, 2d inclined surfaces, 5 adhesive, 6 inclined surfaces.
Claims
1. A semiconductor device comprising: a base plate; and a housing joined to the peripheral edge of the base plate via an adhesive, A concave portion, which is a position where the adhesive is applied, and a slope that descends from the concave portion toward the outer peripheral side or the inner peripheral side are formed on the peripheral edge portion of the base plate.
2. The semiconductor device according to claim 1, wherein The recess is provided on the upper surface of the base plate. The inclined surface is formed so as to descend from the recessed portion toward the outer peripheral side.
3. The semiconductor device according to claim 1, wherein The peripheral edge of the base plate protrudes upward compared to the central portion of the base plate. The inclined surface is formed so as to descend from the recessed portion toward the inner peripheral side.
4. The semiconductor device according to claim 1, wherein The peripheral edge of the base plate protrudes upward compared to the central portion of the base plate. The inclined surface includes a first inclined surface formed so as to descend from the recessed portion toward the outer peripheral side, and a second inclined surface formed so as to descend from the recessed portion toward the inner peripheral side.
5. The semiconductor device according to claim 4, wherein: A protrusion received by the recessed portion is provided at a portion of the housing opposite to the recessed portion.
6. The semiconductor device according to any one of claims 1 to 5, wherein: The inclination angle of the inclined surface is greater than or equal to 45° and less than or equal to 60°.
7. A method for manufacturing a semiconductor device, comprising manufacturing the semiconductor device according to any one of claims 1 to 6, In the method for manufacturing a semiconductor device, When the temperature of the adhesive is 25° C., the viscosity of the adhesive is greater than or equal to 25 Pa·s; when the temperature of the adhesive is greater than or equal to 50° C., the viscosity of the adhesive is less than or equal to 10 Pa·s. The method for manufacturing a semiconductor device comprises the following steps: Step (a), setting the temperature of the adhesive to 25° C., applying the adhesive to the recessed portion of the base plate, and bonding the housing to the peripheral edge of the base plate via the adhesive; and The step (b) is to wet and spread the adhesive having a temperature of 50° C. or higher from the recess along the inclined surface toward the lower side when the sealing resin filled in the housing is cured.
8. The method for manufacturing a semiconductor device according to claim 7, wherein: The recessed portion and the inclined surface are formed by punching or cutting.