1. A rich-lean combustion burner, comprising: a) central rich-side flame holes arranged in one row and extending in the longitudinal direction in the middle relative to the lateral direction, b) lean-side flame holes arranged in two rows sandwiching said central rich-side flame hole row therebetween from both sides relative to the lateral direction and c) outer rich-side flame holes arranged in two rows sandwiching said two lean-side flame hole rows on both sides therebetween from outside, wherein a flame hole formation member forms said lean-side flame holes of said two lean-side flame hole rows, said flame hole formation member being inserted and mounted from above in a formation member forming said central rich-side flame holes, and
wherein said flame hole formation member comprises: i) a pair of flame hole formation parts forming said lean-side flame holes of each of said two lean-side flame hole rows and ii) at least one or more bridge formation parts connecting respective upper end portions or respective side end portions of said pair of said flame hole formation parts, and wherein said pair of said flame hole formation parts are held integrally with each other by said bridge formation part in such a state that said pair of said flame hole formation parts are oriented face-to-face with each other and spaced apart at an interval of a predetermined distance so as to sandwich therebetween said formation member forming said central rich-side flame holes from both sides relative to the lateral direction.
2. The rich-lean combustion burner as set forth in claim 1,
wherein in the upper end area of said pair of said flame hole formation parts, sequential ones of a plurality of said bridge formation parts are spaced apart from one another in the longitudinal direction at intervals of a predetermined distance.
3. The rich-lean combustion burner as set forth in claim 2,
wherein said bridge formation part abuts said formation member forming said central rich-side flame holes in such a state that said bridge formation part sits from above astride the upper end edge of said central rich-side flame hole formation member.
4. The rich-lean combustion burner as set forth in claim 2,
wherein said bridge formation part is shaped as a strip-like plate extending in the lateral direction,
wherein, an engagement groove is formed in the upper end edge of said formation member forming said central rich-side flame holes, said bridge formation part is fitted into the engagement groove, and
wherein by fitting of said bridge formation part into said engagement groove, said flame hole formation member is connected in such a state that its movement in the longitudinal direction is controlled.
5. The rich-lean combustion burner as set forth in claim 2,
wherein said bridge formation part has an upper surface which lies either in flush with or lower than the upper surface of said central rich-side flame holes.
6. The rich-lean combustion burner as set forth in claim 1,
wherein said formation member forming said central rich-side flame holes is disposed, in the vicinity of its upper end, with a projecting part projecting outward in the lateral direction while, a concave part is formed in the innermost surface of said flame hole formation member, said projecting part is received into said concave part to thereby prevent said flame hole formation part from coming loose in the upward direction.
7. The rich-lean combustion burner as set forth in claim 1,
wherein said flame hole formation member is formed from a flame hole formation material in the form of a developed sheet, said material sheet comprising at least two partially connected strip-like plate parts which forming said flame hole formation parts on both sides so that said flame hole formation parts are positioned in opposing relation to each other across said bridge formation part, and said flame hole formation material sheet bending at positions where said bridge formation parts and the strip-like plate parts are connected and said flame hole formation member is an integral construction.
8. The rich-lean combustion burner as set forth in claim 1,
wherein each of said lean-side flame holes is formed by an assembled plurality of distributing plates so that clearance gaps are formed between ones of said plural distributing plates in opposing relation to each other, forming flow channels for lean-side mixture, and
wherein the longitudinal end of the outermost one of said plural distributing plates curves outward so as to describe a convex curve in plan view so that the longitudinal leading end of said outermost distributing plate overlaps the longitudinal leading end of the innermost one of said plural distributing plates.
9. The rich-lean combustion burner as set forth in claim 8,
wherein the longitudinal end of said outermost distributing plate has a material elasticity so that the longitudinal end of said outermost distributing plate elastically deforms to be in close contact with the inner surface of said formation member forming said outer rich-side flame holes.
10. The rich-lean combustion burner as set forth in claim 8,
wherein the longitudinal end of another distributing plate adjacent to said innermost distributing plate is curved in the direction of said innermost distributing plate.
11. A combustion apparatus comprising a rich-lean combustion burner as set forth in any one of claims 1 through 10.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A semiconductor power module molded structure, comprising:
a case; and
a plurality of power semiconductor modules in the case, each of the power semiconductor modules comprising:
one insulating layer,
a copper base substrate having a first copper block and a second copper block, either the first or second copper block being fixed on one side of the one insulating layer and the other being fixed on the other side of the one insulating layer;
a plurality of power semiconductor elements having silicon carbide and formed on the copper base substrate, each having one side fixed onto the first copper block with a first conductive bond layer;
a plurality of implant pins fixed to the other side of each of the plurality of power semiconductor elements with a second conductive bond layer;
a printed circuit board fixed to the plurality of implant pins and disposed to face the plurality of power semiconductor elements;
a first sealing material containing no flame retardant, and disposed only at a portion where the plurality of power semiconductor elements is enclosed, the first sealing material covering an upper portion and side portions of each of the plurality of power semiconductor elements between the copper base substrate and the printed circuit board;
a second sealing material containing a flame retardant, and disposed to cover the first sealing material; and
an external connection terminal extending upwardly from the copper base substrate to cross the printed circuit board,
wherein said plurality of power semiconductor elements is disposed on the one insulating layer with a space therebetween, only the first sealing material being disposed in the space and around said plurality of power semiconductor elements,
the second sealing material encloses an outer circumferential part of the first sealing material surrounding said plurality of power semiconductor elements to directly cover side portions of the first sealing material and indirectly cover an upper portion of the first sealing material through the printed circuit board,
the first sealing material contains no flame retardant to enhance a thermal resistant performance, and the second sealing material contains the flame retardant to resist oxidation degradation, and
the first sealing material encloses the external connection terminal between the copper base substrate and the printed circuit board,
wherein said plurality of power semiconductor modules is arranged side by side in the case,
the printed circuit boards of the plurality of power semiconductors are integrally connected to each other, and
the second sealing material is arranged in the case between the plurality of power semiconductor modules, and
wherein a heat distortion temperature of each of the first sealing materials is 175\xb0 C. to 225\xb0 C., a thermal expansion coefficient of each of the first sealing materials is 1.5\xd710\u22125\xb0 C. to 1.8\xd710\u22125\xb0 C., and a bonding strength of each of the first sealing materials to each of the copper base substrates is 10 MPa to 30 MPa; a heat distortion temperature of each of the second sealing materials is 100\xb0 C. to 175\xb0 C., a thermal expansion coefficient of each of the second sealing materials is 1.5\xd710\u22125\xb0 C. to 1.8\xd710\u22125\xb0 C., and a bonding strength of each of the second sealing materials to each of the copper base substrates is 10 MPa to 30 MPa; and liquid epoxy resin is used in the first sealing materials and the second sealing materials.