A kind of manufacture method of compression joint type IGBT module and compression joint type IGBT module
Technical field
The present invention is mainly concerned with igbt (IGBT) field, refers in particular to a kind of manufacture method and compression joint type IGBT module of compression joint type IGBT module.
Background technology
Igbt (IGBT) has that on-state voltage drop is low, current capacity is large, input impedance is high, fast response time and the simple feature of control, is widely used in industry, information, new forms of energy, medical science, traffic, military affairs and aviation field.Compression joint type IGBT can two-side radiation, and have excellent radiating effect and high reliability, and show short circuit failure mode when device failure, therefore it is widely used in the fields such as intelligent grid.
In prior art, have practitioner to propose a kind of full compression joint type IGBT module, that is: arrange multiple chip positioning device in inside modules, then put molybdenum sheet and chip into positioner successively, then crimping forms.Wherein, the grid of igbt chip is drawn out on PCB by spring terminal and interconnects.After adopting this structure, because needs are located separately each chip, be difficult to during crimping ensure consistent pressure error, easily cause wafer damage.In addition, multiple chip positioning device is needed in a module, and need to cover at pipe to arrange salient point and fix these positioners, the grid of igbt chip need be drawn out on PCB by spring terminal in addition, PCB also needs to cover at pipe to be fixed, make the structure of module more complicated like this, processing and manufacturing difficulty is very large.
Summary of the invention
The technical problem to be solved in the present invention is just: the technical problem existed for prior art, the invention provides that a kind of overall structure is more simply compact, the manufacture method that makes, the better reliability that be connected, heat dispersion better compression joint type IGBT module easier with assembling and compression joint type IGBT module.
For solving the problems of the technologies described above, the present invention by the following technical solutions:
A manufacture method for compression joint type IGBT module, the steps include:
1. when the encapsulation of IGBT module, first bottom molybdenum sheet is placed in a sintering pedestal, and an auxiliary clamp is positioned on the molybdenum sheet of bottom, then multiple power semiconductor chip is positioned on the molybdenum sheet of bottom; Wherein bottom molybdenum sheet is a monoblock molybdenum sheet; Described power semiconductor chip comprises FRD chip and igbt chip, and described igbt chip and FRD chip are that inverse parallel is arranged;
2. by sintering, power semiconductor chip is fixed on the molybdenum sheet of bottom, then auxiliary clamp and sintering pedestal are taken down; That is, by bottom molybdenum sheet, the negative electrode of igbt chip collector electrode with FRD chip back is connected, and as the collector electrode of IGBT module;
3. PCB is installed;
4. PCB is utilized to be fixed by multiple tops molybdenum sheet as the orientation tool of top molybdenum sheet;
5. the crimping of shell is carried out: realize the anode interconnect of igbt chip emitter and FRD chip by the pipe lid of shell during crimping and the contact of top molybdenum sheet, and as the emitter of IGBT module; The cathode interconnect of igbt chip collector electrode and FRD chip is achieved by the base of shell during crimping and the contact of bottom molybdenum sheet, and as the collector electrode of IGBT module; Realize igbt chip gate interconnection and lead to the outside of IGBT module by each contact electrode of PCB during crimping and the contact of igbt chip grid, as the grid of IGBT module.
Further improvement as the inventive method:
Multiple sheet metal is also positioned on the molybdenum sheet of bottom by the present invention, by being sintered to fix together with power semiconductor chip on the molybdenum sheet of bottom, to form the location division being used for fixing PCB.
The thickness of described sheet metal is greater than the thickness of described power semiconductor chip, and the thickness of described sheet metal is less than the thickness sum of power semiconductor chip and PCB.
Arrange at the lower surface of described PCB and be used for locating and the positioning port be connected.
The igbt chip collector electrode at the described igbt chip back side and the negative electrode of described FRD chip back are by being sintered to fix on the molybdenum sheet of bottom, the Central Symmetry be set to about bottom molybdenum sheet of described igbt chip and FRD chip, and it is adjacent igbt chip to be set to grid between two, or it is adjacent to be set to every three igbt chip grids.
The lower surface of described PCB and the place of igbt chip gate contact are provided with splicing ear, and igbt chip grid leads on the interconnecting conductor of PCB and interconnects by described splicing ear, then leads to the outside of module.
Described PCB is provided with a lot of window, and the shape of the surface metalation part in the cellular region of the shape of described window and size and igbt chip and FRD chip is identical with size.
Described top molybdenum sheet is polylith small pieces molybdenum sheets, and the thickness of described molybdenum sheet is identical with the thickness of PCB, and area and the shape of the anode of the area of described molybdenum sheet and shape and igbt chip emitter or FRD chip are identical.
Isolated by ceramic ring between described pipe lid and base.
The present invention further provides a kind of compression joint type IGBT module, it comprises bottom molybdenum sheet, power semiconductor chip, PCB and top molybdenum sheet, described bottom molybdenum sheet provides electric current and thermal dissipating path for a monoblock molybdenum sheet and for power semiconductor chip, described power semiconductor chip is by being sintered to fix on the molybdenum sheet of bottom, described PCB is positioned at the top of power semiconductor chip and is connected with bottom molybdenum sheet by location, and described top molybdenum sheet is fixing by PCB location.
Described power semiconductor chip comprises igbt chip and FRD chip, the igbt chip collector electrode at the described igbt chip back side and the negative electrode of FRD chip back are by being sintered to fix on the molybdenum sheet of bottom, the Central Symmetry be set to about bottom molybdenum sheet of described igbt chip and FRD chip, and it is adjacent igbt chip to be set to grid between two, or it is adjacent to be set to every three igbt chip grids.
By being sintered to fix multiple sheet metal on the molybdenum sheet of described bottom, described sheet metal is in order to form the location division of fixing PCB.
The thickness of described sheet metal is greater than the thickness of described power semiconductor chip, and the thickness of described sheet metal is less than the thickness sum of power semiconductor chip and PCB.
The lower surface of described PCB arranges and is used for locating and the positioning port be connected.
Compared with prior art, the invention has the advantages that: the feature that present invention incorporates welded type and compression joint type, the back side of power semiconductor chip is directly fixed on the molybdenum sheet of bottom by sintering, and such fixed form makes power semiconductor chip obtain larger support force and have better heat dissipation characteristics; Further, all power semiconductor chips, through being sintered to fix bottom monoblock on molybdenum sheet, need not arranging a positioning unit to each chip, simplify modular structure in module; The grid of inside modules igbt chip is drawn and is not adopted spring terminal, but directly adopts PCB to carry out interconnecting and drawing; PCB simultaneously also as the orientation tool of top molybdenum sheet, the auxiliary locator of thorough cancellation module inside.Therefore, module of the present invention combines sintering device and total head connects feature and the advantage of device, and its structure &processes is simpler, and has better heat dissipation characteristics.
Accompanying drawing explanation
Fig. 1 is the dislocation display schematic diagram of IGBT module section of the present invention.
Auxiliary clamp is positioned over the structural representation on the molybdenum sheet of bottom by Fig. 2.
Fig. 3 is the sectional structure schematic diagram at A1-A1 place in Fig. 2.
Fig. 4 is by being sintered to fix the structural representation on the molybdenum sheet of bottom by power semiconductor chip and sheet metal.
Fig. 5 is the structural representation of PCB in the present invention.
PCB is positioned over the structural representation after on power semiconductor chip and sheet metal by Fig. 6.
Top molybdenum sheet is positioned over the structural representation after on PCB by Fig. 7.
Fig. 8 is the schematic diagram of the molybdenum sheet being positioned at FRD chip top in this example.
Fig. 9 is the schematic diagram of the molybdenum sheet being positioned at igbt chip top in this example.
Figure 10 is the sectional structure schematic diagram at A2-A2 place in Fig. 7.
Figure 11 is the IGBT module surface structure schematic diagram after having assembled.
Figure 12 is the structural representation utilizing PCB self poisoning mouth to position in another embodiment.
Figure 13 is structural representation when adopting every three igbt chip grids adjacent in another embodiment.
Figure 14 is the structural representation adopting another kind of PCB in the embodiment of Figure 13.
Marginal data:
1, bottom molybdenum sheet; 2, power semiconductor chip; 21, FRD chip; 211, anode; 212, negative electrode; 22, igbt chip; 221, igbt chip grid; 222, igbt chip emitter; 223, igbt chip collector electrode; 3, PCB; 31, splicing ear; 32, interconnecting conductor; 33, gate interconnection electrode leads to client; 34, positioning port; 35, window; 4, top molybdenum sheet; 5, sheet metal; 6, auxiliary clamp; 7, pedestal is sintered; 80, Guan Gai; 81, base; 82, the grid of IGBT module; 84, ceramic ring.
Embodiment
Below with reference to Figure of description and specific embodiment, the present invention is described in further details.
The present invention is a kind of manufacture method of compression joint type IGBT module, and its concrete steps are:
(1), when the encapsulation of IGBT module, first bottom molybdenum sheet 1 is placed in a sintering pedestal 7, and an auxiliary clamp 6 is positioned on the molybdenum sheet 1 of bottom (see Fig. 1, Fig. 2 and Fig. 3), then the power semiconductor chip 2 of some and sheet metal 5 are positioned on the molybdenum sheet 1 of bottom (see Fig. 4).Wherein, bottom molybdenum sheet 1 is a monoblock molybdenum sheet, and auxiliary clamp 6 is used for positioning power semiconductor chip 2, and power semiconductor chip 2 comprises FRD chip 21 and igbt chip 22, and igbt chip 22 is arranged in inverse parallel with FRD chip 21.
(2), by sintering power semiconductor chip 2 and sheet metal 5 are fixed on the molybdenum sheet 1 of bottom, then auxiliary clamp 6 and sintering pedestal 7 are taken down.Like this, the igbt chip collector electrode 223 being achieved igbt chip 22 back side by bottom molybdenum sheet 1 is connected with the negative electrode 212 at FRD chip 21 back side.Sheet metal 5 is fixed on the molybdenum sheet 1 of bottom and forms location division (" salient point "), facilitates the location of PCB 3 and fixes.What bottom this, molybdenum sheet 1 was power semiconductor chip 2 provides electric current and thermal dissipating path, simultaneously as the collector electrode of IGBT module.In this example, certain thickness sheet metal 5(can be had as aluminium flake in edge's sintering two panels of bottom molybdenum sheet 1), form the location division of " salient point " shape.
(3) location and installation PCB 3(is carried out see Fig. 5 and Fig. 6 in the location division, utilizing sheet metal 5 to be formed); Wherein, the place that the lower surface of PCB 3 contacts with igbt chip grid 221 is provided with splicing ear 31, the interconnecting conductor 32 that igbt chip grid 221 is led to PCB 3 by splicing ear 31 interconnects, then leads to the outside of module.When embody rule, can require that PCB 3 has higher evenness, and there is certain intensity and elasticity.
(4), utilize PCB 3 as the orientation tool of top molybdenum sheet 4, by multiple tops molybdenum sheet 4 fixing (Fig. 7 and Figure 10).Wherein, top molybdenum sheet 4, both as a kind of buffer medium, plays the effect of being drawn by the anode 211 of igbt chip emitter 222 and FRD chip 21.The same with bottom molybdenum sheet 1, top molybdenum sheet 4 both provided the current path of power semiconductor chip, also provided thermal dissipating path.See the structural representation that Fig. 8 and Fig. 9 is two kinds of difform top molybdenum sheets 4.
(5) crimping (see Figure 11) of shell, is carried out.The anode 211 realizing igbt chip emitter 222 and FRD chip 21 by the pipe lid 80 of shell during crimping and the contact of top molybdenum sheet 4 interconnects, and as the emitter of IGBT module; The negative electrode 212 achieving igbt chip collector electrode 223 and FRD chip 21 by the base 81 of shell during crimping and the contact of bottom molybdenum sheet 1 interconnects, and as the collector electrode of IGBT module; Realize igbt chip grid 221 by each contact electrode of PCB 3 during crimping and the contact of igbt chip grid 221 to interconnect and the outside leading to IGBT module, as the grid 82 of IGBT module; By ceramic ring 84(ceramic package between pipe lid 80 and base 81) isolate.
As shown in Figure 1, compression joint type IGBT module of the present invention, the profile of module whole is circular, and it comprises bottom molybdenum sheet 1, power semiconductor chip 2, sheet metal 5, PCB 3 and top molybdenum sheet 4.Wherein, bottom molybdenum sheet 1 is that a monoblock is circular, smooth and have certain thickness molybdenum sheet, is used for supporting power semiconductor chip 2, and provides electric current and thermal dissipating path for power semiconductor chip 2.In this example, bottom molybdenum sheet 1 is one smooth, circular, thickness is 0.2---the molybdenum sheet of 0.5mm, its diameter is depending on the power grade of IGBT module.PCB 3 is used for being carried out interconnecting and drawing by igbt chip grid 221, simultaneously also as the positioner of top molybdenum sheet 4.
See Fig. 4, in the present embodiment, power semiconductor chip 2 comprises igbt chip 22 and FRD chip 21, the igbt chip collector electrode 223 at igbt chip 22 back side and the negative electrode 212 at FRD chip 21 back side by being sintered to fix on bottom molybdenum sheet 1, thus realizing igbt chip collector electrode 223 and are connected with the negative electrode 212 of FRD chip 21.The Central Symmetry be set to about bottom molybdenum sheet 1 of igbt chip 22 and FRD chip 21, and it is adjacent that igbt chip 22 is set to grid between two.
When embody rule, can according to actual needs, igbt chip 22 and FRD chip 21 can be all square, also can be all rectangle, can also take different shapes (that is, being respectively positive direction and rectangle).Die size can be identical, also can not be identical, and according to different current classes, its minimum length of side can be as small as 0.5cm, and its maximal side can greatly to 5cm.When embody rule, igbt chip 22 can be identical with the thickness of FRD chip 21, and according to different electric pressures, scope is 60um---750um.
Sheet metal 5 is for having the little square piece of certain thickness (be greater than the thickness of power semiconductor chip 2 and be less than the thickness sum of power semiconductor chip 2 and PCB 3), and material can be aluminium or other metals.Being fixed on fixed part bottom molybdenum sheet 1 being formed " salient point " shape by the mode (as sintered together with power semiconductor chip) of sintering, being used for assisting PCB 3 to position with fixing.
See Fig. 5 and Fig. 6, in this example, PCB 3 has higher evenness, and has certain intensity and elasticity, and thickness range is 0.5mm---2mm.Be arranged on by PCB 3 above power semiconductor chip 2, its interconnecting conductor 32 is arranged on the inside of PCB 3; The place that PCB 3 lower surface contacts with igbt chip grid 221 is provided with splicing ear 31, and the interconnecting conductor 32 being used for igbt chip grid 221 to be drawn out to PCB 3 interconnects.PCB 3 is also provided with gate interconnection electrode leads to client 33.Above-mentioned interconnection circuit (trend) mode is not unique, can design according to actual needs.It is inner that interconnecting conductor layer is then embedded to PCB 3, and the place except splicing ear 31, the surface of PCB 3 is all through insulation processing.Meanwhile, PCB 3 is provided with a lot of window 35, and the shape of the surface metalation part in the cellular region (active area) of the shape of window 35 and size and igbt chip 22 and FRD chip 21 is identical with size.These windows 35 are used for positioning top molybdenum sheet 4 and fixing.
See Fig. 8 and Figure 10, in this example, top molybdenum sheet 4 is many little slice, thin pieces, and its thickness is identical with the thickness of PCB 3, and area and the shape of the anode 211 of its area and shape and igbt chip emitter 222 or FRD chip 21 are identical.Therefore, the molybdenum sheet on FRD chip 21 top is little square piece (see Fig. 8), and the molybdenum sheet on igbt chip 22 top has a unfilled corner (see Fig. 9), to avoid covering in igbt chip grid 221, facilitates extraction and the interconnection of igbt chip grid 221.
See Fig. 3, in this example, sintering pedestal 7 be the circular of sealed bottom, sintering pedestal 7 interior circular diameter than the diameter of bottom molybdenum sheet 1 large 0.01um(consideration sintering complete after the easy demoulding), material can be high-melting-point (fusing point is higher than the sintering temperature in the present invention) metal or ceramic material.
See Fig. 2 and Fig. 3, auxiliary clamp 6 is high-melting-point (fusing point is higher than the sintering temperature in the present invention) metal or ceramic material.In outmost eight points of auxiliary clamp 6, the distance between distance two points is farthest identical with the diameter of bottom molybdenum sheet 1.According to actual needs, the centre of this auxiliary clamp 6 arranges multiple square (square or rectangular) fixture window, and the size of fixture window is identical with the size of igbt chip 22 and FRD chip 21.
Be appreciated that; in other examples, shown in Figure 13, igbt chip 22 can also be set to every three igbt chip grids 221 adjacent; at this time the shape of PCB 3 will do corresponding adjustment (see Figure 14), and this equally also should belong within protection scope of the present invention.
Be appreciated that in other examples, shown in Figure 12, the location of PCB 3 does not adopt " salient point " shape location division utilizing sheet metal 5 to be formed, but directly by arranging positioning port 34 at PCB 3 lower surface, thus can realize the location of PCB 3.At this time, just no longer need to arrange and sintered metal sheet 5, thus further simplify the overall structure of IGBT module, this equally also should belong within protection scope of the present invention.
Be appreciated that in other examples, igbt chip 22 can be not identical with the thickness of FRD chip 21, so more presses close to actual needs.At this moment, the local thickness of PCB 3 needs corresponding adjustment, to adapt to different chip thickness.Meanwhile, the thickness of top molybdenum sheet 4 also should adjust, and is all in same level with the upper surface realizing crimping rear all top molybdenum sheets 4.
Or the opening degree of depth of the positioning port 34 of PCB 3 local needs corresponding adjustment (with reference to Figure 12), to adapt to different chip thickness; Meanwhile, the thickness of top molybdenum sheet 4 also should adjust, and is all in same level with the upper surface realizing crimping rear all top molybdenum sheets 4.
Below be only the preferred embodiment of the present invention, protection scope of the present invention be not only confined to above-described embodiment, all technical schemes belonged under thinking of the present invention all belong to protection scope of the present invention.It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principles of the present invention, should be considered as protection scope of the present invention.