CN112768438B - A crimping type power module and preparation method thereof - Google Patents

Abstract

A compression-bonded power module comprising: the power module layer comprises a first power module layer and a second power module layer which are arranged from top to bottom; the second power module layer comprises a substrate and n x m bosses arranged on the substrate, and each boss is provided with a subunit chip; the second power module layer further comprises n signal transmission strips for connecting the grid electrodes of the sub-unit chips in each row, the signal transmission strips comprise m layers of stacked and integrated signal transmission sub-strips, and each signal transmission sub-strip is used for transmitting a signal of one sub-unit chip; n >1, m > 1. The invention solves the technical problem that the sub-unit chip in the traditional crimping type power module is difficult to independently remove the fault, and can realize independent control and detection of the sub-unit chip in the power module.

Description

A crimping type power module and preparation method thereof

technical field

The field of semiconductors, specifically the preparation of power electronic devices

Background technique

The invention designs a pressure-bonding device based on a multi-layer PCB board that is convenient for detection, and the device can conveniently test the position of a failed subunit chip of the pressure-bonding device.

In the traditional welded IGBT, the stray parameters of the line are large, and a large voltage spike will be generated during the turn-off process, accompanied by certain electromagnetic interference. When the power system puts forward higher requirements on the power level and requires more chips to be connected in parallel, the parasitic parameters and their differences of the gate, emitter and collector of the chip will be further increased, which will aggravate the voltage overshoot and increase the switching losses and lead to a large current imbalance, which reduces the reliability of the device. Compared with welded IGBTs, crimped IGBTs have the advantages of high voltage, high current, low stray inductance, fast switching speed, and double-sided heat dissipation. Therefore, crimped IGBTs have become the mainstream choice for semiconductor devices in HVDC transmission.

The crimp-type IGBT, because the sub-unit chips are crimped together in parallel by pressure, is often short-circuited during use. However, traditionally, because all the chips are connected in parallel, once there is a short circuit inside the chip, the entire device will be short-circuited. invalid. However, it is very difficult for traditional press-bonded devices to eliminate failed chips, and each chip needs to be taken out for wafer-level testing. The entire testing process is very cumbersome.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the prior art and solve the technical problem that the subunit chips inside the crimped power module are difficult to troubleshoot individually, the present invention can realize the crimped power module structure and its preparation method which can be independently controlled and detected inside the power module.

A crimping type power module, comprising: at least one power module layer arranged in a stack, the power module layer comprising a first power module layer and a second power module layer arranged from top to bottom;

The second power module layer includes a substrate, and n*m bosses arranged on the substrate, each of the bosses is provided with a sub-unit chip; the second power module layer also includes n for connecting each A signal transmission bar for the gate of a row sub-unit chip, the signal transmission bar includes m-layer stacked and integrated signal transmission sub-strips, each signal transmission sub-strip is used to transmit the signal of one sub-unit chip; n>1, m>1 .

Preferably, the signal transmission sub-strips integrated in the m-layer stack have equal widths, and the lengths of the signal transmission sub-strips integrated in each layer decrease sequentially from top to bottom according to the position of the sub-unit chips.

Preferably, the m-layer stacked and integrated signal transmission sub-strip includes a thimble, and the thimble is connected to the subunit chip; the m-layer stacked and integrated signal transmission sub-strip is connected by an insulating material.

Preferably, the first power module layer includes an upper layer of metal end caps and a lower layer of metal end caps, and the lower layer of metal end caps includes an insulating outer frame and n*m metal blocks corresponding to the subunit chips.

Preferably, the sub-unit chips include power chips and FRD chips, and the power chips include MOSFET chips or IGBT chips; the insulating materials are organic silica gel, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue, polyamide One or more combinations of imide gums.

A preparation method of a crimped power module, comprising:

S1: prepare an m-layer stack-integrated signal transmission sub-strip, the first power module layer; m>1;

S2: prepare a second power module layer by using n of the m-layer stacked and integrated signal transmission sub-strips; the second power module layer includes a substrate, and n*m bosses disposed on the substrate, each of the projections A sub-unit chip is arranged on the stage; the signal transmission strip includes m-layer stacked and integrated signal transmission sub-strips, and each signal transmission sub-strip is used to transmit the signal of one sub-unit chip; n>1;

S3: placing the first power module layer on top of the second power module layer, and crimping to prepare the power module layer;

S4: Place at least one of the power module layers vertically and crimp to form a power module.

Preferably, the S1 preparation of the m-layer stacked integrated signal transmission sub-strip includes:

S1.1: Cut out n signal transmission sub-strips of length xi on the printed circuit board, 1<i<m;

S1.2: Select m signal transmission sub-strips with a length of xi, stack them according to the order of length from short to long, and use insulating materials to bond, 1<i<m, to form m-layer stacked and integrated signal transmission sub-strips.

Preferably, during the bonding, a contact position with the ejector pin is reserved on the signal transmission sub-strip beforehand for bonding, and the ejector pin contact position is determined according to the gate signal connection position of the subunit chip.

Preferably, the first power module layer includes an upper layer of metal end caps and a lower layer of metal end caps, and the lower layer of metal end caps includes an insulating outer frame and n*m metal blocks corresponding to the subunit chips.

Preferably, the sub-unit chips include power chips and FRD chips, and the power chips include MOSFET chips or IGBT chips; the insulating material is organic silica gel, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue, polyamide One or more combinations of imide gums.

The invention proposes to change the traditional installation method, separate the upper end cap into two layers, the lower layer is embedded with a separate copper block in the FR4 board and connected to the gates of each chip, and the upper layer is still covered with copper end caps. Multi-layer signal transmission strips are used for gate lead-out, and the copper-clad surfaces of each layer of the external test end leak out in sequence. This special signal transmission strip can realize the driving of designated chips in the device. When the device fails, the upper copper plate of the upper end cap is removed, the gate of a single device is driven independently, and the CE terminal of the chip is connected to achieve the effect of detecting a single chip.

Description of drawings

FIG. 1 is a schematic diagram of a stacked crimp power module provided in Embodiment 1

FIG. 2 is a top view of the stacked crimp power module provided in the first embodiment

FIG. 3 is a top view of the stacked crimping type power module with the end cover removed according to the first embodiment

FIG. 4 is a schematic diagram of a multi-layer signal transmission strip provided in Embodiment 1

FIG. 5 is a schematic diagram of one layer of preparing a multi-layer signal transmission strip provided in Embodiment 1

FIG. 6 is a schematic diagram of a second layer for preparing a multi-layer signal transmission strip provided in Embodiment 1

FIG. 7 is a three-layer schematic diagram of preparing a multi-layer signal transmission strip according to Embodiment 1

FIG. 8 is a five-layer schematic diagram of preparing a multi-layer signal transmission strip provided in Embodiment 1

Detailed ways

The specific implementation of the present invention will be described in detail below. It is necessary to point out that the following implementation is only used for further description of the present invention, and should not be construed as a limitation on the protection scope of the present invention. Some non-essential improvements and adjustments made still belong to the protection scope of the present invention.

Example 1

This embodiment provides a stacked crimp power module and a manufacturing method thereof, as shown in FIGS. 1-8 .

As shown in Figure 1-2, a stacked crimping power module provided by this embodiment includes a chip, an FR4 board, a copper block, and a copper plate arranged in sequence from top to bottom, and the upper end cover is separated into two layers; The bottom layer is embedded with a separate copper block into the FR4 board and connected to the C-level of each chip, and the end cover is covered with an insulating outer frame, and the copper plate is placed on the top layer as the end cover; the gate is drawn out using a multi-layer PCB board. The copper clad surface of each layer of the PCB board at the test end leaks out in turn. This special PCB board can realize the driving of the designated chip in the device.

As shown in Figure 3, it is the multi-layer signal transmission strip provided in this embodiment. A single PCB is cut according to the requirements, and multiple PCBs are staggered and bonded. When bonding, the part connected to the gate signal of the chip and the outermost lead-out part are leaked out. It is not bonded, which is convenient for thimble contact and avoids the subsequent grinding process. The glue can use silicone glue, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue, polyimide glue, etc. The required number of layers can be based on the number of sub-unit chips in the column or row of the crimp power chip. Sure.

When the device fails, it is necessary to individually control each sub-unit chip, and when performing maintenance tests, etc., remove the upper copper plate of the upper end cap, as shown in Figure 3, drive the gate of a single device separately, and connect the CE end of the chip, The effect of detecting a single chip can be achieved.

A method for manufacturing a crimped power module, as shown in Figure 5-8, includes:

The first step is to make a multi-layer signal transmission strip; according to the distance from the five subunit chips in each row to the outer edge of the power module, cut five single strips with a length corresponding to the distance one-to-one on the PCB. If the number of sub-unit chips in each row is another number, or each signal transmission bar is used to transmit the signals of sub-unit chips in each column, the number of single PCB bars is based on the number of sub-unit chips in each column or row of the press-fit power chip. Sure. Figure 5 shows the prepared single-layer PCB. The PCB is staggered and bonded by glue, and the part connected to the gate signal of the chip and the outermost lead-out part are leaked out during bonding, so as to facilitate the contact of the thimble. As shown in Figure 6, the signal transmission strips of two layers of different lengths of PCB are bonded, as shown in Figure 7, the signal transmission strips of three layers of PCBs of different lengths are glued, as shown in Figure 8, the five glued signal transmission strips Signal transmission strips for single PCB strips of different lengths.

In the second step, two layers of end caps are made according to the structural characteristics, and the bottom layer is embedded with a separate copper block in the FR4 board and connected to the C-level of each chip, and the copper plate is placed on the top layer as an end cap; the end cap is covered with an insulator shell; The upper copper plate of the end cap is detachable. When the device fails, the upper copper plate of the end cap is removed, the gate of a single device is driven independently, and the CE end of the chip is connected to achieve the effect of detecting a single chip.

In the third step, after completing the parallel connection of all the subunit chips, a power module is formed and packaged by crimping. Optionally, a plurality of the power modules may be prepared and vertically crimped to form stacked crimped power modules.

The method is simple to prepare, and only adding the step of adopting a multi-layer signal transmission strip obtained by cutting a PCB substrate to the conventional method for preparing a crimping type power module can realize that the above-mentioned manufacturing method of a crimping type power module can be easily manufactured separately. The module for detecting short-circuit failure can drive the specified sub-unit chip in the press-fit IGBT device, and when the device fails, the failed sub-unit chip can be easily detected.

Although exemplary embodiments of the present invention have been described for purposes of illustration, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Carry out various modifications, additions and substitutions, etc., and all these changes should belong to the protection scope of the appended claims of the present invention, and the various steps in the various departments and methods of the products claimed in the present invention can be combined arbitrarily. form together. Accordingly, the description of the embodiments disclosed in the present invention is not intended to limit the scope of the present invention, but to describe the present invention. Accordingly, the scope of the present invention is not limited by the above embodiments, but is defined by the claims or their equivalents.

Claims (10)

1. A crimp-style power module, comprising: the power module layer comprises a first power module layer and a second power module layer which are arranged from top to bottom;

the second power module layer comprises a substrate and n × m bosses arranged on the substrate, and each boss is provided with a subunit chip; the second power module layer further comprises n signal transmission strips for connecting the grid electrodes of the sub-unit chips in each row, the signal transmission strips comprise m layers of stacked and integrated signal transmission sub-strips, and each signal transmission sub-strip is used for transmitting a signal of one sub-unit chip; n >1, m > 1.

2. The crimped power module of claim 1, wherein the m layers of stacked integrated signal transmission sub-strips have the same width, and the length of each layer of integrated signal transmission sub-strip decreases from top to bottom in sequence according to the position of the sub-unit chip.

3. The compression-type power module of claim 2, wherein the m-layer stack integrated signal transmission sub-strip comprises ejector pins, the ejector pins being connected with sub-unit chips; and the m layers of stacked and integrated signal transmission sub-strips are connected by adopting an insulating material.

4. The press-fit power module according to claim 1, wherein the first power module layer comprises an upper metal end cover layer and a lower metal end cover layer, and the lower metal end cover layer comprises an insulating outer frame and n x m metal blocks arranged corresponding to the sub-unit chips.

5. The crimp-type power module of claim 3, wherein the subunit chips comprise power chips and FRD chips, and the power chips comprise MOSFET chips or IGBT chips; the insulating material is one or a combination of more of organic silica gel, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue and polyimide glue.

6. A method for manufacturing a compression joint type power module is characterized by comprising the following steps:

s1: preparing m layers of stacked and integrated signal transmission sub-strips and a first power module layer; m is greater than 1;

s2: preparing a second power module layer by adopting n signal transmission sub-strips stacked and integrated by the m layers; the second power module layer comprises a substrate and n x m bosses arranged on the substrate, and each boss is provided with a subunit chip; the second power module layer further comprises n signal transmission strips for connecting the grid electrodes of the sub-unit chips in each row, the signal transmission strips comprise m layers of stacked and integrated signal transmission sub-strips, and each signal transmission sub-strip is used for transmitting a signal of one sub-unit chip; n is greater than 1;

s3: placing the first power module layer on the top of the second power module layer, and preparing the power module layer by crimping;

s4: and vertically placing at least one power module layer, and crimping to form a power module.

7. The method for preparing a crimped power module according to claim 6, wherein the S1 is used for preparing an m-layer stacked integrated signal transmission sub-strip and comprises the following steps:

s1.1: cutting on printed circuit board to obtain n pieces of x length_iSignal transmission sub-strip of (1)<i<m；

S1.2: and m signal transmission sub-strips with the length of xi are selected, are stacked according to the sequence from short to long in length and are bonded by adopting insulating materials, and 1< i < m, so that m layers of stacked and integrated signal transmission sub-strips are formed.

8. The method for manufacturing a press-fit power module according to claim 7, wherein during the bonding, a contact position with a thimble is reserved on the signal transmission sub-strip in advance and is not bonded, and the contact position of the thimble is determined according to a gate signal connection position of the sub-unit chip.

9. The method for manufacturing a compression-type power module according to claim 6, wherein the first power module layer comprises an upper metal end cover layer and a lower metal end cover layer, and the lower metal end cover layer comprises an insulating outer frame and n × m metal blocks arranged corresponding to the subunit chips.

10. The method for manufacturing a compression joint type power module according to claim 7, wherein the subunit chip comprises a power chip and an FRD chip, the power chip comprises a MOSFET chip or an IGBT chip; the insulating material is one or a combination of more of organic silica gel, phenolic resin glue, urea-formaldehyde resin glue, temperature-resistant epoxy glue and polyimide glue.

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