RU2656030C2 - Method of manufacturing three-dimensional electronic module - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: module is designed so that on the faces of the parts to be joined after the workpiece is divided, the contact pads are opposite each other, in any known way, the workpiece is made, the workpiece is divided into two parts, the chip contacts and the boards are chemically machined to remove oxides and impurities, a removable or non-removable stencil and solder balls are used, and the two parts are connected so that the heat sink bases are located outside the module, soldering control is performed, air cavity is filled with an epoxy adhesive, grinding of the finished module ends is performed to remove residual adhesive and break pads. When the number of connected parts of more than two to one "lower" part of the module, the "upper" parts of the module are installed in one layer so that the total area of "upper" parts is equal to the area of the "lower" parts, and their heat-removing bases are outside the module.

EFFECT: improving the heat removing of the electronic module and increasing its mechanical strength.

2 cl, 9 dwg

Description

The invention relates to electronics. It proposes a new method for manufacturing a three-dimensional electronic module.

Consider known methods of manufacturing a three-dimensional electronic module.

A three-dimensional electronic module is assembled by placing electronic components and microboards having contact pads on the end surfaces parallel to each other, electrically connect them along the side surfaces of the module, and carry out monitoring and sealing. Guaranteed suitable components are used as the initial components, with the help of them and microplates, they form spatially oriented contact pads to create a continuous line of the module structure, dosed apply a gluing heat-conducting electrical insulation composition to the ends of the microplates, while ensuring the integrity and continuity of the adhesive joint, electronic parts are combined over the contact pads components and connect them, polymerize the adhesive, clean the pads of electronic components and microplates from the film of the bonding composition, conductors are sprayed on the faces of the glued three-dimensional electronic module, providing the necessary connections between the electronic components and the microboards on their contact pads; the conductors located on the faces of the three-dimensional electronic module are expanded (RU 2492549 C1).

Here, the necessary connections between electronic components are carried out by building up conductors located on the faces, which is an extremely low-tech solution, especially for mass production, since any work with faces (spraying, building, etc.) implies the exact positioning of the module in space (for example, in spraying installation) using special equipment.

In the method of manufacturing a three-dimensional electronic module, known from RU 2475885 C1, holes (“microplate windows”) are pre-cut in the base substrate onto which the crystals are mounted, which makes the product more expensive and weakens the module design from the point of view of vibration resistance and impact resistance.

In the method according to RU 2193260 C1, the free-standing components are placed in the windows of a group ceramic blank with a contour orientation and observing a uniform plane of arrangement of the active zones of the components and the front surface of the workpiece. The components are fixed in this position and insulate the electrically unprotected zones of the components along their front side. Next conductors are mainly applied by vacuum spraying to the front and back sides of the workpiece and components, while forming a connector and connecting conductors, it is necessary for electrotraining and control. Suitable microboards are cut from a group blank and assembled into a bag, connecting them together by capillary soldering. A heat distributor with external leads is soldered to one of the faces of the bag and seal the manufactured module. "

This method has all the disadvantages of the two previous ones.

The invention has the following properties:

- ensuring a high packing density of electronic components due to the multilayer structure and the use of non-enclosed components-crystals;

- an increase in the area of the heat sink due to heat sink substrates (bases) on both sides of the module;

- an increase in the mechanical strength of the module due to its design: the substrates protect the internal parts from both sides;

- an increase in manufacturability due to a single blank during the formation of module parts;

- before assembly, each of the parts is checked (tested / controlled).

This is achieved as follows (see Fig. 1-9):

1. The module is designed so that on the front sides of the connected parts obtained after the separation of the workpiece, the contact pads are opposite each other.

2. By any known method, a blank is prepared (group microplate). The group microplate is a heat-conducting substrate-base 1 (Fig. 1) with various layers; the composition may include shellless parts, thin-film elements and other components, depending on the purpose of the module.

3. Produce the separation of the workpiece by cutting with a mill or other way into two parts (Fig. 2).

4. The contacts of the microcircuit and the board are subjected to chemical-mechanical treatment in order to remove oxides and contaminants.

5. A metal (or polymer) stencil 2 (Fig. 3) with holes is installed on one of the parts (conditionally the "lower" microplate), which repeats the configuration of the contact pads with its configuration (a non-metallic stencil can be non-removable). The stencil holes are accurately (not worse than 5% of the size of the contact pad) combined with the contact pads of the microplate.

6. A ball of solder is placed in each hole of the stencil (Fig. 4).

7. With a removable stencil, the balls (and the stencil) are heated so that the balls are melted to the contact pads, while maintaining the basis of their shape (up to 70% of the initial height). Then the stencil is removed (Fig. 5).

8. On top of the balls, install the second part of the module (conditionally the “upper” microplate) with the areas down exactly (no worse than 5% of the size of the contact area) on the balls (Fig. 6).

9. Carry out simultaneous heating of the balls, for example, using the required number of synchronously operating infrared sources and solder masks (not shown in the figures). The same heating is used to solder balls to the board in the case of using non-removable stencils (Fig. 7).

10. Perform soldering control.

11. The air cavity is filled with epoxy adhesive (gravy) (Fig. 8).

12. Residues of adhesive are removed from the ends of the finished module. End grinding is carried out in order to open the contact pads on the module ends, which form the external interface of the finished three-dimensional electronic module (power, control) (Fig. 9).

If the number of connected parts is more than two, then on the one “lower” part of the module the “upper” parts of the module are installed in one layer so that the total area of the “upper” parts is equal to the area of the “lower” part and their heat sink bases are outside the module.

The proposed method is effective in large-scale and especially responsible single production (for example, for satellites).

The technical result of the invention is to improve the heat sink of the electronic module and increase its mechanical strength.

Claims (2)

1. A method of manufacturing a three-dimensional electronic module, which consists in the fact that the module is designed in such a way that on the faces of the parts to be joined obtained after the workpiece is separated, the contact pads are opposite each other, the workpiece is made in any known manner (group microplate), separation is made blanks in two parts, the contacts of the microcircuit and the board are subjected to chemical-mechanical treatment in order to remove oxides and contaminants, using a removable or non-removable stencil and ball from solder and connect the two parts so that the heat sink base are outside of the module; carry out soldering control, fill the air cavity with epoxy adhesive, grind the ends of the finished module to remove adhesive residues and open contact pads. 2. A method of manufacturing a three-dimensional electronic module according to claim 1, characterized in that when the number of connected parts is more than two per one "lower" part of the module, the "upper" parts of the module are installed in one layer so that the total area of the "upper" parts is equal to the area the "lower" part, and their heat sink bases were located outside the module.

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