JPH0530363Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field to which the invention pertains) This invention relates to a hybrid integrated circuit (hybrid IC).
This relates to a resin molded case for electronic components and semiconductor chips mounted on a circuit board.

(Prior art and its problems) Hybrid ICs have wiring patterns and resistance patterns formed on a ceramic or epoxy resin substrate, on which semiconductor chips and other chip-shaped electronic components are mounted, and where necessary moisture proofing and mechanical protection are provided. It is a functional circuit unit sealed with various resins for various purposes. Among the components mounted in hybrid ICs, the sealing method and structure of semiconductor chips are
This is one of the challenges to miniaturizing ICs, that is, improving packaging density.

FIG. 8 is a structural diagram showing an example of conventional resin sealing (molding) of a semiconductor chip.

FIG. 8a is a plan view of a portion where the semiconductor chip 6 and its wires 7 mounted on the circuit board 5 are sealed only with the molding resin 40, and FIG.
A cross-sectional view is shown. In this structure, when the molding resin heats and hardens, there is a risk that it will once gel and flow around and expose the wire 7, so the amount of application must be increased. Therefore, the area occupied by the circuit board 5 after heating and curing is large, which is a disadvantage in improving the packaging density. FIG. 8c shows a structure implemented to alleviate the above-mentioned drawbacks, and is a plan view of an example in which a frame 41 is fixed to the circuit board 5 with an adhesive 42 to prevent the mold resin 40 from flowing and spreading. Figure d is the AA cross-sectional view. In this example, an improvement can be seen in the amount of resin applied and the fixed area, but the process of gluing the frame 41 will be added. FIG. 7a shows an outline of the work flowchart in that case, but there is a drawback that the process costs are high because bonding work and molding work are required, respectively, as shown in steps 71 to 74.

Furthermore, in the two examples shown in FIG.
As shown in the cross-sectional views of Figures b and d, the upper surface of the mold is rounded and not flat. This makes it impossible to apply mounting automation using surface mount technology, which has become important in recent mounting technologies. In other words, for automated mounting, resistors and
In order to mount a large number of chip parts such as capacitors and coils, each chip part is picked up by an air suction nozzle from a magazine containing a large number of chip parts, and then transported to a predetermined position on the circuit board surface and mounted. Automatic mounting equipment is used. Therefore, one of the requirements for recent chip parts is that the top surface of the chip part be flat so that it can be sucked by a suction nozzle. hybrid
In order for an IC to be an automatically mounted component, it must have a flat top surface, but none of the conventional mold shapes shown in FIG. 8 satisfy the condition of a flat top surface.

Although not shown in the drawings, one of the conventional mold structures is a structure based on a transfer molding method in which a mold resin is press-fitted using a metal mold. Although this method allows molded products with a flat top surface to be obtained, the mold and press-fitting equipment are expensive, and although it is suitable for mass production, it is not suitable for high-mix, low-volume production due to the recent diversification of equipment.

(Purpose of the present invention) In order to solve the above-mentioned drawbacks, the purpose of the present invention is to provide a resin molded case for a hybrid integrated circuit that has a flat top surface and can be resin-molded by a simple molding operation. It's about doing.

(Structure and operation of the invention) The resin molded case for a hybrid integrated circuit according to the invention has the above-mentioned features in order to protect the electronic components and semiconductor chips mounted on the substrate of the hybrid integrated circuit, and the wiring wires of the semiconductor chips. It has a space formed by an inner periphery surrounding the mounted electronic components and semiconductor chips and wires,
A rectangular frame with dimensions higher than the height of the electronic components, semiconductor chips and wires, a thin thermosetting resin layer fixed to the bottom of the frame, and an outer circumferential area equal to or less than the outer circumference of the frame. a rectangular plate-shaped upper lid having a flat upper surface; and a rectangular plate-shaped upper lid having a flat upper surface; and an outer periphery fixed to the bottom surface of the upper lid and larger than the inner periphery of the frame and smaller than the outer periphery of the frame, and the upper lid is placed on the frame and housed in the space. It is characterized by comprising a heat-curing molding resin layer on which electronic parts and semiconductor chips are molded by heat-curing.

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a perspective view showing a first embodiment of the present invention. FIG. 1a shows a semiconductor chip 6 mounted on a hybrid integrated circuit board 5 and its wiring wires 7, a frame 1 to which an adhesive resin layer 2 according to the present invention is fixed, and an upper lid 3 to which a mold resin layer 4 is fixed. FIG. 1b is a view obliquely viewed from above, and FIG. 1b is a view obliquely viewed from below.

FIG. 2 is a perspective view showing the appearance of the semiconductor chip on the circuit board 5 after being sealed with the molded case of the present invention. Figure 3 a is its plan view, b is
AA cross-sectional view is shown. Reference numeral 10 in FIG. 2 indicates the external electrode, and reference numeral 4' in FIG. 3b indicates the molded resin after being heated and hardened. All other numbers indicate the same parts as in FIG.

FIG. 4 is a longitudinal sectional view showing the upper lid 3 of the embodiment shown in FIG. 1 placed on the frame 1, and shows the state before being heated and hardened. The difference between a to c is the size of the upper lid 3. The areas a, b, and c of the molded resin layer 4 fixed to the upper lid 3 are smaller than the outer circumference of the frame 1 and larger than the inner circumference of the frame, and when placed on the frame 1, the area of the semiconductor chip 6 accommodated in the inner space is The size is such that it does not come into contact with the wire 7, and when the molded resin layer 4 is heated and gelled, it flows into the inside of the frame 1. The area of the upper lid 3 is frame 1 in case of a.
When the inner space is filled with a molded resin layer equal to the outer shape of the frame 1, it comes into contact with the upper surface of the frame 1 and forms a lid for the entire frame.
In the case of b, the outer diameter is smaller than the inner diameter of the frame 1, so after molding, it will be in contact with the top surface of the frame 1, as in the case of a. In the case of c, since it is smaller than the inner shape of the frame 1, it will fit inside the frame 1 after molding.
The mold sealing effect by heat curing is the same in both cases, but in the case of b, the upper lid 3 and the mold resin layer 4
Since the areas of are equal, when manufacturing the top cover 3 with the resin layer 4 fixed, the resin layer is fixed to the top cover material several tens of times the area and then cut to the desired size to create a large number of resin layers. It has excellent mass productivity because it can produce a top cover with a lid.

The amount (volume) of the mold resin layer 4 should be such that at least the semiconductor chip 6 and the wire 7 are covered and partially bonded to the top cover 3 after being heated and hardened, and at most it should protrude slightly from the periphery of the top cover 3. Required experimentally.

FIGS. 5a and 5b are a plan view and a sectional view along line AA, showing a second applied embodiment of the present invention. The difference from the first embodiment described above is that the resin layer 2 fixed to the upper lid 3
2 is formed only in the portion where the upper surface of the frame 1 contacts. This structure is used to protect the wires when the semiconductor chip 6 is already coated, for example with silicon.

FIGS. 5c and 5d are a plan view and an AA sectional view showing a third applied embodiment of the present invention. In this case, the objects to be sealed are a wide variety of chip-shaped electronic components 9 with different dimensions, and an adhesive resin layer 2 is applied to the substrate bonding surface of the box-shaped case 8, which is intended to have a flat top surface for surface mounting. It is a fixed structure.

Figures 5e and 5f are plan views showing the fourth embodiment.
It is an AA sectional view. The objects of the protective mold in this embodiment are a semiconductor chip 6 and a chip-shaped electronic component 9. The other numbers are also the same as those explained in FIGS. 5a to 5d.

FIG. 6 is a characteristic diagram showing resin reaction curves for explaining the adhesive resin layer 2 and the mold resin layer 4 according to the present invention. This characteristic diagram is for example 100
This shows the change in the shape of the resin with respect to the heating time in a heating tank at ~ _{160 °} C. Take it out from the heating tank, cool it, and use it when it becomes solid. Although the adhesive strength of the resin in this state is weaker than that when it is fully cured, there is no need to worry about it peeling off during handling. When mounting the frame 1 with the adhesive resin layer 2 and the upper cover 3 with the mold resin layer 4 formed in this way on a hybrid integrated circuit board as a mold case for sealing, place them in a predetermined position. By heating it, it becomes the gel-like state shown in FIG. 6 again, and by continuing to heat it, it begins to harden, and after a sufficient period of time, it reaches a fully hardened state and the mold is completed.

By applying the sealing mold case of this invention,
Conventionally, the 4 steps 71 to 74 in FIG. 7a are now completed in 2 steps 75 and 76 as shown in FIG. 7b, which greatly reduces the number of work steps. There is.

(Effects of the invention) As explained in detail above, by using the mold case for sealing of the invention, the number of man-hours required for resin molding of semiconductor chips, etc. of hybrid integrated circuits is reduced. The finished product has a significant effect because it meets the requirements for surface mount components for mounting automation.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention;
Figure 2 is a perspective view showing a structure to which the present invention is applied, Figure 3 is a structural diagram of a product to which the present invention is applied, Figure 4 is a sectional view of a product to which the present invention is applied, and Figure 5 is a diagram of the product to which the present invention is applied. Structural diagrams showing the second, third and fourth embodiments; FIG. 6 is a characteristic diagram illustrating a part of the present invention; FIG. 7 a
8 is a conventional flowchart example, b is a flowchart according to the present invention, and FIG. 8 is a plan view and a sectional view showing a conventional structural example. 1...Frame, 2, 22...Adhesive layer, 3...Top lid,
4...Mold resin layer, 4'...Mold resin,
5... Circuit board, 6... Semiconductor chip, 7... Wire, 8... Box-shaped case, 9... Electronic component, 10
...External electrode, 40...Mold resin, 41...
Frame, 42...Adhesive, 71-76...Step number.

Claims (1)

[Claims for Utility Model Registration] In order to protect the electronic components and semiconductor chips mounted on the substrate of the hybrid integrated circuit and the wiring wires of the semiconductor chips, has a space formed by an inner periphery surrounding the
A rectangular frame with dimensions higher than the height of the electronic components, semiconductor chips and wires, a thin thermosetting resin layer fixed to the bottom of the frame, and an outer circumferential area equal to or less than the outer circumference of the frame. a rectangular plate-shaped upper lid having a flat upper surface; and a rectangular plate-shaped upper lid having a flat upper surface; and an outer periphery fixed to the bottom surface of the upper lid and larger than the inner periphery of the frame and smaller than the outer periphery of the frame, and the upper lid is placed on the frame and housed in the space. A resin mold case for a hybrid integrated circuit comprising a thermosetting mold resin layer for molding electronic components and semiconductor chips by heat curing.