JPS63181396A - Method of mounting semiconductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a semiconductor mounting method, and is particularly applicable to the semiconductor field.

C# Latest technology 1 1Q In a circuit printed board on which a semiconductor such as an IS engineer is mounted, each connecting terminal exposed and placed on the top surface of the board is connected to each extending from a semiconductor pellet having a circuit element. When connecting the tips of the leads by welding, conventionally a semiconductor pellet is placed on the mounting part on the board, the tips of each lead of the pellet are overlapped with the connection terminals on the board, and the connection is made by welding. When changing the shape of the punched pellet, each lead is bent into two steps to form a folded stepped portion, so that it can be brought into close contact with the connecting terminal on the board. The thickness of each lead of the pellet is thin, about 30 to 35 μm, and the above-mentioned folded step part may be formed or broken. , Mayu applies a solvent evaporation adhesive or the like as a reinforcing adhesive to at least the bent step part of the lead, and prevents the displacement or bending by curing it. The epoxy reinforcing adhesive for the mold has a low viscosity before it hardens, so even if you apply it to more than the required area of the board, it will flow and spread beyond the required area on the board, reducing the required amount of reinforcement. It's not stupid or difficult, but it takes effort and time. Also.

BACKGROUND ART As the integration and speed of semiconductor devices have dramatically increased, the amount of heat generated by the devices has increased, resulting in a decline in one function, making it difficult to guarantee long-term operation. As a solution, heat dissipation from the fins and each lead has been considered, but there are problems such as thermal stress generation due to differences in thermal expansion coefficients and reinforcing adhesives that impede heat dissipation.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned drawbacks by using an insulating ceramic that covers at least the bending steps of each lead of the semiconductor, and to improve the packaging of the semiconductor. The purpose is to provide a method.

[Structure of the invention]

(Means and effects for solving the problems) The present invention has the following features:
In order to achieve the above object, an insulating ceramic having an opening exposing the upper surface of the semiconductor pellet and having a size that at least covers the bent step of each lead of the pellet is welded to the circuit board via solder. The main feature is that the leads of the semiconductor described above are reinforced to improve heat dissipation.

(Example) The present invention will be explained below based on illustrated embodiments.

FIG. 1 shows a semiconductor packaging method showing an embodiment of the present invention. In Figure 0, which is a perspective view for explanation, reference numeral 11 denotes a circuit printed board, and this board 11 has wiring inside it, connection terminals 12 of a companion printed circuit, and an insulating ceramic 13.
The reference numeral 15 on which the pad 14 on the substrate side for fixing with the substrate 1 is arranged is a semiconductor such as 1, which forms one circuit element, and the entire proximal end is connected to the pellet 16 and this pellet 16. After being sealed with synthetic resin etc., the pellet 1
It consists of a large number of leads 17 extending from the lead 6.

The board 17 is bent in two steps in the middle to form a bent step portion 17a, and the lower end portion of the bent step portion 17a is heavy in opposition to each connection terminal 12 on the board 11. welded fi
It's starting to look like this.

The anti-inflammatory ceramic 13 has an opening 1 that covers at least the bent step portion 17a of each lead 17 of the engineered C pellet 16.
8, and its thickness is preferably about the same thickness as the top surface of the pellet 16 from the substrate 11.

Next, a semiconductor mounting method of the present invention configured as above will be explained. That is, as shown in FIG. 2, the tips of the leads 27 of the semiconductor 25 corresponding to each connection terminal 22 of the circuit printed board 21 are tightly attached.

Next, the upper surface portion of the IO pellet 26 of the semiconductor 25 is fitted into the opening 28 of the insulating ceramic 23 n9. When the substrate-side pad 24 and the fixed bat 29 are polymerized and passed through a heating furnace in this state, the fixed pad 39 is melted and the substrate-side pad 34 is welded, as shown in FIG. The bent step portion 27a and its vicinity are strongly reinforced, and heat dissipation is improved by the contact between the lead 37 and the insulating ceramic 33. Therefore, the drawbacks of the conventional semiconductor of this type described above are eliminated. - Figure 4 shows the insulating ceramic 4 in Figure 1.2 above.
Recommendation 5, in which the pellet surface 46F is thick and does not have the hole 48, further improves heat dissipation by contacting the pellet surface 46F with the insulating ceramic 43 is shown in FIG. By attaching the metal fins 50 to the top surface of the insulating ceramic 43, the cooling effect of the pellets 56 is enhanced, and thermal stress is significantly reduced compared to when the metal fins 50 are directly bonded to the top surface of the pellets 56. . Alternatively, as shown in FIG. 6, the insulating ceramic 63 may have an opening 68 so that the upper surface of the pellet 66 and the metal fin 6o are in direct contact.
There is no need to use adhesive between the upper surface and the metal fins 60.

Note that it is preferable that the insulating ceramic has any circular or polygonal shape depending on the shape of the engineered C pellets.

〔Effect of the invention〕

As explained above, according to the present invention, by simply using an insulating ceramic with a simple structure, it is not only possible to easily reinforce the lead frame, but also it has excellent heat dissipation.
We supply extremely reliable and stable products.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a semiconductor mounting method showing an embodiment of the present invention, FIGS. 2 and 3 are enlarged cross-sectional views of the semiconductor mounting process t-y7z in FIG. 1, and FIG. , FIG. 5 and FIG. 8g6 are cross-sectional views showing other high heat dissipation structures used in the present invention. 11, 12.31.41.51.61... Circuit printed board (board), 12.22.32.42.52
．． 62...Connection terminal, 13, 23.33.43.53
．． 63...Insulating ceramic. 14, 24.34.44.54.64...Substrate side pad, 15°25, 35.45.55.65...Semiconductor, 16.26.36.46°56,66...IC pellet (Pellet l, 17.27°37.47,
57.67...Reed, 18.28.38...
Open hole. 29, 39.49.59.69... fixed pad,
50.60...Metal fin◎ Agent Patent attorney Noriyuki Chika Yudo Kikuo Takehana Figure 1

Claims (1)

[Claims] A semiconductor consisting of a pellet having a circuit element formed thereon, and each lead extending from the pellet and having a bent step, the tip end of which is welded to each connection terminal exposed on a substrate;
The pellet has an aperture that exposes the upper surface of the pellet, and an insulating ceramic that has a capacity to cover at least the bent step of each of the leads and is placed on the lead around the pellet. A method for mounting a semiconductor, comprising: fixing the semiconductor with the wire-connectable ceramic, covering the bent step portion of the lead.